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Lehr M, Miltner M, Friedl A. Removal of wood extractives as pulp (pre-)treatment: a technological review. SN APPLIED SCIENCES 2021. [DOI: 10.1007/s42452-021-04873-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
AbstractWood extractives usually do not exceed five percent of dry wood mass but can be a serious issue for pulping as well as for the pulp itself. They cause contamination and damages to process equipment and negatively influence pulp quality. This paper addresses not only the extractives-related problems but also different solutions for these issues. It is an extensive review of different technologies for removing wood extractives, starting with methods prior to pulping. Several wood yard operations like debarking, knot separation, and wood seasoning are known to significantly decreasing the amount of wood extractives. Biological treatment has also been proven as a feasible method for reducing the extractives content before pulping, but quite hard to handle. During pulping, the extractives reduction efficiency depends on the pulping method. Mechanical pulping removes the accessory compounds of wood just slightly, but chemical pulping, on the other hand, removes them to a large extent. Organosolv pulping even allows almost complete removal of wood extractives. The residual extractives content can be significantly reduced by pulp bleaching. Nevertheless, different extraction-based methods have been developed for removing wood extractives before pulping or bleaching. They range from organic-solvent-based extractions to novel processes like supercritical fluid extractions, ionic liquids extractions, microwave technology, and ultrasonic-assisted extraction. Although these methods deliver promising results and allow utilization of wood extractives in most cases, they suffer from many drawbacks towards an economically viable industrial-scale design, concluding that further research has to be done on these topics.
Graphical abstract
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Zhu J, Chen L, Cai C. Acid Hydrotropic Fractionation of Lignocelluloses for Sustainable Biorefinery: Advantages, Opportunities, and Research Needs. CHEMSUSCHEM 2021; 14:3031-3046. [PMID: 34033701 DOI: 10.1002/cssc.202100915] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/24/2021] [Indexed: 06/12/2023]
Abstract
This Minireview provides a comprehensive discussion on the potential of using acid hydrotropes for sustainably fractionating lignocelluloses for biorefinery applications. Acid hydrotropes are a class of acids that have hydrotrope properties toward lignin, which helps to solubilize lignin in aqueous systems. With the capability of cleaving ether and ester bonds and even lignin-carbohydrate complex (LCC) linkages, these acid hydrotropes can therefore isolate lignin embedded in the plant biomass cell wall and subsequently solubilize the isolated lignin in aqueous systems. Performances of two acid hydrotropes, that is, an aromatic sulfonic acid [p-toluenesulfonic acid (p-TsOH)] and a dicarboxylic acid [maleic acid (MA)], in terms of delignification and dissolution of hemicelluloses, and reducing lignin condensation, were evaluated and compared. The advantages of lignin esterification by MA for producing cellulosic sugars through enzymatic hydrolysis and lignin-containing cellulose nanofibrils (LCNFs) through mechanical fibrillation from the fractionated water insoluble solids (WIS), and for obtaining less condensed lignin with light color, were demonstrated. The excellent enzymatic digestibility of maleic acid hydrotropic fractionation WISs was also demonstrated by comparing with WISs from other fractionation processes. The recyclability and reusability of acid hydrotropes were also reviewed. Finally, perspectives on future research needs to address key technical issues for commercialization were also provided.
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Affiliation(s)
- Junyong Zhu
- USDA Forest Service, Forest Products Laboratory, Madison, WI, USA
| | - Liheng Chen
- Department of Biomedical Engineering, Jinan University, Guangzhou, P. R. China
| | - Cheng Cai
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, P. R. China
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Wu Y, Ge S, Xia C, Cai L, Mei C, Sonne C, Park YK, Kim YM, Chen WH, Chang JS, Lam SS. Using low carbon footprint high-pressure carbon dioxide in bioconversion of aspen branch waste for sustainable bioethanol production. BIORESOURCE TECHNOLOGY 2020; 313:123675. [PMID: 32563796 DOI: 10.1016/j.biortech.2020.123675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/09/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
An innovative approach was developed by incorporating high-pressure CO2 into the separate hydrolysis-fermentation of aspen leftover branches, aiming to enhance the bioethanol production efficiency. The high-pressure CO2 significantly increased the 72-h enzymatic hydrolysis yield of converting aspen into glucose from 53.8% to 82.9%. The hydrolysis process was performed with low enzyme loading (10 FPU g-1 glucan) with the aim of reducing the cost of fuel bioethanol production. The ethanol yield from fermentation of the hydrolyzed glucose using yeast (Saccharomyces cerevisiae) was 8.7 g L-1, showing increment of 10% compared with the glucose control. Techno-economic analysis indicated that the energy consumption of fuel bioethanol production from aspen branch chips was reduced by 35% and the production cost was cut 44% to 0.615 USD L-1, when 68 atm CO2 was introduced into the process. These results furtherly emphasized the low carbon footprint of this sustainable energy production approach.
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Affiliation(s)
- Yingji Wu
- Co-Innovation Center of Efficient Processing and Utilization of Forestry Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Shengbo Ge
- Co-Innovation Center of Efficient Processing and Utilization of Forestry Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Changlei Xia
- Co-Innovation Center of Efficient Processing and Utilization of Forestry Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; Anhui Juke Graphene Technology Co., Ltd., Bozhou, Anhui 233600, China
| | - Liping Cai
- Co-Innovation Center of Efficient Processing and Utilization of Forestry Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Changtong Mei
- Co-Innovation Center of Efficient Processing and Utilization of Forestry Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Christian Sonne
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Young-Kwon Park
- School of Environmental Engineering, University of Seoul, Seoul 02504, Republic of Korea
| | - Young-Min Kim
- Department of Environmental Engineering, Daegu University, Gyeongsan 38453, Republic of Korea
| | - Wei-Hsin Chen
- Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan; Department of Chemical and Materials Engineering, College of Engineering, Tunghai University, Taichung 407, Taiwan; Department of Mechanical Engineering, National Chin-Yi University of Technology, Taichung 411, Taiwan
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, College of Engineering, Tunghai University, Taichung 407, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Su Shiung Lam
- Pyrolysis Technology Research Group, Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Henan Province Engineering Research Center for Biomass Value-Added Products, Henan Agricultural University, Zhengzhou, Henan 450002, China; Anhui Juke Graphene Technology Co., Ltd., Bozhou, Anhui 233600, China.
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Cai C, Li J, Hirth K, Huber GW, Lou H, Zhu JY. Comparison of Two Acid Hydrotropes for Sustainable Fractionation of Birch Wood. CHEMSUSCHEM 2020; 13:4649-4659. [PMID: 32463990 DOI: 10.1002/cssc.202001120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Indexed: 05/19/2023]
Abstract
This study reports on a comparative study of acid hydrotropic fractionation (AHF) of birch wood using maleic acid (MA) and p-toluenesulfonic acid (p-TsOH). Under the same level of delignification, lignin dissolved by MA is much less condensed with a higher content of ether aryl β-O-4 linkages. Lignin depolymerization dominated in MA hydrotropic fractionation (MAHF) and resulted in a single lower molecular weight peak, in contrast to the competitive depolymerization and repolymerization in p-TsOH AHF with a bimodal distribution. The less condensed MA-dissolved lignin facilitated catalytic conversion to monophenols. Carboxylation of residual lignin in fractionated cellulosic water-insoluble solids (WISs) enhanced enzymatic saccharification by decreasing nonproductive cellulase binding to lignin. At a low cellulase loading of 10 FPU g-1 glucan, saccharification of WIS-MT120 from MAHF at 120 °C was 95 % compared with 48 % for WIS-PT85 from p-TsOH AHF at 85 °C under the same level of delignification of 63 %. Residual lignin carboxylation also facilitated nanofibrillation of WIS for producing lignin-containing cellulose nanofibrils (LCNFs) through an enhanced lignin lubrication effect, which substantially decreases fibrillation energy. LCNFs from only one pass of microfluidization of WIS-MT120 have the same morphology as those from WIS-PT85 after three passes. MA also has a lower solubility and higher minimal hydrotropic concentration, which facilitated acid recovery. MA is U.S. Food and Drug Administration (FDA)-approved as an indirect food additive, affording significant advantages compared with p-TsOH for biorefinery applications.
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Affiliation(s)
- Cheng Cai
- USDA Forest Service, Forest Products Laboratory, Madison, WI, USA
- School of Chemistry Chemical Engineering, South China University Technology, Guangzhou, P.R. China
| | - Jian Li
- Dept. of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Kolby Hirth
- USDA Forest Service, Forest Products Laboratory, Madison, WI, USA
| | - George W Huber
- Dept. of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Hongming Lou
- School of Chemistry Chemical Engineering, South China University Technology, Guangzhou, P.R. China
| | - J Y Zhu
- USDA Forest Service, Forest Products Laboratory, Madison, WI, USA
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Prehydrolysis and organosolv delignification process for the recovery of hemicellulose and lignin from beech wood. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.biteb.2020.100506] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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The Production of Lipids Using 5-Hydorxymethy Furfural Tolerant Rhodotorula graminis Grown on the Hydrolyzates of Steam Pretreated Softwoods. SUSTAINABILITY 2020. [DOI: 10.3390/su12030755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Acid catalyzed (SO2) steam pretreated softwoods inevitably contain furans such as 5-hydorxymethy furfural (HMF) and furfural, which are derived from the respective degradation of component hexoses and pentoses. As these materials are known to be inhibitory to fermentation, six oleaginous yeasts were grown on corn steep liquor (CSL) medium containing HMF (0.2%) and furfural (0.1%) to assess their resistance to possible inhibition and its possible influence on lipid production. R. graminis showed the highest tolerance to HMF (0.2%) and furfural (0.1%) when they were added individually to the CSL medium. However, when both HMF (0.2%) and furfural (0.1%) were added together, this inhibited the growth of R. graminis. Subsequent evaporation of the CSL medium successfully removed furfural from the CSL medium and increased the sugar concentration. However, the residual concentration of HMF (0.4%) still inhibited R. graminis growth. To try to improve HMF tolerance, R. graminis was slowly acclimatized in medium containing HMF (0.4%) and was eventually able to produce 1.8 g/L of lipids after four days of growth in the HMF containing medium. This was close to the same amount of lipid produced as when R. graminis was grown in the CSL medium without HMF and furfural. This indicated that an acclimatization strategy is a promising way to enhance lipids production when R. graminis is grown on the hydrolyzates of SO2-catalyzed steam pretreated lignocellulosic substrates.
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Rahmati S, Doherty W, Dubal D, Atanda L, Moghaddam L, Sonar P, Hessel V, Ostrikov K(K. Pretreatment and fermentation of lignocellulosic biomass: reaction mechanisms and process engineering. REACT CHEM ENG 2020. [DOI: 10.1039/d0re00241k] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
At a time of rapid depletion of oil resources, global food shortages and solid waste problems, it is imperative to encourage research into the use of appropriate pre-treatment techniques using regenerative raw materials such as lignocellulosic biomass.
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Affiliation(s)
- Shahrooz Rahmati
- School of Chemistry and Physics
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
- Centre for Agriculture and the Bioeconomy
| | - William Doherty
- Centre for Agriculture and the Bioeconomy
- Institute for Future Environments
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
| | - Deepak Dubal
- School of Chemistry and Physics
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
- Centre for Materials Science
| | - Luqman Atanda
- Centre for Agriculture and the Bioeconomy
- Institute for Future Environments
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
| | - Lalehvash Moghaddam
- Centre for Agriculture and the Bioeconomy
- Institute for Future Environments
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
| | - Prashant Sonar
- School of Chemistry and Physics
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
- Centre for Agriculture and the Bioeconomy
| | - Volker Hessel
- School of Chemical Engineering and Advanced Materials
- The University of Adelaide
- Adelaide
- Australia
- School of Engineering
| | - Kostya (Ken) Ostrikov
- School of Chemistry and Physics
- Queensland University of Technology (QUT)
- Brisbane 4000
- Australia
- Centre for Agriculture and the Bioeconomy
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Hossain A, Rahaman MS, Lee D, Phung TK, Canlas CG, Simmons BA, Renneckar S, Reynolds W, George A, Tulaphol S, Sathitsuksanoh N. Enhanced Softwood Cellulose Accessibility by H 3PO 4 Pretreatment: High Sugar Yield without Compromising Lignin Integrity. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05873] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Anwar Hossain
- Department of Chemical Engineering, University of Louisville, Louisville, Kentucky 40292, United States
| | - Mohammad Shahinur Rahaman
- Department of Chemical Engineering, University of Louisville, Louisville, Kentucky 40292, United States
| | - David Lee
- Joint BioEnergy Institute, 5885 Hollis St, Emeryville, California 94608, United States
| | - Thanh Khoa Phung
- Department of Chemical Engineering, University of Louisville, Louisville, Kentucky 40292, United States
| | - Christian G. Canlas
- King Abdullah University of Science and Technology (KAUST), Core Laboratories, Thuwal, 23955-6900 Saudi Arabia
- College of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
| | - Blake A. Simmons
- Joint BioEnergy Institute, 5885 Hollis St, Emeryville, California 94608, United States
- Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, California 94720, United States
| | - Scott Renneckar
- Faculty of Forestry, University of British Columbia, Vancouver, Canada
| | - William Reynolds
- Department of Materials Science & Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Anthe George
- Joint BioEnergy Institute, 5885 Hollis St, Emeryville, California 94608, United States
- Sandia National Laboratories, 7011 East Ave, Livermore, California 94551, United States
| | - Sarttrawut Tulaphol
- Department of Chemical Engineering, University of Louisville, Louisville, Kentucky 40292, United States
- Department of Chemistry, King Mongkut’s University of Technology Thonburi, Bangkok 10140, Thailand
| | - Noppadon Sathitsuksanoh
- Department of Chemical Engineering, University of Louisville, Louisville, Kentucky 40292, United States
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Zhang S, Yang X, Zhang H, Chu C, Zheng K, Ju M, Liu L. Liquefaction of Biomass and Upgrading of Bio-Oil: A Review. Molecules 2019; 24:E2250. [PMID: 31212889 PMCID: PMC6630481 DOI: 10.3390/molecules24122250] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/06/2019] [Accepted: 06/14/2019] [Indexed: 11/17/2022] Open
Abstract
The liquefaction of biomass is an important technology to converse the biomass into valuable biofuel. The common technologies for liquefaction of biomass are indirect liquefaction and direct liquefaction. The indirect liquefaction refers to the Fischer-Tropsch (F-T) process using the syngas of biomass as the raw material to produce the liquid fuel, including methyl alcohol, ethyl alcohol, and dimethyl ether. The direct liquefaction of biomass refers to the conversion biomass into bio-oil, and the main technologies are hydrolysis fermentation and thermodynamic liquefaction. For thermodynamic liquefaction, it could be divided into fast pyrolysis and hydrothermal liquefaction. In addition, this review provides an overview of the physicochemical properties and common upgrading methods of bio-oil.
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Affiliation(s)
- Shiqiu Zhang
- College of Environmental Science and Engineering, Nankai University, Jinnan District, Tianjin 300350, China.
- Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, Nankai University, Jinnan District, Tianjin 300350, China.
| | - Xue Yang
- College of Environmental Science and Engineering, Nankai University, Jinnan District, Tianjin 300350, China.
- Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, Nankai University, Jinnan District, Tianjin 300350, China.
| | - Haiqing Zhang
- College of Environmental Science and Engineering, Nankai University, Jinnan District, Tianjin 300350, China.
- Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, Nankai University, Jinnan District, Tianjin 300350, China.
| | - Chunli Chu
- College of Environmental Science and Engineering, Nankai University, Jinnan District, Tianjin 300350, China.
- Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, Nankai University, Jinnan District, Tianjin 300350, China.
| | - Kui Zheng
- Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010, China.
| | - Meiting Ju
- College of Environmental Science and Engineering, Nankai University, Jinnan District, Tianjin 300350, China.
- Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, Nankai University, Jinnan District, Tianjin 300350, China.
| | - Le Liu
- College of Environmental Science and Engineering, Nankai University, Jinnan District, Tianjin 300350, China.
- Tianjin Engineering Research Center of Biomass Solid Waste Resources Technology, Nankai University, Jinnan District, Tianjin 300350, China.
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Cheng J, Hirth K, Ma Q, Zhu J, Wang Z, Zhu JY. Toward Sustainable and Complete Wood Valorization by Fractionating Lignin with Low Condensation Using an Acid Hydrotrope at Low Temperatures (≤80 °C). Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b00931] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Jinlan Cheng
- USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin 53726, United States
- Jiangsu Co-innovation Center for Efficient Processing and Utilization of Forest Resources, Jiangsu Provincial Key Lab Pulp & Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China
| | - Kolby Hirth
- USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin 53726, United States
| | - Qianli Ma
- USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin 53726, United States
- State Key Lab Pulp and Paper Eng., South China University of Technology, Guangzhou 510640, China
| | - Junjun Zhu
- USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin 53726, United States
- Jiangsu Co-innovation Center for Efficient Processing and Utilization of Forest Resources, Jiangsu Provincial Key Lab Pulp & Paper Science and Technology, Nanjing Forestry University, Nanjing 210037, China
| | - Zhaojiang Wang
- USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin 53726, United States
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China
| | - J. Y. Zhu
- USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin 53726, United States
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Bağder Elmacı S, Özçelik F. Ionic liquid pretreatment of yellow pine followed by enzymatic hydrolysis and fermentation. Biotechnol Prog 2018; 34:1242-1250. [DOI: 10.1002/btpr.2661] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 04/27/2018] [Indexed: 01/24/2023]
Affiliation(s)
- Simel Bağder Elmacı
- Faculty of Engineering, Dept. of Food EngineeringAnkara University Ankara Turkey
| | - Filiz Özçelik
- Faculty of Engineering, Dept. of Food EngineeringAnkara University Ankara Turkey
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Suckling ID, Jack MW, Lloyd JA, Murton KD, Newman RH, Stuthridge TR, Torr KM, Vaidya AA. A mild thermomechanical process for the enzymatic conversion of radiata pine into fermentable sugars and lignin. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:61. [PMID: 28293291 PMCID: PMC5345204 DOI: 10.1186/s13068-017-0748-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/01/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND Conversion of softwoods into sustainable fuels and chemicals is important for parts of the world where softwoods are the dominant forest species. While they have high theoretical sugar yields, softwoods are amongst the most recalcitrant feedstocks for enzymatic processes, typically requiring both more severe pretreatment conditions and higher enzyme doses than needed for other lignocellulosic feedstocks. Although a number of processes have been proposed for converting softwoods into sugars suitable for fuel and chemical production, there is still a need for a high-yielding, industrially scalable and cost-effective conversion route. RESULTS We summarise work leading to the development of an efficient process for the enzymatic conversion of radiata pine (Pinus radiata) into wood sugars. The process involves initial pressurised steaming of wood chips under relatively mild conditions (173 °C for 3-72 min) without added acid catalyst. The steamed chips then pass through a compression screw to squeeze out a pressate rich in solubilised hemicelluloses. The pressed chips are disc-refined and wet ball-milled to produce a substrate which is rapidly saccharified using commercially available enzyme cocktails. Adding 0.1% polyethylene glycol during saccharification was found to be particularly effective with these substrates, reducing enzyme usage to acceptable levels, e.g. 5 FPU/g OD substrate. The pressate is separately hydrolysed using acid, providing additional hemicellulose-derived sugars, for an overall sugar yield of 535 kg/ODT chips (76% of theoretical). The total pretreatment energy input is comparable to other processes, with the additional energy for attrition being balanced by a lower thermal energy requirement. This pretreatment strategy produces substrates with low levels of fermentation inhibitors, so the glucose-rich mainline and pressate syrups can be fermented to ethanol without detoxification. The lignin from the process remains comparatively unmodified, as evident from the level of retained β-ether interunit linkages, providing an opportunity for conversion into saleable co-products. CONCLUSIONS This process is an efficient route for the enzymatic conversion of radiata pine, and potentially other softwoods, into a sugar syrup suitable for conversion into fuels and chemicals. Furthermore, the process uses standard equipment that is largely proven at commercial scale, de-risking process scale-up.
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Affiliation(s)
| | - Michael W. Jack
- Scion, 49 Sala St, Rotorua, 3046 New Zealand
- Department of Physics, University of Otago, PO Box 56, Dunedin, 9054 New Zealand
| | | | | | | | - Trevor R. Stuthridge
- Scion, 49 Sala St, Rotorua, 3046 New Zealand
- FP Innovations, 2665 East Mall, Vancouver, BC V6T 1Z4 Canada
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Suko AV, Bura R. Enhanced Xylitol and Ethanol Yields by Fermentation Inhibitors in Steam-Pretreated Lignocellulosic Biomass. Ind Biotechnol (New Rochelle N Y) 2016. [DOI: 10.1089/ind.2015.0026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Azra Vajzovic Suko
- University of Washington, School of Environmental and Forest Sciences, Seattle, WA
| | - Renata Bura
- University of Washington, School of Environmental and Forest Sciences, Seattle, WA
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Fermentation of lignocellulosic sugars to acetic acid by Moorella thermoacetica. ACTA ACUST UNITED AC 2016; 43:807-16. [DOI: 10.1007/s10295-016-1756-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 02/29/2016] [Indexed: 10/22/2022]
Abstract
Abstract
A systematic study of bioconversion of lignocellulosic sugars to acetic acid by Moorella thermoacetica (strain ATCC 39073) was conducted. Four different water-soluble fractions (hydrolysates) obtained after steam pretreatment of lignocellulosic biomass were selected and fermented to acetic acid in batch fermentations. M. thermoacetica can effectively ferment xylose and glucose in hydrolysates from wheat straw, forest residues, switchgrass, and sugarcane straw to acetic acid. Xylose and glucose were completely utilized, with xylose being consumed first. M. thermoacetica consumed up to 62 % of arabinose, 49 % galactose and 66 % of mannose within 72 h of fermentation in the mixture of lignocellulosic sugars. The highest acetic acid yield was obtained from sugarcane straw hydrolysate, with 71 % of theoretical yield based on total sugars (17 g/L acetic acid from 24 g/L total sugars). The lowest acetic acid yield was observed in forest residues hydrolysate, with 39 % of theoretical yield based on total sugars (18 g/L acetic acid from 49 g/L total sugars). Process derived compounds from steam explosion pretreatment, including 5-hydroxymethylfurfural (0.4 g/L), furfural (0.1 g/L) and total phenolics (3 g/L), did not inhibit microbial growth and acetic acid production yield. This research identified two major factors that adversely affected acetic acid yield in all hydrolysates, especially in forest residues: (i) glucose to xylose ratio and (ii) incomplete consumption of arabinose, galactose and mannose. For efficient bioconversion of lignocellulosic sugars to acetic acid, it is imperative to have an appropriate balance of sugars in a hydrolysate. Hence, the choice of lignocellulosic biomass and steam pretreatment design are fundamental steps for the industrial application of this process.
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Horisawa S, Ando H, Ariga O, Sakuma Y. Direct ethanol production from cellulosic materials by consolidated biological processing using the wood rot fungus Schizophyllum commune. BIORESOURCE TECHNOLOGY 2015; 197:37-41. [PMID: 26318920 DOI: 10.1016/j.biortech.2015.08.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 05/28/2023]
Abstract
In the present study, ethanol production from polysaccharides or wood chips was conducted in a single reactor under anaerobic conditions using the white rot fungus Schizophyllum commune NBRC 4928, which produces enzymes that degrade lignin, cellulose and hemicellulose. The ethanol yields produced from glucose and xylose were 80.5%, and 52.5%, respectively. The absolute yields of ethanol per microcrystalline cellulose (MCC), xylan and arabinogalactan were 0.26g/g-MCC, 0.0419g/g-xylan and 0.0508g/g-arabinogalactan, respectively. By comparing the actual ethanol yields from polysaccharides with monosaccharide fermentation, it was shown that the rate of saccharification was slower than that in fermentation. S. commune NBRC 4928 is concluded to be suitable for CBP because it can produce ethanol from various types of sugar. From the autoclaved cedar chip, only little ethanol was produced by S. commune NBRC 4928 alone but ethanol production was enhanced by combined use of ethanol fermenting and lignin degrading fungi.
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Affiliation(s)
- Sakae Horisawa
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi 782-8502, Japan.
| | - Hiromasa Ando
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi 782-8502, Japan
| | - Osamu Ariga
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi 782-8502, Japan
| | - Yoh Sakuma
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime 790-8577, Japan
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Silveira MHL, Morais ARC, da Costa Lopes AM, Olekszyszen DN, Bogel-Łukasik R, Andreaus J, Pereira Ramos L. Current Pretreatment Technologies for the Development of Cellulosic Ethanol and Biorefineries. CHEMSUSCHEM 2015; 8:3366-90. [PMID: 26365899 DOI: 10.1002/cssc.201500282] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 06/03/2015] [Indexed: 05/08/2023]
Abstract
Lignocellulosic materials, such as forest, agriculture, and agroindustrial residues, are among the most important resources for biorefineries to provide fuels, chemicals, and materials in such a way to substitute for, at least in part, the role of petrochemistry in modern society. Most of these sustainable biorefinery products can be produced from plant polysaccharides (glucans, hemicelluloses, starch, and pectic materials) and lignin. In this scenario, cellulosic ethanol has been considered for decades as one of the most promising alternatives to mitigate fossil fuel dependence and carbon dioxide accumulation in the atmosphere. However, a pretreatment method is required to overcome the physical and chemical barriers that exist in the lignin-carbohydrate composite and to render most, if not all, of the plant cell wall components easily available for conversion into valuable products, including the fuel ethanol. Hence, pretreatment is a key step for an economically viable biorefinery. Successful pretreatment method must lead to partial or total separation of the lignocellulosic components, increasing the accessibility of holocellulose to enzymatic hydrolysis with the least inhibitory compounds being released for subsequent steps of enzymatic hydrolysis and fermentation. Each pretreatment technology has a different specificity against both carbohydrates and lignin and may or may not be efficient for different types of biomasses. Furthermore, it is also desirable to develop pretreatment methods with chemicals that are greener and effluent streams that have a lower impact on the environment. This paper provides an overview of the most important pretreatment methods available, including those that are based on the use of green solvents (supercritical fluids and ionic liquids).
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Affiliation(s)
- Marcos Henrique Luciano Silveira
- CEPESQ, Research Center in Applied Chemistry, Department of Chemistry, Federal University of Paraná, Curitiba, PR, 81531-970, Brazil
| | - Ana Rita C Morais
- Unit of Bioenergy, National Laboratory of Energy and Geology, 1649-038, Lisbon, Portugal
- LAQV/REQUIMTE, Department of Chemistry, Faculty of Science and Technology, New University of Lisbon, 2829-516, Caparica, Portugal
| | - Andre M da Costa Lopes
- Unit of Bioenergy, National Laboratory of Energy and Geology, 1649-038, Lisbon, Portugal
- LAQV/REQUIMTE, Department of Chemistry, Faculty of Science and Technology, New University of Lisbon, 2829-516, Caparica, Portugal
| | | | - Rafał Bogel-Łukasik
- Unit of Bioenergy, National Laboratory of Energy and Geology, 1649-038, Lisbon, Portugal.
| | - Jürgen Andreaus
- Department of Chemistry, Regional University of Blumenau, Blumenau, SC, 89012 900, Brazil.
| | - Luiz Pereira Ramos
- CEPESQ, Research Center in Applied Chemistry, Department of Chemistry, Federal University of Paraná, Curitiba, PR, 81531-970, Brazil.
- INCT Energy and Environment (INCT E&A), Department of Chemistry, Federal University of Paraná.
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17
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Improvement of acetone, butanol, and ethanol production from woody biomass using organosolv pretreatment. Bioprocess Biosyst Eng 2015; 38:1959-72. [DOI: 10.1007/s00449-015-1437-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 06/30/2015] [Indexed: 11/25/2022]
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Hu J, Chandra R, Arantes V, Gourlay K, Susan van Dyk J, Saddler JN. The addition of accessory enzymes enhances the hydrolytic performance of cellulase enzymes at high solid loadings. BIORESOURCE TECHNOLOGY 2015; 186:149-153. [PMID: 25812819 DOI: 10.1016/j.biortech.2015.03.055] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 05/05/2023]
Abstract
The pretreatment process used and the nature of the biomass feedstock will influence the role that accessory enzymes can play in synergistically interacting with cellulases to effectively deconstruct the substrate. The work reported here assessed the possible boosting effects of the xylanase and lytic polysaccharide monooxygenase (AA9, formerly known as GH61) on the hydrolytic potential of cellulase enzyme mixtures during hydrolysis of steam pretreated poplar and corn stover at high (10-20% w/v) substrate concentrations. A higher proportion of xylanase was required when the substrate had a relatively high xylan content and at high substrate concentrations. In contrast, a relatively small amount of AA9 (about 2 mg/g cellulose) was enough, regardless of the nature or concentration of the substrate. The overall protein loading required to achieve effective hydrolysis of high concentrations of pretreated biomass substrates could be substantially reduced by optimizing the ratio of enzymes in the "cellulase" mixture.
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Affiliation(s)
- Jinguang Hu
- Forest Products Biotechnology and Bioenergy Group, University of British Columbia, Vancouver, BC, Canada
| | - Richard Chandra
- Forest Products Biotechnology and Bioenergy Group, University of British Columbia, Vancouver, BC, Canada
| | - Valdeir Arantes
- Forest Products Biotechnology and Bioenergy Group, University of British Columbia, Vancouver, BC, Canada
| | - Keith Gourlay
- Forest Products Biotechnology and Bioenergy Group, University of British Columbia, Vancouver, BC, Canada
| | - J Susan van Dyk
- Forest Products Biotechnology and Bioenergy Group, University of British Columbia, Vancouver, BC, Canada
| | - Jack N Saddler
- Forest Products Biotechnology and Bioenergy Group, University of British Columbia, Vancouver, BC, Canada.
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Chandra RP, Arantes V, Saddler J. Steam pretreatment of agricultural residues facilitates hemicellulose recovery while enhancing enzyme accessibility to cellulose. BIORESOURCE TECHNOLOGY 2015; 185:302-7. [PMID: 25780906 DOI: 10.1016/j.biortech.2015.02.106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/25/2015] [Accepted: 02/26/2015] [Indexed: 05/11/2023]
Abstract
The origins of lignocellulosic biomass and the pretreatment used to enhance enzyme accessibility to the cellulosic component are known to be strongly influenced by various substrate characteristics. To assess the impact that fibre properties might have on enzymatic hydrolysis, seven agricultural residues were characterised before and after steam pretreatment using a single pretreatment condition (190°C, 5min, 3% SO2) previously shown to enhance fractionation and hydrolysis of the cellulosic component of corn stover. When the fibre length, width and coarseness, viscosity, water retention value and cellulose crystallinity were monitored, no clear correlation was observed between any single substrate characteristic and the substrate's ease of enzymatic hydrolysis. However, the amount of hemicellulose that was solubilised during pretreatment correlated (r(2)=0.98) with the effectiveness of enzyme hydrolysis of each pretreated substrate. Simons's staining, to measure the cellulose accessibility, showed good correlation (r(2)=0.83) with hemicellulose removal and the extent of enzymatic hydrolysis.
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Affiliation(s)
- Richard P Chandra
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| | - Valdeir Arantes
- Lorena School of Engineering, University of São Paulo, Brazil
| | - Jack Saddler
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada.
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20
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Lai C, Tu M, Yong Q, Yu S. Disparate roles of solvent extractable lignin and residual bulk lignin in enzymatic hydrolysis of pretreated sweetgum. RSC Adv 2015. [DOI: 10.1039/c5ra22308c] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The roles of solvent extractable lignin and residual bulk lignin in enzymatic hydrolysis of Avicel and lignocellulosic biomass were distinguished in this study. The extractable lignin showed the positive effects on enzymatic hydrolysis.
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Affiliation(s)
- Chenhuan Lai
- College of Light Industry Science and Engineering
- Nanjing Forestry University
- Nanjing
- China
| | - Maobing Tu
- Department of Biomedical, Chemical and Environmental Engineering
- University of Cincinnati
- Cincinnati
- USA
| | - Qiang Yong
- College of Chemical Engineering
- Nanjing Forestry University
- Nanjing
- China
| | - Shiyuan Yu
- College of Chemical Engineering
- Nanjing Forestry University
- Nanjing
- China
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21
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Gabhane J, William SPMP, Gadhe A, Rath R, Vaidya AN, Wate S. Pretreatment of banana agricultural waste for bio-ethanol production: individual and interactive effects of acid and alkali pretreatments with autoclaving, microwave heating and ultrasonication. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:498-503. [PMID: 24268472 DOI: 10.1016/j.wasman.2013.10.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 09/23/2013] [Accepted: 10/18/2013] [Indexed: 06/02/2023]
Abstract
Banana agricultural waste is one of the potential lignocellulosic substrates which are mostly un-utilized but sufficiently available in many parts of the world. In the present study, suitability of banana waste for biofuel production with respect to pretreatment and reducing sugar yield was assessed. The effectiveness of both acid and alkali pretreatments along with autoclaving, microwave heating and ultrasonication on different morphological parts of banana (BMPs) was studied. The data were statistically analyzed using ANOVA and numerical point prediction tool of MINITAB RELEASE 14. Accordingly, the optimum cumulative conditions for maximum recovery of reducing sugar through acid pretreatment are: leaf (LF) as the substrate with 25 min of reaction time and 180°C of reaction temperature using microwave. Whereas, the optimum conditions for alkaline pretreatments are: pith (PH) as the substrate with 51 min of reaction time and 50°C of reaction temperature using ultrasonication (US).
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Affiliation(s)
- Jagdish Gabhane
- Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, Maharashtra, India
| | - S P M Prince William
- Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, Maharashtra, India.
| | - Abhijit Gadhe
- Vishweshraiya National Institute of Technology, Nagpur, Maharashtra, India
| | - Ritika Rath
- Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, Maharashtra, India
| | - Atul Narayan Vaidya
- Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, Maharashtra, India
| | - Satish Wate
- Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, Maharashtra, India
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Arantes V, Gourlay K, Saddler JN. The enzymatic hydrolysis of pretreated pulp fibers predominantly involves "peeling/erosion" modes of action. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:87. [PMID: 24976863 PMCID: PMC4062648 DOI: 10.1186/1754-6834-7-87] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 05/23/2014] [Indexed: 05/07/2023]
Abstract
BACKGROUND There is still considerable debate regarding the actual mechanism by which a "cellulase mixture" deconstructs cellulosic materials, with accessibility to the substrate at the microscopic level being one of the major restrictions that limits fast, complete cellulose hydrolysis. In the work reported here we tried to determine the predominant mode of action, at the fiber level, of how a cellulase mixture deconstructs pretreated softwood and hardwood pulp fibers. Quantitative changes in the pulp fibers derived from different pretreated biomass substrates were monitored throughout the course of enzymatic hydrolysis to see if the dominant mechanisms involved either the fragmentation/cutting of longer fibers to shorter fibers or their "peeling/delamination/erosion," or if both cutting and peeling mechanisms occurred simultaneously. RESULTS Regardless of the source of biomass, the type of pretreatment and the chemical composition of the substrate, under typical hydrolysis conditions (50°C, pH 4.8, mixing) longer pulp fibers (fiber length >200 μm) were rapidly broken down until a relatively constant fiber length of 130 to 160 μm was reached. In contrast, shorter fibers with an initial average fiber length of 130 to 160 μm showed no significant change in length despite their substantial hydrolysis. The fragmentation/cutting mode of deconstruction was only observed on longer fibers at early stages of hydrolysis. Although the fiber fragmentation mode of deconstruction was not greatly influenced by enzyme loading, it was significantly inhibited by glucose and was mainly observed during initial mixing of the enzyme and substrate. In contrast, significant changes in the fiber width occurred throughout the course of hydrolysis for all of the substrates, suggesting that fiber width may limit the rate and extent of cellulose hydrolysis. CONCLUSION It appears that, at the fiber level, pretreated pulp fibers are hydrolyzed through a two-step mode of action involving an initial rapid fragmentation followed by simultaneous swelling and peeling/erosion of the fragmented fibers. This latter mechanism is the predominant mode of action involved in effectively hydrolyzing the cellulose present in pretreated wood substrates.
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Affiliation(s)
- Valdeir Arantes
- University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Keith Gourlay
- University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Jack N Saddler
- University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
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Lim WS, Lee JW. Influence of pretreatment condition on the fermentable sugar production and enzymatic hydrolysis of dilute acid-pretreated mixed softwood. BIORESOURCE TECHNOLOGY 2013; 140:306-311. [PMID: 23708848 DOI: 10.1016/j.biortech.2013.04.103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 06/02/2023]
Abstract
In this study, the effects of different acid catalysts and pretreatment factors on the hydrolysis of mixed softwood were investigated over a range of thermochemical pretreatments. Maleic, oxalic, and sulfuric acids were each used, under different pretreatment conditions. The most influential factor for fermentable sugar production in the dicarboxylic acid pretreatment of softwood was the pH. Reaction temperature was the next significant factor. However, during sulfuric acid pretreatment, fermentable sugar production was more dependent on reaction temperature, than time or pH. Enzymatic hydrolysis yields differed, depending on acid catalyst and pretreatment factor, regardless of lignin content in pretreated biomass. The highest enzymatic hydrolysis yield was found following maleic acid pretreatment, which reached 61.23%. The trend in enzymatic hydrolysis yields that were detected concomitantly with pretreatment condition or type of acid catalyst was closely related to the fermentable sugar production in the hydrolysate.
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Affiliation(s)
- Woo-Seok Lim
- Department of Forest Products and Technology, BK21 Program, Chonnam National University, Gwangju 500-757, Republic of Korea
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Lim WS, Kim JY, Kim HY, Choi JW, Choi IG, Lee JW. Structural properties of pretreated biomass from different acid pretreatments and their effects on simultaneous saccharification and ethanol fermentation. BIORESOURCE TECHNOLOGY 2013; 139:214-219. [PMID: 23665216 DOI: 10.1016/j.biortech.2013.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/03/2013] [Accepted: 04/03/2013] [Indexed: 06/02/2023]
Abstract
The aim of this study was to investigate the effects of different acid pretreatments on the hydrolysis of biomass and ethanol production. Maleic, oxalic, and sulfuric acids were used individually as catalysts. The fermentable sugar concentration in hydrolysate was high at more than 30 g/L, which obtained at the dicarboxylic acid pretreatment. On the structural change of pretreated biomass, the S/G ratio ranged from 1.7 to 2.0, which was lower than that of raw material. The amount of phenolic OH group was significantly increased by acid pretreatment, which ranged 17.5-32.8%, compared to 4.7% of the raw material. The amounts of phenolic OH group in lignin sensitively affected simultaneous saccharification and fermentation. The maleic acid pretreated biomass, which included 17.5% of the phenolic OH group, was very effective for attaining high glucose yields and ethanol yield, after simultaneous saccharification and fermentation. At the same time, the highest ethanol yield was 0.48.
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Affiliation(s)
- Woo-Seok Lim
- Department of Forest Products and Technology, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, Republic of Korea
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Burkhardt S, Kumar L, Chandra R, Saddler J. How effective are traditional methods of compositional analysis in providing an accurate material balance for a range of softwood derived residues? BIOTECHNOLOGY FOR BIOFUELS 2013; 6:90. [PMID: 23800175 PMCID: PMC3704954 DOI: 10.1186/1754-6834-6-90] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 06/11/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND Forest residues represent an abundant and sustainable source of biomass which could be used as a biorefinery feedstock. Due to the heterogeneity of forest residues, such as hog fuel and bark, one of the expected challenges is to obtain an accurate material balance of these feedstocks. Current compositional analytical methods have been standardised for more homogenous feedstocks such as white wood and agricultural residues. The described work assessed the accuracy of existing and modified methods on a variety of forest residues both before and after a typical pretreatment process. RESULTS When "traditional" pulp and paper methods were used, the total amount of material that could be quantified in each of the six softwood-derived residues ranged from 88% to 96%. It was apparent that the extractives present in the substrate were most influential in limiting the accuracy of a more representative material balance. This was particularly evident when trying to determine the lignin content, due to the incomplete removal of the extractives, even after a two stage water-ethanol extraction. Residual extractives likely precipitated with the acid insoluble lignin during analysis, contributing to an overestimation of the lignin content. Despite the minor dissolution of hemicellulosic sugars, extraction with mild alkali removed most of the extractives from the bark and improved the raw material mass closure to 95% in comparison to the 88% value obtained after water-ethanol extraction. After pretreatment, the extent of extractive removal and their reaction/precipitation with lignin was heavily dependent on the pretreatment conditions used. The selective removal of extractives and their quantification after a pretreatment proved to be even more challenging. Regardless of the amount of extractives that were originally present, the analytical methods could be refined to provide reproducible quantification of the carbohydrates present in both the starting material and after pretreatment. CONCLUSION Despite the challenges resulting from the heterogeneity of the initial biomass substrates a reasonable summative mass closure could be obtained before and after steam pretreatment. However, method revision and optimisation was required, particularly the effective removal of extractives, to ensure that representative and reproducible values for the major lignin and carbohydrate components.
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Affiliation(s)
- Sabrina Burkhardt
- Forest Products Biotechnology/Bioenergy, 2424 Main Mall University of British Columbia, Greater Vancouver, Canada
| | - Linoj Kumar
- Forest Products Biotechnology/Bioenergy, 2424 Main Mall University of British Columbia, Greater Vancouver, Canada
| | - Richard Chandra
- Forest Products Biotechnology/Bioenergy, 2424 Main Mall University of British Columbia, Greater Vancouver, Canada
| | - Jack Saddler
- Forest Products Biotechnology/Bioenergy, 2424 Main Mall University of British Columbia, Greater Vancouver, Canada
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Ramachandriya KD, Wilkins MR, Hiziroglu S, Dunford NT, Atiyeh HK. Development of an efficient pretreatment process for enzymatic saccharification of Eastern redcedar. BIORESOURCE TECHNOLOGY 2013; 136:131-139. [PMID: 23567673 DOI: 10.1016/j.biortech.2013.02.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 02/18/2013] [Accepted: 02/18/2013] [Indexed: 06/02/2023]
Abstract
This study investigates the potential for extracting sugars from the polysaccharides of Eastern redcedar. Pretreatment temperature, time, sulfuric acid loading, sodium bisulfite loading and impregnation time were varied using factorial treatment design experiments for identifying near optimal overall wood glucan-to-glucose yields during acid bisulfite pretreatments. The highest overall wood glucan-to-glucose yield of 87% was achieved when redcedar was impregnated with pretreatment liquor containing 3.75 g of sulfuric acid/100g of dry wood and 20 g of sodium bisulfite/100g of dry wood at 90 °C for 3h followed by increasing the temperature to 200 °C with a hold time of 10 min. Hemicellulose and lignin removal during pretreatments made the substrate amenable to enzymatic hydrolysis using 0.5 ml of Accelerase® 1500/g of glucan at 2% (w/w) solid loading. Preliminary mass balances showed 97% glucan recovery at pretreatment condition with 87% overall wood glucan-to-glucose yield and 59% delignification.
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Tan L, Yu Y, Li X, Zhao J, Qu Y, Choo YM, Loh SK. Pretreatment of empty fruit bunch from oil palm for fuel ethanol production and proposed biorefinery process. BIORESOURCE TECHNOLOGY 2013. [PMID: 23186670 DOI: 10.1016/j.biortech.2012.10.134] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
This study evaluates the effects of some pretreatment processes to improve the enzymatic hydrolysis of oil palm empty fruit bunch (EFB) for ethanol production. The experimental results show that the bisulfite pretreatment was practical for EFB pretreatment. Moreover, the optimum pretreatment conditions of the bisulfite pretreatment (180 °C, 30 min, 8% NaHSO3, 1% H2SO4) were identified. In the experiments, a biorefinery process of EFB was proposed to produce ethanol, xylose products, and lignosulfonates.
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Affiliation(s)
- Liping Tan
- State Key Laboratory of Microbial Technology, Shandong University, Ji-nan City 250100, China
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Kapu NS, Piddocke M, Saddler JN. High gravity and high cell density mitigate some of the fermentation inhibitory effects of softwood hydrolysates. AMB Express 2013; 3:15. [PMID: 23410516 PMCID: PMC3576264 DOI: 10.1186/2191-0855-3-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 12/02/2022] Open
Abstract
After steam pretreatment of lignocellulosic substrates the fermentation of the biomass derived sugars to ethanol is typically problematic because of both the generally low sugar concentrations that can be supplied and the presence of naturally occurring and process derived inhibitors. As the majority of the inhibitory materials are usually associated with the hemicellulose rich, water soluble component, this fraction was supplemented with glucose to simulate high solids, un-detoxified substrate to see if a high gravity/high cell consistency approach might better cope with inhibition. Several yeast strains were assessed, with the Tembec T1, T2 and Lallemand LYCC 6469 strains showing the greatest ethanol productivity and yield. The addition of supplemental glucose enabled the faster and quantitatively higher removal of hydroxymethylfurfural (HMF). High cell density could provide effective fermentation at high sugar concentrations while enhancing inhibitor reduction. A 77% ethanol yield could be achieved using strain LYCC 6469 after 48 h at high cell density. It was apparent that a high cell density approach improved ethanol production by all of the evaluated yeast strains.
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Tooyserkani Z, Kumar L, Sokhansanj S, Saddler J, Bi XT, Lim CJ, Lau A, Melin S. SO2-catalyzed steam pretreatment enhances the strength and stability of softwood pellets. BIORESOURCE TECHNOLOGY 2013; 130:59-68. [PMID: 23347905 DOI: 10.1016/j.biortech.2012.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/28/2012] [Accepted: 12/01/2012] [Indexed: 06/01/2023]
Abstract
Densification can partially resolve the logistical challenges encountered when large volumes of biomass are required for bioconversion processes to benefit from economies-of-scale. Despite the higher bulk density of pellets, their lower mechanical strength and sensitivity to moisture are still recurring issues hindering long term transportation and storage. In this study, we have evaluated the potential benefits of SO(2)-catalyzed steam treatment to achieve both the needed size reduction prior to pelletization while improving the stability of the produced pellets. This pretreatment substantially reduced the particle size of the woodchips eliminating any further grinding. The treated pellets had a higher density and exhibited a two-time higher mechanical strength compared to untreated pellets. Despite a higher moisture adsorption capacity, treated pellets remained intact even under highly humid conditions. The high heating values, low ash content and good overall carbohydrate recovery of treated pellets indicated their potential suitability for both biochemical and thermochemical applications.
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Affiliation(s)
- Zahra Tooyserkani
- Biomass and Bioenergy Research Group, Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, Canada V6T 1Z3.
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Nitsos CK, Matis KA, Triantafyllidis KS. Optimization of hydrothermal pretreatment of lignocellulosic biomass in the bioethanol production process. CHEMSUSCHEM 2013. [PMID: 23180649 DOI: 10.1002/cssc.201200546] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The natural resistance to enzymatic deconstruction exhibited by lignocellulosic materials has designated pretreatment as a key step in the biological conversion of biomass to ethanol. Hydrothermal pretreatment in pure water represents a challenging approach because it is a method with low operational costs and does not involve the use of organic solvents, difficult to handle chemicals, and "external" liquid or solid catalysts. In the present work, a systematic study has been performed to optimize the hydrothermal treatment of lignocellulosic biomass (beech wood) with the aim of maximizing the enzymatic digestibility of cellulose in the treated solids and obtaining a liquid side product that could also be utilized for the production of ethanol or valuable chemicals. Hydrothermal treatment experiments were conducted in a batch-mode, high-pressure reactor under autogeneous pressure at varying temperature (130-220 °C) and time (15-180 min) regimes, and at a liquid-to-solid ratio (LSR) of 15. The intensification of the process was expressed by the severity factor, log R(o). The major changes induced in the solid biomass were the dissolution/removal of hemicellulose to the process liquid and the partial removal and relocation of lignin on the external surface of biomass particles in the form of recondensed droplets. The above structural changes led to a 2.5-fold increase in surface area and total pore volume of the pretreated biomass solids. The enzymatic hydrolysis of cellulose to glucose increased from less than 7 wt% for the parent biomass to as high as 70 wt% for the treated solids. Maximum xylan recovery (60 wt%) in the hydrothermal process liquid was observed at about 80 wt% hemicellulose removal; this was accomplished by moderate treatment severities (log R(o)=3.8-4.1). At higher severities (log R(o)=4.7), xylose degradation products, mainly furfural and formic acid, were the predominant chemicals formed.
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Affiliation(s)
- Christos K Nitsos
- Laboratory of General and Inorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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Kumar L, Tooyserkani Z, Sokhansanj S, Saddler JN. Does densification influence the steam pretreatment and enzymatic hydrolysis of softwoods to sugars? BIORESOURCE TECHNOLOGY 2012; 121:190-198. [PMID: 22858485 DOI: 10.1016/j.biortech.2012.06.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/14/2012] [Accepted: 06/15/2012] [Indexed: 06/01/2023]
Abstract
The global trade in wood pellets continues to grow. However, their potential as a feedstock for large scale cellulosic ethanol production has not been evaluated. We anticipated that the reduced moisture content and pressure exerted on the wood biomass during the pelletisation process would result in some carbohydrate loss as well as making the biomass more recalcitrant to pretreatment and subsequent hydrolysis. However, when softwood chips and pellets were steam pretreated at medium severity, little hemicellulose loss occurred while more than two-thirds of the cellulose present in the cellulose rich water insoluble fractions were hydrolysed (at 20 FPU cellulase/g cellulose). In addition, prior steaming substantially reduced the particle size of the wood chips enabling direct pelletisation without the need for grinding. Surprisingly, it was also possible to apply a single steam pretreatment to facilitate both pelletisation and subsequent enzymatic hydrolysis without the need for a further pretreatment step.
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Affiliation(s)
- Linoj Kumar
- Forest Products Biotechnology/Bioenergy, University of British Columbia, Vancouver, BC, Canada
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Pang F, Xue S, Yu S, Zhang C, Li B, Kang Y. Effects of microwave power and microwave irradiation time on pretreatment efficiency and characteristics of corn stover using combination of steam explosion and microwave irradiation (SE-MI) pretreatment. BIORESOURCE TECHNOLOGY 2012; 118:111-119. [PMID: 22705513 DOI: 10.1016/j.biortech.2012.05.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 05/09/2012] [Accepted: 05/10/2012] [Indexed: 06/01/2023]
Abstract
The effects of microwave power and microwave irradiation time on pretreatment efficiency and characteristics of corn stover were investigated based on a new process named combination of steam explosion and microwave irradiation (SE-MI) pretreatment. Results showed that with microwave power and microwave irradiation time increasing, glucose and xylose that released into hydrolyzate, as well as enzymatic hydrolysis yields and sugar yields of glucose and xylose were all slightly increased after SE-MI pretreatment. The maximum sugar yield was 72.1 g per 100 g glucose and xylose in feedstock, achieved at 540 W microwave power and 5 min microwave irradiation time. XRD analysis showed that the crystallinity of biomass was 15.6-19.9% lower for SE-MI pretreatment with microwave effect than that without microwave effect. However, low microwave power and short microwave irradiation time were favorable for SE-MI pretreatment considering energy consumption.
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Affiliation(s)
- Feng Pang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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Iakovlev M, van Heiningen A. Efficient fractionation of spruce by SO(2)-ethanol-water treatment: closed mass balances for carbohydrates and sulfur. CHEMSUSCHEM 2012; 5:1625-37. [PMID: 22740146 DOI: 10.1002/cssc.201100600] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 12/19/2011] [Indexed: 05/18/2023]
Abstract
SO(2)-ethanol-water (SEW) lignocellulosic fractionation has the potential to overcome the present techno-economic barriers that hinder the commercial implementation of renewable transportation fuel production. In this study, SEW fractionation of spruce wood chips is examined for its ability to separate the main wood components, hemicelluloses, lignin, and cellulose, and the potential to recover SO(2) and ethanol from the spent fractionation liquid. Therefore, overall sulfur and carbohydrate mass balances are established. 95-97 % of the charged SO(2) remains in the liquid and can be fully recovered by distillation. During fractionation, hemicelluloses and lignin are effectively dissolved, whereas cellulose is preserved in the solid (fibre) phase. Hemicelluloses are hydrolysed, producing up to 50 % monomeric sugars, whereas dehydration and oxidation of carbohydrates are insignificant. The latter is proven by the closed carbohydrate material balances as well as by the near absence of corresponding by-products (furfural, hydroxymethylfurfural (HMF) and aldonic acids). In addition, acid methanolysis/GC and acid hydrolysis/high performance anion exchange chromatography (HPAEC) methods for the carbohydrate determination are compared.
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Affiliation(s)
- Mikhail Iakovlev
- Department of Forest Products Technology, Aalto University School of Chemical Technology, 00076 Aalto, Finland
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Chandra RP, Saddler JN. Use of the Simons' Staining Technique to Assess Cellulose Accessibility in Pretreated Substrates. Ind Biotechnol (New Rochelle N Y) 2012. [DOI: 10.1089/ind.2012.0016] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Richard P. Chandra
- Bioenergy/Forest Products Biotechnology Group, Department of Wood Science, University of British Columbia, Vancouver BC
| | - Jack N. Saddler
- Bioenergy/Forest Products Biotechnology Group, Department of Wood Science, University of British Columbia, Vancouver BC
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Extrusion Pretreatment of Pine Wood Chips. Appl Biochem Biotechnol 2012; 167:81-99. [DOI: 10.1007/s12010-012-9662-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/28/2012] [Indexed: 10/28/2022]
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37
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Arantes V, Jellison J, Goodell B. Peculiarities of brown-rot fungi and biochemical Fenton reaction with regard to their potential as a model for bioprocessing biomass. Appl Microbiol Biotechnol 2012; 94:323-38. [DOI: 10.1007/s00253-012-3954-y] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 11/24/2022]
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38
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Fractionation of barley straw with dilute sulfuric acid for improving hemicellulose recovery. KOREAN J CHEM ENG 2012. [DOI: 10.1007/s11814-011-0218-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Schmitt E, Bura R, Gustafson R, Cooper J, Vajzovic A. Converting lignocellulosic solid waste into ethanol for the State of Washington: an investigation of treatment technologies and environmental impacts. BIORESOURCE TECHNOLOGY 2012; 104:400-9. [PMID: 22119432 DOI: 10.1016/j.biortech.2011.10.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 09/11/2011] [Accepted: 10/25/2011] [Indexed: 05/14/2023]
Abstract
There is little research literature on the conversion of lignocellulosic rich waste streams to ethanol, and even fewer have investigated both the technical aspects and environmental impacts together. This study assessed technical and environmental challenges of converting three lignocellulosic waste streams to ethanol: municipal solid waste (MSW), low grade mixed waste paper (MWP), and organic yard waste (YW). Experimental results showed high conversion yields for all three streams using suitable conversion methods. Environmental impacts are highly dependent on conversion technology, and process conditions used. Life cycle assessment results showed that both chemicals production and waste collection are important factors to be included within a waste-to-ethanol study.
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Affiliation(s)
- Elliott Schmitt
- School of Forest Resources, University of Washington, Box 352100, Seattle, WA 98195, USA
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40
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Effect of steam explosion pretreatment with ultra-high temperature and pressure on effective utilization of softwood biomass. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2011.09.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Wang G, Zhang X, Wang L, Wang K, Peng F, Wang L. The activity and kinetic properties of cellulases in substrates containing metal ions and acid radicals. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/abc.2012.24048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hawkins GM, Doran-Peterson J. A strain of Saccharomyces cerevisiae evolved for fermentation of lignocellulosic biomass displays improved growth and fermentative ability in high solids concentrations and in the presence of inhibitory compounds. BIOTECHNOLOGY FOR BIOFUELS 2011; 4:49. [PMID: 22074982 PMCID: PMC3256112 DOI: 10.1186/1754-6834-4-49] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 11/10/2011] [Indexed: 05/04/2023]
Abstract
BACKGROUND Softwoods are the dominant source of lignocellulosic biomass in the northern hemisphere, and have been investigated worldwide as a renewable substrate for cellulosic ethanol production. One challenge to using softwoods, which is particularly acute with pine, is that the pretreatment process produces inhibitory compounds detrimental to the growth and metabolic activity of fermenting organisms. To overcome the challenge of bioconversion in the presence of inhibitory compounds, especially at high solids loading, a strain of Saccharomyces cerevisiae was subjected to evolutionary engineering and adaptation for fermentation of pretreated pine wood (Pinus taeda). RESULTS An industrial strain of Saccharomyces, XR122N, was evolved using pretreated pine; the resulting daughter strain, AJP50, produced ethanol much more rapidly than its parent in fermentations of pretreated pine. Adaptation, by preculturing of the industrial yeast XR122N and the evolved strains in 7% dry weight per volume (w/v) pretreated pine solids prior to inoculation into higher solids concentrations, improved fermentation performance of all strains compared with direct inoculation into high solids. Growth comparisons between XR122N and AJP50 in model hydrolysate media containing inhibitory compounds found in pretreated biomass showed that AJP50 exited lag phase faster under all conditions tested. This was due, in part, to the ability of AJP50 to rapidly convert furfural and hydroxymethylfurfural to their less toxic alcohol derivatives, and to recover from reactive oxygen species damage more quickly than XR122N. Under industrially relevant conditions of 17.5% w/v pretreated pine solids loading, additional evolutionary engineering was required to decrease the pronounced lag phase. Using a combination of adaptation by inoculation first into a solids loading of 7% w/v for 24 hours, followed by a 10% v/v inoculum (approximately equivalent to 1 g/L dry cell weight) into 17.5% w/v solids, the final strain (AJP50) produced ethanol at more than 80% of the maximum theoretical yield after 72 hours of fermentation, and reached more than 90% of the maximum theoretical yield after 120 hours of fermentation. CONCLUSIONS Our results show that fermentation of pretreated pine containing liquid and solids, including any inhibitory compounds generated during pretreatment, is possible at higher solids loadings than those previously reported in the literature. Using our evolved strain, efficient fermentation with reduced inoculum sizes and shortened process times was possible, thereby improving the overall economic viability of a woody biomass-to-ethanol conversion process.
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Affiliation(s)
- Gary M Hawkins
- Microbiology Department, University of Georgia, Athens, GA 30602, USA
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Kumar L, Chandra R, Saddler J. Influence of steam pretreatment severity on post-treatments used to enhance the enzymatic hydrolysis of pretreated softwoods at low enzyme loadings. Biotechnol Bioeng 2011; 108:2300-11. [DOI: 10.1002/bit.23185] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/04/2011] [Accepted: 04/11/2011] [Indexed: 11/10/2022]
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44
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Asada C, Kita A, Sasaki C, Nakamura Y. Ethanol production from disposable aspen chopsticks using delignification pretreatments. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.02.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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García-Aparicio M, Parawira W, Van Rensburg E, Diedericks D, Galbe M, Rosslander C, Zacchi G, Görgens J. Evaluation of steam-treated giant bamboo for production of fermentable sugars. Biotechnol Prog 2011; 27:641-9. [PMID: 21448931 DOI: 10.1002/btpr.580] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 01/10/2011] [Indexed: 11/06/2022]
Abstract
Giant bamboo plantations are currently being established in the Southern Africa region and can be considered as potential lignocellulosic feedstock for the production of second generation bioethanol. In this study, giant bamboo internodal material was subjected to sulphur dioxide (SO(2)) impregnated steam pretreatment prior to enzymatic hydrolysis. The effect of temperature, residence time, and acidity on the overall sugar recovery and byproduct formation was studied using response surface response technology according to a central composite experimental design (CCD) at a fixed SO(2) concentration of 2.5% (w/w liquid) after impregnation. The results showed that pretreatment conditions with combined severity factor (CSF) values and enzyme dosages greater than 1.72 and 30 FPU/g water insoluble solid, respectively, were required to obtain an efficient glucan digestibility and a good overall glucose recovery. Up to 81.2% of the sugar in the raw material was recovered for a CSF of 2.25. However, considering overall sugar yield and byproducts concentration, the pretreated material obtained with a CSF of 1.62 can be considered as the most appropriate for SSF experiments using a xylose-utilizing yeast. At these conditions, it could be possible to obtain up to 247 L of ethanol per dry ton of giant bamboo considering hexose and pentose sugars fermentation. This amount could be increased up to 292 L of ethanol per dry ton of giant bamboo with the maximum sugar yield obtained (CSF = 2.25) if the microorganism possesses robust fermentative characteristics as well as a high resistance to pretreatment by-products.
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Affiliation(s)
- María García-Aparicio
- Dept. of Process Engineering, Stellenbosch University, Private Bag X1 Stellenbosch 7602 South Africa.
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Zhang J, Wang X, Chu D, He Y, Bao J. Dry pretreatment of lignocellulose with extremely low steam and water usage for bioethanol production. BIORESOURCE TECHNOLOGY 2011; 102:4480-8. [PMID: 21277774 DOI: 10.1016/j.biortech.2011.01.005] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 01/02/2011] [Accepted: 01/03/2011] [Indexed: 05/06/2023]
Abstract
Two rarely noticed but important parameters of the dilute sulfuric acid pretreatment of lignocellulose biomass, the feedstock filling ratio to the pretreatment reactor and the solids/liquid presoaking ratio, were extensively studied. The effects of the two parameters on the steam consumption, waste water generation, and pretreatment efficiency were investigated. At the full filling ratio and high solids/liquid presoaking ratio, this "dry" pretreatment method provided at least the following advantages: (1) the steam consumption was significantly reduced; (2) no aqueous acid containing waste water was generated; (3) high solids content of the pretreated materials were obtained and the consequent saccharification and fermentation was carried out at high solids loading easily. This method was applied to various lignocellulose feedstocks successfully and provided a practical means to produce ethanol economically feasible.
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Affiliation(s)
- Jian Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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Nakagame S, Chandra RP, Kadla JF, Saddler JN. The isolation, characterization and effect of lignin isolated from steam pretreated Douglas-fir on the enzymatic hydrolysis of cellulose. BIORESOURCE TECHNOLOGY 2011; 102:4507-17. [PMID: 21256740 DOI: 10.1016/j.biortech.2010.12.082] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 12/22/2010] [Accepted: 12/22/2010] [Indexed: 05/02/2023]
Abstract
Douglas-fir was SO(2)-steam pretreated at different severities (190, 200, and 210°C) to assess the possible negative effect of the residual and isolated lignins on the enzymatic hydrolysis of the steam pretreated substrates. When various isolated lignins were added to the Avicel hydrolysis reactions, the decrease in glucose yields ranged from 15.2% to 29.0% after 72 h. It was apparent that the better hydrolysis yields obtained at higher pretreatment severities were more a result of the greater accessibly of the cellulose rather than any specific change in the non-productive binding of the lignin to the enzymes. FTIR and (13)C NMR characterization indicated that the lignin in the steam pretreated substrates became more condensed with increasing severity, suggesting that the cellulases were adsorbed to the lignin by hydrophobic interactions. Electrostatic interactions were also involved as the positively charged cellulase components were preferentially adsorbed to the lignins.
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Affiliation(s)
- Seiji Nakagame
- Department of Wood Science, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia, Canada
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Chen WH, Pen BL, Yu CT, Hwang WS. Pretreatment efficiency and structural characterization of rice straw by an integrated process of dilute-acid and steam explosion for bioethanol production. BIORESOURCE TECHNOLOGY 2011; 102:2916-24. [PMID: 21134742 DOI: 10.1016/j.biortech.2010.11.052] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 11/09/2010] [Accepted: 11/11/2010] [Indexed: 05/22/2023]
Abstract
The combined pretreatment of rice straw using dilute-acid and steam explosion followed by enzymatic hydrolysis was investigated and compared with acid-catalyzed steam explosion pretreatment. In addition to measuring the chemical composition, including glucan, xylan and lignin content, changes in rice straw features after pretreatment were investigated in terms of the straw's physical properties. These properties included crystallinity, surface area, mean particle size and scanning electron microscopy imagery. The effect of acid concentration on the acid-catalyzed steam explosion was studied in a range between 1% and 15% acid at 180°C for 2 min. We also investigated the influence of the residence time of the steam explosion in the combined pretreatment and the optimum conditions for the dilute-acid hydrolysis step in order to develop an integrated process for the dilute-acid and steam explosion. The optimum operational conditions for the first dilute-acid hydrolysis step were determined to be 165°C for 2 min with 2% H(2)SO(4) and for the second steam explosion step was to be carried out at 180°C for 20 min; this gave the most favorable combination in terms of an integrated process. We found that rice straw pretreated by the dilute-acid/steam explosions had a higher xylose yield, a lower level of inhibitor in the hydrolysate and a greater degree of enzymatic hydrolysis; this resulted in a 1.5-fold increase in the overall sugar yield when compared to the acid-catalyzed steam explosion.
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Affiliation(s)
- Wen-Hua Chen
- Institute of Nuclear Energy Research, Atomic Energy Committee, Taoyuan, Taiwan, ROC.
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49
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Ewanick S, Bura R. The effect of biomass moisture content on bioethanol yields from steam pretreated switchgrass and sugarcane bagasse. BIORESOURCE TECHNOLOGY 2011; 102:2651-8. [PMID: 21109425 DOI: 10.1016/j.biortech.2010.10.117] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/22/2010] [Accepted: 10/25/2010] [Indexed: 05/25/2023]
Abstract
This study aimed to determine the effect of moisture content of three different feedstocks on overall ethanol yield. Switchgrass and sugarcane bagasse from two sources were either soaked in water (∼80% moisture) or left dry (∼12% moisture), and half each of these were impregnated with 3%w/w SO(2) and all were steam pretreated. The twelve resulting substrates were compared based on overall sugar recovery after pretreatment, cellulose conversion following enzymatic hydrolysis, and ethanol yield following simultaneous saccharification and fermentation. The overall ethanol yield after simultaneous saccharification and fermentation of hexoses was 18-28% higher in samples that were soaked prior to SO(2) addition than in SO(2)-catalyzed samples that were not soaked. In samples that were uncatalyzed, soaking made little difference, indicating that the positive effect of increased moisture content may be related to increased permeability of the biomass to SO(2).
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Affiliation(s)
- Shannon Ewanick
- University of Washington, School of Forest Resources, Seattle, WA 98195-2100, USA.
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50
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Chandra RP, Au-Yeung K, Chanis C, Roos AA, Mabee W, Chung PA, Ghatora S, Saddler JN. The influence of pretreatment and enzyme loading on the effectiveness of batch and fed-batch hydrolysis of corn stover. Biotechnol Prog 2010; 27:77-85. [DOI: 10.1002/btpr.508] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Indexed: 11/07/2022]
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