1
|
Application of Aspergillus niger in Practical Biotechnology of Industrial Recovery of Potato Starch By-Products and Its Flocculation Characteristics. Microorganisms 2022; 10:microorganisms10091847. [PMID: 36144450 PMCID: PMC9505473 DOI: 10.3390/microorganisms10091847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 09/08/2022] [Accepted: 09/11/2022] [Indexed: 11/17/2022] Open
Abstract
This study developed a practical recovery for potato starch by-products by A. niger and applied it on a plant scale to completely solve the pollution problems. Soughing to evaluate the effect of A. niger applied towards the production of by-products recycling and analyze the composition and characteristics of flocculating substances (FS) by A. niger and advance a possible flocculation mechanism for by-product conversion. After fermentation, the chemical oxygen demand (COD) removal rate, and the conversion rates of cellulose, hemicellulose, pectin, and proteins were 58.85%, 40.19%, 53.29%, 50.14%, and 37.09%, respectively. FS was predominantly composed of proteins (45.55%, w/w) and polysaccharides (28.07%, w/w), with two molecular weight distributions of 7.3792 × 106 Da and 1.7741 × 106 Da and temperature sensitivity. Flocculation was mainly through bridging and ionic bonding, furthermore, sweeping effects may occur during sediment. Flocculation was related to by-products conversion. However, due to severe pollution problems and resource waste, and deficiencies of existing recovery technologies, converting potato starch by-products via A. niger liquid fermentation merits significant consideration.
Collapse
|
2
|
Vital-Jacome MA, Buitrón G. Thermophilic anaerobic digestion of winery effluents in a two-stage process and the effect of the feeding frequency on methane production. CHEMOSPHERE 2021; 272:129865. [PMID: 33592509 DOI: 10.1016/j.chemosphere.2021.129865] [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: 08/28/2020] [Revised: 01/16/2021] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
This investigation evaluates a two-stage process to treat highly concentrated winery effluents, including a thermophilic methanogenic stage. The inoculum adaptation, the effect of the organic loading rates on both stages, and the methanogenic reactor's feeding frequency on the process performance were studied. An active thermophilic inoculum was obtained by a one-step temperature increase from 35 to 55 °C. The application of organic loads above 120 kg COD m-3 d-1 in the acidogenic stage ensured the highest acetic acid concentration, while methane production rates as high as 7.1 Nm3 CH4 m-3 d-1 and a yield of 348 L CH4 kg-1 COD were obtained in the thermophilic methanogenic stage using an organic loading rate of 29.9 kg COD m-3 d-1. However, a lower removal of organic matter was observed under that condition. Lower feeding frequencies improved methane productivity and yield, suggesting that this parameter is a useful process optimization tool.
Collapse
Affiliation(s)
- Miguel A Vital-Jacome
- Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, 76230, Querétaro, Mexico
| | - Germán Buitrón
- Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, 76230, Querétaro, Mexico.
| |
Collapse
|
3
|
Miramontes-Martínez LR, Rivas-García P, Albalate-Ramírez A, Botello-Álvarez JE, Escamilla-Alvarado C, Gomez-Gonzalez R, Alcalá-Rodríguez MM, Valencia-Vázquez R, Santos-López IA. Anaerobic co-digestion of fruit and vegetable waste: Synergy and process stability analysis. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2021; 71:620-632. [PMID: 33406015 DOI: 10.1080/10962247.2021.1873206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/22/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
Anaerobic mono- and co-digestion of fruits and vegetable waste (FVW), slaughterhouse waste (SHW), and cattle manure (CM) under mesophilic conditions (35°C) were conducted through biochemical methane potential tests to investigate how the FVW in a co-substrate formulation improves the methane yield, the degradative synergy between substrates, and especially the stability of the process. The co-digestion of FVW:SHW and FVW:CM were evaluated with volatile solids (VS) ratios of 1:2, 1:1, and 2:1. The results indicated that the highest synergistic effect was found in the co-digestion FVW:CM at 1:1 VS ratio. However, the co-digestion FWV:SHW at 1:2 VS ratio increased the methane yield by 74.2% compared to the mono-digestion of FVW (776.3 mL CH4 g VSadded-1). As a critical condition in these processes, the stability was evaluated using the early warning indicator VFA/TA (volatile fatty acids/total alkalinity). The co-substrate SHW promotes greater stability in methane production as the soluble carbohydrate content in FVW increases. It was proposed that the high protein (49.04 ± 0.96% VS) and ammonia content (693 ± 3 mg L-1) of SHW leads to the formation of a dampening system known as a carbonate-acetic buffer. It was concluded that balanced distribution between carbohydrates, proteins, and lipids is crucial to increase methane yields, and the low methane productions were associated with low N-NH4+ concentrations (FVW:CM co-digestions). The results obtained in this study can serve as a basis to design full-scale digesters under similar operating conditions and with the same substrate:co-substrate relationships.Implications: The production of methane from the anaerobic digestion process of food, and lose waste presents a viable alternative of valorization and could help to mitigate environmental impacts. However, anaerobic digestion from these substrates carries high instabilities and low methane yields. The need to increase these yields and contribute to process stability must be considered in the selection of a co-substrate. In this context, this work aims to evaluate the best fruits and vegetable waste: co-substrateformulation, that promotes higher methane yield, a synergy between substrates, and to improve the AD process stability in the presence of perturbations in the substrate composition. We believe that our results could be helpful for the design processes for methane production from fruit and vegetable waste, to contribute to competitiveness with conventional energies and promote the sustainability of these processes.
Collapse
Affiliation(s)
- Luis Ramiro Miramontes-Martínez
- Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza
- Centro De Investigacion En Biotecnologia Y Nanotecnologia, Facultad De Ciencias Quimicas, Universidad Autonoma De Nuevo Leon. Parque De Investigacion E Innovacion Tecnologica, Apodaca, Nuevo Leon, Mexico
| | - Pasiano Rivas-García
- Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza
- Centro De Investigacion En Biotecnologia Y Nanotecnologia, Facultad De Ciencias Quimicas, Universidad Autonoma De Nuevo Leon. Parque De Investigacion E Innovacion Tecnologica, Apodaca, Nuevo Leon, Mexico
| | - Alonso Albalate-Ramírez
- Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza
- Centro De Investigacion En Biotecnologia Y Nanotecnologia, Facultad De Ciencias Quimicas, Universidad Autonoma De Nuevo Leon. Parque De Investigacion E Innovacion Tecnologica, Apodaca, Nuevo Leon, Mexico
| | | | - Carlos Escamilla-Alvarado
- Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza
- Centro De Investigacion En Biotecnologia Y Nanotecnologia, Facultad De Ciencias Quimicas, Universidad Autonoma De Nuevo Leon. Parque De Investigacion E Innovacion Tecnologica, Apodaca, Nuevo Leon, Mexico
| | - Ricardo Gomez-Gonzalez
- Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza
| | | | - Roberto Valencia-Vázquez
- Departamento de Ingenieria Quimica y Bioquimica, CONACYT-TECNM/Instituto Tecnologico De Durango, Maestria En Sistemas Ambientales, Durango, Mexico
| | | |
Collapse
|
4
|
Differences of methanogenesis between mesophilic and thermophilic in situ biogas-upgrading systems by hydrogen addition. ACTA ACUST UNITED AC 2019; 46:1569-1581. [DOI: 10.1007/s10295-019-02219-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/11/2019] [Indexed: 11/25/2022]
Abstract
Abstract
To investigate the differences in microbial community structure between mesophilic and thermophilic in situ biogas-upgrading systems by H2 addition, two reactors (35 °C and 55 °C) were run for four stages according to different H2 addition rates (H2/CO2 of 0:1, 1:1, and 4:1) and mixing mode (intermittent and continuous). 16S rRNA gene-sequencing technology was applied to analyze microbial community structure. The results showed that the temperature is a crucial factor in impacting succession of microbial community structure and the H2 utilization pathway. For mesophilic digestion, most of added H2 was consumed indirectly by the combination of homoacetogens and strict aceticlastic methanogens. In the thermophilic system, most of added H2 may be used for microbial cell growth, and part of H2 was utilized directly by strict hydrogenotrophic methanogens and facultative aceticlastic methanogens. Continuous stirring was harmful to the stabilization of mesophilic system, but not to the thermophilic one.
Collapse
|
5
|
Biogas Potential from the Anaerobic Digestion of Potato Peels: Process Performance and Kinetics Evaluation. ENERGIES 2019. [DOI: 10.3390/en12122311] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This article intends to promote the usage of potato peels as efficient substrate for the anaerobic digestion process for energy recovery and waste abatement. This study examined the performance of anaerobic digestion of potato peels in different inoculum-to-substrate ratios. In addition, the impact of combined treatment with cow manure and pretreatment of potato peels was examined. It was found that co-digestion of potato peel waste and cow manure yielded up to 237.4 mL CH4/g VSadded, whereas the maximum methane yield from the mono-digestion of potato peels was 217.8 mL CH4/g VSadded. Comparing the co-digestion to mono-digestion of potato peels, co-digestion in PPW/CM ratio of 60:40 increased the methane yield by 10%. In addition, grinding and acid hydrolysis applied to potato peels were positively effective in increasing the methane amount reaching 260.3 and 283.4 mL CH4/g VSadded respectively. Likewise, compared to untreated potato peels, pretreatment led to an elevation of the methane amount by 9% and 17% respectively and alleviated the kinetics of biogas production.
Collapse
|
6
|
Krümpel JH, Illi L, Lemmer A. Intrinsic gas production kinetics of selected intermediates in anaerobic filters for demand-orientated energy supply. ENVIRONMENTAL TECHNOLOGY 2018; 39:558-565. [PMID: 28303760 DOI: 10.1080/09593330.2017.1308439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 02/28/2017] [Indexed: 06/06/2023]
Abstract
As a consequence of a growing share of solar and wind power, recent research on biogas production highlighted a need for demand-orientated, flexible gas production to provide grid services and enable a decentralized stabilization of the electricity infrastructure. Two-staged anaerobic digestion is particularly suitable for shifting the methane production into times of higher demand due to the spatio-temporal separation of hydrolysis and methanogenesis. To provide a basis for predicting gas production in an anaerobic filter, kinetic parameters of gas production have been determined experimentally in this study. A new methodology is used, enabling their determination during continuous operation. An order in methane production rate could be established by comparing the half lives of methane production. The order was beginning with the fastest: acetic acid>ethanol>butyric acid>iso-butyric acid>valeric acid>propionic acid>1,2propanediol>lactic acid. However, the mixture of a natural hydrolysate from the acidification tank appeared to produce methane faster than all single components tested.
Collapse
Affiliation(s)
- Johannes Hagen Krümpel
- a State Institute for Agricultural Engineering and Bioenergy , University of Hohenheim , Stuttgart , Germany
| | - Lukas Illi
- a State Institute for Agricultural Engineering and Bioenergy , University of Hohenheim , Stuttgart , Germany
| | - Andreas Lemmer
- a State Institute for Agricultural Engineering and Bioenergy , University of Hohenheim , Stuttgart , Germany
| |
Collapse
|
7
|
Poszytek K, Pyzik A, Sobczak A, Lipinski L, Sklodowska A, Drewniak L. The effect of the source of microorganisms on adaptation of hydrolytic consortia dedicated to anaerobic digestion of maize silage. Anaerobe 2017; 46:46-55. [DOI: 10.1016/j.anaerobe.2017.02.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/28/2017] [Accepted: 02/14/2017] [Indexed: 12/26/2022]
|
8
|
Zhu X, Treu L, Kougias PG, Campanaro S, Angelidaki I. Characterization of the planktonic microbiome in upflow anaerobic sludge blanket reactors during adaptation of mesophilic methanogenic granules to thermophilic operational conditions. Anaerobe 2017; 46:69-77. [PMID: 28057558 DOI: 10.1016/j.anaerobe.2016.12.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/22/2016] [Accepted: 12/30/2016] [Indexed: 10/20/2022]
|
9
|
Merkle W, Baer K, Lindner J, Zielonka S, Ortloff F, Graf F, Kolb T, Jungbluth T, Lemmer A. Influence of pressures up to 50bar on two-stage anaerobic digestion. BIORESOURCE TECHNOLOGY 2017; 232:72-78. [PMID: 28214447 DOI: 10.1016/j.biortech.2017.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 01/30/2017] [Accepted: 02/03/2017] [Indexed: 06/06/2023]
Abstract
The concept of pressurized two-stage anaerobic digestion integrates biogas production, purification and pressure boosting within one process. The produced methane-rich biogas can be fed into gas grids with considerably less purification effort. To investigate biogas production under high pressures up to 50bar, a lab scale two-stage anaerobic digestion system was constructed including one continuously operated pressurized methane reactor. This investigation examined the effects of different operating pressures in methane reactor (10, 25, 50bar) on biogas quantity and quality, pH value and process stability. By increasing operating pressures in methane reactor, the pH value decreased from 6.65 at 10bar to 6.55 at 50bar. Simultaneously, methane content increased from 79.08% at 10bar to 90.45% at 50bar. The results show that methane reactors can be operated up to 50bar pressure continuously representing a viable alternative to commonly used gas upgrading methods because of reduced purification effort.
Collapse
Affiliation(s)
- Wolfgang Merkle
- University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany.
| | - Katharina Baer
- DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany
| | - Jonas Lindner
- University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany
| | - Simon Zielonka
- University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany
| | - Felix Ortloff
- DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany
| | - Frank Graf
- DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany
| | - Thomas Kolb
- DVGW - Research Center at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany
| | - Thomas Jungbluth
- University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany
| | - Andreas Lemmer
- University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy, Garbenstrasse 9, 70599 Stuttgart, Germany
| |
Collapse
|
10
|
Merkle W, Baer K, Haag NL, Zielonka S, Ortloff F, Graf F, Lemmer A. High-pressure anaerobic digestion up to 100 bar: influence of initial pressure on production kinetics and specific methane yields. ENVIRONMENTAL TECHNOLOGY 2017; 38:337-344. [PMID: 27215165 DOI: 10.1080/09593330.2016.1192691] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/17/2016] [Indexed: 06/05/2023]
Abstract
To ensure an efficient use of biogas produced by anaerobic digestion, in some cases it would be advisable to upgrade the biogenic gases and inject them into the transnational gas grids. To investigate biogas production under high-pressure conditions up to 100 bar, new pressure batch methane reactors were developed for preliminary lab-scale experiments with a mixture of grass and maize silage hydrolysate. During this investigation, the effects of different initial pressures (1, 50 and 100 bar) on pressure increase, gas production and the specific methane yield using nitrogen as inert gas were determined. Based on the experimental findings increasing initial pressures alter neither significantly, further pressure increases nor pressure increase rates. All supplied organic acids were degraded and no measurable inhibition of the microorganisms was observed. The results show that methane reactors can be operated at operating pressures up to 100 bar without any negative effects on methane production.
Collapse
Affiliation(s)
- Wolfgang Merkle
- a State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim , Stuttgart , Germany
| | - Katharina Baer
- b DVGW - Research Centre at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT) , Karlsruhe , Germany
| | - Nicola Leonard Haag
- a State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim , Stuttgart , Germany
| | - Simon Zielonka
- a State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim , Stuttgart , Germany
| | - Felix Ortloff
- b DVGW - Research Centre at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT) , Karlsruhe , Germany
| | - Frank Graf
- b DVGW - Research Centre at the Engler-Bunte-Institute, Karlsruhe Institute of Technology (KIT) , Karlsruhe , Germany
| | - Andreas Lemmer
- a State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim , Stuttgart , Germany
| |
Collapse
|
11
|
Zhu X, Kougias PG, Treu L, Campanaro S, Angelidaki I. Microbial community changes in methanogenic granules during the transition from mesophilic to thermophilic conditions. Appl Microbiol Biotechnol 2016; 101:1313-1322. [DOI: 10.1007/s00253-016-8028-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/14/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022]
|
12
|
Liang S, McDonald AG. Anaerobic digestion of pre-fermented potato peel wastes for methane production. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 46:197-200. [PMID: 26421481 DOI: 10.1016/j.wasman.2015.09.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/19/2015] [Accepted: 09/21/2015] [Indexed: 05/11/2023]
Abstract
This study investigated the feasibility of anaerobic digestion (AD) of potato peel waste (PPW) and its lactic acid fermentation residue (PPW-FR) for methane (CH4) production. The experimental results showed that about 60-70% CH4 content was obtained. The digester using PPW-FR as feedstock exhibited better performance and produced a highest cumulative CH4 production of 273 L/kg VS fed, followed by 239 L/kg VS fed using PPW under the same conditions. However, with increasing solid loadings of PPW-FR feedstock from 6.4% to 9.1%, the CH4 production was inhibited. The generation, accumulation, and degradation of volatile fatty acids (VFAs) in digesters were also investigated in this research.
Collapse
Affiliation(s)
- Shaobo Liang
- Renewable Materials Program, Department of Forest, Rangeland and Fire Sciences, University of Idaho, 875 Perimeter Drive MS1132, Moscow, ID 83844, United States
| | - Armando G McDonald
- Renewable Materials Program, Department of Forest, Rangeland and Fire Sciences, University of Idaho, 875 Perimeter Drive MS1132, Moscow, ID 83844, United States.
| |
Collapse
|
13
|
Liang S, McDonald AG, Coats ER. Lactic acid production from potato peel waste by anaerobic sequencing batch fermentation using undefined mixed culture. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 45:51-56. [PMID: 25708409 DOI: 10.1016/j.wasman.2015.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/29/2014] [Accepted: 02/03/2015] [Indexed: 06/04/2023]
Abstract
Lactic acid (LA) is a necessary industrial feedstock for producing the bioplastic, polylactic acid (PLA), which is currently produced by pure culture fermentation of food carbohydrates. This work presents an alternative to produce LA from potato peel waste (PPW) by anaerobic fermentation in a sequencing batch reactor (SBR) inoculated with undefined mixed culture from a municipal wastewater treatment plant. A statistical design of experiments approach was employed using set of 0.8L SBRs using gelatinized PPW at a solids content range from 30 to 50 g L(-1), solids retention time of 2-4 days for yield and productivity optimization. The maximum LA production yield of 0.25 g g(-1) PPW and highest productivity of 125 mg g(-1) d(-1) were achieved. A scale-up SBR trial using neat gelatinized PPW (at 80 g L(-1) solids content) at the 3 L scale was employed and the highest LA yield of 0.14 g g(-1) PPW and a productivity of 138 mg g(-1) d(-1) were achieved with a 1 d SRT.
Collapse
Affiliation(s)
- Shaobo Liang
- Environmental Science Program, University of Idaho, Moscow, ID 83844-3006, United States
| | - Armando G McDonald
- Environmental Science Program, University of Idaho, Moscow, ID 83844-3006, United States; Renewable Materials Program, Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 8323844-1132, United States.
| | - Erik R Coats
- Department of Civil Engineering, University of Idaho, Moscow, ID 83844-1022, United States
| |
Collapse
|
14
|
Ward AJ, Hobbs PJ, Holliman PJ, Jones DL. Optimisation of the anaerobic digestion of agricultural resources. BIORESOURCE TECHNOLOGY 2008; 99:7928-40. [PMID: 18406612 DOI: 10.1016/j.biortech.2008.02.044] [Citation(s) in RCA: 429] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 02/25/2008] [Accepted: 02/28/2008] [Indexed: 05/16/2023]
Abstract
It is in the interest of operators of anaerobic digestion plants to maximise methane production whilst concomitantly reducing the chemical oxygen demand of the digested material. Although the production of biogas through anaerobic digestion is not a new idea, commercial anaerobic digestion processes are often operated at well below their optimal performance due to a variety of factors. This paper reviews current optimisation techniques associated with anaerobic digestion and suggests possible areas where improvements could be made, including the basic design considerations of a single or multi-stage reactor configuration, the type, power and duration of the mixing regime and the retention of active microbial biomass within the reactor. Optimisation of environmental conditions within the digester such as temperature, pH, buffering capacity and fatty acid concentrations is also discussed. The methane-producing potential of various agriculturally sourced feedstocks has been examined, as has the advantages of co-digestion to improve carbon-to-nitrogen ratios and the use of pre-treatments and additives to improve hydrolysis rates or supplement essential nutrients which may be limiting. However, perhaps the greatest shortfall in biogas production is the lack of reliable sensory equipment to monitor key parameters and suitable, parallelised control systems to ensure that the process continually operates at optimal performance. Modern techniques such as software sensors and powerful, flexible controllers are capable of solving these problems. A direct comparison can be made here with, for instance, oil refineries where a more mature technology uses continuous in situ monitoring and associated feedback procedures to routinely deliver continuous, optimal performance.
Collapse
Affiliation(s)
- Alastair J Ward
- School of Chemistry, University of Wales - Bangor, Bangor, Gwynedd LL57 2UW, UK.
| | | | | | | |
Collapse
|