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Wang F, Peng W, Zeng X, Sun D, Cui G, Han Z, Wang C, Xu G. Insight into staged gasification of biomass waste: Essential fundamentals and applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 953:175954. [PMID: 39244064 DOI: 10.1016/j.scitotenv.2024.175954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/21/2024] [Accepted: 08/30/2024] [Indexed: 09/09/2024]
Abstract
This article delves into the principle, essence, definitions, classifications, fundamentals, and industrial applications of staged gasification for biomass, offering an insightful exploration into its multifaceted dimensions. By segmenting the gasification process based on its intricate reaction network into distinct sub-processes implemented in separate reactors or reaction zones, staged gasification facilitates nuanced reaction control and sub-process intensification. It aims to optimize the gasification process by minimizing inhibitory effects and maximizing promotional interactions among chemical reactions, intermediates, or targeted products. This approach has been extensively tested, yielding significant technical benefits such as in-situ tar component conversion and efficiency enhancements. A clear categorization of the diverse staged gasification processes documented in literature is presented, distinguishing them based on the nature of interactions among separated stages, namely, chemical interaction, thermal interaction, and sequential staging. Definitions are provided for key concepts such as decoupling gasification, dual-bed or twin-bed gasification, and gasification with in-situ tar removal. Core fundamentals discussed include the reaction characteristics and kinetics of sub-processes, in-situ conversion of heteroatomic components, reactor configuration, and reaction regulation strategies. The article also presents an analysis of several industrial applications to elucidate the technical characteristics of staged gasification. Concluding with a discussion on prospective research concerns, this review underscores the evolving landscape of staged gasification technology and its pivotal role in advancing biomass conversion efficiencies.
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Affiliation(s)
- Fang Wang
- School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China
| | - Weini Peng
- School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China
| | - Xi Zeng
- School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China.
| | - Duo Sun
- School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China
| | - Guannan Cui
- School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China
| | - Zhennan Han
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Chao Wang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Guangwen Xu
- Key Laboratory on Resources of Chemicals and Materials of Ministry of Education, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China.
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Manali A, Pothoulaki A, Gikas P. The state of the art in biosolids gasification. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 364:121385. [PMID: 38875979 DOI: 10.1016/j.jenvman.2024.121385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 05/23/2024] [Accepted: 06/03/2024] [Indexed: 06/16/2024]
Abstract
Biosolids is a by-product of wastewater treatment that needs to be further processed. Traditional biosolids treatment and disposal technologies are inefficient under the current demanding standards. Thermochemical conversion technologies have been employed for biosolids management, with gasification being the most promising due to the production of syngas, a gaseous product that may be used for the production of energy or high-added-value substances through reforming reactions. Gasification is a complex thermochemical process; its performance and yield are strongly affected by the type of feedstock, but also by the system configuration and process conditions. Gasification usually takes place at temperatures between 700 and 1,200 °C, but it may also occur at lower temperatures (above 375 °C: supercritical water gasification) or at higher temperatures (above 3,000 °C: plasma gasification). The present review briefly presents the biosolids management practices, focusing on the gasification process and syngas treatment, while the state of the art in biosolids gasification is critically presented and discussed. A number of types of gasifiers (more frequently fluidized bed, but also fixed bed, rotary kiln, downdraft, etc.), gasifying agents, and operational conditions have been used for biosolids gasification. The key results of the study regarding biosolids gasification are: (i) the increase of temperature and equivalence ratio enhances the gasification performance, resulting in high syngas yield and quality, high cold gas efficiency, and low tar and char production; (ii) the calorific value of the obtained syngas tends to decrease with the increase of equivalence ratio; and (iii) the use of catalysts has been proven to substantially improve the gasification performance, compared to non-catalytic gasification. The proper selection of technical parameters determines the effectiveness of biosolids gasification, which is considered as a promising technology for the energy recovery from biosolids, so to upgrade wastewater treatment and improve environmental quality.
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Affiliation(s)
- Anthoula Manali
- Design of Environmental Processes Laboratory, School of Chemical and Environmental Engineering, Technical University of Crete, 73100, Chania, Greece.
| | - Aikaterini Pothoulaki
- Design of Environmental Processes Laboratory, School of Chemical and Environmental Engineering, Technical University of Crete, 73100, Chania, Greece.
| | - Petros Gikas
- Design of Environmental Processes Laboratory, School of Chemical and Environmental Engineering, Technical University of Crete, 73100, Chania, Greece.
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Courtois N, Pochard I, Remery M, Hihn JY, Tourneret L. Influence of the characteristics of paper mill sludges on their anaerobic digestion. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2022; 40:1256-1266. [PMID: 34937463 DOI: 10.1177/0734242x211065698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The objective of this study was to characterise the anaerobic degradation of three paper mill waste water treatment residues in the shape of sludges and to correlate this anaerobic digestion to the physico-chemical characteristics of the paper sludges. After a deep characterisation of each paper sludge in their initial stage, several parameters were analysed on each paper sludge in mesophilic conditions for 40-50 days: pH, conductivity, chemical oxygen demand, total organic acids and organic fibres degradation. A special care was taken to identify and quantify the volatile fatty acids (VFAs) produced by the digestion using gas chromatography coupled with a mass spectrometer. The results showed that in paper sludges, cellulose mainly degrades over time while the degradation of the other fibres (hemicellulose and lignin) is limited. Consequently, the greater the cellulose content in a paper sludge, the greater the digestion and formation of VFAs. However, not all the cellulose degrades because of a shielding effect of lignin on cellulose, and a pH buffering effect of the calcium carbonate present in the paper sludges limits the hydrolysis-acidogenesis step of the anaerobic digestion. Finally, the gas chromatography-mass spectrometry (GC-MS) investigations showed that acetic acid is the main VFA produced by the anaerobic digestion of paper sludges. This work helps predicting paper mill sludge evolution in the purpose of using them in circular economy.
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Affiliation(s)
- Noemie Courtois
- Institut UTINAM UMR 6213 CNRS Univ Bourgogne Franche Comte, Besancon, France
- R&D Laboratory, Wienerberger, Lantenne-Vertieres, France
| | - Isabelle Pochard
- Institut UTINAM UMR 6213 CNRS Univ Bourgogne Franche Comte, Besancon, France
| | - Marielle Remery
- Institut UTINAM UMR 6213 CNRS Univ Bourgogne Franche Comte, Besancon, France
| | - Jean-Yves Hihn
- Institut UTINAM UMR 6213 CNRS Univ Bourgogne Franche Comte, Besancon, France
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Hernández AB, Okonta F, Freeman N. Thermal decomposition of sewage sludge under N 2, CO 2 and air: Gas characterization and kinetic analysis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 196:560-568. [PMID: 28351822 DOI: 10.1016/j.jenvman.2017.03.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 03/12/2017] [Accepted: 03/14/2017] [Indexed: 06/06/2023]
Abstract
Thermochemical valorisation processes that allow energy to be recovered from sewage sludge, such as pyrolysis and gasification, have demonstrated great potential as convenient alternatives to conventional sewage sludge disposal technologies. Moreover, these processes may benefit from CO2 recycling. Today, the scaling up of these technologies requires an advanced knowledge of the reactivity of sewage sludge and the characteristics of the products, specific to the thermochemical process. In this study the behaviour of sewage sludge during thermochemical conversion, under different atmospheres (N2, CO2 and air), was studied, using TGA-FTIR, in order to understand the effects of different atmospheric gases on the kinetics of degradation and on the gaseous products. The different steps observed during the solid degradation were related with the production of different gaseous compounds. A higher oxidative degree of the atmosphere surrounding the sample resulted in higher reaction rates and a shift of the degradation mechanisms to lower temperatures, especially for the mechanisms taking place at temperatures above 400 °C. Finally, a multiple first-order reaction model was proposed to compare the kinetic parameters obtained under different atmospheres. Overall, the highest activation energies were obtained for combustion. This work proves that CO2, an intermediate oxidative atmosphere between N2 and air, results in an intermediate behaviour (intermediate peaks in the derivative thermogravimetric curves and intermediate activation energies) during the thermochemical decomposition of sewage sludge. Overall, it can be concluded that the kinetics of these different processes require a different approach for their scaling up and specific consideration of their characteristic reaction temperatures and rates should be evaluated.
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Affiliation(s)
- Ana Belén Hernández
- University of Johannesburg, Chemical Engineering Department, Doorfontein Campus, PO Box 17011, Doorfontein, 2028, Johannesburg, South Africa; University of Johannesburg, Department of Civil Engineering Science, Kingsway Campus, PO Box 524, Auckland Park, 2006, Johannesburg, South Africa.
| | - Felix Okonta
- University of Johannesburg, Department of Civil Engineering Science, Kingsway Campus, PO Box 524, Auckland Park, 2006, Johannesburg, South Africa
| | - Ntuli Freeman
- University of Johannesburg, Chemical Engineering Department, Doorfontein Campus, PO Box 17011, Doorfontein, 2028, Johannesburg, South Africa
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Ganigué R, Sánchez-Paredes P, Bañeras L, Colprim J. Low Fermentation pH Is a Trigger to Alcohol Production, but a Killer to Chain Elongation. Front Microbiol 2016; 7:702. [PMID: 27252682 PMCID: PMC4877396 DOI: 10.3389/fmicb.2016.00702] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/26/2016] [Indexed: 11/13/2022] Open
Abstract
Gasification of organic wastes coupled to syngas fermentation allows the recovery of carbon in the form of commodity chemicals, such as carboxylates and biofuels. Acetogenic bacteria ferment syngas to mainly two-carbon compounds, although a few strains can also synthesize four-, and six-carbon molecules. In general, longer carbon chain products have a higher biotechnological (and commercial) value due to their higher energy content and their lower water solubility. However, de-novo synthesis of medium-chain products from syngas is quite uncommon in acetogenic bacteria. An alternative to de-novo synthesis is bioproduction of short-chain products (C2 and C4), and their subsequent elongation to C4, C6, or C8 through reversed β-oxidation metabolism. This two-step synergistic approach has been successfully applied for the production of up to C8 compounds, although the accumulation of alcohols in these mixed cultures remained below detection limits. The present work investigates the production of higher alcohols from syngas by open mixed cultures (OMC). A syngas-fermenting community was enriched from sludge of an anaerobic digester for a period of 109 days in a lab-scale reactor. At the end of this period, stable production of ethanol and butanol was obtained. C6 compounds were only transiently produced at the beginning of the enrichment phase, during which Clostridium kluyveri, a bacterium able to carry out carbon chain elongation, was detected in the community. Further experiments showed pH as a critical parameter to maintain chain elongation activity in the co-culture. Production of C6 compounds was recovered by preventing fermentation pH to decrease below pH 4.5–5. Finally, experiments showed maximal production of C6 compounds (0.8 g/L) and alcohols (1.7 g/L of ethanol, 1.1 g/L of butanol, and 0.6 g/L of hexanol) at pH 4.8. In conclusion, low fermentation pH is critical for the production of alcohols, although detrimental to C. kluyveri. Fine control of fermentation pH to final values around 4.8 could allow sustained production of higher alcohols.
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Affiliation(s)
- Ramon Ganigué
- LEQUIA, Institute of the Environment, University of Girona, Campus de MontiliviGirona, Spain; Center for Microbial Ecology and Technology (CMET) - FBE - Ghent UniversityGent, Belgium
| | | | - Lluis Bañeras
- Institute of Aquatic Ecology, University of Girona, Campus de Montilivi Girona, Spain
| | - Jesús Colprim
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi Girona, Spain
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Ganigué R, Ramió-Pujol S, Sánchez P, Bañeras L, Colprim J. Conversion of sewage sludge to commodity chemicals via syngas fermentation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 72:415-420. [PMID: 26204073 DOI: 10.2166/wst.2015.222] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Gasification of sewage sludge allows the recovery of energy, and produces a mix of CO, CO₂and H₂called synthesis gas (or syngas), which can be fermented by acetogenic bacteria to added-value products. This work presents the conversion of syngas to organic acids and alcohols using both pure and mixed cultures. Pure culture kinetic experiments with Clostridium carboxidivorans P7 resulted in the production of high concentrations of acetate (454 mgC/L) and ethanol (167 mgC/L). The pH was the main factor driving solventogenesis, with about 50% of the products in the form of alcohols at pH 5. Conversely, laboratory-scale experiments using a carboxydotrophic mixed culture of the genus Clostridium enriched from anaerobic digester sludge of a municipal wastewater treatment plant was capable of producing mainly butyrate, with maximum concentration of 1,184 mgC/L.
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Affiliation(s)
- Ramon Ganigué
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail:
| | - Sara Ramió-Pujol
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail: ; Institute of Aquatic Ecology (IEA), University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain
| | - Patricia Sánchez
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail:
| | - Lluís Bañeras
- Institute of Aquatic Ecology (IEA), University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain
| | - Jesús Colprim
- LEQUIA, Institute of the Environment, University of Girona, Campus de Montilivi, Girona E-17071, Catalonia, Spain E-mail:
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