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Cited by 7Algal biology and biofuel productionBioenergy crop production and managementMicrobial Metabolic Engineering and Bioproduction

Implications of Pond Reliability on the Techno-Economic and Life Cycle Environmental Impacts of Algal Biofuels

Open access
Quiroz, David, McGowen, John, Quinn, Jason C.·2024·Journal of Cleaner Production
DOI 10.1016/j.jclepro.2024.143178
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AI snapshot

Written from the paper’s full text.

TL;DR

This study couples a stochastic pond-reliability model with algal growth, techno-economic analysis, and life cycle assessment to quantify how mean-time-to-failure (MTTF) affects algal biofuel cost and environmental impacts. It finds that improving pond reliability lowers MFSP and GWP but with diminishing returns, and no modeled scenario reaches commercial viability.

Key findings

  • Average MFSPs were $3.52 and $2.10 per liter of gasoline equivalent for 20-day and 350-day MTTF scenarios, respectively; the abstract reports a 32% MFSP decrease from 20 to 54 days and a 12% decrease from 54 to 350 days.
  • Global warming potentials were 131, 96, and 83 g CO2eq MJ⁻¹ for MTTFs of 20, 54, and 350 days, respectively; all scenarios fail to meet the Renewable Fuel Standard of 45 g CO2eq MJ⁻¹.
  • Commercial viability was not achieved in any modeled scenario even when productivities were doubled to 35 g m⁻² d⁻¹, and none met the U.S. Department of Energy target of $0.80 LGE⁻¹.
  • Water consumption impacts ranged from 23 to 32 m³ GJ⁻¹, and pond failure increased water consumption by 30% because evaporation remains constant while biomass production decreases.

Methods

  • A dynamic open raceway pond biological model for *Scenedesmus obliquus* (UTEX 393) was coupled with a two-state Markov Chain pond reliability model based on MTTF; Monte Carlo simulation tracked pond failure in 4-hectare ponds using Phoenix, AZ weather data over a 30-year facility lifetime, with 10,050 iterations (335 facilities).
  • The process model included a three-stage seed train, dewatering, anaerobic storage, hydrothermal liquefaction, and upgrading to renewable diesel and naphtha; outputs fed a discounted cash flow rate of return TEA to solve for MFSP and an attributional well-to-wheels LCA using TRACI 2.1 plus water consumption, Ecoinvent 3.7, OpenLCA, and GREET.
  • Five MTTF scenarios were modeled: 20, 54, 80, 120, and 350 days; productivity improvement scenarios increased biomass yields by 25% to 100% relative to each MTTF baseline.

Limitations

  • The paper states that MTTF data are uncertain and variable across locations, seasons, species, and pest management strategies; only one location (Phoenix, AZ) was modeled, the 7-day mean time to reset is conservative but not experimentally validated, and the model does not capture consequential yield effects of pest management due to lack of validation data.
  • The paper states it assumes semi-continuous cultivation with seed needed only after culture crashes, does not characterize catastrophic failure, and models productivity improvements as independent of MTTF.
  • Evident from the text: only one algal strain (*Scenedesmus obliquus* UTEX 393) and one conversion pathway (HTL and upgrading) are modeled, and the HTL pathway does not include high-value co-products.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.jclepro.2024.143178

Cites

29 of 29 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 44 cited sources checked · 0 supported · 0 flagged

  • Findingreasoning
    § 3.1 Techno-Economic Analysis Results · p. 8

    The impacts of biomass losses and the additional costs of the inoculum seed train increase the operational and capital costs of cultivation.

    “As expected, the impacts of biomass losses and the additional costs of the inoculum seed train increase the operational and capital costs of cultivation.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.
  • Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 8

    Average minimum fuel selling prices of the 335 simulations (10,050 years) exponentially decrease with pond reliability improvements.

    “As observed in Fig. 2A, average MFSPs of the 335 simulations (10,050 years) exponentially decrease with pond reliability improvements.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.
  • Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 8

    When the mean-time-to-failure increases to 54 days, the average minimum fuel selling price decreases by 25% relative to the calculated average for the 20-day scenario.

    “When the MTTF increases to 54 days, the average MFSP decreases by 25% relative to the calculated average for the 20-day scenario.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.
  • Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 10

    Variability in the prices of algal products can be minimized by operating at higher MTTFs.

    “As observed, in Figs. 2B-C, the variability in the prices of algal products can be minimized by operating at higher MTTFs.”
    • Also stated in: § 4. Conclusions · p. 15 · plain
      “The variability in MFSP was found to increase with lower MTTFs, providing information on the risk of algal outdoor cultivation and a benchmark of comparison to other biomass feedstocks.”
    Quote in the paperSubstantial claim
  • Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 8

    In the 20-day mean-time-to-failure scenario, the costs of seed production and biomass cultivation make up about 62% of the total minimum fuel selling price ($3.23-LGE-1).

    “This is readily visible in the 20-day MTTF scenario, where the costs of seed production and biomass cultivation make up about 62% of the total MFSP ($3.23-LGE -1 ).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.
  • May combine two claims. 29
  • Classified as probably not a substantial claim. 15

  • May combine two claims.

    Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 8

    The average minimum fuel selling price decreases by only 5% between the 120-day to the 350-day scenarios, which corresponds to a 4% increase in biomass yields.

    “For example, the average MFSP decreases by only 5% between the 120-day to the 350-day scenarios, which corresponds to a 4% increase in biomass yields.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Findingnone given
    § Abstract · p. 1

    Ten additional environmental metrics were examined with most tracking with electricity impacts.

    “Ten additional environmental metrics were examined with most tracking with electricity impacts.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Findingown data
    § Abstract · p. 1

    Increasing mean-time-to-failure yields diminishing returns, with a 32% decrease observed in minimum fuel selling price by increasing mean-time-to-failure from 20 to 54 days but only a 12% decrease observed from increasing mean-time-to-failure from 54 to 350 days.

    “The results of this work demonstrate that increasing MTTF yields diminishing returns, with a 32% decrease observed in MFSP by increasing MTTF from 20 to 54 days but only an 12% decrease observed from increasing MTTF from 54 to 350 days.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Findingreasoning
    § 3.1 Techno-Economic Analysis Results · p. 8

    The range of minimum fuel selling prices for the 20-day mean-time-to-failure scenario was $0.37-LGE-1 while a range of $0.05-LGE-1 was calculated for a mean-time-to-failure of 350 days.

    “For instance, the range of MFSPs for the 20-day MTTF scenario was found to be $0.37-LGE -1 while a range of $0.05-LGE -1 was calculated for an MTTF of 350 days.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 8

    At higher mean-time-to-failures, the capital expenses of the seed train become negligible as less inoculum is needed to restart cultivation, and minimum fuel selling price reductions are primarily derived from increments in biomass yields.

    “At higher MTTFs, the capital expenses of the seed train become negligible as less inoculum is needed to restart cultivation, and MFSP reductions are primarily derived from the increments in biomass yields (Fig. 2A).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 12

    The baseline scenario (MTTF of 54 days) has a net GWP of 95 g CO2eq MJ-1, and GWPs are 90, 87, and 83 g CO2eq MJ-1 for MTTFs of 80, 120, and 350 days, respectively, showing diminishing returns.

    “The baseline scenario presented a net GWP of 95 g CO2eq MJ -1 and diminishing returns are apparent as pond reliability increases above the 54 days with GWPs of 90, 87, and 83 g CO2eq MJ -1 for MTTFs of 80, 120, and 350 days, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 13

    28% and 29% of the total fossil fuel depletion impacts estimated for the 350-day MTTF scenario are attributed to hydrogen and nutrients.

    “As an example, 28% and 29% of the total fossil fuel depletion impacts estimated for the 350-day MTTF scenario are attributed to hydrogen and nutrients.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 13

    TRACI categories illustrated in Figs. 3I-3K track strongly with other inputs used in cultivation and conversion processes, besides being affected by upstream electricity impacts.

    “Besides being affected by upstream electricity impacts, the TRACI categories illustrated in Figs. 3I-3K track strongly with other inputs used in the cultivation and conversion processes.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 11

    At a MTTF of 350 days, contributions from the seed train to TRACI categories shown in Figs. 3A-G are minimal (2%), and other energy-intensive processes such as CO2 delivery and biomass cultivation drive the results.

    “When the MTTF is increased to 350 days, contributions from the seed train are minimal (2%) and other energy-intensive processes in the system such as the CO2 delivery and biomass cultivation drive the results of these TRACI categories (Figs. 3A-G).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 4. Conclusions · p. 15

    Most TRACI categories track strongly with electricity consumption except for fossil fuel and ozone depletion, which are dominated by supply-chain impacts of nutrient and hydrogen inputs.

    “Most of the TRACI categories were found to track strongly with electricity consumption except for fossil fuel and ozone depletion, which are dominated by the supply-chain impacts of nutrient and hydrogen inputs.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 12

    The net GWP for the conservative scenario (MTTF of 20 days) is 131 g CO2eq MJ-1, of which 32% (43 g CO2eq MJ-1) is attributed to the seed train.

    “This is exemplified by the net GWP of 131 g CO2eq MJ -1 calculated for the conservative scenario (MTTF of 20 days), for which 32% (43 g CO2eq MJ -1 ) is attributed to the seed train.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 11

    Net life cycle impacts of algal biofuels decrease with improvements in pond reliability, with diminishing returns at high MTTFs.

    “As illustrated in Fig. 3, net life cycle impacts of algal biofuels were found to decrease with improvements in pond reliability but diminishing returns were observed at high MTTFs.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 3.1 Techno-Economic Analysis Results · p. 10

    Coefficients of variation in annual algal biomass yields due to pond failure were 8.8% for the 20-day MTTF scenario, 5.8% for the 54-day scenario, 4.8% for the 80-day scenario, and 4% for the 120-day scenario.

    “For comparison, coefficients of variation in annual yields due to pond failure for the 20-day (8.8%), 54-day (5.8%), 80-day (4.8%), and 120-day (4%) scenarios were found to be higher, suggesting that at MTTFs lower than 120 days, crashing-related variability might be more significant than weather-related variability.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data
    § 3.2 Life Cycle Impact Assessment · p. 13

    Evaporation losses from open raceway ponds accounted for most of the water consumed by the system, and upstream water consumption of other process inputs was negligible.

    “Contrastingly, evaporation losses from the open raceway ponds accounted for most of the water consumed by the system and the upstream water consumption of other process inputs was determined to be negligible (Fig. 3K).”
    Quote in the paperSubstantial claim

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

    Premisecitation
    § 1. Introduction · p. 1

    Despite intensive research, multiple technical challenges must be addressed to produce low-cost algal biomass at the industrial scale.

    “Despite intensive research, multiple technical challenges must be addressed to produce low-cost algal biomass at the industrial scale [2], [4], [7], [8].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [2] [2] J. R. Cruce et al. , 'Driving toward sustainable algal fuels: A harmonization of techno-economic and life cycle assessments,' Algal Research , vol. 54. Elsevier B.V., p. 102169, Apr. 01, 2021. doi: 10.1016/j.algal.2020.102169. - source

      Not checked in the free run.

    • cites [4] [4] I. Gifuni, A. Pollio, C. Safi, A. Marzocchella, and G. Olivieri, 'Current Bottlenecks and Challenges of the Microalgal Biorefinery,' Trends Biotechnol , vol. 37, no. 3, pp. 242-252, Mar. 2019, doi: 10.1016/J.TIBTECH.2018.09.006. - source

      Not checked in the free run.

    • cites [7], [8]

      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.

    Premisecitation
    § 1. Introduction · p. 1

    Microalgae have been extensively studied as a renewable feedstock for biofuel production due to their rich biochemical composition and significantly faster growth rates compared to traditional biomass sources.

    “Microalgae have been extensively studied as a renewable feedstock for biofuel production [1]-[3] due to its rich biochemical composition and significantly faster growth rates compared to traditional biomass sources [4]-[6].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [1]-[3]

      Not checked in the free run.

    • cites [4]-[6]

      Not checked in the free run.

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

    Study design and conductown data
    § 2.1.2 Pond Reliability Model · p. 5

    The integrated model was verified for convergence by running 10,050 iterations of a single year (8760 hours), equivalent to 335 facilities with a 30-year lifetime.

    “The integrated model was programmed in MATLAB and verified for convergence by running 10,050 iterations of a single year (8760 hours), equivalent to 335 facilities with a 30-year lifetime.”
    Quote in the paperNot a substantial claim

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

    Interpretationreasoning
    § 1. Introduction · p. 2

    A detailed analysis of the impacts of pond failure and its implications on process design is key to understanding the true profitability and environmental sustainability of algal-based biofuels.

    “Based on the state of the field, a detailed analysis of the impacts of pond failure and its implications on process design is key to understanding the true profitability and environmental sustainability of algal-based biofuels.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning
    § 3.1 Techno-Economic Analysis Results · p. 8

    As biomass yields are directly correlated to the functional unit, an increase in the frequency of pond failure results not only in higher minimum fuel selling prices but also in a wider range of minimum fuel selling prices.

    “As biomass yields are directly correlated to the functional unit, an increase in the frequency of pond failure results not only in higher MFSPs but also in a wider range of MFSPs.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Interpretationown data
    § 3.1 Techno-Economic Analysis Results · p. 8

    Moderate reductions in minimum fuel selling price can be achieved by increasing pond reliability, but there are marked diminishing returns beyond the 120-day mean-time-to-failure.

    “Results of the analysis indicate that moderate reductions in MFSP can be achieved by increasing pond reliability, but there are marked diminishing returns beyond the 120-day MTTF.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Premisecitation
    § 1. Introduction · p. 2

    Previous modeling efforts have leveraged dynamic thermal models to estimate potential facility downtime caused by pond freezing events but neglect the effects of pest contamination.

    “In addition, previous modeling efforts [5], [13], [14] have leveraged dynamic thermal models to estimate potential facility downtime caused by pond freezing events but neglect the effects of pest contamination.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [5] [5] J. W. Moody, C. M. McGinty, and J. C. Quinn, 'Global evaluation of biofuel potential from microalgae,' Proc Natl Acad Sci U S A , vol. 111, no. 23, pp. 86918696, Jun. 2014, doi: 10.1073/pnas.1321652111. - source

      Not checked in the free run.

    • cites [13] [13] D. Quiroz, J. M. Greene, and J. C. Quinn, 'Regionalized Life-Cycle Water Impacts of Microalgal-Based Biofuels in the United States,' Environ Sci Technol , vol. 56, no. 22, pp. 16400-16409, Nov. 2022, doi: 10.1021/ACS.EST.2C05552/SUPPL\_FILE/ES2C05552\_SI\_002.XLSX. - source

      Not checked in the free run.

    • cites [14] [14] D. Quiroz, J. M. Greene, J. McGowen, and J. C. Quinn, 'Geographical assessment of open pond algal productivity and evaporation losses across the United States,' Algal Res , vol. 60, p. 102483, Dec. 2021, doi: 10.1016/J.ALGAL.2021.102483. - source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning
    § 3.1 Techno-Economic Analysis Results · p. 8

    The higher rate of crashing events results in larger biomass losses, increasing the variability in yields.

    “The higher rate of crashing events results in larger biomass losses, increasing the variability in yields.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

  • May combine two claims.

    Interpretationreasoning
    § 3.1 Techno-Economic Analysis Results · p. 8

    Outputs from the stochastic simulation demonstrate that operating an algae facility at lower mean-time-to-failure leads to a higher economic risk than that shown by high-mean-time-to-failure scenarios, for which the variability of biomass yields is smaller.

    “Outputs from the stochastic simulation demonstrate that operating an algae facility at lower MTTF leads to a higher economic risk than that shown by high-MTTF scenarios, for which the variability of biomass yields is smaller.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Transitions between pond operational and failed states follow an exponential distribution.
    • The authors state this as an assumption: During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

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

    Premisecitation
    § 2.3 Life Cycle Assessment · p. 7

    Rainwater consumption has a minimal contribution to the total water consumption impacts of algal biorefineries in Phoenix, AZ.

    “Rainwater consumption was disregarded as it has a minimal contribution to the total water consumption impacts of algal biorefineries in Phoenix, AZ [13].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [13] [13] D. Quiroz, J. M. Greene, and J. C. Quinn, 'Regionalized Life-Cycle Water Impacts of Microalgal-Based Biofuels in the United States,' Environ Sci Technol , vol. 56, no. 22, pp. 16400-16409, Nov. 2022, doi: 10.1021/ACS.EST.2C05552/SUPPL\_FILE/ES2C05552\_SI\_002.XLSX. -

      Not checked in the free run.

  • May combine two claims.

    Premisereasoning
    § 1. Introduction · p. 2

    There is a limited understanding of the different factors impacting pond reliability and the potential strategies to manage pest contamination.

    “As shown by the wide range of MTTF data in the literature, there is a limited understanding of the different factors impacting pond reliability and the potential strategies to managed pest contamination.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation
    § 2.1.1 Cultivation Model · p. 4

    The photon efficiency of 1.5 g biomass mol-1 photons was based on validation done by Quiroz et al.

    “The photon efficiency was set to 1.5 g biomass mol -1 photons based on the validation done by Quiroz et al. [14].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [14] [14] D. Quiroz, J. M. Greene, J. McGowen, and J. C. Quinn, 'Geographical assessment of open pond algal productivity and evaporation losses across the United States,' Algal Res , vol. 60, p. 102483, Dec. 2021, doi: 10.1016/J.ALGAL.2021.102483. - source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data
    § 3.3 Impacts of Productivity Improvements · p. 14

    Pond reliability influences fuel selling prices, particularly at low MTTF, and increasing biomass yields is important to improve the economics of algal-based fuels.

    “The TEA results emphasize the influence of pond reliability on fuel selling prices (particularly with low-MTTF) and underscore the importance of increasing biomass yields to improve the economics of algal-based fuels.”
    Quote in the paperSubstantial claim

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

    Premisecitation
    § 3.3 Impacts of Productivity Improvements · p. 15

    Solutions that eliminate the need for capturing, compressing, and transporting carbon, such as operating ponds at higher alkalinity to promote atmospheric CO2 transfer, are being explored at the lab-scale.

    “Similarly, solutions that eliminate the need for capturing, compressing, and transporting carbon such as operating ponds at higher alkalinity to promote atmospheric CO2 transfer are being explored at the lab-scale [41].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [41] [41] C. Zhu et al. , 'Efficient CO2 capture from the air for high microalgal biomass production by a bicarbonate Pool,' Journal of CO2 Utilization , vol. 37, pp. 320327, Apr. 2020, doi: 10.1016/J.JCOU.2019.12.023.

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data
    § 4. Conclusions · p. 15

    Operating at MTTFs above 54 days can offer marginal reductions in MFSP, but improvements in pond reliability alone are not sufficient to achieve commercially viable levels.

    “Operating at MTTFS above 54 days can offer marginal reductions in MFSP, but improvements in pond reliability alone are not sufficient to achieve commercially viable levels.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning
    § 3.3 Impacts of Productivity Improvements · p. 15

    The findings identify additional process areas that, with focused research and development, may provide larger reductions in the MFSP of the system than advances in MTTF.

    “In a broader context, the findings of this study identify additional process areas that, with focused research and development, may provide larger reductions in the MFSP of the system than advances in MTTF.”
    Quote in the paperSubstantial claim

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

    Interpretationnone given
    § 3.3 Impacts of Productivity Improvements · p. 15

    The availability of contaminated water might limit the scalability of algal biofuels.

    “However, the availability of contaminated water might limit the scalability of algal biofuels.”
    Quote in the paperNot a substantial claim

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

    Premisecitation
    § 3.3 Impacts of Productivity Improvements · p. 14

    Current experimental productivity achieved stands at 17.6 g m-2 d-1.

    “For context, it is worth noting that the current experimental productivity achieved stands at 17.6 g m -2 d -1 [9].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [9] [9] J. McGowen, E. P. Knoshaug, L. M. L. Laurens, and J. Forrester, 'Outdoor annual algae productivity improvements at the pre-pilot scale through crop rotation and pond operational management strategies,' Algal Res , vol. 70, p. 102995, Mar. 2023, doi: 10.1016/J.ALGAL.2023.102995. -

      Not checked in the free run.

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

    Premisereasoning
    § 3.2 Life Cycle Impact Assessment · p. 13

    Water consumption impacts can significantly vary across regions due to the influence of local climates on pond evaporation rates.

    “It is important to note that water consumption impacts can significantly vary across regions due to the influence of local climates on pond evaporation rates.”
    Quote in the paperNot a substantial claim

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

    Premisecitation
    § 3.3 Impacts of Productivity Improvements · p. 15

    The HTL pathway may not offer the opportunity for co-products, but current research efforts are evaluating alternative conversion pathways that can yield high-value chemical coproducts.

    “While the HTL pathway may not offer the opportunity for co-products, there are current research efforts focused on evaluating alternative conversion pathways that can yield high-value chemical coproducts [1].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [1] [1] R. Davis and M. Wiatrowski, 'Algal Biomass Conversion to Fuels via Combined Algae Processing (CAP): 2019 State of Technology and Future Research,' 2019, Accessed: Mar. 21, 2022. [Online]. Available: www.nrel.gov/publications. -

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

  • May combine two claims.

    Interpretationreasoning
    § 3.2 Life Cycle Impact Assessment · p. 13

    Supply-chain impacts drive the results of the different TRACI categories, while biomass yields and on-site water losses are the main contributors to the water consumption impacts of the system.

    “The analysis highlights that supply-chain impacts drive the results of the different TRACI categories while biomass yields and on-site water losses are the main contributors to the water consumption impacts of the system.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning
    § 3.2 Life Cycle Impact Assessment · p. 13

    Pond reliability improvements have limits on reducing the GWP of algal-based biofuels, and areas of research have potential to generate larger reductions in emissions than culture stability improvements.

    “The results presented here illustrate the limits of pond reliability improvements on reducing the GWP of algal-based biofuels and highlight areas of research with the potential to generate larger reductions in emissions than culture stability improvements.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning
    § 4. Conclusions · p. 15

    The sustainability of algal biofuels depends on substantial productivity improvements, reductions in process inputs, and development of conversion pathways that can generate high-value co-products.

    “This work demonstrates that the sustainability of algal biofuels depends on substantial productivity improvements, reductions in process inputs, and the development of conversion pathways that can generate high-value co-products.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data
    § 3.3 Impacts of Productivity Improvements · p. 14

    Improvements in pond reliability and productivity alone will not be enough to achieve commercially viable levels, and a substantial decrease in the capital costs of the system is necessary as well.

    “In general, the findings presented in Fig. 4 highlight that improvements in pond reliability and productivity alone will not be enough to achieve commercially viable levels and a substantial decrease in the capital costs of the system are necessary as well.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationown data
    § 4. Conclusions · p. 15

    Results highlight the importance of incorporating pond downtime and biomass loss caused by failure events into process models used to inform sustainability assessments of algal bioproducts.

    “Results highlight the importance of incorporating pond downtime and biomass loss caused by failure events into process models used to inform sustainability assessments of algal bioproducts.”
    Quote in the paperSubstantial claim

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

    Interpretationreasoning
    § 4. Conclusions · p. 15

    Continued research on algal crop protection and pest management is needed to reduce variability and uncertainty around pond MTTF.

    “Results from this work show the need for continued research on algal crop protection and pest management to reduce the variability and uncertainty around pond MTTF.”
    Quote in the paperNot a substantial claim

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

    Premisecitation
    § 3.3 Impacts of Productivity Improvements · p. 15

    There has been growing interest in water bioremediation through algal treatment, which might eliminate the need for additional nutrients and offers the opportunity for environmental services credits.

    “Recently, there has been a growing interest in water bioremediation through algal treatment which might eliminate the need for additional nutrients and offers the opportunity for environmental services credits [39], [40].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [39] [39] A. B. Banks, P. H. Chen, C. Quiroz-Arita, R. W. Davis, and J. C. Quinn, 'Geographically-resolved evaluation of the economic and environmental services from renewable diesel derived from attached algae flow-ways across the United States,' Algal Res , vol. 72, p. 103100, May 2023, doi: 10.1016/J.ALGAL.2023.103100. - source

      Not checked in the free run.

    • cites [40] [40] J. Clippinger and R. Davis, 'Techno-Economic Assessment for Opportunities to Integrate Algae Farming with Wastewater Treatment,' 2021, Accessed: Jul. 20, 2023. [Online]. Available: https://www.nrel.gov/docs/fy21osti/75237.pdf. - source

      Not checked in the free run.

41 of 41

  • The authors state this as an assumption.

    Transitions between pond operational and failed states follow an exponential distribution.

    “Transitions between states are determined by assuming that probabilities follow an exponential distribution [1].”

  • The authors state this as an assumption.

    During a pond failure event, all accumulated biomass in the pond up to that time step is lost.

    “During failure events, the model simulated culture crash resulting in complete loss of the accumulated biomass in the pond up to that specific time step.”

  • The authors state this as an assumption.

    Gray water consumption, or the water needed to dilute waste streams to acceptable pollution levels, is negligible.

    “Gray water consumption or the water needed to dilute waste streams to acceptable pollution levels was assumed to be negligible following assumptions in Quiroz et al. [13].”

  • The paper relies on this without support.

    No prior work has explored the implications of pond failure on the sustainability of algal biofuels.

    “This is the first work exploring the implications of pond failure on the sustainability of algal biofuels and provides valuable insights to algae farmers on how to reduce the financial risks of algal cultivation through process design and pond management strategies.”

  • The authors state this as an assumption.

    Ponds are operated in a semi-continuous mode and seed is only needed after culture crashing.

    “this work assumes that ponds are operated in a semi-continuous mode and seed is only needed after culture crashing.”

  • The authors state this as an assumption.

    Water removed from the ponds after crashing is recycled back to the cultivation facility after on-site ultraviolet sterilization.

    “the water removed from the ponds after crashing was assumed to be recycled back to the cultivation facility after on-site ultraviolet sterilization.”

  • The authors state this as an assumption.

    Productivity improvements modeled in Fig. 4 are independent of increases in pond MTTF.

    “results presented in Fig. 4 assume that productivity improvements are independent of increases in pond MTTF.”
7 of 7

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Cultivation-pond harvest densities differ

    Major

    The cultivation-model description says ponds are harvested upon reaching 0.5 g L -1, but Table 1 lists the cultivation-pond harvest density as 0.3 g L -1.

  • Conflicting 20-day minimum fuel selling prices

    Major

    The abstract reports an average MFSP of $3.52 per liter of gasoline equivalent for the 20-day scenario, while the results section calls $3.23 the total MFSP for that scenario.

  • Conflicting MFSP reductions from 20 to 54 days

    Major

    The abstract reports a 32% decrease in MFSP from a 20-day to a 54-day MTTF, but the results section reports a 25% decrease for the same comparison.

  • Conflicting baseline GWP values

    Minor

    The abstract gives 96 g CO2eq MJ -1 for the 54-day MTTF, whereas the results section gives 95 g CO2eq MJ -1 for the baseline 54-day scenario.

  • Nine impact categories are listed as ten

    Minor

    The text says it analyzed ten TRACI impact categories but names only nine.

5 of 5

Cites

Flagged first, then by citations

Research works printed but not linked: 2

  1. Jenkins, 2019, Chemical engineering plant cost index annual average, Chem. Eng.
  2. 2012, NIST/SEMATECH e-Handbook of Statistical Methods

Cited by

Sorted by citations

Related

Authors
Quiroz, D., McGowen, J., & Quinn, J. C.
Affiliations
  • Colorado State University (US)
  • Arizona State University (US)
Corresponding author
Quiroz, David
ORCID
Venue
Journal of Cleaner Production
Publisher
Elsevier BV
Published
2024-09
Volume
469
Pages
143178
ISSN
0959-6526 (ISSN-L)
DOI
10.1016/j.jclepro.2024.143178
OpenAlex
W4400698433
Semantic Scholar
c48ab8fedc34d4ae57ca5620088e5bf8929e9a25
Cited by
7
References
29
Citations by year
2026: 3 · 2025: 4
FWCI
0.47
Type
journal article
Language
en
Open access
Licence
Locations
  • Journal of Cleaner Production (acceptedVersion)
  • OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) (submittedVersion)
Funders
U.S. Department of Energy (DE-EE0008902)
Topics
  • Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
  • Life Sciences › Agricultural and Biological Sciences › Agronomy and Crop Science › Bioenergy crop production and management
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Microbial Metabolic Engineering and Bioproduction
Keywords
algal biofuels, mean time to failure, techno-economic analysis, life cycle assessment, global warming potential, freshwater use, minimum fuel selling price, algae cultivation, greenhouse gas emissions, cost competitiveness

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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