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Sun C, Meng X, Sun F, Zhang J, Tu M, Chang JS, Reungsang A, Xia A, Ragauskas AJ. Advances and perspectives on mass transfer and enzymatic hydrolysis in the enzyme-mediated lignocellulosic biorefinery: A review. Biotechnol Adv 2023; 62:108059. [PMID: 36402253 DOI: 10.1016/j.biotechadv.2022.108059] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/04/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
Abstract
Enzymatic hydrolysis is a critical process for the cellulase-mediated lignocellulosic biorefinery to produce sugar syrups that can be converted into a whole range of biofuels and biochemicals. Such a process operating at high-solid loadings (i.e., scarcely any free water or roughly ≥ 15% solids, w/w) is considered more economically feasible, as it can generate a high sugar concentration at low operation and capital costs. However, this approach remains restricted and incurs "high-solid effects", ultimately causing the lower hydrolysis yields with increasing solid loadings. The lack of available water leads to a highly viscous system with impaired mixing that exhibits strong transfer resistance and reaction limitation imposed on enzyme action. Evidently, high-solid enzymatic hydrolysis involves multi-scale mass transfer and multi-phase enzyme reaction, and thus requires a synergistic perspective of transfer and biotransformation to assess the interactions among water, biomass components, and cellulase enzymes. Porous particle characteristics of biomass and its interface properties determine the water form and distribution state surrounding the particles, which are summarized in this review aiming to identify the water-driven multi-scale/multi-phase bioprocesses. Further aided by the cognition of rheological behavior of biomass slurry, solute transfer theories, and enzyme kinetics, the coupling effects of flow-transfer-reaction are revealed under high-solid conditions. Based on the above basic features, this review lucidly explains the causes of high-solid hydrolysis hindrances, highlights the mismatched issues between transfer and reaction, and more importantly, presents the advanced strategies for transfer and reaction enhancements from the viewpoint of process optimization, reactor design, as well as enzyme/auxiliary additive customization.
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Affiliation(s)
- Chihe Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xianzhi Meng
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Junhua Zhang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China
| | - Maobing Tu
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan
| | - Alissara Reungsang
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China
| | - Arthur J Ragauskas
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, The University of Tennessee, Knoxville, TN 37996, USA; Joint Institute of Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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2
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Lignocellulose particle size and rheological properties changes in periodic peristalsis enzymatic hydrolysis at high solids. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2021.108284] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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3
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Santos ACF, Ximenes E, Thompson D, Ray AE, Szeto R, Erk K, Dien BS, Ladisch MR. Effect of using a nitrogen atmosphere on enzyme hydrolysis at high corn stover loadings in an agitated reactor. Biotechnol Prog 2020; 36:e3059. [PMID: 32748574 DOI: 10.1002/btpr.3059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/22/2020] [Accepted: 07/31/2020] [Indexed: 01/01/2023]
Affiliation(s)
- Antonio Carlos Freitas Santos
- Laboratory of Renewable Resources Engineering Purdue University West Lafayette Indiana USA
- Department of Agricultural and Biological Engineering Purdue University West Lafayette Indiana USA
| | - Eduardo Ximenes
- Laboratory of Renewable Resources Engineering Purdue University West Lafayette Indiana USA
- Department of Agricultural and Biological Engineering Purdue University West Lafayette Indiana USA
| | - David Thompson
- Energy and Environment Science & Technology Directorate Idaho National Laboratory Idaho Falls Idaho USA
| | - Allison E. Ray
- Energy and Environment Science & Technology Directorate Idaho National Laboratory Idaho Falls Idaho USA
| | - Ryan Szeto
- School of Materials Engineering Purdue University West Lafayette Indiana USA
| | - Kendra Erk
- School of Materials Engineering Purdue University West Lafayette Indiana USA
| | - Bruce S. Dien
- National Center for Agricultural Utilization Research ARS, USDA Peoria Illinois USA
| | - Michael R. Ladisch
- Laboratory of Renewable Resources Engineering Purdue University West Lafayette Indiana USA
- Department of Agricultural and Biological Engineering Purdue University West Lafayette Indiana USA
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4
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Zhang J, Wang L, Chen H. Effect of periodic high-frequency vibration with rigid spheres added on high solids enzymatic hydrolysis of steam-exploded corn straw. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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5
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Estimation of Biomass Enzymatic Hydrolysis State in Stirred Tank Reactor through Moving Horizon Algorithms with Fixed and Dynamic Fuzzy Weights. Processes (Basel) 2020. [DOI: 10.3390/pr8040407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Second generation ethanol faces challenges before profitable implementation. Biomass hydrolysis is one of the bottlenecks, especially when this process occurs at high solids loading and with enzymatic catalysts. Under this setting, kinetic modeling and reaction monitoring are hindered due to the conditions of the medium, while increasing the mixing power. An algorithm that addresses these challenges might improve the reactor performance. In this work, a soft sensor that is based on agitation power measurements that uses an Artificial Neural Network (ANN) as an internal model is proposed in order to predict free carbohydrates concentrations. The developed soft sensor is used in a Moving Horizon Estimator (MHE) algorithm to improve the prediction of state variables during biomass hydrolysis. The algorithm is developed and used for batch and fed-batch hydrolysis experimental runs. An alteration of the classical MHE is proposed for improving prediction, using a novel fuzzy rule to alter the filter weights online. This alteration improved the prediction when compared to the original MHE in both training data sets (tracking error decreased 13%) and in test data sets, where the error reduction obtained is 44%.
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da Silva AS, Espinheira RP, Teixeira RSS, de Souza MF, Ferreira-Leitão V, Bon EPS. Constraints and advances in high-solids enzymatic hydrolysis of lignocellulosic biomass: a critical review. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:58. [PMID: 32211072 PMCID: PMC7092515 DOI: 10.1186/s13068-020-01697-w] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 03/11/2020] [Indexed: 05/22/2023]
Abstract
The industrial production of sugar syrups from lignocellulosic materials requires the conduction of the enzymatic hydrolysis step at high-solids loadings (i.e., with over 15% solids [w/w] in the reaction mixture). Such conditions result in sugar syrups with increased concentrations and in improvements in both capital and operational costs, making the process more economically feasible. However, this approach still poses several technical hindrances that impact the process efficiency, known as the "high-solids effect" (i.e., the decrease in glucan conversion yields as solids load increases). The purpose of this review was to present the findings on the main limitations and advances in high-solids enzymatic hydrolysis in an updated and comprehensive manner. The causes for the rheological limitations at the onset of the high-solids operation as well as those influencing the "high-solids effect" will be discussed. The subject of water constraint, which results in a highly viscous system and impairs mixing, and by extension, mass and heat transfer, will be analyzed under the perspective of the limitations imposed to the action of the cellulolytic enzymes. The "high-solids effect" will be further discussed vis-à-vis enzymes end-product inhibition and the inhibitory effect of compounds formed during the biomass pretreatment as well as the enzymes' unproductive adsorption to lignin. This review also presents the scientific and technological advances being introduced to lessen high-solids hydrolysis hindrances, such as the development of more efficient enzyme formulations, biomass and enzyme feeding strategies, reactor and impeller designs as well as process strategies to alleviate the end-product inhibition. We surveyed the academic literature in the form of scientific papers as well as patents to showcase the efforts on technological development and industrial implementation of the use of lignocellulosic materials as renewable feedstocks. Using a critical approach, we expect that this review will aid in the identification of areas with higher demand for scientific and technological efforts.
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Affiliation(s)
- Ayla Sant’Ana da Silva
- Biocatalysis Laboratory, National Institute of Technology, Ministry of Science, Technology, Innovation and Communication, Rio de Janeiro, RJ 20081-312 Brazil
- Bioethanol Laboratory, Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-909 Brazil
| | - Roberta Pereira Espinheira
- Biocatalysis Laboratory, National Institute of Technology, Ministry of Science, Technology, Innovation and Communication, Rio de Janeiro, RJ 20081-312 Brazil
- Bioethanol Laboratory, Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-909 Brazil
| | - Ricardo Sposina Sobral Teixeira
- Bioethanol Laboratory, Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-909 Brazil
| | - Marcella Fernandes de Souza
- Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Viridiana Ferreira-Leitão
- Biocatalysis Laboratory, National Institute of Technology, Ministry of Science, Technology, Innovation and Communication, Rio de Janeiro, RJ 20081-312 Brazil
- Bioethanol Laboratory, Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-909 Brazil
| | - Elba P. S. Bon
- Bioethanol Laboratory, Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-909 Brazil
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Lu M, Li J, Han L, Xiao W. High-solids enzymatic hydrolysis of ball-milled corn stover with reduced slurry viscosity and improved sugar yields. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:77. [PMID: 32336988 PMCID: PMC7171840 DOI: 10.1186/s13068-020-01717-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/13/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND High-solids enzymatic hydrolysis has attracted increasing attentions for the production of bioethanol from lignocellulosic biomass with its advantages of high product concentration, water saving, and low energy and capital costs. However, the increase of solids content would worsen the rheological properties, resulting in heat/mass transfer limitation and higher mixing energy. To address these issues, ball milling was applied to corn stover prior to enzymatic hydrolysis, and the rheological behaviors and digestibility of ball-milled corn stover under high-solids loading were investigated. RESULTS Ball milling significantly modified the physicochemical properties of corn stover. The apparent viscosity of slurries at 30% solid loading decreased by a factor of 500 after milling for 60 min, and the yield stress was less than 10 Pa. The dramatic decrease of viscosity and yield stress enabled the hydrolysis process to be conducted in shake flask, and remained good mixing. Meanwhile, the estimated energy consumption for mixing during saccharification decreased by 400-fold compared to the untreated one. The resultant hydrolysate using 10 FPU g-1 solids was determined to contain 130.5 g L-1 fermentable sugar, and no fermentation inhibitors were detected. CONCLUSIONS The proposed ball milling pretreatment improved rheological behavior and sugar yield of high-solids corn stover slurry. Ball milling enables high-solids slurry to maintain low viscosity and yield stress while obtaining a non-toxic high-concentration fermentable syrup, which is undoubtedly of great significance for inter-unit processing, mixing and downstream process. In addition, the energy input for ball milling could be balanced by the reduced mixing energy. Our study indicates ball milling a promising pretreatment process for industrial bioethanol production.
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Affiliation(s)
- Minsheng Lu
- College of Engineering, China Agricultural University (East Campus), P.O. Box 191, 17 Qing-Hua-Dong-Lu, Hai-Dian District, Beijing, 100083 People’s Republic of China
| | - Junbao Li
- College of Engineering, China Agricultural University (East Campus), P.O. Box 191, 17 Qing-Hua-Dong-Lu, Hai-Dian District, Beijing, 100083 People’s Republic of China
| | - Lujia Han
- College of Engineering, China Agricultural University (East Campus), P.O. Box 191, 17 Qing-Hua-Dong-Lu, Hai-Dian District, Beijing, 100083 People’s Republic of China
| | - Weihua Xiao
- College of Engineering, China Agricultural University (East Campus), P.O. Box 191, 17 Qing-Hua-Dong-Lu, Hai-Dian District, Beijing, 100083 People’s Republic of China
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8
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Zhang H, Liu H, Sun J, Mai M, Fu S, Xu X. A New Multiple-Dilution-Assays Method for Determining Glucose Yield from Enzymatic Saccharification of Biomass at High-Solids Loadings. CURR ANAL CHEM 2019. [DOI: 10.2174/1573411014666180518085855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Determination of the accurate mass of glucose generated from high-solids
biomass saccharification is vital but problematic due to the uncertainty of liquid volume and slurry density.
Methods:
Herein, a new multiple-dilution-assays method was established to deduce the accurate glucose
mass from the hydrolyzing biomass slurry.
Results:
This method was applicable for slurries of pretreated corn stover with a solids consistency up
to 30 wt%, showing a high accuracy and good reproducibility. Dryness did not interfere with the accuracy.
Ethanol at a high level, e.g. 10%, caused only a small negative error (<2%). This method can be
used in either single- or fed-batch high-solids biomass saccharification, allowing to quantify the maldistribution
of glucose in the slurry.
Conclusion:
The significant advantage of the present method was that only one single variable, glucose
concentration, was to be determined, rendering it unnecessary to wash the insoluble or to measure the
changing liquid density.
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Affiliation(s)
- Han Zhang
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Hao Liu
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Jianliang Sun
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Mingqian Mai
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Shiyu Fu
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Xiangyang Xu
- Zaozhuang Jienuo Enzyme Co., Ltd, Zaozhuang, 277100, China
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Kadhum HJ, Mahapatra DM, Murthy GS. A comparative account of glucose yields and bioethanol production from separate and simultaneous saccharification and fermentation processes at high solids loading with variable PEG concentration. BIORESOURCE TECHNOLOGY 2019; 283:67-75. [PMID: 30901590 DOI: 10.1016/j.biortech.2019.03.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/09/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
A process strategy to aid in optimal enzymatic hydrolysis through the addition of polyethylene glycol (PEG6000) was tested for separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). Pretreated wheat straw at 30% solids (w/w) loading was enzymatically hydrolyzed with 0, 0.5, 1, 1.5, 2 and 2.5% of PEG6000 through SHF and SSF. During SHF, bioethanol concentration of 107.5 g/L (2.5% PEG6000) was achieved. SSF ethanol concentration were about 113 g/L at 1.5% PEG6000 addition. A technoeconomic feasibility showed a return on investment (ROI) of 8.13% using 0.5% PEG6000 for SHF (96 h) and 12.25% ROI for SSF control (72 h). Life cycle assessment for the various scenarios indicated higher environmental gains for best cases of SSF over SHF. The study shows the SSF approach (0% PEG6000; 72 h) facilitates higher process efficiencies; technoeconomic gains and high environmental sustainability for future scale-up and commercial realization.
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Affiliation(s)
- Haider Jawad Kadhum
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States; College of Agriculture, Al-Qasim Green University, Babylon, Iraq.
| | - Durga Madhab Mahapatra
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States.
| | - Ganti S Murthy
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States.
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Kadhum HJ, Mahapatra DM, Murthy GS. A novel method for real-time estimation of insoluble solids and glucose concentrations during enzymatic hydrolysis of biomass. BIORESOURCE TECHNOLOGY 2019; 275:328-337. [PMID: 30594844 DOI: 10.1016/j.biortech.2018.12.071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
The study describes a novel method using instantaneous mixing torque and rotational speed to estimate insoluble solids and glucose concentrations during enzymatic hydrolysis of biomass. This method is cost-effective for real-time monitoring and control of enzymatic hydrolysis and potentially scalable. The model was developed using biomass slurries at three solids loading (20, 30 and 45%) at various rotational speeds from 50 to 400 rpm. The results showed a significant drop in mixing torque at 12 h with high solids loading. Maximum glucose concentration (205 g/l) during hydrolysis was achieved at 45% solids loading. Insoluble solids and glucose concentration as a function of torque and rotational speeds were modeled using a modified Herschell-Bulkley model. The model describes the experimental observations with high fidelity (R2 = 0.84) and can be used for real time monitoring of many multiphase reaction systems as enzymatic hydrolysis of lignocellulosic biomass and dry grind corn ethanol processes.
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Affiliation(s)
- Haider Jawad Kadhum
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States; College of Agriculture, Al-Qasim Green University, Babylon, Iraq
| | - Durga Madhab Mahapatra
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States
| | - Ganti S Murthy
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States.
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Using in-situ viscosimetry and morphogranulometry to explore hydrolysis mechanisms of filter paper and pretreated sugarcane bagasse under semi-dilute suspensions. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2017.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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van der Zwan T, Hu J, Saddler JN. Mechanistic insights into the liquefaction stage of enzyme-mediated biomass deconstruction. Biotechnol Bioeng 2017; 114:2489-2496. [PMID: 28691220 DOI: 10.1002/bit.26381] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 06/12/2017] [Accepted: 07/02/2017] [Indexed: 11/11/2022]
Abstract
Effective enzyme-mediated viscosity reduction, disaggregation, or "liquefaction," is required to overcome the rheological challenges resulting from the fibrous, hygroscopic nature of lignocellulosic biomass, particularly at the high solids loadings that will be required for an economically viable process. However, the actual mechanisms involved in enzyme-mediated liquefaction, as determined by viscosity or yield stress reduction, have yet to be fully resolved. Particle fragmentation, interparticle interaction, material dilution, and water-retention capacity were compared for their ability to quantify enzyme-mediated liquefaction of model and more realistic pretreated biomass substrates. It was apparent that material dilution and particle fragmentation occurred simultaneously and that both mechanisms contributed to viscosity/yield stress reduction. However, their relative importance was dependent on the nature of the biomass substrate. Interparticle interaction and enzyme-mediated changes to these interactions was shown to have a significant effect on slurry rheology. Liquefaction was shown to result from the combined action of material dilution, particle fragmentation, and alteration of interactions at particle surfaces. However, the observed changes in water retention capacity did not correlate with yield stress reduction. The relative importance of each mechanism was significantly influenced by the nature of the biomass substrate and its physicochemical properties. An ongoing challenge is that mechanisms, such as refining, which enhance enzyme accessibility to the cellulosic component of the substrate, are detrimental to slurry rheology and will likely impede enzyme-mediated liquefaction when high substrate concentrations are used.
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Affiliation(s)
- Timo van der Zwan
- Forest Products Biotechnology and Bioenergy Group, Faculty of Forestry, Department of Wood Science, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jinguang Hu
- Forest Products Biotechnology and Bioenergy Group, Faculty of Forestry, Department of Wood Science, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jack N Saddler
- Forest Products Biotechnology and Bioenergy Group, Faculty of Forestry, Department of Wood Science, The University of British Columbia, Vancouver, British Columbia, Canada
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Abstract
This study investigated the effects of two soil moisture levels (SM) (30% and 70% soil available water) and three harvests (90 days, 118 days, and 151 days after seeding) on sweet (S506) and fiber (B133) sorghum genotypes under rain-sheltered conditions. Juice and bagasse-derived ethanol and their sum (EtOHBJ, EtOHB, and EtOHJ+B, respectively) were assessed. Water use efficiency (WUE) was determined for sorghum dry weight (DW) and EtOHJ+B. S506 had similar DW, but higher sugar content than B133, resulting in higher EtOHJ (+32%) and EtOHJ+B (+9%). High SM-enhanced DW, juice and sugars content, determining a strong EtOHJ+B increase (+99% vs. low SM). Late harvest enhanced DW and EtOHJ+B (+107% vs. early harvest), despite decreasing extractives and increasing structural fiber components. Water use efficiency of EtOHJ+B improved with high vs. low SM, although differences faded in late harvest. Upscale of EtOHJ+B and WUE data indicated a range of 21,000–82,000 ha of sorghum cultivation and 60–117 Mm3 of irrigation water, as amounts of resources needed to supply an 85,000 m3·yr−1 bio-ethanol plant. This large variation in land and water needs depended on specific combinations between crop factors SM and harvests.
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Tervasmäki P, Sotaniemi V, Kangas J, Taskila S, Ojamo H, Tanskanen J. A discretized model for enzymatic hydrolysis of cellulose in a fed-batch process. BIORESOURCE TECHNOLOGY 2017; 227:112-124. [PMID: 28013127 DOI: 10.1016/j.biortech.2016.12.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 12/12/2016] [Accepted: 12/14/2016] [Indexed: 05/24/2023]
Abstract
In the enzymatic hydrolysis of cellulose, several phenomena have been proposed to cause a decrease in the reaction rate with increasing conversion. The importance of each phenomenon is difficult to distinguish from batch hydrolysis data. Thus, kinetic models for the enzymatic hydrolysis of cellulose often suffer from poor parameter identifiability. This work presents a model that is applicable to fed-batch hydrolysis by discretizing the substrate based on the feeding time. Different scenarios are tested to explain the observed decrease in reaction rate with increasing conversion, and comprehensive assessment of the parameter sensitivities is carried out. The proposed model performed well in the broad range of experimental conditions used in this study and when compared to literature data. Furthermore, the use of data from fed-batch experiments and discretization of the model substrate to populations was found to be very informative when assessing the importance of the rate-decreasing phenomena in the model.
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Affiliation(s)
- Petri Tervasmäki
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, FI-90014 Oulun yliopisto, Finland.
| | - Ville Sotaniemi
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, FI-90014 Oulun yliopisto, Finland
| | - Jani Kangas
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, FI-90014 Oulun yliopisto, Finland
| | - Sanna Taskila
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, FI-90014 Oulun yliopisto, Finland
| | - Heikki Ojamo
- Department of Biotechnology and Chemical Technology, School of Chemical Technology, Aalto University, P.O. Box 16100, 00076, Aalto, Finland
| | - Juha Tanskanen
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, FI-90014 Oulun yliopisto, Finland
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15
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Fed-Batch Enzymatic Saccharification of High Solids Pretreated Lignocellulose for Obtaining High Titers and High Yields of Glucose. Appl Biochem Biotechnol 2017; 182:1108-1120. [DOI: 10.1007/s12010-016-2385-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 12/27/2016] [Indexed: 10/20/2022]
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16
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Weiss ND, Thygesen LG, Felby C, Roslander C, Gourlay K. Biomass-water interactions correlate to recalcitrance and are intensified by pretreatment: An investigation of water constraint and retention in pretreated spruce using low field NMR and water retention value techniques. Biotechnol Prog 2016; 33:146-153. [DOI: 10.1002/btpr.2398] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/28/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Noah D. Weiss
- Dept. of Geosciences and Natural Resource Management; University of Copenhagen; Copenhagen Denmark
| | | | - Claus Felby
- Dept. of Geosciences and Natural Resource Management; University of Copenhagen; Copenhagen Denmark
| | | | - Keith Gourlay
- Dept. of Forest Products, Biotechnology and Bioenergy; University of British Columbia; Vancouver Canada
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17
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Janssen M, Xiros C, Tillman AM. Life cycle impacts of ethanol production from spruce wood chips under high-gravity conditions. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:53. [PMID: 26949414 PMCID: PMC4779266 DOI: 10.1186/s13068-016-0468-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 02/19/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Development of more sustainable biofuel production processes is ongoing, and technology to run these processes at a high dry matter content, also called high-gravity conditions, is one option. This paper presents the results of a life cycle assessment (LCA) of such a technology currently in development for the production of bio-ethanol from spruce wood chips. RESULTS The cradle-to-gate LCA used lab results from a set of 30 experiments (or process configurations) in which the main process variable was the detoxification strategy applied to the pretreated feedstock material. The results of the assessment show that a process configuration, in which washing of the pretreated slurry is the detoxification strategy, leads to the lowest environmental impact of the process. Enzyme production and use are the main contributors to the environmental impact in all process configurations, and strategies to significantly reduce this contribution are enzyme recycling and on-site enzyme production. Furthermore, a strong linear correlation between the ethanol yield of a configuration and its environmental impact is demonstrated, and the selected environmental impacts show a very strong cross-correlation ([Formula: see text] in all cases) which may be used to reduce the number of impact categories considered from four to one (in this case, global warming potential). Lastly, a comparison with results of an LCA of ethanol production under high-gravity conditions using wheat straw shows that the environmental performance does not significantly differ when using spruce wood chips. For this comparison, it is shown that eutrophication potential also needs to be considered due to the fertilizer use in wheat cultivation. CONCLUSIONS The LCA points out the environmental hotspots in the ethanol production process, and thus provides input to the further development of the high-gravity technology. Reducing the number of impact categories based only on cross-correlations should be done with caution. Knowledge of the analyzed system provides further input to the choice of impact categories.
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Affiliation(s)
- Matty Janssen
- />Department of Energy and Environment, Division of Environmental Systems Analysis, Chalmers University of Technology, Rännvägen 6B, SE-41296 Göteborg, Sweden
| | - Charilaos Xiros
- />Department of Biology and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, Kemigården 4, SE-41296 Göteborg, Sweden
- />School of Agricultural, Forest and Food Sciences HAFL, Bern University of Applied Sciences, Länggasse 85, 3052 Zollikofen, Switzerland
| | - Anne-Marie Tillman
- />Department of Energy and Environment, Division of Environmental Systems Analysis, Chalmers University of Technology, Rännvägen 6B, SE-41296 Göteborg, Sweden
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Mixing design for enzymatic hydrolysis of sugarcane bagasse: methodology for selection of impeller configuration. Bioprocess Biosyst Eng 2015; 39:285-94. [DOI: 10.1007/s00449-015-1512-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 11/18/2015] [Indexed: 12/01/2022]
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Liguori R, Ventorino V, Pepe O, Faraco V. Bioreactors for lignocellulose conversion into fermentable sugars for production of high added value products. Appl Microbiol Biotechnol 2015; 100:597-611. [PMID: 26572518 PMCID: PMC4703634 DOI: 10.1007/s00253-015-7125-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 10/22/2015] [Accepted: 10/26/2015] [Indexed: 11/30/2022]
Abstract
Lignocellulosic biomasses derived from dedicated crops and agro-industrial residual materials are promising renewable resources for the production of fuels and other added value bioproducts. Due to the tolerance to a wide range of environments, the dedicated crops can be cultivated on marginal lands, avoiding conflict with food production and having beneficial effects on the environment. Besides, the agro-industrial residual materials represent an abundant, available, and cheap source of bioproducts that completely cut out the economical and environmental issues related to the cultivation of energy crops. Different processing steps like pretreatment, hydrolysis and microbial fermentation are needed to convert biomass into added value bioproducts. The reactor configuration, the operative conditions, and the operation mode of the conversion processes are crucial parameters for a high yield and productivity of the biomass bioconversion process. This review summarizes the last progresses in the bioreactor field, with main attention on the new configurations and the agitation systems, for conversion of dedicated energy crops (Arundo donax) and residual materials (corn stover, wheat straw, mesquite wood, agave bagasse, fruit and citrus peel wastes, sunflower seed hull, switchgrass, poplar sawdust, cogon grass, sugarcane bagasse, sunflower seed hull, and poplar wood) into sugars and ethanol. The main novelty of this review is its focus on reactor components and properties.
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Affiliation(s)
- Rossana Liguori
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo via Cintia 4, 80126, Naples, Italy
| | - Valeria Ventorino
- Department of Agriculture, University of Naples Federico II, Portici, Italy
| | - Olimpia Pepe
- Department of Agriculture, University of Naples Federico II, Portici, Italy
| | - Vincenza Faraco
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo via Cintia 4, 80126, Naples, Italy.
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Co-optimization of sugar yield and input energy by the stepwise reduction of agitation rate during lignocellulose hydrolysis. FOOD AND BIOPRODUCTS PROCESSING 2015. [DOI: 10.1016/j.fbp.2015.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Rheology of Lignocellulose Suspensions and Impact of Hydrolysis: A Review. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 149:325-57. [PMID: 25786712 DOI: 10.1007/10_2015_323] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
White biotechnologies have several challenges to overcome in order to become a viable industrial process. Achieving highly concentrated lignocellulose materials and releasing fermentable substrates, with controlled kinetics in order to regulate micro-organism activity, present major technical and scientific bottlenecks. The degradation of the main polymeric fractions of lignocellulose into simpler molecules is a prerequisite for an integrated utilisation of this resource in a biorefinery concept. The characterisation methods and the observations developed for rheology, morphology, etc., that are reviewed here are strongly dependent on the fibrous nature of lignocellulose, are thus similar or constitute a good approach to filamentous culture broths. This review focuses on scientific works related to the study of the rheological behaviour of lignocellulose suspensions and their evolution during biocatalysis. In order to produce the targeted molecules (synthon), the lignocellulose substrates are converted by enzymatic degradation and are then metabolised by micro-organisms. The dynamics of the mechanisms is limited by coupled phenomena between flow, heat and mass transfers in regard to diffusion (within solid and liquid phases), convection (mixing, transfer coefficients, homogeneity) and specific inhibitors (concentration gradients). As lignocellulose suspensions consist of long entangled fibres for the matrix of industrial interest, they exhibit diverse and complex properties linked to this fibrous character (rheological, morphological, thermal, mechanical and biochemical parameters). Among the main variables to be studied, the rheological behaviour of such suspensions appears to be determinant for process efficiency. It is this behaviour that will determine the equipment to be used and the strategies applied (substrate and biocatalysis feed, mixing, etc.). This review provides an overview of (i) the rheological behaviour of fibrous materials in suspension, (ii) the methods and experimental conditions for their measurements, (iii) the main models used and (iv) their evolution during biocatalytic reactions with a focus on enzymatic hydrolysis.
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Geng W, Jin Y, Jameel H, Park S. Strategies to achieve high-solids enzymatic hydrolysis of dilute-acid pretreated corn stover. BIORESOURCE TECHNOLOGY 2015; 187:43-48. [PMID: 25836373 DOI: 10.1016/j.biortech.2015.03.067] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 03/11/2015] [Accepted: 03/12/2015] [Indexed: 05/08/2023]
Abstract
Three strategies were presented to achieve high solids loading while maximizing carbohydrate conversion, which are fed-batch, splitting/thickening, and clarifier processes. Enzymatic hydrolysis was performed at water insoluble solids (WIS) of 15% using washed dilute-acid pretreated corn stover. The carbohydrate concentration increased from 31.8 to 99.3g/L when the insoluble solids content increased from 5% to 15% WIS, while the final carbohydrate conversion was decreased from 78.4% to 73.2%. For the fed-batch process, a carbohydrate conversion efficiency of 76.8% was achieved when solid was split into 60:20:20 ratio, with all enzymes added first. For the splitting/thickening process, a carbohydrate conversion of 76.5% was realized when the filtrate was recycled to simulate a steady-state process. Lastly, the clarifier process was evaluated and the highest carbohydrate conversion of 81.4% was achieved. All of these results suggests the possibility of enzymatic hydrolysis at high solids to make the overall conversion cost-competitive.
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Affiliation(s)
- Wenhui Geng
- Jiangsu Provincial Key Lab of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China; Department of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695-8005, USA
| | - Yongcan Jin
- Jiangsu Provincial Key Lab of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China
| | - Hasan Jameel
- Department of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695-8005, USA
| | - Sunkyu Park
- Department of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695-8005, USA.
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Kadić A, Palmqvist B, Lidén G. Effects of agitation on particle-size distribution and enzymatic hydrolysis of pretreated spruce and giant reed. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:77. [PMID: 24920958 PMCID: PMC4035727 DOI: 10.1186/1754-6834-7-77] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 04/25/2014] [Indexed: 05/13/2023]
Abstract
BACKGROUND Mixing is an energy demanding process which has been previously shown to affect enzymatic hydrolysis. Concentrated biomass slurries are associated with high and non-Newtonian viscosities and mixing in these systems is a complex task. Poor mixing can lead to mass and/or heat transfer problems as well as inhomogeneous enzyme distribution, both of which can cause possible yield reduction. Furthermore the stirring energy dissipation may impact the particle size which in turn may affect the enzymatic hydrolysis. The objective of the current work was to specifically quantify the effects of mixing on particle-size distribution (PSD) and relate this to changes in the enzymatic hydrolysis. Two rather different materials were investigated, namely pretreated Norway spruce and giant reed. RESULTS Changes in glucan hydrolysis and PSD were measured as a function of agitation during enzymatic hydrolysis at fiber loadings of 7 or 13% water-insoluble solids (WIS). Enzymatic conversion of pretreated spruce was strongly affected by agitation rates at the higher WIS content. However, at low WIS content the agitation had almost no effect on hydrolysis. There was some effect of agitation on the hydrolysis of giant reed at high WIS loading, but it was smaller than that for spruce, and there was no measurable effect at low WIS loading. In the case of spruce, intense agitation clearly affected the PSD and resulted in a reduced mean particle size, whereas for giant reed the decrease in particle size was mainly driven by enzymatic action. However, the rate of enzymatic hydrolysis was not increased after size reduction by agitation. CONCLUSIONS The impact of agitation on the enzymatic hydrolysis clearly depends not only on feedstock but also on the solids loading. Agitation was found to affect the PSD differently for the examined pretreated materials spruce and giant reed. The fact that the reduced mean particle diameter could not explain the enhanced hydrolysis rates found for spruce at an elevated agitation suggests that mass transfer at sustained high viscosities plays an important role in determining the rate of enzymatic hydrolysis.
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Affiliation(s)
- Adnan Kadić
- Department of Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Benny Palmqvist
- Department of Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Gunnar Lidén
- Department of Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
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Koppram R, Tomás-Pejó E, Xiros C, Olsson L. Lignocellulosic ethanol production at high-gravity: challenges and perspectives. Trends Biotechnol 2014; 32:46-53. [DOI: 10.1016/j.tibtech.2013.10.003] [Citation(s) in RCA: 253] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/07/2013] [Accepted: 10/10/2013] [Indexed: 11/30/2022]
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Erdei B, Hancz D, Galbe M, Zacchi G. SSF of steam-pretreated wheat straw with the addition of saccharified or fermented wheat meal in integrated bioethanol production. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:169. [PMID: 24286350 PMCID: PMC4176987 DOI: 10.1186/1754-6834-6-169] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 10/08/2013] [Indexed: 05/05/2023]
Abstract
BACKGROUND Integration of second-generation (2G) bioethanol production with existing first-generation (1G) production may facilitate commercial production of ethanol from cellulosic material. Since 2G hydrolysates have a low sugar concentration and 1G streams often have to be diluted prior to fermentation, mixing of streams is beneficial. Improved ethanol concentrations in the 2G production process lowers energy demand in distillation, improves overall energy efficiency and thus lower production cost. There is also a potential to reach higher ethanol yields, which is required in economically feasible ethanol production. Integrated process scenarios with addition of saccharified wheat meal (SWM) or fermented wheat meal (FWM) were investigated in simultaneous saccharification and (co-)fermentation (SSF or SSCF) of steam-pretreated wheat straw, while the possibility of recovering the valuable protein-rich fibre residue from the wheat was also studied. RESULTS The addition of SWM to SSF of steam-pretreated wheat straw, using commercially used dried baker's yeast, S. cerevisiae, resulted in ethanol concentrations of about 60 g/L, equivalent to ethanol yields of about 90% of the theoretical. The addition of FWM in batch mode SSF was toxic to baker's yeast, due to the ethanol content of FWM, resulting in a very low yield and high accumulation of glucose. The addition of FWM in fed-batch mode still caused a slight accumulation of glucose, but the ethanol concentration was fairly high, 51.2 g/L, corresponding to an ethanol yield of 90%, based on the amount of glucose added.In batch mode of SSCF using the xylose-fermenting, genetically modified S. cerevisiae strain KE6-12, no improvement was observed in ethanol yield or concentration, compared with baker's yeast, despite the increased xylose utilization, probably due to the considerable increase in glycerol production. A slight increase in xylose consumption was seen when glucose from SWM was fed at a low feed rate, after 48 hours, compared with batch SSCF. However, the ethanol yield and concentration remained in the same range as in batch mode. CONCLUSION Ethanol concentrations of about 6% (w/v) were obtained, which will result in a significant reduction in the cost of downstream processing, compared with SSF of the lignocellulosic substrate alone. As an additional benefit, it is also possible to recover the protein-rich residue from the SWM in the process configurations presented, providing a valuable co-product.
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Affiliation(s)
- Borbála Erdei
- Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Dóra Hancz
- Department of Experimental Medical Science, Lund University, BMC D14, 221 84 Lund, Sweden
| | - Mats Galbe
- Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Guido Zacchi
- Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
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Bals BD, Gunawan C, Moore J, Teymouri F, Dale BE. Enzymatic hydrolysis of pelletized AFEX™-treated corn stover at high solid loadings. Biotechnol Bioeng 2013; 111:264-71. [DOI: 10.1002/bit.25022] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/24/2013] [Accepted: 08/05/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Bryan D. Bals
- MBI; 3815 Technology Boulevard Lansing Michigan 48910-8596
| | - Christa Gunawan
- Department of Chemical Engineering and Materials Science; Michigan State University; Lansing Michigan
- Great Lakes Bioenergy Research Center; Michigan State University; East Lansing Michigan
| | - Janette Moore
- MBI; 3815 Technology Boulevard Lansing Michigan 48910-8596
| | | | - Bruce E. Dale
- Department of Chemical Engineering and Materials Science; Michigan State University; Lansing Michigan
- Great Lakes Bioenergy Research Center; Michigan State University; East Lansing Michigan
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Hoyer K, Galbe M, Zacchi G. The effect of prehydrolysis and improved mixing on high-solids batch simultaneous saccharification and fermentation of spruce to ethanol. Process Biochem 2013. [DOI: 10.1016/j.procbio.2012.12.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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