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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. Biotechnol 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Xu C, Zhang J, Zhang Y, Guo Y, Xu H, Xu J, Wang Z. Enhancement of high-solids enzymatic hydrolysis efficiency of alkali pretreated sugarcane bagasse at low cellulase dosage by fed-batch strategy based on optimized accessory enzymes and additives. Bioresour Technol 2019; 292:121993. [PMID: 31442837 DOI: 10.1016/j.biortech.2019.121993] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Obtaining higher amount of final sugars with low cellulase dosage has great economic benefits for the industrial biorefinery of lignocellulosic biomass. The optimization of accessory enzymes and additives were performed using single factor and orthogonal experiment firstly, after that, fed-batch strategy was applied to enhance the high-solids enzymatic hydrolysis efficiency of alkali pretreated sugarcane bagasse (SCB). A novel enzymatic hydrolysis procedure with 22% (w/v) substrate content and cellulase dosage of only 4 FPU/g dry biomass (DM) was developed, after digested for 48 h, the achieved glucose titer, yield and productivity were 122 g/L, 80% and 2.54 g L-1 h-1, respectively. Results obtained in this study indicated a potential finding for the industrial application of lignocellulosic biomass.
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Affiliation(s)
- Chao Xu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Key Laboratory of Renewable Energy, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China; University of China Academy of Sciences, Beijing 100049, China
| | - Jun Zhang
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Key Laboratory of Renewable Energy, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China; University of China Academy of Sciences, Beijing 100049, China
| | - Yu Zhang
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Ying Guo
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Huijuan Xu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Jingliang Xu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China.
| | - Zhongming Wang
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China
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Capson-Tojo G, Trably E, Rouez M, Crest M, Steyer JP, Delgenès JP, Escudié R. Dry anaerobic digestion of food waste and cardboard at different substrate loads, solid contents and co-digestion proportions. Bioresour Technol 2017; 233:166-175. [PMID: 28282607 DOI: 10.1016/j.biortech.2017.02.126] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 06/06/2023]
Abstract
The increasing food waste production calls for developing efficient technologies for its treatment. Anaerobic processes provide an effective waste valorization. The influence of the initial substrate load on the performance of batch dry anaerobic co-digestion reactors treating food waste and cardboard was investigated. The load was varied by modifying the substrate to inoculum ratio (S/X), the total solids content and the co-digestion proportions. The results showed that the S/X was a crucial parameter. Within the tested values (0.25, 1 and 4gVS·gVS-1), only the reactors working at 0.25 produced methane. Methanosarcina was the main archaea, indicating its importance for efficient methanogenesis. Acidogenic fermentation was predominant at higher S/X, producing hydrogen and other metabolites. Higher substrate conversions (≤48%) and hydrogen yields (≤62mL·gVS-1) were achieved at low loads. This study suggests that different value-added compounds can be produced in dry conditions, with the initial substrate load as easy-to-control operational parameter.
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Affiliation(s)
- Gabriel Capson-Tojo
- LBE, INRA, 102 Avenue des Etangs, 11100 Narbonne, France; Suez, CIRSEE, 38 rue du Président Wilson, 78230 Le Pecq, France
| | - Eric Trably
- LBE, INRA, 102 Avenue des Etangs, 11100 Narbonne, France
| | - Maxime Rouez
- Suez, CIRSEE, 38 rue du Président Wilson, 78230 Le Pecq, France
| | - Marion Crest
- Suez, CIRSEE, 38 rue du Président Wilson, 78230 Le Pecq, France
| | | | | | - Renaud Escudié
- LBE, INRA, 102 Avenue des Etangs, 11100 Narbonne, France.
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Massé DI, Saady NMC. High rate psychrophilic anaerobic digestion of undiluted dairy cow feces. Bioresour Technol 2015; 187:128-135. [PMID: 25846182 DOI: 10.1016/j.biortech.2015.03.110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 06/04/2023]
Abstract
Novel high rate psychrophilic (20°C) anaerobic digestion (PAD) of undiluted cow feces (11.5-13.5% total solids) was demonstrated using sequence batch reactor in long-term operation with successive cycles of 21days treatment cycle length (TCL). At organic loading rates (OLR) 9.0, 10.0, 11.0 and 12.0g TCOD kg(-1) inoculum d(-1) average specific methane yield (SMY) was 154.0±11.7, 152.1±12.2, 126.0±2.8 and 116.0±6.1NL CH4 per kg of VS fed, respectively. Volatile solids removal averaged around 31.7±3.3%, 32.2±1.0%, 27.9±2.2% and 23.4±0.5%, respectively. Substrate-to-inoculum ratio (SIR; wet-mass basis) ranged between 1.17±0.06 and 1.43±0.05. Concentration of volatile fatty acids in the bioreactors during the TCL indicated that hydrolysis was the rate limiting reaction. High rate PAD of undiluted cow feces is possible at OLR (g TCOD kg(-1) inoculum d(-1)) 9.0 and 10.0 with a TCL of 21days; however, OLR of 11.0 and 12.0 are also possible but require longer TCL to maintain the SMY.
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Affiliation(s)
- Daniel I Massé
- Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, Quebec J1M 0C8, Canada
| | - Noori M Cata Saady
- Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, Quebec J1M 0C8, Canada.
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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. Bioresour Technol 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Aymerich E, Esteban-Gutiérrez M, Sancho L. Analysis of the stability of high-solids anaerobic digestion of agro-industrial waste and sewage sludge. Bioresour Technol 2013; 144:107-114. [PMID: 23859986 DOI: 10.1016/j.biortech.2013.06.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/19/2013] [Accepted: 06/20/2013] [Indexed: 06/02/2023]
Abstract
The pilot-scale high-solids anaerobic digestion (HS-AD) of agro-industrial wastes and sewage sludge was analysed in terms of stability by monitoring the most common parameters used to check the performance of anaerobic digesters, i.e. Volatile Fatty Acids (VFA), ammonia nitrogen, pH, alkalinity and methane production. The results reflected similar evolution for the parameters analysed, except for an experiment that presented an unsuccessful start-up. The rest of the experiments ran successfully, although the threshold values proposed in the literature for the detection of an imbalance in wet processes were exceeded, proving the versatility of HS-AD to treat different wastes. The results evidence the need for understanding the dynamics of a high-solids system so as to detect periods of imbalance and to determine inhibitory levels for different compounds formed during anaerobic decomposition. Moreover, the findings presented here could be useful in developing an experimental basis to construct new control strategies for HS-AD.
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Affiliation(s)
- E Aymerich
- CEIT and Tecnun (University of Navarra), 15 Paseo Manuel de Lardizabal, San Sebastián 20018, Spain
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