Strategies to recover and minimize boil-off losses during liquid hydrogen storage

May combine two claims.

Liquid hydrogen (LH2) offers the highest storage density compared to other forms of storage, without requiring a chemical reaction.

“Liquid hydrogen (LH2) offers the highest storage density compared to other forms of storage, without requiring a chemical reaction.”

• Also stated in: § 2. Liquid Hydrogen storage · boosted

  “Among the various well-established technologies for storing H2 by physical methods, LH2 offers the largest storage capacity per unit volume as well as safety advantages due to its low storage pressure (0.1013-0.6 MPa) [19-21].”

• cites [19] [19] A.M. Abdalla, S. Hossain, O.B. Nisfindy, A.T. Azad, M. Dawood, A.K. Azad, Hydrogen production, storage, transportation and key challenges with applications: A review, Energy Convers Manag. 165 (2018) 602-627. https://doi.org/10.1016/J.ENCONMAN.2018.03.088. - sourceNot checked — no full text of the source
• cites [20] [20] Z. Abdin, A. Zafaranloo, A. Rafiee, W. Mérida, W. Lipiński, K.R. Khalilpour, Hydrogen as an energy vector, Renewable and Sustainable Energy Reviews. 120 (2020). https://doi.org/10.1016/j.rser.2019.109620. - sourcePartly supported

  Section 5.2, “Liquid hydrogen,” says liquid-state hydrogen has the highest energy intensity among current hydrogen storage options and contrasts it with liquid carriers that require dehydrogenation. But Table 5 gives a metal hydride a higher volumetric hydrogen density than liquid hydrogen (115 versus 70.8 kg/m³), so the unqualified claim of the highest storage density overstates the source. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites [21] [21] F. Ustolin, N. Paltrinieri, F. Berto, Loss of integrity of hydrogen technologies: A critical review, Int J Hydrogen Energy. 45 (2020) 23809-23840. https://doi.org/10.1016/j.ijhydene.2020.06.021. - sourceDisputed

  The Storage section says liquid hydrogen has a higher density than some other storage solutions, but it identifies cryo-compressed storage—not liquid hydrogen—as achieving the maximum hydrogen density: 80 versus 70.9 kg/m³. Thus the claim that liquid hydrogen has the highest density among storage forms is contrary to the source. The storage comparison distinguishes liquid hydrogen from chemical-bond storage methods. (LLM, conf=0.88)

  Checked by a reasoning model — may be wrong.

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

The application of LH2 has long been limited to the spacecraft industry because of its high energy consumption.

“Due to its high energy consumption, the application of LH2 has long been limited to the spacecraft industry [19-21], where budgetary issues or market prices are not a concern [22].”

• cites [19] [19] A.M. Abdalla, S. Hossain, O.B. Nisfindy, A.T. Azad, M. Dawood, A.K. Azad, Hydrogen production, storage, transportation and key challenges with applications: A review, Energy Convers Manag. 165 (2018) 602-627. https://doi.org/10.1016/J.ENCONMAN.2018.03.088. - sourceNot checked — no full text of the source
• cites [20] [20] Z. Abdin, A. Zafaranloo, A. Rafiee, W. Mérida, W. Lipiński, K.R. Khalilpour, Hydrogen as an energy vector, Renewable and Sustainable Energy Reviews. 120 (2020). https://doi.org/10.1016/j.rser.2019.109620. - sourcePartly supported

  Section 5.2 (page unavailable) says hydrogen liquefaction requires energy equivalent to about 35% of the liquid hydrogen’s lower heating value and that cryogenic hydrogen storage is widely used in the space industry. It does not say high energy consumption confined LH2 applications to that industry; it also reports vehicle trials. The claimed historical limitation and its cause therefore go beyond the source. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [21] [21] F. Ustolin, N. Paltrinieri, F. Berto, Loss of integrity of hydrogen technologies: A critical review, Int J Hydrogen Energy. 45 (2020) 23809-23840. https://doi.org/10.1016/j.ijhydene.2020.06.021. - sourcePartly supported

  The Related equipment section reports that liquefaction requires more energy than compression, and the Mobile systems—Aerospace industry section describes hydrogen use in space missions. The paper does not say that energy demand kept LH2 applications limited to spacecraft for a long period; its Storage section also describes LH2 road delivery. No page number is available for these passages. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [22] [22] I.A. Hassan, H.S. Ramadan, M.A. Saleh, D. Hissel, Hydrogen storage technologies for stationary and mobile applications: Review, analysis and perspectives, Renewable and Sustainable Energy Reviews. 149 (2021) 111311. https://doi.org/10.1016/J.RSER.2021.111311. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

LH2 storage has safety advantages due to its low storage pressure (0.1013-0.6 MPa).

“Among the various well-established technologies for storing H2 by physical methods, LH2 offers the largest storage capacity per unit volume as well as safety advantages due to its low storage pressure (0.1013-0.6 MPa) [19-21].”

• cites [19] [19] A.M. Abdalla, S. Hossain, O.B. Nisfindy, A.T. Azad, M. Dawood, A.K. Azad, Hydrogen production, storage, transportation and key challenges with applications: A review, Energy Convers Manag. 165 (2018) 602-627. https://doi.org/10.1016/J.ENCONMAN.2018.03.088. - sourceNot checked — no full text of the source
• cites [20] [20] Z. Abdin, A. Zafaranloo, A. Rafiee, W. Mérida, W. Lipiński, K.R. Khalilpour, Hydrogen as an energy vector, Renewable and Sustainable Energy Reviews. 120 (2020). https://doi.org/10.1016/j.rser.2019.109620. - sourcePartly supported

  Table 5 lists low pressure as a merit of liquid-hydrogen storage, and §5.2 describes liquid hydrogen as having the highest energy intensity among current hydrogen-storage options (page numbers unavailable). But our copy does not give the claimed 0.1013–0.6 MPa range or say that liquid hydrogen's low pressure confers a safety advantage; Table 5 instead lists public perception as a safety drawback. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [21] [21] F. Ustolin, N. Paltrinieri, F. Berto, Loss of integrity of hydrogen technologies: A critical review, Int J Hydrogen Energy. 45 (2020) 23809-23840. https://doi.org/10.1016/j.ijhydene.2020.06.021. - sourcePartly supported

  The Storage section reports LH2 at atmospheric pressure and lists operating pressures up to 7 bar (0.7 MPa), supporting that it is stored at relatively low pressure. It does not give the claimed upper limit of 0.6 MPa or state that low pressure confers a safety advantage; the Discussion section notes unresolved LH2 explosion risks. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

The flashing phenomenon is quick vaporization occurring over transfer of LH2 from a tank to another with a pressure difference.

“The reason is the quick vaporization, known as the flashing phenomenon, occurring over the transfer of LH2 from a tank to another with a difference of pressure.”

• cites [44] [44] S.A. Sherif, N. Zeytinoglu, T.N. Veziroglu, Liquid hydrogen: Potential, problems, and a proposed research program, Int J Hydrogen Energy. 22 (1997) 683-688. https://doi.org/10.1016/S0360-3199(96)00201-7. - sourceNot checked — no full text of the source
• cites [65] [65] M. Aziz, Liquid Hydrogen: A Review on Liquefaction, Storage, Transportation, and Safety, Energies (Basel). 14 (2021) 5917. https://doi.org/10.3390/en14185917. - sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The boil-off rate of NASA spherical tanks was estimated to be 563 kg/day, which translates to an evaporation rate of nearly 0.25% per day.

“The boil-off rate was estimated to be 563 kg/day [30], which translates to an evaporation rate of nearly 0.25 % per day [31].”

• cites [30] [30] A.G. Krenn, R.C. Youngquist, S.O. Starr, Annular Air Leaks in a liquid hydrogen storage tank, IOP Conf Ser Mater Sci Eng. 278 (2017). https://doi.org/10.1088/1757899X/278/1/012065. - sourceSupported
• cites [31] [31] D. Berstad, S. Gardarsdottir, S. Roussanaly, M. Voldsund, Y. Ishimoto, P. Nekså, Liquid hydrogen as prospective energy carrier: A brief review and discussion of underlying assumptions applied in value chain analysis, Renewable and Sustainable Energy Reviews. 154 (2022) 111772. https://doi.org/10.1016/J.RSER.2021.111772. - sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Linde estimates cylindrical tanks with capacity 300 m3 can have boil-off rates of less than 0.3% per day, while spherical tanks between 1,100 and 2,300 m3 have boil-off rates of less than 0.1% per day.

“This company estimates that cylindrical tanks with a capacity of 300 m 3 can have boil-off rates of less than 0.3 % per day, while spherical tanks with a size between 1,100 and 2,300 m 3 have boil-off rates of less than 0.1 % per day [31,62].”

• cites [31] [31] D. Berstad, S. Gardarsdottir, S. Roussanaly, M. Voldsund, Y. Ishimoto, P. Nekså, Liquid hydrogen as prospective energy carrier: A brief review and discussion of underlying assumptions applied in value chain analysis, Renewable and Sustainable Energy Reviews. 154 (2022) 111772. https://doi.org/10.1016/J.RSER.2021.111772. - sourceSupported
• cites [62] [62] L. Decker, Liquid Hydrogen Distribution Technology - HYPER closing seminar, Linde. (2020) 27. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Commercial oxide-based catalysts currently used for o- to p-H2 conversion include IONEX® (Fe2O3.2%H2O) and OXISORB® (CrO.SiO2).

“Commercial oxide-based catalysts currently used for o- to p-H2 conversion include IONEX® (Fe2O3.2%H2O) and OXISORB® (CrO.SiO2) [56].”

• cites [56] [56] M. Hartl, R.C. Gillis, L. Daemen, D.P. Olds, K. Page, S. Carlson, Y. Cheng, T. Hügle, E.B. Iverson, A.J. Ramirez-Cuesta, Y. Lee, G. Muhrer, Hydrogen adsorption on two catalysts for the ortho- to parahydrogen conversion: Cr-doped silica and ferric oxide gel, Physical Chemistry Chemical Physics. 18 (2016) 17281-17293. https://doi.org/10.1039/C6CP01154C. - sourceSupported

May combine two claims.

Space travel requires proper storage and management of cryogens under microgravity conditions for long duration missions, which led NASA to implement cryogenic refrigeration systems such as the 20K cryocooler to achieve zero boil-off (ZBO) of LH2.

“For that purpose, space travel requires proper storage and management of cryogens under microgravity conditions for long duration missions, which led NASA to implement cryogenic refrigeration systems such as the 20K cryocooler to achieve zero boil-off (ZBO) of LH2 [71].”

• cites [71] [71] D. Plachta, J. Stephens, W. Johnson, M. Zagarola, NASA cryocooler technology developments and goals to achieve zero boil-off and to liquefy cryogenic propellants for space exploration, Cryogenics (Guildf). 94 (2018) 95-102. https://doi.org/10.1016/j.cryogenics.2018.07.005. - sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

May combine two claims.

LH2 transport at lower pressures (near atmospheric) mitigates boil-off formation due to flashing, though at the expense of storing a smaller volume of LH2.

“LH2 transport at lower pressures (near atmospheric) is a way to mitigate boil-off formation due to flashing, though at the expense of storing a smaller volume of LH2 [44,65].”

• cites [44] [44] S.A. Sherif, N. Zeytinoglu, T.N. Veziroglu, Liquid hydrogen: Potential, problems, and a proposed research program, Int J Hydrogen Energy. 22 (1997) 683-688. https://doi.org/10.1016/S0360-3199(96)00201-7. - sourceNot checked — no full text of the source
• cites [65] [65] M. Aziz, Liquid Hydrogen: A Review on Liquefaction, Storage, Transportation, and Safety, Energies (Basel). 14 (2021) 5917. https://doi.org/10.3390/en14185917. - sourceSupported

Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing). May combine two claims.

Some authors have suggested that the introduction of an LN2 pre-cooling unit upstream of the liquefaction zone could lead to an increase in EXE of about 50-70% since the mechanical energy of the turbine rotation can be recovered and better cooling is achieved.

“However, some authors have suggested that the introduction of an LN2 pre-cooling unit upstream of the liquefaction zone could lead to an increase in EXE of about 50-70% [94] since the mechanical energy of the turbine rotation can be recovered and better cooling is achieved [83].”

• cites [94] [94] K.D. Timmerhaus, T.M. Flynn, Cryogenic Process Engineering, Springer, Berlin/Heidelberg, Germany, 2013. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [83] [83] S.Z. Al Ghafri, S. Munro, U. Cardella, T. Funke, W. Notardonato, J.P.M. Trusler, J. Leachman, R. Span, S. Kamiya, G. Pearce, A. Swanger, E.D. Rodriguez, P. Bajada, F. Jiao, K. Peng, A. Siahvashi, M.L. Johns, E.F. May, Hydrogen liquefaction: a review of the fundamental physics, engineering practice and future opportunities, Energy Environ Sci. 15 (2022) 2690-2731. https://doi.org/10.1039/D2EE00099G. - sourcePartly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The cycles can also include a pre-cooling section with LN2 to reduce compressor work, although it is not mandatory.

“The cycles can also include a pre-cooling section with LN2 to reduce compressor work, although it is not mandatory [65].”

• cites [65] [65] M. Aziz, Liquid Hydrogen: A Review on Liquefaction, Storage, Transportation, and Safety, Energies (Basel). 14 (2021) 5917. https://doi.org/10.3390/en14185917. - sourceSupported

May combine two claims.

Although NASA has previously investigated two types of cooling cycles such as the reverse Brayton cycle and the Stirling cycle, the reverse Brayton cycle remains the preferred distributed cooling system.

“Although NASA has previously investigated two types of cooling cycles such as the reverse Brayton cycle and the Stirling cycle, in which the working fluid circulation directly cools the tank wall [71], the reverse Brayton cycle remains the preferred distributed cooling system [74].”

• cites [71] [71] D. Plachta, J. Stephens, W. Johnson, M. Zagarola, NASA cryocooler technology developments and goals to achieve zero boil-off and to liquefy cryogenic propellants for space exploration, Cryogenics (Guildf). 94 (2018) 95-102. https://doi.org/10.1016/j.cryogenics.2018.07.005. - sourceSupported
• cites [74] [74] D.W. Plachta, W.L. Johnson, J.R. Feller, Zero boil-off system testing, Cryogenics (Guildf). 74 (2016) 88-94. https://doi.org/10.1016/j.cryogenics.2015.10.009. - sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

The H2 liquefaction process includes two cooling stages.

“The H2 liquefaction process includes two cooling stages [81] as can be appreciated graphically in Figure 6a.”

• cites [81] [81] M. Choi, W. Jung, S. Lee, T. Joung, D. Chang, Thermal Efficiency and Economics of a Boil-Off Hydrogen Re-Liquefaction System Considering the Energy Efficiency Design Index for Liquid Hydrogen Carriers, Energies (Basel). 14 (2021) 4566. https://doi.org/10.3390/en14154566. - sourcePartly supported

  The Introduction describes a hydrogen-liquefaction configuration with two sections: precooling and cryogenic liquefaction. It presents this as one proposed configuration, not as a two-stage structure shared by all H₂ liquefaction processes. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

May combine two claims.

The J-T expansion cannot be omitted because the expander is not intended for liquefaction but only for cooling since the expander usually does not handle liquid fluids.

“The J-T expansion cannot be omitted because the expander (Figure 6c) is not intended for liquefaction but only for cooling since the expander usually does not handle liquid fluids [65].”

• cites [65] [65] M. Aziz, Liquid Hydrogen: A Review on Liquefaction, Storage, Transportation, and Safety, Energies (Basel). 14 (2021) 5917. https://doi.org/10.3390/en14185917. - sourcePartly supported

  Section 3.1 (page not provided) describes Joule–Thomson expansion through a throttling valve as the liquefaction step in the Linde process. It does not say that J–T expansion cannot be omitted from the arrangement in the citing sentence, or that an expander is used only for cooling because it cannot handle liquid fluids; searches for “expander” and “turbine” found no matching passage. (LLM, conf=0.76)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

An ejector is a work-producing device without moving parts that can enhance the efficiency of the refrigeration cycle by utilizing the high-pressure gas leaving the compressor to increase the cooling capacity of the refrigeration system.

“An ejector is a work-producing device without moving parts that can enhance the efficiency of the refrigeration cycle by utilizing the high-pressure gas leaving the compressor to increase the cooling capacity of the refrigeration system [92,95].”

• cites [92] [92] H.S. Cao, H.J.M. ter Brake, Progress and challenges in utilization of ejectors for cryogenic cooling, Appl Therm Eng. 167 (2020) 114783. https://doi.org/10.1016/j.applthermaleng.2019.114783. - sourceNot checked — no full text of the source
• cites [95] [95] H.S. Cao, L.H. Geng, G. Hammink, T. Tirolien, H.J.M. ter Brake, Performance of a miniature ejector for application in a nitrogen Joule-Thomson cycle: Experimental and numerical analysis, Appl Therm Eng. 186 (2021). https://doi.org/10.1016/j.applthermaleng.2020.116357. - sourcePartly supported

  The Introduction describes ejectors as work-producing devices that use high-pressure gas to improve cryocooler performance, and Section 2 traces that gas from the compressor to the ejector (pages not provided). The paper says JT cryocoolers have no moving parts, but does not explicitly say this of ejectors. It describes lower evaporator temperature or reduced compressor power, not an increase in cooling capacity. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

According to Aasadnia et al., the specific energy consumption (SEC) of liquefaction plants is usually around 10-15 kWh/kg LH2 while EXE values are between 19% and 24%.

“According to Aasadnia et al. [86], the specific energy consumption (SEC) of liquefaction plants is usually around 10-15 kWh/kg LH2 while EXE values are between 19 % and 24 % [6,86-89].”

• cites [86] [86] M. Aasadnia, M. Mehrpooya, Large-scale liquid hydrogen production methods and approaches: A review, Appl Energy. 212 (2018) 57-83. https://doi.org/10.1016/j.apenergy.2017.12.033. - sourceNot checked — no full text of the source
• cites [6] [6] U. Cardella, L. Decker, H. Klein, Roadmap to economically viable hydrogen liquefaction, Int J Hydrogen Energy. 42 (2017) 13329-13338. https://doi.org/10.1016/j.ijhydene.2017.01.068. - sourceNot checked — no full text of the source
• cites [87] [87] A. Naquash, M.A. Qyyum, S. Min, S. Lee, M. Lee, Carbon-dioxide-precooled hydrogen liquefaction process: An innovative approach for performance enhancementEnergy, exergy, and economic perspectives, Energy Convers Manag. 251 (2022) 114947. https://doi.org/10.1016/j.enconman.2021.114947. - sourceNot checked — no full text of the source
• cites [88] [88] Y. Bi, L. Yin, T. He, Y. Ju, Optimization and analysis of a novel hydrogen liquefaction process for circulating hydrogen refrigeration, Int J Hydrogen Energy. 47 (2022) 348364. https://doi.org/10.1016/j.ijhydene.2021.10.012. - sourceNot checked — no full text of the source
• cites [89] [89] S.ZS. Al Ghafri, S. Munro, U. Cardella, T. Funke, W. Notardonato, J.P.M. Trusler, J. Leachman, R. Span, S. Kamiya, G. Pearce, A. Swanger, E.D. Rodriguez, P. Bajada, F. Jiao, K. Peng, A. Siahvashi, M.L. Johns, E.F. May, Hydrogen liquefaction: a review of the fundamental physics, engineering practice and future opportunities, Energy Environ Sci. 15 (2022) 2690-2731. https://doi.org/10.1039/D2EE00099G. - sourcePartly supported

  Section 3.2 (page not provided) reports SEC of 10–15 kWh/kg LH₂ for existing industrial liquefiers, matching that part of the claim. It gives exergy efficiencies of 20–30%, not the claimed 19–24%. (LLM, conf=0.92)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

In industrial H2 liquefaction processes, both types of expanders are used on the refrigeration side.

“In industrial H2 liquefaction processes, both types of expanders are used on the refrigeration side [89].”

• cites [89] [89] S.ZS. Al Ghafri, S. Munro, U. Cardella, T. Funke, W. Notardonato, J.P.M. Trusler, J. Leachman, R. Span, S. Kamiya, G. Pearce, A. Swanger, E.D. Rodriguez, P. Bajada, F. Jiao, K. Peng, A. Siahvashi, M.L. Johns, E.F. May, Hydrogen liquefaction: a review of the fundamental physics, engineering practice and future opportunities, Energy Environ Sci. 15 (2022) 2690-2731. https://doi.org/10.1039/D2EE00099G. - sourceSupported

May combine two claims.

The use of ejectors can reduce throttling losses and increase the suction pressure of refrigeration systems, thereby reducing the compression work required for the process.

“The use of ejectors can reduce throttling losses and increase the suction pressure of refrigeration systems, thereby reducing the compression work required for the process [99].”

• cites [99] [99] G. Besagni, Ejectors on the cutting edge: The past, the present and the perspective, Energy. 170 (2019) 998-1003. https://doi.org/10.1016/j.energy.2018.12.214. - sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

The maximum LH2 production of existing plants worldwide is about 32 ton/day per liquefaction train.

“The maximum LH2 production of existing plants worldwide is about 32 ton/day per liquefaction train [89].”

• cites [89] [89] S.ZS. Al Ghafri, S. Munro, U. Cardella, T. Funke, W. Notardonato, J.P.M. Trusler, J. Leachman, R. Span, S. Kamiya, G. Pearce, A. Swanger, E.D. Rodriguez, P. Bajada, F. Jiao, K. Peng, A. Siahvashi, M.L. Johns, E.F. May, Hydrogen liquefaction: a review of the fundamental physics, engineering practice and future opportunities, Energy Environ Sci. 15 (2022) 2690-2731. https://doi.org/10.1039/D2EE00099G. - sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Gi et al. confirmed the superdense state of H2 not only on MOFs but also on activated carbons at temperatures below 33 K and at 0.1013 MPa.

“Gi et al. [147] confirmed the superdense state of H2 not only on MOFs but also on activated carbons at temperatures below 33 K and at 0.1013 MPa.”

• cites [147] [147] H. Gi, Y. Kashiwara, Y. Itoh, K. Sharma, N. Ogita, H. Miyaoka, T. Ogawa, M. Simanullang, L. Prost, T. Ichikawa, Superdense state of the monolayer hydrogen on adsorbent under liquefied temperature, Int J Hydrogen Energy. 48 (2023) 3534-3540. https://doi.org/10.1016/j.ijhydene.2022.10.081. sourcePartly supported

  The Introduction and Hydrogen adsorption at 20.4 K section report superdense H₂ on MOF-177 and superactivated carbon MSC-30 below 33 K, including at approximately 0.1013 MPa (reported as 0.1 MPa) at 20.4 K. The Temperature dependence section reports higher pressures for the measurements at 23.3, 26.5, and 30.6 K, so the stated pressure is not supported across the temperatures studied. Page numbers are unavailable in our copy. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

The adsorption compressor concept has been applied to methane compression using metal organic frameworks and activated carbons as adsorbents.

“More recently, the concept has been applied to methane compression using metal organic frameworks and activated carbons as adsorbents [141].”

• cites [141] [141] L. Qin, H. Cao, J. Li, Y. Wu, M. ter Brake, Performance comparison of sorption compressors for methane using metal-organic frameworks and activated carbon as adsorbents, Cryogenics (Guildf). 123 (2022) 103441. https://doi.org/10.1016/j.cryogenics.2022.103441. - sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

H2 liquefaction requires refrigeration cycles to go from ambient conditions to 20 K, which is an energy-intensive process.

“However, H2 liquefaction requires refrigeration cycles to go from ambient conditions to 20 K, which is an energy-intensive process.”

Probably not a substantial claim: may not pass S4 (based).

Boil-off hydrogen (BOH) is the result of evaporation of LH2, primarily due to heat leakage into the cryogenic tank.

“Boil-off hydrogen (BOH) is the result of the evaporation of LH2, primarily due to heat leakage into the cryogenic tank.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The energy consumption of H2 liquefaction is estimated to be 30-40% of the energy content of LH2, i.e., 8 MJ/L on a lower heating value basis.

“The energy consumption of H2 liquefaction is estimated to be 30-40 % of the energy content of LH2 [22,27,28], i.e., 8 MJ/L on a lower heating value basis [29].”

• cites [22] [22] I.A. Hassan, H.S. Ramadan, M.A. Saleh, D. Hissel, Hydrogen storage technologies for stationary and mobile applications: Review, analysis and perspectives, Renewable and Sustainable Energy Reviews. 149 (2021) 111311. https://doi.org/10.1016/J.RSER.2021.111311. - sourceNot checked — no full text of the source
• cites [27] [27] Z. Yanxing, G. Maoqiong, Z. Yuan, D. Xueqiang, S. Jun, Thermodynamics analysis of hydrogen storage based on compressed gaseous hydrogen, liquid hydrogen and cryo- - compressed hydrogen, Int J Hydrogen Energy. 44 (2019) 16833-16840. https://doi.org/10.1016/J.IJHYDENE.2019.04.207. - sourceNot checked — no full text of the source
• cites [28] [28] H. Barthelemy, M. Weber, F. Barbier, Hydrogen storage: Recent improvements and industrial perspectives, Int J Hydrogen Energy. 42 (2017) 7254-7262. https://doi.org/10.1016/j.ijhydene.2016.03.178. - sourceNot checked — no full text of the source
• cites [29] [29] D.J. Durbin, C. Malardier-Jugroot, Review of hydrogen storage techniques for on board vehicle applications, Int J Hydrogen Energy. 38 (2013) 14595-14617. https://doi.org/10.1016/j.ijhydene.2013.07.058. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

H2 has the advantage of having the highest gravimetric capacity.

“However, H2 has the advantage of having the highest gravimetric capacity.”

May combine two claims.

LH2 storage is associated with unavoidable evaporation of a fraction of LH2, known as boil-off, which results in process inefficiency and energy losses.

“BOH is an undesirable but somewhat unavoidable effect occurring in cryogenic tanks.”

Probably not a substantial claim: may not pass S3 (load-bearing).

LH2 has a lower volumetric energy density than common liquid fuels such as gasoline or diesel.

“Although LH2 is the most densified version of all physical H2 storage methods, its volumetric energy density is still lower than that of other common liquid fuels, such as gasoline or diesel, as illustrated in Figure 1b.”

• cites [22] [22] I.A. Hassan, H.S. Ramadan, M.A. Saleh, D. Hissel, Hydrogen storage technologies for stationary and mobile applications: Review, analysis and perspectives, Renewable and Sustainable Energy Reviews. 149 (2021) 111311. https://doi.org/10.1016/J.RSER.2021.111311. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

Reliquefaction can be an optimal option for LH2-fueled applications or for LH2 transportation.

“Reliquefaction can be an optimal option for LH2-fueled applications or for LH2 transportation.”

May combine two claims.

H2 is inherently a difficult molecule to maintain in the liquid state due to its low boiling point and low enthalpy of evaporation (0.45 kJ/g), which is almost 18 times lower than that of LNG.

“H2 is inherently a difficult molecule to maintain in the liquid state due to its low boiling point, which complicates its liquefaction, but also due to its low enthalpy of evaporation (0.45 kJ/g) that is almost 18 times lower than that of liquefied natural gas (LNG).”

May combine two claims.

During collection, the gas temperature increases, and thus the required cooling energy depends on the feed temperature of the BOH into the reliquefaction system.

“During collection, the gas temperature increases, and thus the required cooling energy depends on the feed temperature of the BOH into the reliquefaction system.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The BOH rate of KHI tanks has remained the same, at values below 0.2%, with no sign of deteriorating performance over the past 30 years.

“In fact, according to company reports, the BOH rate has remained the same, at values below 0.2 %, with no sign of deteriorating performance over the past 30 years [36].”

• cites [36] [36] Kawasaki Heavy Industries., Japan's Largest Liquid Hydrogen Storage Tank. The Intricacies of Keeping Hydrogen at -253°C, (2017). https://answers.khi.co.jp/en/energy-environment/20170227e-01/ (accessed August 30, 2022). -Not checked yet

  Not checked in the free run.

May combine two claims.

The o- to p-H2 conversion usually takes time since the perturbations involving the nuclear spins are small in magnitude and a non-equilibrium mixture may occur.

“This reaction, known as ortho to para conversion, usually takes time since the perturbations involving the nuclear spins are small in magnitude [47] and a non-equilibrium mixture may occur [48].”

• cites [47] [47] G. Petitpas, S.M. Aceves, M.J. Matthews, J.R. Smith, Para-H2 to ortho-H2 conversion in a full-scale automotive cryogenic pressurized hydrogen storage up to 345 bar, Int J Hydrogen Energy. 39 (2014) 6533-6547. https://doi.org/10.1016/j.ijhydene.2014.01.205. - sourceNot checked — no full text of the source
• cites [48] [48] O.A. evna Boeva, A.A. Odintzov, R.D. Solovov, E.V. Abkhalimov, K.N. Zhavoronkova, B.G. evich Ershov, Low-temperature ortho-para hydrogen conversion catalyzed by gold nanoparticles: Particle size does not affect the rate, Int J Hydrogen Energy. 42 (2017) 22897-22902. https://doi.org/10.1016/j.ijhydene.2017.07.187. - sourceNot checked — no full text of the source

May combine two claims.

The type of insulation is critical to prevent BOH formation; the insulation design must balance the savings from BOH reduction with the cost of the insulation system.

“The type of insulation is critical to prevent BOH formation, i.e., the insulation design must be able to balance the savings from BOH reduction with the cost of the insulation system [40].”

• cites [40] [40] K.D. Timmerhaus, Cryogenic Process Engineering, in: R.A.B.T.-E. of P.S. and T. (Third E. Meyers (Ed.), Encyclopedia of Physical Science and Technology, Elsevier, New York, 2003: pp. 13-36. https://doi.org/10.1016/B0-12-227410-5/00156-3. - sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Venting a fuel is a waste of energy, especially for a gas that is expensive to liquefy.

“While it is true that this method can be the simplest way to eliminate BOH by avoiding investment in adequate infrastructure to use the gas for other purposes, venting a fuel is a waste of energy, especially for a gas that is expensive to liquefy [68].”

• cites [68] [68] DEMACO, What to do with hydrogen boil-off gas?, (n.d.). https://demacocryogenics.com/blog/what-to-do-with-hydrogen-boil-off-gas/ (accessed May 12, 2022). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

The boil-off rate can be different depending on the sophistication of the Dewar insulation technology, and the shape and the size of the tank.

“The boil-off rate can be different depending on the sophistication of the Dewar insulation technology, and the shape and the size of the tank.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Sloshing is the movement of LH2 due to acceleration or deceleration and occurs when impact energy due to movement inside the tank is converted into thermal energy.

“The movement of LH2 due to acceleration or deceleration is known as sloshing and occurs when the impact energy due to the movement of LH2 inside the tank is converted into thermal energy.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The alternating layers of MLI typically consist of reflective materials (aluminum foil or aluminized Mylar) and low-conductivity insulating materials (fiberglass mat or paper, glass cloth, or nylon netting), all under high vacuum.

“Typically, the alternating layers consist of reflective materials, namely aluminum foil or aluminized Mylar, and lowconductivity insulating materials, such as fiberglass mat or paper, glass cloth, or nylon netting, all under high vacuum [40].”

• cites [40] [40] K.D. Timmerhaus, Cryogenic Process Engineering, in: R.A.B.T.-E. of P.S. and T. (Third E. Meyers (Ed.), Encyclopedia of Physical Science and Technology, Elsevier, New York, 2003: pp. 13-36. https://doi.org/10.1016/B0-12-227410-5/00156-3. - sourceNot checked — no full text of the source

Classified as probably not a substantial claim. May combine two claims.

ZBO may not be suitable for all types of applications since cryogenic tank design is quite sophisticated and is currently limited to the spacecraft industry.

“Nevertheless, ZBO may not be suitable for all types of applications since cryogenic tank design is quite sophisticated and is currently limited to the spacecraft industry.”

May combine two claims.

The combination of heat leakage, low H2 vaporization temperature, low pressure inside the tank, and transportation of the vessel itself contribute to BOH generation during conventional LH2 storage in Dewars.

“In summary, the combination of different aspects, such as the heat leakage, low H2 vaporization temperature, low pressure inside the tank, and transportation of the vessel itself, contribute to BOH generation during conventional LH2 storage in Dewars [66,67].”

• cites [66] [66] M.D. Paster, R.K. Ahluwalia, G. Berry, A. Elgowainy, S. Lasher, K. McKenney, M. Gardiner, Hydrogen storage technology options for fuel cell vehicles: Well-to-wheel costs, energy efficiencies, and greenhouse gas emissions, Int J Hydrogen Energy. 36 (2011) 14534-14551. https://doi.org/10.1016/j.ijhydene.2011.07.056. - sourceNot checked — no full text of the source
• cites [67] [67] T.Q. Hua, R.K. Ahluwalia, Off-board regeneration of ammonia borane for use as a hydrogen carrier for automotive fuel cells, Int J Hydrogen Energy. 37 (2012) 1438214392. https://doi.org/10.1016/j.ijhydene.2012.07.013. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Compression can be a useful method to recover H2 in its gaseous state for applications such as fuel cell vehicle refueling stations or high-pressure buffer storage.

“Compression can be a useful method to recover H2 in its gaseous state for various applications such as fuel cell vehicle refueling stations or highpressure buffer storage.”

May combine two claims.

Although LH2 evaporation is an endothermic process, the cooling provided by vaporization is insufficient to counteract temperature increase of LH2 due to heat leakage.

“Although LH2 evaporation is an endothermic process, the cooling provided by vaporization is insufficient to counteract temperature increase of LH2 due to heat leakage.”

Classified as probably not a substantial claim.

Normal H2 contains 75% ortho-hydrogen and 25% para-hydrogen.

“Normal H2 contains two spin isomers of H2 of different composition: 75% ortho-hydrogen (o-H2) and 25% para-hydrogen (p-H2).”

Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing). May combine two claims.

KHI announced completion of the basic design of what the company claims would be the world's largest spherical LH2 tank with a total volume of 11,200 m3 and a H2 storage capacity of 10,000 m3 with a negligible boil-off rate of ≤0.1% per day.

“KHI also announced the completion of the basic design of what the company claims would be the world's largest spherical LH2 tank with a total volume of 11,200 m 3 and a H2 storage capacity of 10,000 m 3 with a negligible boil-off rate of ≤ 0.1 % per day [38].”

• cites [38] [38] Kawasaki Heavy Industries., Kawasaki Completes Basic Design for World's Largest Class (11,200-cubic-meter) Spherical Liquefied Hydrogen Storage Tank, (2020). https://global.kawasaki.com/en/corp/newsroom/news/detail/?f=20201224\_8018 (accessed August 30, 2022). -Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

LH2 tanks are generally of three types: double-jacketed tanks with liquid nitrogen on the outer jacket, super-insulated tanks with reflective powder or multi-layer insulation (MLI), and vapor-cooled shielded (VCS) tanks employing super-insulation.

“LH2 tanks are generally of three types: i) double-jacketed tanks with liquid nitrogen on the outer jacket, ii) super-insulated tanks with reflective powder or multi-layer insulation (MLI), and iii) vapor-cooled shielded (VCS) tanks employing super-insulation [34,44] as graphically described in Figure 4.”

• cites [34] [34] S.A. Sherif, F. Barbir, T.N. Veziroglu, Towards a Hydrogen Economy, The Electricity Journal. 18 (2005) 62-76. https://doi.org/10.1016/J.TEJ.2005.06.003. - sourceNot checked — no full text of the source
• cites [44] [44] S.A. Sherif, N. Zeytinoglu, T.N. Veziroglu, Liquid hydrogen: Potential, problems, and a proposed research program, Int J Hydrogen Energy. 22 (1997) 683-688. https://doi.org/10.1016/S0360-3199(96)00201-7. - sourceNot checked — no full text of the source

May combine two claims.

BOH may be generated by ortho- to para-H2 conversion, heat leaks, sloshing, and flashing.

“According to Sherif et al. [34,44], BOH may be generated for the following reasons, detailed below:”

• Also stated in: § 3.2. Causes of boil-off hydrogen · plain

  “Ortho- to para-H2 conversion”

• Also stated in: § 3.2. Causes of boil-off hydrogen · plain

  “Heat leaks (shape and size effect, thermal stratification, thermal overfill, insulation, conduction, radiation, cooling)”

• cites [34] [34] S.A. Sherif, F. Barbir, T.N. Veziroglu, Towards a Hydrogen Economy, The Electricity Journal. 18 (2005) 62-76. https://doi.org/10.1016/J.TEJ.2005.06.003. - sourceNot checked — no full text of the source
• cites [44] [44] S.A. Sherif, N. Zeytinoglu, T.N. Veziroglu, Liquid hydrogen: Potential, problems, and a proposed research program, Int J Hydrogen Energy. 22 (1997) 683-688. https://doi.org/10.1016/S0360-3199(96)00201-7. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

H2 venting must be carried out with adequate safety precautions because of the risk of explosion if evaporated H2 meets oxygen or any oxidizing agent.

“H2 venting must be carried out with adequate safety precautions because of the risk of explosion if the evaporated H2 meets oxygen or any oxidizing agent [68].”

• cites [68] [68] DEMACO, What to do with hydrogen boil-off gas?, (n.d.). https://demacocryogenics.com/blog/what-to-do-with-hydrogen-boil-off-gas/ (accessed May 12, 2022). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S2 (checkable).

Mitigation strategies incorporating active cooling with multilayer insulation, such as zero boil-off (ZBO), could be an attractive option.

“To counter this, mitigation strategies incorporating active cooling with multilayer insulation, such as zero boiloff (ZBO), could be an attractive option.”

May combine two claims.

If H2 liquefaction is carried out without catalytic conversion of o- to p-H2, the ortho isomer will be at a higher concentration than its equilibrium concentration and will spontaneously convert to the para isomer, generating a significant amount of heat.

“If H2 liquefaction is carried out without catalytic conversion of o- to p-H2, the ortho isomer will be at a higher concentration than its equilibrium concentration and will thus spontaneously convert to the para isomer, generating a significant amount of heat [50].”

• cites [50] [50] M.S. Sadaghiani, M. Mehrpooya, Introducing and energy analysis of a novel cryogenic hydrogen liquefaction process configuration, Int J Hydrogen Energy. 42 (2017) 60336050. https://doi.org/10.1016/j.ijhydene.2017.01.136. - sourceNot checked — no full text of the source

May combine two claims.

The main drawback of reliquefaction is the need for additional adjacent space for the reliquefaction facility and the relatively high OPEX and CAPEX of the cooling process.

“The main drawback of this method is the need for additional adjacent space for the reliquefaction facility and the relatively high OPEX and CAPEX of the cooling process.”

May combine two claims.

H2 venting is generally safe for the environment if amounts released are small, but venting can become hazardous when large amounts of BOH are vented into confined spaces.

“Although H2 venting is generally safe for the environment if the amounts released are small, venting can become hazardous when large amounts of BOH are vented into confined spaces.”

May combine two claims.

Boil-off losses due to heat leakage are proportional to the surface-to-volume ratio, so the boil-off rate decreases sharply as the storage tank size increases.

“Since boil-off losses due to heat leakage are proportional to the surface-to-volume ratio, the boil-off rate decreases sharply as the storage tank size increases [58,59].”

• cites [58] [58] L. Schlapbach, A. Züttel, for Mobile Applications, Nature. 414 (2001) 353-358. https://doi.org/10.1038/35104634. - sourceNot checked — no full text of the source
• cites [59] [59] B.P. Tarasov, M. V. Lototskii, V.A. Yartys', Problem of hydrogen storage and prospective uses of hydrides for hydrogen accumulation, Russ J Gen Chem. 77 (2007) 694-711. https://doi.org/10.1134/S1070363207040329. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

The choice of the type of recovery strategy depends on the industry, location and application of the LH2, as well as the space available for additional facilities if required.

“The choice of the type of recovery strategy depends on the industry, location and application of the LH2, as well as the space available for additional facilities if required.”

May combine two claims.

High-conductivity plates produce low-resistance heat paths between the bottom and top of the tank and are therefore able to prevent excessive temperature gradients and pressures.

“The plates produce low-resistance heat paths between the bottom and top of the tank and are therefore able to prevent excessive temperature gradients and pressures.”

May combine two claims.

BOH must be vented to maintain tank pressure; otherwise, the warmer stratified column of LH2 can potentially cause cavitation and damage the LH2 pump.

“Therefore, the BOH must be vented to maintain the pressure of the tank, otherwise, the warmer stratified column of LH2 can potentially cause cavitation and damage the LH2 pump [44,64].”

• cites [44] [44] S.A. Sherif, N. Zeytinoglu, T.N. Veziroglu, Liquid hydrogen: Potential, problems, and a proposed research program, Int J Hydrogen Energy. 22 (1997) 683-688. https://doi.org/10.1016/S0360-3199(96)00201-7. - sourceNot checked — no full text of the source
• cites [64] [64] T.K. Khurana, B.V.S.S.S. Prasad, K. Ramamurthi, S.S. Murthy, Thermal stratification in ribbed liquid hydrogen storage tanks, Int J Hydrogen Energy. 31 (2006) 2299-2309. https://doi.org/10.1016/j.ijhydene.2006.02.032. - sourceNot checked — no full text of the source

May combine two claims.

The obtained BOH is in equilibrium with the LH2 and the density of each phase does not vary with time.

“The obtained BOH is in equilibrium with the LH2 and, therefore, the density of each phase does not vary with time [43].”

• cites [43] [43] G. Petitpas, P. Bénard, L.E. Klebanoff, J. Xiao, S. Aceves, A comparative analysis of the cryo-compression and cryo-adsorption hydrogen storage methods, Int J Hydrogen Energy. 39 (2014) 10564-10584. https://doi.org/10.1016/j.ijhydene.2014.04.200. - sourceNot checked — no full text of the source

May combine two claims.

Materials with low thermal conductivity or the insertion of long heat transfer paths can reduce convective losses, while various types of radiation shielding can reduce radiation losses.

“Materials with low thermal conductivity or the insertion of long heat transfer paths (e.g., by reducing the heat flow crosssection) can reduce convective losses, while various types of radiation shielding (e.g., multilayer insulation, boil-off vapor-cooled shields and opacifiers in powder insulation) can reduce radiation losses [40].”

• cites [40] [40] K.D. Timmerhaus, Cryogenic Process Engineering, in: R.A.B.T.-E. of P.S. and T. (Third E. Meyers (Ed.), Encyclopedia of Physical Science and Technology, Elsevier, New York, 2003: pp. 13-36. https://doi.org/10.1016/B0-12-227410-5/00156-3. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

It is crucial to ensure that recovery strategies are not overly expensive to maintain a positive OPEX, i.e., the energy used to recover the BOH should not exceed its own cost.

“However, it is crucial to ensure that the recovery strategies employed are not overly expensive to maintain a positive OPEX, i.e. , the energy used to recover the BOH should not exceed its own cost [69].”

• cites [69] [69] G. Petitpas, Boil-off losses along LH2 pathway, Livermore, CA (United States), 2018. https://doi.org/10.2172/1466121. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S4 (based).

State-of-the-art insulation systems are essential to prevent heat leakage into the LH2 storage vessel.

“State-of-the-art insulation systems are essential to prevent heat leakage into the LH2 storage vessel.”

Probably not a substantial claim: may not pass S4 (based).

All types of heat transfer are mitigated by providing multilayer insulation with considerably low thermal conductivities.

“The reason could lie in the fact that all types of heat transfer are mitigated by providing multilayer insulation with considerably low thermal conductivities.”

May combine two claims.

For spherical, vacuum-insulated, double-walled Dewars, boil-off losses are typically between 0.3 and 0.5% per day for 50 m3 storage tanks, 0.2% for 103 m3 tanks, and approximately 0.06% for 19,000 m3 tanks.

“For spherical, vacuum-insulated, double-walled Dewars, boil-off losses are typically between 0.3 and 0.5 % per day for 50 m 3 storage tanks, 0.2 % for 103 m 3 tanks, and approximately 0.06 % for 19,000 m 3 tanks [60].”

• cites [60] [60] H.H. Ewe, H.-J. Selbach, The Storage of Hydrogen, in: A Solar-Hydrogen Energy System, 1st ed., Plenum Press, New York, 1987: pp. 243-263. https://doi.org/10.1007/978-1-4613-1781-4\_11. - sourceNot checked — no full text of the source

May combine two claims.

The o- to p-H2 conversion reaction is primarily due to magnetic properties, while the heat of conversion increases as the reaction from o- to p-H2 proceeds.

“The o- to p-H2 conversion reaction is primarily due to magnetic properties [57], while the heat of conversion increases as the reaction from o- to p-H2 proceeds, as shown in Figure 3b.”

• cites [57] [57] Y. Ishii, Theory of non-dissociative ortho-para conversion on magnetic surfaces, Prog Surf Sci. 21 (1986) 163-208. https://doi.org/10.1016/0079-6816(86)90012-2. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S4 (based).

Over extended periods, heat transfer is virtually unavoidable with passive cooling alone.

“However, over extended periods, heat transfer is virtually unavoidable with passive cooling alone.”

Probably not a substantial claim: may not pass S3 (load-bearing).

BOH rate estimates around 1.5-3% per day have been reported.

“Similarly, BOH rate estimates around 1.5-3% per day have been reported elsewhere [58,61].”

• cites [58] [58] L. Schlapbach, A. Züttel, for Mobile Applications, Nature. 414 (2001) 353-358. https://doi.org/10.1038/35104634. - sourceNot checked — no full text of the source
• cites [61] [61] F. Zhang, P. Zhao, M. Niu, J. Maddy, The survey of key technologies in hydrogen energy storage, Int J Hydrogen Energy. 41 (2016) 14535-14552. https://doi.org/10.1016/j.ijhydene.2016.05.293. - sourceNot checked — no full text of the source

May combine two claims.

In general, the reverse Brayton refrigeration cycle is less efficient than the Claude process, but it has the advantage of simpler and safer operation, because the pressure levels of the helium cycle can be much lower (1 MPa or less).

“In general, the reverse Brayton refrigeration cycle is less efficient than the Claude process, but it has the advantage of simpler and safer operation, because the pressure levels of the helium cycle can be much lower (1 MPa or less) [85,91].”

• cites [85] [85] H.-M. Chang, B.H. Kim, B. Choi, Hydrogen liquefaction process with Brayton refrigeration cycle to utilize the cold energy of LNG, Cryogenics (Guildf). 108 (2020) 103093. https://doi.org/10.1016/j.cryogenics.2020.103093. - sourceNot checked — no full text of the source
• cites [91] [91] H.-M. Chang, K.N. Ryu, J.H. Baik, Thermodynamic design of hydrogen liquefaction systems with helium or neon Brayton refrigerator, Cryogenics (Guildf). 91 (2018) 6876. https://doi.org/10.1016/j.cryogenics.2018.02.007. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The refrigerant in the heat exchanger section is H2 gas from both the cooled expanded gas and the incoming cold BOH.

“The refrigerant in the heat exchanger section is H2 gas from both the cooled expanded gas and the incoming cold BOH.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Most large-scale H2 liquefaction plants are based on the Claude process with LN2 precooling, as reported by Bi and Ju.

“Most large-scale H2 liquefaction plants are based on the Claude process with LN2 precooling, as reported by Bi and Ju [109].”

• cites [109] [109] Y. Bi, Y. Ju, Conceptual design and optimization of a novel hydrogen liquefaction process based on helium expansion cycle integrating with mixed refrigerant precooling, Int J Hydrogen Energy. 47 (2022) 16949-16963. https://doi.org/10.1016/j.ijhydene.2022.03.202. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The performance indicators for the liquefaction plants presented in Table 1 were obtained from simulations performed primarily via Aspen Plus® or Aspen HYSYS®.

“The performance indicators for the liquefaction plants presented in Table 1 were obtained from simulations performed primarily via Aspen Plus® or Aspen HYSYS®.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The Claude process configuration avoids the need for LN2 cooling as in the Linde process.

“The Claude process configuration avoids the need for LN2 cooling as in the Linde process.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Liquefaction of gaseous fuels is an inherently energy-intensive process, but it has the advantage of densifying the fluid and thus reducing storage volume and facilitating fluid transport.

“Liquefaction of gaseous fuels is an inherently energy-intensive process, but it has the advantage of densifying the fluid and thus reducing storage volume and facilitating fluid transport.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Turbine expanders, such as radial flow turbines and axial flow turbines, are commonly used in H2 liquefiers, leading to higher exergy efficiency.

“Turbine expanders, such as radial flow turbines and axial flow turbines, are commonly used in H2 liquefiers, leading to higher exergy efficiency.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The Linde process (Linde-Hampson) is similar to the refrigeration process pioneered by John Dewar, where liquid nitrogen (LN2) is used as the refrigerant.

“The Linde process, also known as the Linde-Hampson process, is similar to the refrigeration process pioneered by John Dewar, where liquid nitrogen (LN2) is used as the refrigerant.”

May combine two claims.

Although the pressure record inside the Glenn Research Center tank showed a steady decrease demonstrating that the cryocooler could remove part of the heat load, the thermal gradient between the LH2 and the cryocooler was high enough (~8 K) to cause a substantial loss of lift rate and thus an increase in power.

“Although the pressure record inside the tank showed a steady decrease demonstrating that the cryocooler could remove part of the heat load, the thermal gradient between the LH2 and the cryocooler was high enough (~8 K) to cause a substantial loss of lift rate and thus an increase in power.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The choice of refrigeration cycle process is made based on plant capacity, location and electricity prices.

“The choice of refrigeration cycle process is made based on plant capacity, location and electricity prices [6].”

• cites [6] [6] U. Cardella, L. Decker, H. Klein, Roadmap to economically viable hydrogen liquefaction, Int J Hydrogen Energy. 42 (2017) 13329-13338. https://doi.org/10.1016/j.ijhydene.2017.01.068. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Of all the fuels that are gaseous under normal conditions, H2 has the lowest boiling point.

“Of all the fuels that are gaseous under normal conditions, H2 has the lowest boiling point.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The first ZBO proof-of-concept test was conducted at NASA Glenn Research Center in 1998 and the second was held at NASA Marshall Space Flight Center two years later.

“The first ZBO proof-of-concept test was conducted at NASA Glenn Research Center in 1998 and the second was held at NASA Marshall Space Flight Center two years later.”

• cites [75] [75] A. Hedayat, L.J. Hastings, C. Bryant, D.W. Plachta, Large scale demonstration of liquid hydrogen storage with zero boiloff, 1276 (2003) 1276-1283. https://doi.org/10.1063/1.1472155. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The US Department of Energy (DOE) has set the ultimate energy consumption target for H2 liquefaction to 6 kWh/kg LH2 for large-scale 300 ton/day liquefaction plants.

“The US Department of Energy (DOE) has set the ultimate energy consumption target for H2 liquefaction to 6 kWh/kg LH2 for large-scale 300 ton/day liquefaction plants [118].”

• cites [118] [118] DOE's Hydrogen and Fuel Cell Technologies Office, US Deparment of Energy (DOE) Technical Targets for Hydrogen Delivery, (n.d.). https://www.energy.gov/eere/fuelcells/doe-technical-targets-hydrogen-delivery (accessed October 27, 2022). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Refrigeration cycles for H2 liquefaction are currently being extensively studied and modified with the aim of improving the EXE of the process and reducing the SEC of future large-scale liquefaction plants.

“Refrigeration cycles for H2 liquefaction are currently being extensively studied and modified with the aim of improving the EXE of the process and reducing the SEC of future large-scale liquefaction plants [84].”

• cites [84] [84] L. Yin, Y. Ju, Review on the design and optimization of hydrogen liquefaction processes, Frontiers in Energy. 14 (2020) 530-544. https://doi.org/10.1007/s11708019-0657-4. - sourceNot checked — no full text of the source

May combine two claims.

Although the DOE target appears to be achievable by implementing process integration and proposed liquefaction design changes, the CAPEX for liquefaction systems remains an open issue, as they account for nearly 50% of the total liquefaction process assuming a plant capacity of 100 ton/day.

“Although this figure appears to be achievable by implementing process integration and proposed liquefaction design changes, the CAPEX for liquefaction systems remains an open issue [6], as they account for nearly 50% of the total liquefaction process assuming a plant capacity of 100 ton/day [90].”

• cites [6] [6] U. Cardella, L. Decker, H. Klein, Roadmap to economically viable hydrogen liquefaction, Int J Hydrogen Energy. 42 (2017) 13329-13338. https://doi.org/10.1016/j.ijhydene.2017.01.068. - sourceNot checked — no full text of the source
• cites [90] [90] U. Cardella, L. Decker, J. Sundberg, H. Klein, Process optimization for large-scale hydrogen liquefaction, Int J Hydrogen Energy. 42 (2017) 12339-12354. https://doi.org/10.1016/j.ijhydene.2017.03.167. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The principles of reliquefaction are basically the same as those of liquefaction, except that the feed conditions can change.

“The principles of reliquefaction are basically the same as those of liquefaction, except that the feed conditions can change.”

Probably not a substantial claim: may not pass S3 (load-bearing).

H2 is liquefied by Joule-Thompson (J-T) expansion down to 20 K at atmospheric pressure.

“Finally, H2 is liquefied by Joule-Thompson (J-T) expansion down to 20 K at atmospheric pressure.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the second stage, the pre-cooled H2 passes through a heat exchanger to reach 30 K through a cryocooling system, which operates with refrigeration cycles such as the helium reverse Brayton cycle or the H2 Claude cycle.

“In the second stage, the pre-cooled H2 passes through a heat exchanger to reach 30 K through a cryocooling system, which operates with refrigeration cycles such as the helium reverse Brayton cycle (possibly with H2 as well, but there is a minimum temperature limitation [80]) or the H2 Claude cycle [79].”

• cites [79] [79] M.S. Sadaghiani, M. Mehrpooya, Introducing and energy analysis of a novel cryogenic hydrogen liquefaction process configuration, Int J Hydrogen Energy. 42 (2017) 60336050. https://doi.org/10.1016/j.ijhydene.2017.01.136. - sourceNot checked — no full text of the source
• cites [80] [80] H.T. Walnum, D. Berstad, M. Drescher, P. Neksa, H. Quack, C. Haberstroh, J. Essler, Principles for the liquefaction of hydrogen with emphasis on precooling processes, Refrigeration Science and Technology. 2012 (2012) 273-280. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

In the reverse Brayton cycle, cryocooling is performed by a refrigeration cycle using helium as the coolant.

“In the reverse Brayton cycle, cryocooling is performed by a refrigeration cycle using helium as the coolant, as shown in Figure 6d.”

Probably not a substantial claim: may not pass S3 (load-bearing).

New ZBO projects considering the integration of the cryocooler through a circulated gas loop coupled outside the tank have been proposed.

“Therefore, new ZBO projects considering the integration of the cryocooler through a circulated gas loop coupled outside the tank have been proposed [76].”

• cites [76] [76] D.W. Plachta, W.L. Johnson, J.R. Feller, Cryogenic Boil - Off Reduction System Testing, Advanced Cryogenic Engineering. 53B (2008) 1457-66. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Small to mid-size liquefiers typically operate in a helium Brayton cycle or a hydrogen Claude cycle.

“On the other hand, small to mid-size liquefiers typically operate in a helium Brayton cycle or a hydrogen Claude cycle [115,116].”

• cites [115] [115] D.L. Ohlig K, Hydrogen liquefaction, Wiley-VCH Verlag GmbH & Co. KGaA, n.d. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites [116] [116] K. Ohlig, L. Decker, The latest developments and outlook for hydrogen liquefaction technology, AIP Conf Proc. 1573 (2014) 1311-1317. https://doi.org/10.1063/1.4860858. - sourceNot checked — no full text of the source

May combine two claims.

Lee et al.'s partial BOH reliquefaction system for LH2 tankers with hybrid LNG and H2 propulsion had an estimated SEC of 3.30 kWh/kg LH2, lower than characteristic SECs for liquefaction processes from ambient conditions.

“The SEC was estimated at 3.30 kWh/kg LH2 [129], a value lower than the characteristic SECs for liquefaction processes from ambient conditions.”

• cites [129] [129] H. Lee, Y. Shao, S. Lee, G. Roh, K. Chun, H. Kang, Analysis and assessment of partial re-liquefaction system for liquefied hydrogen tankers using liquefied natural gas (LNG)and H2 hybrid propulsion, Int J Hydrogen Energy. 44 (2019) 15056-15071. https://doi.org/10.1016/j.ijhydene.2019.03.277. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

ZBO systems for LH2 storage in spaceflight are being consolidated.

“ZBO systems for LH2 storage in spaceflight are being consolidated.”

May combine two claims.

Although ZBO was easily achieved at Marshall Space Flight Center, some inefficiencies derived from heat leakage through the pump and bypass loop affected the successful operation of the system.

“Although ZBO was easily achieved, some inefficiencies derived from heat leakage through the pump and bypass loop affected the successful operation of the system.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Another reason is the simplicity of LN2 pre-cooling, which, despite its low heat transfer efficiency, does not have a high investment cost.

“Another reason is the simplicity of LN2 pre-cooling, which, despite its low heat transfer efficiency, does not have a high investment cost.”

Classified as probably not a substantial claim.

A cryocooler coupled to a cryogenic tank must be able to remove the amount of heat load necessary to maintain the tank at the desired temperature.

“A cryocooler coupled to a cryogenic tank must be able to remove the amount of heat load necessary to maintain the tank at the desired temperature.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Cao and ter Brake identified four main categories of ejector use in refrigeration systems.

“Cao and ter Brake [92] identified four main categories of ejector use in refrigeration systems:”

• cites [92] [92] H.S. Cao, H.J.M. ter Brake, Progress and challenges in utilization of ejectors for cryogenic cooling, Appl Therm Eng. 167 (2020) 114783. https://doi.org/10.1016/j.applthermaleng.2019.114783. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Numerous designs have been proposed to reduce both the CAPEX and OPEX of liquefaction plants and, consequently, the cost of the H2 production chain.

“Numerous designs have been proposed to reduce both the CAPEX and OPEX of liquefaction plants and, consequently, the cost of the H2 production chain [90].”

• cites [90] [90] U. Cardella, L. Decker, J. Sundberg, H. Klein, Process optimization for large-scale hydrogen liquefaction, Int J Hydrogen Energy. 42 (2017) 12339-12354. https://doi.org/10.1016/j.ijhydene.2017.03.167. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Several refrigeration processes can be used for H2 liquefaction, including the Linde process, the Claude process, and the reverse Brayton cycle.

“Several refrigeration processes can be used for H2 liquefaction, including the Linde process, the Claude process, and the reverse Brayton cycle.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In the first cooling stage (precooling), the H2 feed gas is cooled to around 80 K.

“In the first cooling stage, also called precooling, the H2 feed gas is cooled to a temperature of around 80 K.”

Classified as probably not a substantial claim.

A reliquefaction system must have suitable volumetric capacity to handle the actual boil-off generation rate.

“Second, a reliquefaction system must have the suitable volumetric capacity to handle the actual boil-off generation rate.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The Claude process was first developed by Georges Claude in the early 20th century.

“The Claude process was first developed by Georges Claude in the early 20 th century [93].”

• cites [93] [93] S. Krasae-in, J.H. Stang, P. Neksa, Development of large-scale hydrogen liquefaction processes from 1898 to 2009, Int J Hydrogen Energy. 35 (2010) 4524-4533. https://doi.org/10.1016/j.ijhydene.2010.02.109. - sourceNot checked — no full text of the source

May combine two claims.

H2 must not only be below 200 K, but its pressure must also be reasonably high before passing through the valve for successful liquefaction.

“As a result, H2 must not only be below 200 K, but its pressure must also be reasonably high before passing through the valve for successful liquefaction [91].”

• cites [91] [91] H.-M. Chang, K.N. Ryu, J.H. Baik, Thermodynamic design of hydrogen liquefaction systems with helium or neon Brayton refrigerator, Cryogenics (Guildf). 91 (2018) 6876. https://doi.org/10.1016/j.cryogenics.2018.02.007. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The p-H2 content after liquefaction processes is between 95% and 98%.

“The p-H2 content after liquefaction processes is between 95 % and 98 % [85].”

• cites [85] [85] H.-M. Chang, B.H. Kim, B. Choi, Hydrogen liquefaction process with Brayton refrigeration cycle to utilize the cold energy of LNG, Cryogenics (Guildf). 108 (2020) 103093. https://doi.org/10.1016/j.cryogenics.2020.103093. - sourceNot checked — no full text of the source

May combine two claims.

SEC values below 10 kWh/kg LH2 and EXE values close to 50% are higher than those of existing H2 liquefaction plants, suggesting that, despite being merely theoretical estimates, they already give an idea of how much room for improvement there is in actual liquefaction plants.

“SEC values below 10 kWh/kg LH2 and EXE values close to 50 % are higher than those of existing H2 liquefaction plants, suggesting that, despite being merely theoretical estimates, they already give an idea of how much room for improvement there is in actual liquefaction plants.”

Probably not a substantial claim: may not pass S3 (load-bearing).

H2 liquefaction can be divided into several steps: H2 compression, pre-cooling, cryocooling and liquefaction.

“H2 liquefaction can be divided into several steps, namely H2 compression, pre-cooling, cryocooling and liquefaction [80].”

• cites [80] [80] H.T. Walnum, D. Berstad, M. Drescher, P. Neksa, H. Quack, C. Haberstroh, J. Essler, Principles for the liquefaction of hydrogen with emphasis on precooling processes, Refrigeration Science and Technology. 2012 (2012) 273-280. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

H2 must be cooled to a temperature 90 K lower than natural gas (i.e., a boiling point of 110 K), which implies the use of more efficient thermally insulated tanks to store the liquid.

“As an example, H2 must be cooled to a temperature 90 K lower than natural gas (i.e., a boiling point of 110 K), which implies the use of more efficient thermally insulated tanks to store the liquid [78].”

• cites [78] [78] O. Muragishi, S. Inatsu, R. Uraguchi, K. Yamashiro, T. Imai, T. Ohashi, T. Shimogaki, T. Yoshida, T. Koumoto, Hydrogen Transportation - Development of Liquefied Hydrogen Carrier, Kawasaki Technical Description No 182. (2021). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

H2 can be an alternative refrigerant, but helium is preferred because it has a lower boiling point and can therefore reach temperatures below 20 K in the gaseous state.

“H2 can be an alternative refrigerant, but helium is preferred because it has a lower boiling point and can therefore reach temperatures below 20 K in the gaseous state [91].”

• cites [91] [91] H.-M. Chang, K.N. Ryu, J.H. Baik, Thermodynamic design of hydrogen liquefaction systems with helium or neon Brayton refrigerator, Cryogenics (Guildf). 91 (2018) 6876. https://doi.org/10.1016/j.cryogenics.2018.02.007. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Reverse Brayton cycles can have various configurations depending on the arrangement and number of heat exchangers.

“Reverse Brayton cycles can have various configurations depending on the arrangement and number of heat exchangers.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The ZBO approach based on cooling the cryogenic fluid in the tank was abandoned in search of a better system to integrate the cryocooler for application in larger tanks.

“While each test had a purpose, the ZBO approach based on cooling the cryogenic fluid in the tank was abandoned in search of a better system to integrate the cryocooler for application in larger tanks.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Rietdijk was the first to suggest the implementation of ejectors in cryogenic cooling systems to generate subatmospheric pressure in a liquid helium evaporator, with the aim of achieving cooling temperatures below 4.2 K.

“Rietdijk [100] was the first to suggest the implementation of ejectors in cryogenic cooling systems to generate subatmospheric pressure in a liquid helium evaporator, with the aim of achieving cooling temperatures below 4.2 K.”

• cites [100] [100] Rietdijk J.A., The Expansion-Ejector, A New Device for Liquefaction and Refrigeration at 4°K and Lower, in: 1966: pp. 241-249. https://doi.org/10.1016/B9780-08-012409-4.50023-1. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Chang et al. conducted a study to determine the optimal pressure for maximizing the thermodynamic performance of a conventional Linde liquefaction system.

“Chang et al. [91] thus conducted a study to determine the optimal pressure for maximizing the thermodynamic performance of a conventional Linde liquefaction system.”

• cites [91] [91] H.-M. Chang, K.N. Ryu, J.H. Baik, Thermodynamic design of hydrogen liquefaction systems with helium or neon Brayton refrigerator, Cryogenics (Guildf). 91 (2018) 6876. https://doi.org/10.1016/j.cryogenics.2018.02.007. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Available data on performance indicators such as EXE and SEC of current large-scale liquefaction plants are very limited.

“Available data on performance indicators such as EXE and SEC of current large-scale liquefaction plants are very limited [6].”

• cites [6] [6] U. Cardella, L. Decker, H. Klein, Roadmap to economically viable hydrogen liquefaction, Int J Hydrogen Energy. 42 (2017) 13329-13338. https://doi.org/10.1016/j.ijhydene.2017.01.068. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

In Lee et al.'s partial BOH reliquefaction system, the boil-off feed was performed at 53 K due to heat leakage in the pipes.

“Due to heat leakage in the pipes, the boil-off feed was performed at 53 K to the reliquefaction system.”

• cites [129] [129] H. Lee, Y. Shao, S. Lee, G. Roh, K. Chun, H. Kang, Analysis and assessment of partial re-liquefaction system for liquefied hydrogen tankers using liquefied natural gas (LNG)and H2 hybrid propulsion, Int J Hydrogen Energy. 44 (2019) 15056-15071. https://doi.org/10.1016/j.ijhydene.2019.03.277. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Open issues include the need to increase the lift rate while maintaining the cryogenic system at a practical size and weight suitable for NASA space missions.

“Open issues include the need to increase the lift rate while maintaining the cryogenic system at a practical size and weight suitable for NASA space missions.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Figure 6b shows a flow chart of the Linde-Hampson process where, in addition to LN2, low-temperature BOH is also used as a refrigerant.

“Figure 6b shows a flow chart of the Linde-Hampson process where, in addition to LN2, low-temperature BOH is also used as a refrigerant.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The ejector primarily consists of a suction section with a nozzle, a mixing chamber and a diffuser.

“The ejector, as shown in Figure 1c, primarily consists of a suction section with a nozzle, a mixing chamber and a diffuser.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Nicolas et al. optimized the compressor by modeling and simulating its delivery operation using an axisymmetric 2D geometry in COMSOL Multiphysics under various thermal conditions.

“In a follow-up study, Nicolas et al. [144] focused on the optimization of the latter compressor by performing a parametric study under a variety of possible thermal conditions by modeling and simulating the delivery operation of the compressor using an axisymmetric 2D geometry in COMSOL Multiphysics®.”

• cites [144] [144] V. Nicolas, G. Sdanghi, K. Mozet, S. Schaefer, G. Maranzana, A. Celzard, V. Fierro, Numerical simulation of a thermally driven hydrogen compressor as a performance optimization tool, Appl Energy. 323 (2022) 119628. https://doi.org/10.1016/j.apenergy.2022.119628. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

Non-mechanical compressors are attracting attention because they are more compact, quieter, more efficient and less expensive than traditional mechanical compressors.

“Non-mechanical compressors are attracting a lot of attention because they are more compact, quieter, more efficient and less expensive than traditional mechanical compressors.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

In the LNG industry, boil-off compression is a mature operation.

“as is the case in the LNG industry, where boil-off compression is a mature operation.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The CHC has a H2 delivery capacity of up to 57 m3/h at 289 K under pressures up to 69 MPa.

“The CHC has a H2 delivery capacity of up to 57 m 3 /h at 289 K under pressures up to 69 MPa [134].”

• cites [134] [134] Air Products, The Cryogenic Hydrogen Compressor System. A Low-Cost Way to Meet Your Production Requirements, (2016). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Giner ELX Inc. has created standard EHC systems with H2 flow rate delivery of either 10 kg/h or 0.5 kg/h, operating at inlet pressures of about 0.1-10 MPa and achievable outlet pressures up to 87.5 MPa.

“Giner ELX Inc, based in the USA but acquired in 2020 by Plugpower, also headquartered in the USA, has created standard EHC systems with H2 flow rate delivery of either 10 kg/h or 0.5 kg/h, operating at inlet pressures of about 0.1-10 MPa and achievable outlet pressures up to 87.5 MPa.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Kinetic studies of adsorption compressors in the field of cryocoolers have been performed by NASA's Jet Propulsion Laboratories in Pasadena, California.

“In the field of cryocoolers, kinetic studies of adsorption compressors have been performed by NASA's Jet Propulsion Laboratories in Pasadena, California [140].”

• cites [140] [140] C.K. Chan, E. Tward, D.D. Elleman, Kinetics of a gas adsorption compressor, Adv Cryog Eng. (1984) 533-534. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The diffusion of non-mechanical compressors on the markets is not yet sufficient because their maturity levels differ or some lack appropriate H2 delivery capacity for certain high-pressure applications.

“Unfortunately, their diffusion on the markets is not yet sufficient because the level of maturity of the different types of non-mechanical compressors is different or because some of them do not yet have the appropriate H2 delivery capacity for certain high-pressure applications.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Giner ELX claimed to have achieved stack efficiencies in the range of 2.0 kWh/kg H2 at 350 MPa and 4.4 kWh/kg H2 at 87.5 MPa.

“Consequently, it has achieved stack efficiencies in the range of 2.0 kWh/kg H2 at 350 MPa and 4.4 kWh/kg H2 at 87.5 MPa [138].”

• cites [138] [138] Giner ELX Inc, Electrochemical Compression, 2019 DOE Hydrgoen and Fuel Cell Program Annual Merit Review. (2019) 1-6. -Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

An important advantage of H2 reliquefaction is that H2 is already at low temperature, so o- to p-H2 catalytic conversion is not necessary if the reliquefaction process is properly integrated into the cryogenic LH2 tank.

“An important advantage is that H2 is already at low temperature, so the o- to p-H2 catalytic conversion is not necessary if the reliquefaction process is properly integrated into the cryogenic LH2 tank.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The ionic compressor 90© has allowable inlet pressures from 0.6 to 20 MPa and an energy consumption of up to 3.3 kWh/kg H2 with a noise level of 70 dB at 10 m.

“The ionic compressor 90©, for example, has a flexible range of allowable inlet pressures from 0.6 to 20 MPa and an energy consumption of up to 3.3 kWh/kg H2 with a noise level of 70 dB at a distance of 10 m [133].”

• cites [133] [133] Linde, IC90 / 60 Ionic Compressor Compressor module for gaseous hydrogen refueling station, (2021) 2021. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

Most commercially available non-mechanical compressors are not suitable for operating at the boiling temperature of H2, which requires a heater to raise the inlet gas temperature.

“However, most commercially available non-mechanical compressors are not suitable for operating at the boiling temperature of H2, which requires a heater to raise the inlet gas temperature.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

A metal hydride compressor requires thermal management because its operation is driven by absorption/desorption cycles, and Hystorsys compressors use hot and cold water with typical inlet temperatures of 288-298 K (cooling) and 358-368 K (heating).

“A metal hydride compressor requires thermal management since its operation is driven by absorption/desorption cycles. Hystorsys compressors use hot and cold water for that purpose. Typical inlet temperatures are 288-298 K (cooling) and 358-368 K (heating).”

Probably not a substantial claim: may not pass S3 (load-bearing).

The H2 industry is technologically less mature than the LNG industry.

“Another likely cause is that the growing interest in LH2 as a fuel or energy carrier is more recent than for LNG., i.e., the H2 industry is technologically less mature than LNG.”

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

The use of highly porous adsorbents in cryo-adsorption-based storage systems offers a promising alternative for transporting H2 over long distances while achieving high volumetric density comparable to LH2 and reducing boil-off losses.

“The use of highly porous adsorbents in cryo-adsorption-based storage systems offers a promising alternative for transporting H2 over long distances while achieving high volumetric density that is comparable to LH2 and reducing boil-off losses.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based). May combine two claims.

New non-mechanical compressors with inlet gas temperatures near 20 K may be beneficial in advancing LH2 logistics and contributing to the global energy transition.

“New non-mechanical compressors with inlet gas temperatures near 20 K may be beneficial in advancing LH2 logistics and, in turn, contribute to the global energy transition.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Nicolas et al. concluded that increasing convective heat transfer with the surrounding air can reduce the time to reach room temperature by almost 75%.

“The authors concluded that increasing convective heat transfer with the surrounding air can reduce the time to reach room temperature by almost 75%.”

• cites [144] [144] V. Nicolas, G. Sdanghi, K. Mozet, S. Schaefer, G. Maranzana, A. Celzard, V. Fierro, Numerical simulation of a thermally driven hydrogen compressor as a performance optimization tool, Appl Energy. 323 (2022) 119628. https://doi.org/10.1016/j.apenergy.2022.119628. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The main problem with H2 reliquefaction systems is the cost of liquefaction.

“The main problem with H2 reliquefaction systems is the cost of liquefaction.”

Probably not a substantial claim: may not pass S3 (load-bearing).

LH2 shipping compressors and BOH compressors have already been tested on a 9,000 km journey from the eastern coast of Australia to Kobe Airport Island in Japan in 2020.

“LH2 shipping compressors and BOH compressors have already been tested on a 9,000 km journey from the eastern coast of Australia to Kobe Airport Island in Japan in 2020.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Skyre Inc. offers smaller capacity EHCs, about 0.6 kg/day.

“Skyre Inc. offers smaller capacity EHCs, about 0.6 kg/day.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

H2 compression will play an important role in the deployment of the hydrogen economy because many applications of gaseous H2 require high pressures (>30 MPa).

“Finally, H2 compression will play an important role in the deployment of the hydrogen economy, since many applications of gaseous H2 require high pressures (> 30 MPa).”

Probably not a substantial claim: may not pass S3 (load-bearing).

Sdanghi et al. built a proof-of-concept compressor based on thermally driven adsorption/desorption cycles using activated carbons with high BET area (≥ 3,000 m2/g).

“Sdanghi et al. [143] built a proof-of-concept compressor based on thermally driven adsorption/desorption cycles using activated carbons with high BET area (≥ 3,000 m 2 /g).”

• cites [143] [143] G. Sdanghi, V. Nicolas, K. Mozet, S. Schaefer, G. Maranzana, A. Celzard, V. Fierro, A 70 MPa hydrogen thermally driven compressor based on cyclic adsorption-desorption on activated carbon, Carbon N Y. 161 (2020) 466-478. https://doi.org/10.1016/j.carbon.2020.01.099. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

HyET Hydrogen offers modular designs of electrochemical compressors (EHCs) consisting of various stacks, and the more stacks, the higher the compressor capacity.

“The Dutch company HyET Hydrogen offers modular designs of electrochemical compressors (EHCs) consisting of various stacks. The more stacks, the higher the compressor capacity.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

In reliquefaction systems for stationary applications, it must be considered to what extent reliquefaction can be a cost-effective option.

“In the space industry, budgetary issues are not a concern, while in reliquefaction systems, for example in stationary applications, it must be considered to what extent reliquefaction can be a cost-effective option.”

• AssumptionRests on an assumption: In the space industry, budgetary issues are not a concern.

Probably not a substantial claim: may not pass S3 (load-bearing).

The single-stage turbo compressor was used to ensure that H2 remained at 20 K in liquid form.

“The single-stage turbo compressor was used to ensure that H2 remained at 20 K in liquid form.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Inserting a heat exchanger in front of the compressor is an alternative way to increase BOH temperature, allowing compressors to operate at higher temperatures, but it would imply additional energy expenditure.

“If BOH compressors evolve sufficiently from an operational and design standpoint, inserting a heat exchanger in front of the compressor (as in Figure 8) is an alternative way to increase the BOH temperature, allowing compressors to operate at higher temperatures. Nonetheless, this would imply additional energy expenditure.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The Skyre EHC, designed and proven for NASA, is based on a patented electrochemical technology and can capture, separate and compress H2 up to 20 MPa from mixed gas streams such as biogas, natural gas reformate, syngas or industrial effluent.

“Additionally, as it is the differentiating characteristic of EHCs, the system is able to capture, separate and compress H2 up to 20 MPa from a variety of mixed gas streams such as biogas, natural gas reformate, syngas or effluent from a given industrial process [137].”

• cites [137] [137] SKYRE, SKYRE H2RENEW, (2019) 1-2. -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Adsorption compressors for applications other than H2 compression have been reported in the literature since the 1980s.

“Adsorption compressors for applications other than H2 compression have already been reported in the literature since the 1980s.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Hystorsys standard hydrogen metal hydride compressors can operate with capacities ranging from 1 Nm3/h up to 12 Nm3/h (8.5 to 25.5 kg/day) and achieve pressure levels up to 25 MPa.

“Standard hydrogen metal hydride compressors from Hystorsys can operate with capacities ranging from 1 Nm³/h up to 12 Nm³/h (8.5 to 25.5 kg/day) and achieve pressure levels up to 25 MPa.”

• cites [139] [139] HYSTORSYS, HYMEHC hydrogen compressor, (n.d.). https://www.hystorsys.no/mhcompressor/ (accessed September 5, 2022). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

In Sdanghi et al.'s cyclic experiments, a cooling and heating step was performed from an initial pressure of 8 MPa at 77 K to a final pressure of 70 MPa in a single step when heating the compressor to 315 K.

“Cyclic experiments comprising a cooling and a heating step were performed from an initial pressure of 8 MPa at 77 K to a final pressure of 70 MPa in a single step when heating the compressor to 315 K.”

• cites [143] [143] G. Sdanghi, V. Nicolas, K. Mozet, S. Schaefer, G. Maranzana, A. Celzard, V. Fierro, A 70 MPa hydrogen thermally driven compressor based on cyclic adsorption-desorption on activated carbon, Carbon N Y. 161 (2020) 466-478. https://doi.org/10.1016/j.carbon.2020.01.099. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Linde offers standardized compressors with H2 delivery capacities of up to 900 kg/day at a maximum pressure of 90 MPa and up to 1,344 kg/day at a maximum pressure of 50 MPa.

“The company offers a broad portfolio of standardized compressors with H2 delivery capacities of up to 900 kg/day at a maximum pressure of 90 MPa and up to 1,344 kg/day at a maximum pressure of 50 MPa [132].”

• cites [132] [132] Linde, Linde Hydrogen Fueltech. Tomorrow´s fuel today, (2020). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Non-mechanical compressors are considered a potential alternative to traditional mechanical compressors due to their compactness, negligible noise, superior efficiency, and lack of wear and moving parts.

“Due to their compactness, negligible noise, superior efficiency, lack of wear and moving parts, non-mechanical compressors are considered a potential alternative to traditional mechanical compressors.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The BOH was stored on board after in situ liquefaction in a 116 m-long, 8,000-ton cylindrical tank in a 1,250-m3 double-jacketed, vacuum-insulated, single tank.

“The BOH was stored on board after in situ liquefaction in a 116 m-long, 8,000ton cylindrical tank in a 1,250-m 3 double-jacketed, vacuum-insulated, single tank [131].”

• cites [131] [131] F. La Porta, H. Usuda, Hydrogen compression. Charting a path for hydrogen transportation, 63. (2022). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

A centrifugal compressor for BOH, designed by Atlas Copco Gas and Process, was set up to operate at 20 K in the LH2 shipping pilot study conducted by Kawasaki Heavy Industries (KHI).

“A centrifugal compressor for BOH, designed by Atlas Copco Gas and Process, was set up to operate at 20 K in this LH2 shipping pilot study conducted by Kawasaki Heavy Industries (KHI).”

Classified as probably not a substantial claim.

H2 poses additional operational challenges at cryogenic temperatures, such as material embrittlement or gas seal reliability.

“but also that H2 poses additional operational challenges, such as material embrittlement or gas seal reliability at this temperature.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

HyET Hydrogen offers standardized EHCs with H2 flowrate capacities ranging from 2 to 600 kg/day and an outlet pressure of almost 90 MPa.

“This company thus offers a wide variety of standardized EHCs with several H2 flowrate capacities ranging from 2 to 600 kg/day and an outlet pressure of almost 90 MPa [135].”

• cites [135] [135] HyET Hydrogen, HyET H2 Compression and Purification systems, (2020). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Air Products' Cryogenic Hydrogen Compressor (CHC) system has a pump claimed to operate with both vapor and liquid phases without an additional compressor.

“The US company Air Products is proposing a Cryogenic Hydrogen Compressor (CHC) system with a pump claimed to able to operate with both vapor and liquid phases without the need of an additional compressor [134].”

• cites [134] [134] Air Products, The Cryogenic Hydrogen Compressor System. A Low-Cost Way to Meet Your Production Requirements, (2016). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

Cryo-adsorption storage allows for higher H2 densities than LH2 and extends the dormancy period to higher temperatures than traditional cryogenic tanks.

“This approach allows for even higher H2 densities than those achievable by LH2 and extends the dormancy period to higher temperatures than traditional cryogenic tanks.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

According to HyET Hydrogen, OPEX is around 0.30-0.60 USD/kg H2 and CAPEX between 150 and 300 USD/kg H2/day, compared to a CAPEX of 1000-1500 USD/kg H2/day for mechanical compressors.

“According to HyET Hydrogen, OPEX and CAPEX are very competitive with mechanical compressors: OPEX is around 0.30-0.60 USD/kg H2 and CAPEX between 150 and 300 USD/kg H2/day (compared to a CAPEX of 1000-1500 USD/kg H2/day for mechanical compressors) [136].”

• cites [136] [136] HyET Hydrogen, Cost effective hydrogen processing technologies. Presentation., 2020. (n.d.). https://www.youtube.com/watch?v=OrMVOibGfGA (accessed August 17, 2022). -Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Hystorsys compressors are based on a flexible and expandable design, so additional compression chambers can be added to increase volumetric capacity if more H2 delivery capacity is required.

“The compressors are based on a flexible and expandable design. Hence, if more H2 delivery capacity is required, additional compression chambers can be added to increase the volumetric capacity[139].”

• cites [139] [139] HYSTORSYS, HYMEHC hydrogen compressor, (n.d.). https://www.hystorsys.no/mhcompressor/ (accessed September 5, 2022). -Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

The temperature at which H2 desorption starts depends on the textural properties of the MOFs, resulting in an extended dormancy time for the tank system.

“The temperature at which H2 desorption starts depends on the textural properties of the MOFs, resulting in an extended dormancy time for the tank system.”

• cites [146] [146] J. Park, J. Ha, R. Muhammad, H.K. Lee, R. Balderas-Xicohtencatl, Y. Cheng, A.J. Ramirez-Cuesta, B. Streppel, M. Hirscher, H.R. Moon, H. Oh, 20 K H2Physisorption on Metal-Organic Frameworks with Enhanced Dormancy Compared to Liquid Hydrogen Storage, ACS Appl Energy Mater. (2022). https://doi.org/10.1021/acsaem.2c01907. - sourceNot checked — no full text of the source

May combine two claims.

Compressing BOH at cryogenic temperatures is a major engineering challenge because current commercial compressors hardly work at 20 K and because energy is required for possible upstream H2 heating.

“However, compressing BOH at cryogenic temperatures is a major engineering challenge, not only because current commercial compressors hardly work with fluids at such a low temperature (20 K), but also because of the energy required for possible upstream H2 heating.”

• AssumptionRests on an assumption: BOH compressors operating at 20 K do not exist commercially.

Classified as probably not a substantial claim.

Park et al. observed that van der Waals interactions between adsorbate and adsorbent in these MOFs result in superdense H2 adsorption at 20 K, compensating for the adsorbent skeleton and resulting in a volumetric storage capacity comparable to LH2 tanks (~96%).

“They observed that van der Waals interactions between the adsorbate and adsorbent in these MOFs results in superdense H2 adsorption at 20 K, compensating for the space occupied by the adsorbent skeleton, resulting in a volumetric storage capacity comparable to that of LH2 tanks ( ∼ 96 %).”

• cites [146] [146] J. Park, J. Ha, R. Muhammad, H.K. Lee, R. Balderas-Xicohtencatl, Y. Cheng, A.J. Ramirez-Cuesta, B. Streppel, M. Hirscher, H.R. Moon, H. Oh, 20 K H2Physisorption on Metal-Organic Frameworks with Enhanced Dormancy Compared to Liquid Hydrogen Storage, ACS Appl Energy Mater. (2022). https://doi.org/10.1021/acsaem.2c01907. - sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Ionic liquid compressors have the lowest noise level among mechanical compressors and operate almost at isothermal compression because they have fewer moving parts and mechanical seals.

“While mechanical compressors are known to be noisy due to their numerous moving parts, ionic liquid compressors have the lowest noise level among mechanical compressors as they have fewer moving parts and mechanical seals, so they operate almost at isothermal compression.”

Probably not a substantial claim: may not pass S4 (based).

The boiling temperature of H2 is nearly 90 K lower than that of natural gas.

“One possible reason is that the boiling temperature of H2 is nearly 90 K lower than that of natural gas”