Acid-catalyzed atmospheric glycerol organosolv pretreatment of sugarcane bagasse and its enzymatic hydrolysis

doi:10.16085/j.issn.1000-6613.2019-0207

Abstract

Abstract:

Pretreatment tends to disrupt the recalcitrant structure of lignocellulosic biomass consisting predominantly of cellulose, hemicellulose and lignin, thereby improving the enzymatic hydrolyzability of the substrate. To avoid too long pretreatment time during the current atmospheric glycerol organosolv pretreatment process, acid was taken as catalyst in the pretreatment process to shorten the pretreatment time. The acid-catalyzed atmospheric glycerol organosolv (ac-AGO) pretreatment was optimized by single factor selection and response surface Box-Behnken design optimization as below:pretreatment temperature 245℃, pretreatment time 38min, sulfuric acid addition 0.1% (mass yatio). Under optimized condition, the prediction value of 48h enzymatic hydrolysis yield was 94.0%, and the practical value was 91.4%. Results showed that the response surface optimization scheme and regression model was fit. The ac-AGO pretreatment significantly improved the substrate hydrolyzability. Enzymatic hydrolysis of substrate at high solid concentration (15%—20%) underlined the outstanding enzymatic hydrolysability of substrate, with 72h enzymatic hydrolysis yield being 60% and glucose titer being 83.4g/L at 20% of solid content and 5FPU/g dry substrate of the enzyme loading. The ac-AGO pretreatment can significantly improve the enzymatic hydrolysis of lignocellulose substrate, making it possible to afford downstream ethanol fermentation industry with high-titer fermentable sugars.

Key words: glycerol, organosolv pretreatment, acid catalysis, sugarcane bagasse, enzymatic hydrolysis

摘要：

预处理可以打破木质纤维素原料纤维素、半纤维素和木质素三大组分间的顽抗结构，从而提升纤维素基质可酶解性。本文针对目前常压甘油有机溶剂预处理花费时间过长的问题，尝试开展酸催化的常压甘油有机溶剂预处理研究以缩短预处理时间。实验通过单因素选择和响应面Box-Behnken设计优化，获得酸催化常压甘油有机溶剂预处理的最佳条件为：预处理温度245℃，预处理时间38min，硫酸添加质量0.1%。在此条件下获得基质48h酶解率的响应面预测值为94.0%，实际值为91.4%。结果表明响应面优化方案和回归模型适用于本实验，预处理显著提高了基质可酶解性。高浓度基质（15%～20%）酶解进一步证明了预处理后基质具有突出的可酶解性，20%浓度基质在酶载量5FPU/g干基质条件下批次酶解72h，酶解率达60%，葡萄糖浓度达83.4g/L。酸催化常压甘油有机溶剂酸预处理在明显缩短预处理时间的同时，能显著提高木质纤维素基质可酶解性，使后续工业化意义的浓醪酶解糖化成为可能。

关键词: 甘油, 有机溶剂预处理, 酸催化, 甘蔗渣, 酶解

CLC Number:

TQ35

Linqing YANG,Danlei MA,Fubao SUN,Cheng ZENG,Yanjun TANG,Haiyan SUN. Acid-catalyzed atmospheric glycerol organosolv pretreatment of sugarcane bagasse and its enzymatic hydrolysis[J]. Chemical Industry and Engineering Progress, 2019, 38(9): 4247-4254.

杨林青,马丹蕾,孙付保,曾诚,唐艳军,孙海彦. 甘蔗渣的酸催化常压甘油有机溶剂预处理及其酶解[J]. 化工进展, 2019, 38(9): 4247-4254.

Figures/Tables 10

References 31

1	生瑜, 颜荣宾, 朱德钦. 甘蔗渣纤维素提取分离技术进展[J]. 广州化工, 2016, 44(17): 5-7.
	SHENGYu, YANRongbin, ZHUDeqin. Progress in cellulose extraction and separation technology of sugarcane bagasse[J]. Guangzhou Chemical Industry, 2016, 44(17): 5-7.
2	符瑞华, 高俊永, 梁磊, 等. 甘蔗渣利用现状及致密成型研究发展[J].甘蔗糖业, 2013(2): 47-51.
3	FURuihua, GAOJunyong, LIANGLei, et al. Present situation of bagasse utilization and development of dense forming[J]. Sugarcane and Canesugar, 2013(2): 47-51.
4	刘海燕, 黄枭, 高星爱, 等. 农作物秸秆酶解制糖研究进展[J]. 江苏农业科学, 2014, 42(3): 10-12.
	LIUHaiyan, HUANGXiao, GAOXingai, et al. Research progress in enzymatic hydrolysis of crop straws[J]. Jiangsu Agricultural Sciences, 2014, 42(3): 10-12.
5	邢静润, 申锋, 仇茉, 等. NaOH/尿素冻融预处理纤维素及其酸催化水解[J].化工进展, 2018, 37(6): 2159-2165.
	XINGJingrun, SHENFeng, CHOU Mo, et al. NaOH/urea freeze-thaw pretreatment of cellulose and its acid-catalyzed hydrolysis[J]. Chemical Industry and Engineering Progress, 2018, 37(6): 2159-2165.
6	孙付保, 王亮, 谭玲, 等.木质纤维素糖平台基质组成结构的分析表征技术研究进展[J]. 化工进展, 2014, 33(4): 883-890.
	SUNFubao, WANGLiang, TANLing,et al. Advances in analytical characterization techniques of lignocellulosic sugar platform matrix structure[J]. Chemical Industry and Engineering Progress, 2014, 33(4): 883-890.
7	SUNF , CHENH. Organosolv pretreatment by crude glycerol from oleochemicals industry for enzymatic hydrolysis of wheat straw[J]. Bioresource Technology, 2008, 99(13): 5474-5479.
8	王亮, 刘建权, 张喆, 等. 常压甘油自催化预处理麦草浓醪发酵纤维素乙醇[J]. 生物工程学报, 2015, 31(10): 1468-1483.
	WANGLiang, LIUJianquan, ZHANGZhe, et al. Self-catalytic pretreatment of wheat straw concentrated fermented cellulosic ethanol with atmospheric pressure glycerol[J]. Chinese Journal of Biotechnology, 2015, 31(10): 1468-1483.
9	ELENAD, ALOIAR, JOSEL A, et al. A biorefinery approach based on fractionation with a cheap industrial by-product for getting value from an invasive woody species[J]. Bioresource Technology, 2014, 173: 301-308.
10	GURAGAINY N, DEC J, HUSSONF, et al. Comparison of some new pretreatment methods for second generation bioethanol production from wheat straw and water hyacinth[J]. Bioresour Technology, 2011, 102(6): 4416-4424.
11	HUNDTM, SCHNITZLEINK, SCHNITZLEINM G. Alkaline polyol pulping and enzymatic hydrolysis of softwood: effect of pulping severity and pulp properties on cellulase activity and overall sugar yield[J]. Bioresource Technology, 2013, 134(2): 307-315.
12	MARTINC, PULSJ, SAAKEB, et al. Effect of glycerol preatreatment on component recovery and enzymatic hydrolysis of sugarcane bagasse [J]. Cellulose Chemistry & Technology, 2011, 45(7): 487-494.
13	LISIASP N, LEANDROV A G, MARABEZIK , et al. Delignification of sugarcane bagasse using glycerol-water mixtures to produce pulps for saccharification[J]. Bioresource Technology, 2011, 102(21): 10040-10046.
14	ROMANIA, RUIZH A, PEREIRAF B, et al. Fractionation of eucalyptus globulus wood by glycerol-water pretreatment: optimization and modeling [J]. Industrial & Engineering Chemistry Research, 2013, 52(40): 14342-14352.
15	ZHANGZ, WONGH H, ALBERTSONP L, et al. Laboratory and pilot scale pretreatment of sugarcane bagasse by acidified aqueous glycerol solution[J]. Bioresource Technology, 2013, 138(6): 14-21.
16	SLUIITERA, HAMESB, RUIZR, et al. Determination of structural carbohydrates and lignin in biomass[M]. Golden, Colo:National Renewable Energy Laboratory,2008: 530-537.
17	GHOSET. Measurement of cellulase activities [J]. Pure and Applied Chemistry, 1987, 59(2): 257-268.
18	洪嘉鹏, 岳春, 赵晓琴, 等. 常压甘油有机溶剂预处理甘蔗渣的浓醪酶解[J]. 食品与发酵工业, 2017,43(10): 41-47.
	HONGJiapeng, YUEChun, ZHAOXiaoqin, et al. Preconcentration enzymatic hydrolysis of sugarcane bagasse by atmospheric pressure glycerol organic solvent[J]. Food and Fermentation Industries, 2017,43(10): 41-47.
19	TANS S Y, MACFARLANED R, UPFALJ, et al. Extraction of lignin from lignocellulose at atmospheric pressure using alkylbenzenesulfonate ionic liquid[J]. Green Chemistry, 2009, 11(3): 339.
20	亢能. 木质纤维原料预处理技术的进展与展望[J]. 吉林农业, 2015(11): 118-119.
	KANGNeng. Progress and prospect of pretreatment technology of lignocellulosic materials[J]. Jilin Agriculture, 2015(11): 118-119.
21	陈倩, 陈京环, 王堃, 等. 热水预处理生物质原料及其生物转化研究进展[J]. 林业科学, 2017, 53(9): 97-104.
	CHENQian, CHENJinghuan, WANGKun, et al. Research progress on hot water pretreatment of biomass feedstock and its biotransformation[J]. Forestry Science, 2017, 53(9): 97-104.
22	谢慧, 张东, 张兆昆, 等. 稀酸和蒸汽爆破预处理玉米秸秆对琥珀酸发酵的影响[J]. 食品与发酵工业, 2018, 44(5): 57-62.
	XIEHui, ZHANGDong, ZHANGZhaokun, et al. Effect of pretreatment of corn stover with dilute acid and steam explosion on succinic acid fermentation[J]. Food and Fermentation Industries, 2018, 44(5): 57-62.
23	余洪波, 张晓昱, 柯静, 等. 生物-碱氧化预处理玉米秸秆酶解条件的优化[J]. 农业工程学报, 2009, 25(4): 201-205.
	YUHongbo, ZHANGXiaoyu, KEJing, et al. Optimization of enzymatic hydrolysis conditions of corn-stalks pretreated by bio-alkali oxidation[J]. Transactions of the Chinese Society of Agricultural Engineering, 2009, 25(4): 201-205.
24	GREGGD J, SADDLERJ N. Factors affecting cellulose hydrolysis and the potential of enzyme recycle to enhance the efficiency of an integrated wood to ethanol process[J]. Biotechnology and Bioengineering, 2015, 51(4): 375-383.
25	ZHANGX, QINW, PAICEM G, et al. High consistency enzymatic hydrolysis of hardwood substrates[J].Bioresource Technology, 2009, 100(23): 5890-5897.
26	SUNF F, ZHAOX, HONGJ, et al. Industrially relevant hydrolyzability and fermentability of sugarcane bagasse improved effectively by glycerol organosolv pretreatment[J]. Biotechnology for Biofuels, 2016, 9(1): 59-62.
27	郑志, 李超孟, 杨培周, 等. 不同预处理对玉米芯酶解特性和形态结构的影响研究[J]. 可再生能源, 2012, 30(3): 43-48.
	ZHENGZhi, LIChaomeng, YANGPeizhou,et al. Effects of different pretreatments on enzymatic hydrolysis characteristics and morphological structure of corncobs[J]. Renewable Energy, 2012, 30(3): 43-48.
28	邓学群, 仲兆平, 艾特玲. 硫酸-乙醇预处理玉米芯制取生物乙醇研究[J]. 安全与环境学报, 2016, 16(2): 237-241.
	DENGXuequn, ZHONGZhaoping, AITeling. Study on preparation of bioethanol from corncob by pretreatment of sulfuric acid-ethanol[J]. Journal of Safety and Environment, 2016, 16(2): 237-241.
29	ZHANGZ, OHARAI M, DOHERTYW O S. Pretreatment of sugarcane bagasse by acid-catalysed process in aqueous ionic liquid solutions[J]. Bioresource Technology, 2012, 120(3): 149-156.
30	DEMIRBAA. Aqueous glycerol delignification of wood chips and ground wood[J]. Bioresource Technology, 1998, 63(2): 179-185.
31	HARRISONM D, ZHANGZ, SHNDK, et al. Effect of pretreatment on saccharification of sugarcane bagasse by complex and simple enzyme mixtures[J]. Bioresource Technology, 2013, 148(7): 105-113.

预处理条件		预处理量/%	三大组分含量/%			48h酶解率/%
温度/加酸量	时间 /min	预处理量/%	纤维素	半纤维素	木质素	48h酶解率/%
230℃/0.1%	10	60.0	49.5	12.2	25.1	56.6
	30	58.0	50.3	10.6	24.1	80.9
	60	56.0	55.1	8.1	23.1	61.7
	90	48.1	54.3	6.3	21.8	55.3

预处理条件		预处理量/%	三大组分含量/%			48h酶解率/%
温度/加酸量	时间 /min	预处理量/%	纤维素	半纤维素	木质素	48h酶解率/%
230℃/0.1%	10	60.0	49.5	12.2	25.1	56.6
	30	58.0	50.3	10.6	24.1	80.9
	60	56.0	55.1	8.1	23.1	61.7
	90	48.1	54.3	6.3	21.8	55.3

加酸量/%	预处理量/%	三大组分含量/%			48h酶解率/%
加酸量/%	预处理量/%	纤维素	半纤维素	木质素	48h酶解率/%
0.01	67.0	45.7	19.3	24.8	62.4
0.05	58.3	46.9	13.8	25.9	63.6
0.10	58.0	50.3	10.6	24.1	80.9
0.15	51.1	43.4	3.9	26.8	57.3
0.20	49.0	44.2	1.2	23.6	50.3

加酸量/%	预处理量/%	三大组分含量/%			48h酶解率/%
加酸量/%	预处理量/%	纤维素	半纤维素	木质素	48h酶解率/%
0.01	67.0	45.7	19.3	24.8	62.4
0.05	58.3	46.9	13.8	25.9	63.6
0.10	58.0	50.3	10.6	24.1	80.9
0.15	51.1	43.4	3.9	26.8	57.3
0.20	49.0	44.2	1.2	23.6	50.3

温度/℃	预处理量 /%	三大组分含量/%			48h酶解率/%
温度/℃	预处理量 /%	纤维素	半纤维素	木质素	48h酶解率/%
160	83.0	40.5	22.2	24.5	34.8
190	68.0	46.7	16.2	20.0	46.8
210	63.2	49.7	13.7	25.5	55.0
230	58.0	50.3	10.1	24.1	80.9
260	48.0	56.0	3.7	23.4	73.5