Cited by 111Adsorption and biosorption for pollutant removalThermochemical Biomass Conversion ProcessesAdsorption, diffusion, and thermodynamic properties of materials

The DOI matches its Crossref record; 35 of the 35 references it cites were found in a registry or an index; none of the 16 sources its claims cite is checked for support yet.

Activated Carbon Produced by Pyrolysis of Waste Wood and Straw for Potential Wastewater Adsorption

Open access

Abstract

Pyrolysis of straw pellets and wood strips was performed in a fixed bed reactor. The chars, solid products of thermal degradation, were used as potential materials for activated carbon production. Chemical and physical activation processes were used to compare properties of the products. The chemical activation agent KOH was chosen and the physical activation was conducted with steam and carbon dioxide as oxidising gases. The effect of the activation process on the surface area, pore volume, structure and composition of the biochar was examined. The samples with the highest surface area (1349.6 and 1194.4 m2/g for straw and wood activated carbons, respectively) were obtained when the chemical activation with KOH solution was applied. The sample with the highest surface area was used as an adsorbent for model wastewater contamination removal.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

Pyrolysis of waste straw pellets and beech wood strips at 800 °C produced biochars that were activated chemically with KOH or physically with steam/CO₂. KOH activation gave the highest surface areas, and the best straw-derived activated carbon removed Rhodamine B from model aqueous solutions.

Key findings

  • Chemical activation with KOH produced the highest surface areas: 1349.6 m²/g for straw-derived activated carbon and 1194.4 m²/g for wood-derived activated carbon.
  • Physical activation with CO₂ at a 1:1 gas-to-carbon molar ratio gave lower surface areas: 682.1 m²/g and 0.35 cm³/g pore volume for straw, and 385 m²/g and 0.2 cm³/g for wood; lower gas ratios (1:0.5) gave less extended surface area.
  • Unactivated biochars had low surface areas: 3.1 m²/g for straw char and 27.3 m²/g for wood char.
  • In Rhodamine B adsorption tests using the 1349.6 m²/g straw-based activated carbon, 4.1 mg of AC decreased RhB concentration by 30%, and total removal of the model solution colour occurred when 15.3 mg AC was added.

Methods

  • Fast pyrolysis of about 100 g biomass was performed in a fixed-bed steel reactor at 800 °C for 30 min with a heating rate of 100 °C/min under limited air; char yields used were 23.8 g for straw pellets and 22.5 g for wood chips.
  • Activation methods: chemical activation with solid KOH at a 1:2 char:KOH mass ratio, heated at 850 °C for 1 h under N₂ at 50 mL/min; physical activation with steam or CO₂ at 850 °C, gas flow 10 dm³/h for 0.5 or 1 h, using biochar-to-gas molar ratios of 1:0.5 and 1:1.
  • Materials were characterised by CHNS-O analysis, thermogravimetry, moisture and calorific value analysis, BET N₂ adsorption–desorption at 77 K, and SEM; RhB adsorption was tested at 25 °C with 20 mL of 30 mg/dm³ dye solution, AC doses from 2.7 to 20.6 mg, 30 min shaking at 120 rpm, and UV-VIS at 553 nm.

Limitations

  • The paper states that in the adsorption study the authors used only one, but the most important parameter, to confirm sorption properties of the straw-derived AC; pH, temperature, ionic strength, and other solution parameters were kept constant rather than varied.
  • Evident from the text: adsorption was tested only with Rhodamine B as a model contaminant, at a single initial concentration of 30 mg/dm³, and only with the highest-surface-area straw-based KOH-activated carbon.
  • Evident from the text: no regeneration, reusability, continuous-flow, or real wastewater tests are reported, and the adsorption analysis does not include kinetic or equilibrium isotherm modelling.

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

Integrity signals

Registry

Crossref · 10.3390/ma13092047

Cites

35 of 35 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Figures

Figure 1 Raw materials before and after pyrolysis: (A) beech wood chips; and (B) straw pellets.
Figure 1 Raw materials before and after pyrolysis: (A) beech wood chips; and (B) straw pellets.CC BY · PubMed Central
Figure 2 Scheme of the pyrolysis reactor.
Figure 2 Scheme of the pyrolysis reactor.CC BY · PubMed Central
Figure 3 (A) Thermal analysis of the straw and wood samples; (B) derivative of mass loss in time for straw and wood samples obtained at 15 °C/min under a nitrogen atmosphere.
Figure 3 (A) Thermal analysis of the straw and wood samples; (B) derivative of mass loss in time for straw and wood samples obtained at 15 °C/min under a nitrogen atmosphere.CC BY · PubMed Central
Figure 4 Scanning electron microscopy (SEM) micrographs presenting comparison of wood and straw samples after different activation methods. The molar ratio of biochar to the activating gas or mass ratio of biochar to KOH are shown in parentheses.
Figure 4 Scanning electron microscopy (SEM) micrographs presenting comparison of wood and straw samples after different activation methods. The molar ratio of biochar to the activating gas or mass ratio of biochar to KOH are shown in parentheses.CC BY · PubMed Central
Figure 5 Discoloration of the RhB solution by the application of the activated carbon obtained by the pyrolysis of the straw pellet and chemical activation with KOH (the sample to KOH mass ratio of 1:2). The numbered pictures represent various dosages of activated carbon: no. 2–6 depict 2.7, 4.1, 11.2, 15.3 and 20.6 mg, respectively, used for sorption of 30 mg/dm3 of Rhodamine B at 25 °C.
Figure 5 Discoloration of the RhB solution by the application of the activated carbon obtained by the pyrolysis of the straw pellet and chemical activation with KOH (the sample to KOH mass ratio of 1:2). The numbered pictures represent various dosages of activated carbon: no. 2–6 depict 2.7, 4.1, 11.2, 15.3 and 20.6 mg, respectively, used for sorption of 30 mg/dm3 of Rhodamine B at 25 °C.CC BY · PubMed Central
Figure 6 Effect of the activated carbon dosage (chemical activation 1:2, straw pellet sample) in the range 2.7–20.6 mg AC for 30 mg/dm3 of Rhodamine B solution, sorption at 25 °C determined by UV-VIS analysis, where: q—the activated carbon per mass of the dye adsorbed, AC/RhB. % dye removal—percentage of RhB dye adsorbed by the activated carbon (with unchanging initial concentration of dye).
Figure 6 Effect of the activated carbon dosage (chemical activation 1:2, straw pellet sample) in the range 2.7–20.6 mg AC for 30 mg/dm3 of Rhodamine B solution, sorption at 25 °C determined by UV-VIS analysis, where: q—the activated carbon per mass of the dye adsorbed, AC/RhB. % dye removal—percentage of RhB dye adsorbed by the activated carbon (with unchanging initial concentration of dye).CC BY · PubMed Central

Verification

Claims the paper makes

24 Own result · 11 No full text of the sources · 6 Own interpretation · 3 Not checked yet · 2 Own method · 2 No basis given

Verify all 2 references — free account

Show all 21 claims

  • It may state two separate claims as one. 16
  • Probably not a substantial claim. 16
27 of 27
  • The paper relies on this without support.

    Wood is composed of relatively more densely packed cells and is therefore a harder material (hardness above 500 KG/cm2).

    “Wood is composed of relatively more densely packed cells, and is therefore a harder material (hardness above 500 KG/cm2).”
  • The paper relies on this without support.

    Rhodamine B is a suitable model contaminant for wastewater adsorption.

    “In this experiment, Rhodamine B was used as a model water contaminant to observe the efficiency of the adsorption by the activated carbon.”
  • The paper relies on this without support.

    Straw pellets are a heterogeneous mixture of various waste straw, like wheat and rye, and are commonly used in Polish agriculture and commercially available.

    “Typically, the straw pellets are a heterogeneous mixture of various waste straw, like wheat and rye. This pellet is commonly used in Polish agriculture and is commercially available, therefore such biomass was chosen for the experiments.”
  • The paper relies on this without support.

    The final surface properties and functionalities of the char are determined by the nature of pyrolyzed precursors and the type of activation process.

    “The final surface properties and functionalities of the char are determined by the nature of pyrolyzed precursors and the type of activation process.”
4 of 4

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.

3 of 3

Citations

Cites

Show all 35 references

Research works printed but not linked: 4

  1. Pawel, 2017, Utjecaj temperature na sastav proizvoda pirolize drva, Drv. Ind., 68, 307
  2. McMillan, J.D., Adney, W.S., Mielenz, J.R., and Klasson, K.T. (2006). Applied Biochemistry and Biotechnology, Humana Press.
  3. Karcz, 2013, The feasibility of straw as a fuel source for power generating boilers, Inżynieria środowiska, XI–XII, 8
  4. Enaime, 2017, Preparation and characterization of activated carbons from olive wastes by physical and chemical activation: Application to Indigo carmine adsorption, J. Mater. Environ. Sci., 8, 4125

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Metadata

Authors
Januszewicz, K., Kazimierski, P., Klein, M., Kardaś, D., & Łuczak, J.
Affiliations
  • Gdańsk University of Technology (PL)
  • Institute of Fluid Flow-Machinery (PL)
  • Nanyang Technological University (SG)
Corresponding author
Januszewicz, Katarzyna
Venue
Materials
Publisher
MDPI AG
Published
2020-04-27
Volume
13
Issue
9
Pages
2047
ISSN
1996-1944 (ISSN-L)
OpenAlex
W3017937534
Cited by
111
References
35
Citations by year
2026: 9 · 2025: 19 · 2024: 17 · 2023: 26 · 2022: 16 · 2021: 16 · 2020: 8
FWCI
5.13
Type
journal article
Language
en
Open access
Locations
  • Materials (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • DR-NTU (Nanyang Technological University) (submittedVersion, cc-by)
Topics
  • Physical Sciences › Environmental Science › Water Science and Technology › Adsorption and biosorption for pollutant removal
  • Physical Sciences › Energy › Fuel Technology › Thermochemical Biomass Conversion Processes
  • Physical Sciences › Chemistry › Physical and Theoretical Chemistry › Adsorption, diffusion, and thermodynamic properties of materials
Keywords
activated carbon, pyrolysis, wood waste, straw, biochar, chemical activation, KOH activation, physical activation, steam activation, CO2 activation, surface area, pore volume, fixed-bed reactor

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