1
|
Sathitkowitchai W, Ayimbila F, Nitisinprasert S, Keawsompong S. Selection of pretreatment method and mannanase enzyme to improve the functionality of palm kernel cake. J Biosci Bioeng 2022:S1389-1723(22)00187-6. [PMID: 35970725 DOI: 10.1016/j.jbiosc.2022.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 11/22/2022]
Abstract
Palm kernel cake (PKC) is a by-product of palm kernel oil extraction with moderate nutritional value, containing 30-35% β-mannan, which is indigestible, slows growth, and reduces feed efficiency. PKC can be improved by mannanase hydrolysis, but the effectiveness of mannanase is dependent on the microbial source. Thus, the effect of steam pretreatment and bacterial mannanases on PKC quality was investigated. PKC was pretreated by steaming and hydrolyzed in the small intestine by various mannanases. The contents of reducing sugar, total sugar, and protein release were measured. Steamed PKC had a significant increase in protein (16.95 ± 0.14 to 20.98 ± 0.13%) and a substantial decrease in hemicellulose (29.52 ± 0.44 to 3.46 ± 0.88%) and lignin (8.94 ± 0.28 to 1.40 ± 0.22%). Mannanases from Escherichia coli-KMAN-3 and E. coli-Man6.7 recorded the highest activities, followed by commercial mannanase, Bacillus circulans NT6.7 and B. amyloliquefaciens NT6.3 mannanases, orderly. B. circulans NT6.7 and B. amyloliquefaciens NT6.3 had multi-activities that include glucanase (3.10 ± 0.04% and 2.47 ± 0.02%) and amylase (1.74 ± 0.03% and 1.38 ± 0.04%), respectively. B. amyloliquefaciens NT6.3 mannanase hydrolyzed steamed PKC to release more reducing sugar, total sugar, and protein than hydrolyzed raw PKC. In raw and steamed PKC, B. amyloliquefaciens NT6.3 mannanase produced the highest reducing sugar release. As a result, steam pretreatment and mannanase hydrolysis, particularly from B. amyloliquefaciens, can be used to increase the functioning of PKC and develop new feed ingredients for monogastric animals at a reasonable cost.
Collapse
|
2
|
Wu J, Ebadian M, Kim KH, Kim CS, Saddler J. The use of steam pretreatment to enhance pellet durability and the enzyme-mediated hydrolysis of pellets to fermentable sugars. Bioresour Technol 2022; 347:126731. [PMID: 35074465 DOI: 10.1016/j.biortech.2022.126731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/10/2021] [Revised: 01/13/2022] [Accepted: 01/15/2022] [Indexed: 06/14/2023]
Abstract
Although densified wood pellets are an attractive biomass feedstock for bioenergy and biofuels production, partly due to their ease of transport, their friability and hygroscopic nature (attraction of moisture) have proven problematic in terms of storage and handling. Pre-steaming the biomass was shown to reduce the need for size reduction, significantly increasing pellet durability by relocating the plant cell wall lignin to the fibre surface and consequently enhancing binding between particles. Although steam pretreatment has been shown to facilitate enzyme-mediated hydrolysis of biomass, by increasing cellulose accessibility, drying and pelletization partially impeded enzymatic hydrolysis. However, the incorporation of alkaline deacetylation or neutral sulfonation step prior to pre-steaming was shown to mitigate many of the negative effects of drying. Although drying and pelletization did not significantly impact the redistribution of lignin, a mild mechanical refining step was shown to further enhance the hydrolysis of the cellulose component of the pelletized biomass.
Collapse
Affiliation(s)
- Jie Wu
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver BC V6T 1Z4, Canada
| | - Mahmood Ebadian
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver BC V6T 1Z4, Canada
| | - Kwang Ho Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Chang Soo Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jack Saddler
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver BC V6T 1Z4, Canada.
| |
Collapse
|
3
|
Peng J, Lu L, Zhu KX, Guo XN, Chen Y, Zhou HM. Effect of rehydration on textural properties, oral behavior, kinetics and water state of textured wheat gluten. Food Chem 2021; 376:131934. [PMID: 34973643 DOI: 10.1016/j.foodchem.2021.131934] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/03/2021] [Accepted: 12/20/2021] [Indexed: 12/01/2022]
Abstract
To reduce the rehydration time and improve the quality of textured wheat gluten (TWG), the effects of steam pretreatment and water temperature (45 °C, 65 °C, and 85 °C) on the rehydration of TWG were investigated. Four different models were used to describe the rehydration kinetics: Peleg, Weibull, first-order, and exponential association models, with the Weibull model found to give the best fit. High temperature induced deterioration of textural properties and oral processing behavior and increased the rehydration loss ratio, while steam pretreatment reduced these negative changes. Morphological results showed that the surface and cross-sectional structure were conducive to water diffusion with steam pretreatment. Low-field nuclear magnetic resonance and infrared thermal results indicated that steam pretreatment promoted the diffusion of water and reduced the time required to reach thermal equilibrium. This work provides a fast rehydration method for TWG to help in the future production of high-quality meat analogues.
Collapse
Affiliation(s)
- Jing Peng
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Lu Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Ke-Xue Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiao-Na Guo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yuan Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Hui-Ming Zhou
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| |
Collapse
|
4
|
Lee EJ, Yun S, Kim H. Effects of steam pretreatment on fouled membrane in chemical cleaning for flux recovery in drinking water treatment. Environ Sci Pollut Res Int 2020; 27:35703-35711. [PMID: 32601869 DOI: 10.1007/s11356-020-09831-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 03/06/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
This paper shows the possibility of using steam pretreatment to improve the efficiency of membrane recovery chemical cleaning. Before applying chemicals to clean a fouled membrane, steam pretreatment was employed to loosen the structure of the foulant layer and weaken the attachment of those foulants on the membrane. Although longer steam contact times would lead to even better cleaning efficiency, the steam pretreatment duration was limited to less than 2 min to maintain membrane integrity. When cleaning fouled membranes with 1 mol/L HCl, the cleaning efficiency without steam pretreatment went from 83.3 to 90.2% as cleaning time increased from 30 to 180 min. As for 90-s steam pretreatment, the cleaning efficiency showed high values of more than 93% regardless of cleaning time. When the concentration of HCl was decreased to 0.2 mol/L, the cleaning efficiencies with a 90-s steam pretreatment was 78.6% and 92.6% for relatively short cleaning times of 30 and 60 min, respectively; this is much higher than the 62.2% and 76.7% achieved when cleaning without steam pretreatment. In addition, when using alkaline solution as the cleaning chemical, similar results were obtained. This implies that the application of steam before chemical cleaning is effective in improving cleaning efficiency, and so, this technique has the potential to reduce the amount of cleaning chemical required for membrane recovery cleaning.
Collapse
Affiliation(s)
- Eui-Jong Lee
- Department of Environmental Engineering, Daegu University, 201 Daegudae-ro, Jillyang, Gyeongsan-si, Gyeongbuk, 38453, Republic of Korea.
| | - Seunghyeon Yun
- Graduate School of Water Resources, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 440746, Republic of Korea
| | - Hyungsoo Kim
- Graduate School of Water Resources, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 440746, Republic of Korea
| |
Collapse
|
5
|
Sanchis-Sebastiá M, Erdei B, Kovacs K, Galbe M, Wallberg O. Introducing low-quality feedstocks in bioethanol production: efficient conversion of the lignocellulose fraction of animal bedding through steam pretreatment. Biotechnol Biofuels 2019; 12:215. [PMID: 31528203 PMCID: PMC6737725 DOI: 10.1186/s13068-019-1558-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Animal bedding remains an underutilized source of raw material for bioethanol production, despite the economic and environmental benefits of its use. Further research concerning the optimization of the production process is needed, as previously tested pretreatment methods have not increased the conversion efficiency to the levels necessary for commercialization of the process. RESULTS We propose steam pretreatment of animal bedding, consisting of a mixture of straw and cow manure, to deliver higher ethanol yields. The temperature, residence time and pH were optimized through response-surface modeling, where pretreatment was evaluated based on the ethanol yield obtained through simultaneous saccharification and fermentation of the whole pretreated slurry. The results show that the best conditions for steam pretreatment are 200 °C, for 5 min at pH 2, at which an ethanol yield of about 70% was obtained. Moreover, the model also showed that the pH had the greatest influence on the ethanol yield, followed by the temperature and then the residence time. CONCLUSIONS Based on these results, it appears that steam pretreatment could unlock the potential of animal bedding, as the same conversion efficiencies were achieved as for higher-quality feedstocks such as wheat straw.
Collapse
Affiliation(s)
| | - Borbála Erdei
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Krisztina Kovacs
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Mats Galbe
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Ola Wallberg
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| |
Collapse
|
6
|
Olsson J, Novy V, Nielsen F, Wallberg O, Galbe M. Sequential fractionation of the lignocellulosic components in hardwood based on steam explosion and hydrotropic extraction. Biotechnol Biofuels 2019; 12:1. [PMID: 30622643 PMCID: PMC6318938 DOI: 10.1186/s13068-018-1346-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/22/2018] [Indexed: 05/03/2023]
Abstract
BACKGROUND The forest biorefinery plays an important part in the evolving circular bioeconomy due to its capacity to produce a portfolio of bio-based and sustainable fuels, chemicals, and materials. To tap into its true potential, more efficient and environmentally benign methods are needed to fractionate woody biomass into its main components (cellulose, hemicellulose, and lignin) without reducing their potential for valorization. This work presents a sequential fractionation method for hardwood based on steam pretreatment (STEX) and hydrotropic extraction (HEX) with sodium xylene sulfonate. By prehydrolyzing the hemicellulose (STEX) and subsequently extract the lignin from the cellulose fraction (HEX), the major wood components can be recovered in separate process streams and be further valorized. RESULTS Using autocatalyzed STEX and HEX, hemicellulose (> 70%) and lignin (~ 50%) were successfully fractionated and recovered in separate liquid streams and cellulose preserved (99%) and enriched (~ twofold) in the retained solids. Investigation of pretreatment conditions during HEX showed only incremental effects of temperature (150-190 °C) and hold-up time (2-8 h) variations on the fractionation efficiency. The hydrolyzability of the cellulose-rich solids was analyzed and showed higher cellulose conversion when treated with the combined process (47%) than with HEX alone (29%), but was inferior to STEX alone (75%). Protein adsorption and surface structure analysis suggested decreased accessibility due to the collapse of the fibrillose cellulose structure and an increasingly hydrophobic lignin as potential reasons. CONCLUSION This work shows the potential of sequential STEX and HEX to fractionate and isolate cellulose, hemicellulose, and a sulfur-free lignin in separate product streams, in an efficient, sustainable, and scalable process.
Collapse
Affiliation(s)
- Johanna Olsson
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Vera Novy
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Fredrik Nielsen
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Ola Wallberg
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Mats Galbe
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| |
Collapse
|
7
|
Yuan Z, Li G, Hegg EL. Enhancement of sugar recovery and ethanol production from wheat straw through alkaline pre-extraction followed by steam pretreatment. Bioresour Technol 2018; 266:194-202. [PMID: 29982039 DOI: 10.1016/j.biortech.2018.06.065] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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: 05/30/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
To improve sugar recovery and ethanol production from wheat straw, a sequential two-stage pretreatment process combining alkaline pre-extraction and acid catalyzed steam treatment was investigated. The results showed that alkaline pre-extraction using 8% (w/w) sodium hydroxide at 80 °C for 90 min followed by steam pretreatment with 3% (w/w) sulfur dioxide at 151 °C for 16 min was sufficient to prepare a substrate that could be efficiently hydrolyzed at high solid loadings. Moreover, alkaline pre-extraction reduced the process severity of steam pretreatment and decreased the generation of inhibitory compounds. During enzymatic hydrolysis, increasing solid loading decreased the yield of monomeric sugars. Enzymatic hydrolysis at 25% (w/v) solid loading, the yields of approximately 80% of glucose and 65% of xylose could be reached with an enzyme dosage of 25 mg protein/g glucan. Following fermentation of hydrolysate with sugar concentration of approximately 120 g/L, an ethanol concentration of 54.5 g/L was achieved.
Collapse
Affiliation(s)
- Zhaoyang Yuan
- Department of Biochemistry & Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824, USA
| | - Guodong Li
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China.
| | - Eric L Hegg
- Department of Biochemistry & Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824, USA
| |
Collapse
|
8
|
Zhai R, Hu J, Saddler JN. Minimizing cellulase inhibition of whole slurry biomass hydrolysis through the addition of carbocation scavengers during acid-catalyzed pretreatment. Bioresour Technol 2018; 258:12-17. [PMID: 29518686 DOI: 10.1016/j.biortech.2018.02.124] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [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: 01/01/2018] [Revised: 02/25/2018] [Accepted: 02/26/2018] [Indexed: 05/20/2023]
Abstract
The aim of this work was to study how to minimize cellulase inhibition of whole slurry biomass hydrolysis through addition of carbocation scavengers during acid-catalyzed pretreatment. Various potential carbocation scavengers were compared and their inhibition mitigating effects towards the hydrolytic performance of cellulase enzymes was assessed. The results indicated that the addition of carbocation scavengers during the pretreatment process could not only alleviate the inhibitory effect of the phenolics on the enzymatic hydrolysis but also increase the accessibility of cellulases to the pretreated substrates. It appeared that lignin-derived compounds such as 4-hydroxybenzoic acid, vanillic acid, syringic acid could all serve as efficient scavengers to alleviate the inhibitory effect of phenolics on cellulose hydrolysis where the syringic acid showed the best mitigating effect. By combining the carbocation scavengers in the pretreatment process, an improved cellulose hydrolysis of the pretreated whole slurry could be achieved without any post detoxification step.
Collapse
Affiliation(s)
- Rui Zhai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China; Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada
| | - Jinguang Hu
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada.
| | - Jack N Saddler
- Forest Products Biotechnology and Bioenergy Group, Department of Wood Science, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada
| |
Collapse
|
9
|
Frankó B, Carlqvist K, Galbe M, Lidén G, Wallberg O. Removal of Water-Soluble Extractives Improves the Enzymatic Digestibility of Steam-Pretreated Softwood Barks. Appl Biochem Biotechnol 2018; 184:599-615. [PMID: 28808883 DOI: 10.1007/s12010-017-2577-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/02/2017] [Indexed: 11/25/2022]
Abstract
Softwood bark contains a large amounts of extractives—i.e., soluble lipophilic (such as resin acids) and hydrophilic components (phenolic compounds, stilbenes). The effects of the partial removal of water-soluble extractives before acid-catalyzed steam pretreatment on enzymatic digestibility were assessed for two softwood barks—Norway spruce and Scots pine. A simple hot water extraction step removed more than half of the water-soluble extractives from the barks, which improved the enzymatic digestibility of both steam-pretreated materials. This effect was more pronounced for the spruce than the pine bark, as evidenced by the 30 and 11% glucose yield improvement, respectively, in the enzymatic digestibility. Furthermore, analysis of the chemical composition showed that the acid-insoluble lignin content of the pretreated materials decreased when water-soluble extractives were removed prior to steam pretreatment. This can be explained by a decreased formation of water-insoluble “pseudo-lignin” from water-soluble bark phenolics during the acid-catalyzed pretreatment, which otherwise results in distorted lignin analysis and may also contribute to the impaired enzymatic digestibility of the barks. Thus, this study advocates the removal of extractives as the first step in the processing of bark or bark-rich materials in a sugar platform biorefinery.
Collapse
|
10
|
Tian D, Chandra RP, Lee JS, Lu C, Saddler JN. A comparison of various lignin-extraction methods to enhance the accessibility and ease of enzymatic hydrolysis of the cellulosic component of steam-pretreated poplar. Biotechnol Biofuels 2017; 10:157. [PMID: 28649276 PMCID: PMC5477284 DOI: 10.1186/s13068-017-0846-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND Current single-stage delignification-pretreatment technologies to overcome lignocellulosic biomass recalcitrance are usually achieved at the expense of compromising the recovery of the polysaccharide components, particularly the hemicellulose fraction. One way to enhance overall sugar recovery is to tailor an efficient two-stage pretreatment that can pre-extract the more labile hemicellulose component before subjecting the cellulose-rich residual material to a second-stage delignification process. Previous work had shown that a mild steam pretreatment could recover >65% of the hemicellulose from poplar while limiting the acid-catalysed condensation of lignin. This potentially allowed for subsequent lignin extraction using various lignin solvents to produce a more accessible cellulosic substrate. RESULTS A two-stage approach using steam and/or solvent pretreatment was assessed for its ability to separate hemicellulose and lignin from poplar wood chips while providing a cellulose-rich fraction that could be readily hydrolysed by cellulase enzymes. An initial steam-pretreatment stage was performed over a range of temperatures (160-200 °C) using an equivalent severity factor of 3.6. A higher steam temperature of 190 °C applied over a shorter residence time of 10 min effectively solubilized and recovered 75% of the hemicellulose while enhancing the ability of various solvents [deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone (soda/AQ) or a hydrotrope] to extract lignin in a second stage. When the second-stage treatments were compared, the mild DES treatment (lactic acid and betaine) at 130 °C, removed comparable amounts of lignin with higher selectivity than did the soda/AQ and organosolv pretreatments at 170 °C. However, the cellulose-rich substrates obtained after the second-stage organosolv and soda/AQ pretreatments showed the highest cellulose accessibility, as measured by the Simon's staining technique. They were also the most susceptible to subsequent enzymatic hydrolysis. CONCLUSIONS The second-stage pretreatments varied in their ability to solubilize and extract the lignin component of steam-pretreated poplar while enhancing the enzymatic hydrolysis of the resulting cellulose-rich residual fractions. Although DES extraction was more selective in extracting lignin from the steam-pretreated substrates, the organosolv and soda/AQ post treatments disrupted the cellulose structure to a greater extent while enhancing the ease of enzymatic hydrolysis. Graphical abstractEffective hemicellulose removal via steam pretreatment followed by subsequent lignin extraction under acidic, alkaline or solvolytic conditions results in a highly accessible, more readily hydrolysed cellulose fraction.
Collapse
Affiliation(s)
- Dong Tian
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4 Canada
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China
| | - Richard P. Chandra
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4 Canada
| | - Jin-Suk Lee
- Clean Fuel Department, Korea Institute of Energy Research, Jeongeup, Jeonbuk 580-185 South Korea
| | - Canhui Lu
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065 China
| | - Jack N. Saddler
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4 Canada
| |
Collapse
|
11
|
Bondesson PM, Galbe M. Process design of SSCF for ethanol production from steam-pretreated, acetic-acid-impregnated wheat straw. Biotechnol Biofuels 2016; 9:222. [PMID: 27777624 PMCID: PMC5070003 DOI: 10.1186/s13068-016-0635-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 10/07/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND Pretreatment is an important step in the production of ethanol from lignocellulosic material. Using acetic acid together with steam pretreatment allows the positive effects of an acid catalyst to be retained, while avoiding the negative environmental effects associated with sulphuric acid. Acetic acid is also formed during the pretreatment and hydrolysis of hemicellulose, and is a known inhibitor that may impair fermentation at high concentrations. The purpose of this study was to improve ethanol production from glucose and xylose in steam-pretreated, acetic-acid-impregnated wheat straw by process design of simultaneous saccharification and co-fermentation (SSCF), using a genetically modified pentose fermenting yeast strain Saccharomyces cerevisiae. RESULTS Ethanol was produced from glucose and xylose using both the liquid fraction and the whole slurry from pretreated materials. The highest ethanol concentration achieved was 37.5 g/L, corresponding to an overall ethanol yield of 0.32 g/g based on the glucose and xylose available in the pretreated material. To obtain this concentration, a slurry with a water-insoluble solids (WIS) content of 11.7 % was used, using a fed-batch SSCF strategy. A higher overall ethanol yield (0.36 g/g) was obtained at 10 % WIS. CONCLUSIONS Ethanol production from steam-pretreated, acetic-acid-impregnated wheat straw through SSCF with a pentose fermenting S. cerevisiae strain was successfully demonstrated. However, the ethanol concentration was too low and the residence time too long to be suitable for large-scale applications. It is hoped that further process design focusing on the enzymatic conversion of cellulose to glucose will allow the combination of acetic acid pretreatment and co-fermentation of glucose and xylose.
Collapse
Affiliation(s)
- Pia-Maria Bondesson
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Mats Galbe
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| |
Collapse
|
12
|
Chandra RP, Chu Q, Hu J, Zhong N, Lin M, Lee JS, Saddler J. The influence of lignin on steam pretreatment and mechanical pulping of poplar to achieve high sugar recovery and ease of enzymatic hydrolysis. Bioresour Technol 2016; 199:135-141. [PMID: 26391968 DOI: 10.1016/j.biortech.2015.09.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [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: 07/09/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 05/05/2023]
Abstract
With the goal of enhancing overall carbohydrate recovery and reducing enzyme loading refiner mechanical pulping and steam pretreatment (210°C, 5 min) were used to pretreat poplar wood chips. Neutral sulphonation post-treatment indicated that, although the lignin present in the steam pretreated substrate was less reactive, the cellulose-rich, water insoluble component was more accessible to cellulases and Simons stain. This was likely due to lignin relocation as the relative surface lignin measured by X-ray photoelectron spectroscopy increased from 0.4 to 0.8. The integration of sulphite directly into steam pretreatment resulted in the solubilisation of 60% of the lignin while more than 80% of the carbohydrate present in the original substrate was recovered in the water insoluble fraction after Na2CO3 addition. More than 80% of the sugars present in the original cellulose and xylan could be recovered after 48 h using an enzyme loading of 20 mg protein/g cellulose at a 10% substrate concentration.
Collapse
Affiliation(s)
- Richard P Chandra
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| | - QiuLu Chu
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| | - Jinguang Hu
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| | - Na Zhong
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| | - Mandy Lin
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| | - Jin-Suk Lee
- Clean Fuel Department, Korea Institute of Energy Research, Jeongeup, Jeonbuk 580-185, South Korea
| | - Jack Saddler
- Forest Products Biotechnology/Bioenergy Group, University of British Columbia, Faculty of Forestry, British Columbia, Canada
| |
Collapse
|
13
|
Vera RM, Bura R, Gustafson R. Synergistic effects of mixing hybrid poplar and wheat straw biomass for bioconversion processes. Biotechnol Biofuels 2015; 8:226. [PMID: 26705420 PMCID: PMC4690274 DOI: 10.1186/s13068-015-0414-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/09/2015] [Indexed: 05/27/2023]
Abstract
BACKGROUND Low cost of raw materials and good process yields are necessary for future lignocellulosic biomass biorefineries to be sustainable and profitable. A low cost feedstock will be diverse, changing as a function of seasonality and price and will most likely be available from multiple sources to the biorefinery. The efficacy of the bioconversion process using mixed biomass, however, has not been thoroughly investigated. Considering the seasonal availability of wheat straw and the year round availability of hybrid poplar in the Pacific Northwest, this study aims to determine the impact of mixing wheat straw and hybrid poplar biomass on the overall sugar production via steam pretreatment and enzymatic saccharification. RESULTS Steam pretreatment proved to be effective for processing different mixtures of hybrid poplar and wheat straw. Following SO2-catalyzed steam explosion pretreatment, on average 22 % more sugar monomers were recovered using mixed feedstock than either single biomass. Improved sugar recovery with mixtures of poplar and wheat straw continued through enzymatic hydrolysis. After steam pretreatment and saccharification, the mixtures showed 20 % higher sugar yields than that produced from hybrid poplar and wheat straw alone. CONCLUSIONS Blending hybrid poplar and wheat straw resulted in more monomeric sugar recovery and less sugar degradation. This synergistic effect is attributable to interaction of hybrid poplar's high acetic acid content and the presence of ash supplied by wheat straw. As a consequence on average 20 % more sugar was yielded by using the different biomass mixtures. Combining hybrid poplar and wheat straw enables sourcing of the lowest cost biomass, reduces seasonal dependency, and results in increasing biofuels and chemicals productivity in a cellulosic biorefinery.
Collapse
Affiliation(s)
- Rodrigo Morales Vera
- School of Environmental and Forest Sciences, University of Washington, Box 352100, Seattle, WA 98195-2100 USA
| | - Renata Bura
- School of Environmental and Forest Sciences, University of Washington, Box 352100, Seattle, WA 98195-2100 USA
| | - Rick Gustafson
- School of Environmental and Forest Sciences, University of Washington, Box 352100, Seattle, WA 98195-2100 USA
| |
Collapse
|
14
|
Chandra RP, Arantes V, Saddler J. Steam pretreatment of agricultural residues facilitates hemicellulose recovery while enhancing enzyme accessibility to cellulose. Bioresour Technol 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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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.
| |
Collapse
|
15
|
Olsen C, Arantes V, Saddler J. Optimization of chip size and moisture content to obtain high, combined sugar recovery after sulfur dioxide-catalyzed steam pretreatment of softwood and enzymatic hydrolysis of the cellulosic component. Bioresour Technol 2015; 187:288-298. [PMID: 25863206 DOI: 10.1016/j.biortech.2015.03.084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 02/10/2015] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 06/04/2023]
Abstract
The influence of chip size and moisture content on the combined sugar recovery after steam pretreatment of lodgepole pine and subsequent enzymatic hydrolysis of the cellulosic component were investigated using response surface methodology. Chip size had little influence on sugar recovery after both steam pretreatment and enzymatic hydrolysis. In contrast, the moisture of the chips greatly influenced the relative severity of steam pretreatment and, as a result, the combined sugar recovery from the hemicellulosic and cellulosic fractions. Irrespective of chip size and the pretreatment temperature, time, and SO2 loading that were used, the relative severity of pretreatment was highest at a moisture of 30-40w/w%. However, the predictive model indicated that an elevated moisture content of roughly 50w/w% (about the moisture content of a standard softwood mill chip) would result in the highest, combined sugar recovery (80%) over the widest range of steam pretreatment conditions.
Collapse
Affiliation(s)
- Colin Olsen
- Neucel Specialty Cellulose Ltd, PO Box 2000, 300 Marine Drive, Port Alice, BC V0N 2N0, Canada.
| | - Valdeir Arantes
- Lorena School of Engineering, University of São Paulo Estrada Municipal do Campinho s/n, CP 116, 12602-810 Lorena, SP, Brazil.
| | - Jack Saddler
- Forestry Products Biotechnology/Bioenergy Group, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada.
| |
Collapse
|
16
|
Frankó B, Galbe M, Wallberg O. Influence of bark on fuel ethanol production from steam-pretreated spruce. Biotechnol Biofuels 2015; 8:15. [PMID: 25705256 PMCID: PMC4336487 DOI: 10.1186/s13068-015-0199-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/07/2015] [Indexed: 05/13/2023]
Abstract
BACKGROUND Bark and bark-containing forest residues have the potential for utilization as raw material for lignocellulosic ethanol production due to their abundance and low cost. However, the different physical properties and chemical composition of bark compared to the conventionally used wood chips may influence the spruce-to-ethanol bioconversion process. This study assesses the impact of bark on the overall bioconversion in two process configurations, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF), utilizing steam-pretreated spruce bark and wood mixtures. RESULTS Mixtures of different proportions of spruce bark and wood chips were subjected to SO2-catalyzed steam pretreatment at 210°C for five minutes, which has been shown to be effective for the pretreatment of spruce wood chips. The final ethanol concentration was the highest without bark and decreased significantly with increasing proportions of bark in both process configurations. However, this decrease cannot be attributed solely to the lower availability of the carbohydrates in mixtures containing bark, as the ethanol yield also decreased, from 85 to 59% in SSF and from 84 to 51% in SHF, as the mass fraction of bark was increased from 0 to 100%. CONCLUSIONS The results show that it was significantly more difficult to hydrolyse spruce bark to monomeric sugars than wood chips. Bark had an adverse effect on the whole bioconversion process due to its lower enzymatic hydrolyzability. On the other hand, bark inclusion had no detrimental effect on the fermentability of steam-pretreated spruce wood and bark mixtures. It was also observed that lower amounts of inhibitory degradation products were formed during the steam pretreatment of spruce bark than during the steam pretreatment of wood chips.
Collapse
Affiliation(s)
- Balázs Frankó
- Department of Chemical Engineering, Lund University, PO Box 124, Getingevägen 60, Lund, SE-221 00 Sweden
| | - Mats Galbe
- Department of Chemical Engineering, Lund University, PO Box 124, Getingevägen 60, Lund, SE-221 00 Sweden
| | - Ola Wallberg
- Department of Chemical Engineering, Lund University, PO Box 124, Getingevägen 60, Lund, SE-221 00 Sweden
| |
Collapse
|
17
|
Kuglarz M, Gunnarsson IB, Svensson SE, Prade T, Johansson E, Angelidaki I. Ethanol production from industrial hemp: effect of combined dilute acid/ steam pretreatment and economic aspects. Bioresour Technol 2014; 163:236-43. [PMID: 24821202 DOI: 10.1016/j.biortech.2014.04.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 02/12/2014] [Revised: 04/14/2014] [Accepted: 04/16/2014] [Indexed: 05/23/2023]
Abstract
In the present study, combined steam (140-180°C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis and ethanol yields was also evaluated. Pretreatment with 1% sulfuric acid at 180°C resulted in the highest glucose yield (73-74%) and ethanol yield of 75-79% (0.38-0.40 g-ethanol/g-glucose). Taking into account the costs of biomass processing, from field to ethanol facility storage, the field-dried hemp pretreated at the optimal conditions showed positive economic results. The type of hemp cultivation (organic or conventional) did not influence significantly the effectiveness of the pretreatment as well as subsequent enzymatic hydrolysis and ethanol fermentation.
Collapse
Affiliation(s)
- Mariusz Kuglarz
- Faculty of Materials and Environmental Sciences, University of Bielsko-Biala, Willowa 2, 43-309 Bielsko-Biala, Poland
| | - Ingólfur B Gunnarsson
- Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800 Lyngby, Denmark
| | - Sven-Erik Svensson
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Box 103, SE-230 53 Alnarp, Sweden
| | - Thomas Prade
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Box 103, SE-230 53 Alnarp, Sweden
| | - Eva Johansson
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Box 101, SE-230 53 Alnarp, Sweden
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Building 113, DK-2800 Lyngby, Denmark.
| |
Collapse
|