温和条件下乙二醇苯醚高效分离回收甘蔗渣组分

doi:10.11949/0438-1157.20240049

摘要/Abstract

摘要：

使用酸性乙二醇苯醚体系对甘蔗渣进行预处理，在最优条件下（110 ℃、0.05 M H₂SO₄，60 min）实现了90.47 %的纤维素保留率，去除了90.33 %的木质素和76.70 %的半纤维素。回收得到的富含纤维素的残渣最高酶解率为89.71%，较未经处理的甘蔗渣的酶解率（15.93%）提高了近6倍。用异丙醚从预处理液中回收了74.29%的木质素（纯度为93.53%）。使用SEM、XRD、FTIR对预处理后残渣及原料的组成及结构进行表征，发现甘蔗渣的形貌结构被破坏，结晶度提高，因而酶解率大幅度提高。通过2D HSQC表征发现在预处理过程中乙二醇苯醚和木质素的醚化反应抑制了木质素的缩合。本研究建立了酸性乙二醇苯醚预处理体系，实现了甘蔗渣组分的高效分离，并高效回收高纯木质素与可发酵糖，可为生物质高值化利用提供参考。

关键词: 生物质, 生物分离, 预处理, 酶解, 木质素, 生物能源

Abstract:

In this study, efficient fractionation of sugarcane bagasse (SCB) with acidified phenoxyethanol (EPH) was investigated. High lignin (90.33%) and hemicellulose (76.70%) removal efficiency with 90.47% cellulose retention was achieved using EPH at 110℃, 60 min, with 0.05 M acid loading for SCB. The enzymatic digestibility of residue reached 89.71%, which was nearly 6 times higher than that of the untreated sugarcane bagasse (15.93%). 74.29% lignin of 93.52% purification was recovered from the pretreatment solution with isopropyl ether. Basing on the analyzing and testing the composition and structure with scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FTIR), it was found that the morphological structure of bagasse was destroyed, the crystallinity was improved, and the enzymatic digestibility was greatly improved. Additionally, the etherification of phenoxyethanol and lignin to suppress the condensation of lignin was disclosed by 2D HSQC characterization. Overall, EPH pretreatment achieved efficient fractionation and recovery of high purity lignin and fermentable sugars under mild condition from sugarcane bagasse. This study can provide reference for the high-value utilization of lignocellulosic biomass.

Key words: biomass, bioseparation, pretreatment, enzymatic hydrolysis, lignin, bioenergy

中图分类号:

TK 6

张祎琪, 谭雪松, 李吾环, 张权, 苗长林, 庄新姝. 温和条件下乙二醇苯醚高效分离回收甘蔗渣组分[J]. 化工学报, DOI: 10.11949/0438-1157.20240049.

Yiqi ZHANG, Xuesong TAN, Wuhuan LI, Quan ZHANG, Changlin MIAO, Xinshu ZHUANG. Efficient fractionation of sugarcane bagasse with phenoxyethanol under mild condition[J]. CIESC Journal, DOI: 10.11949/0438-1157.20240049.

图/表 10

表1 不同温度下乙二醇苯醚预处理甘蔗渣的效果和酶解率

Table 1 Effect and cellulose enzymatic digestibility of sugarcane bagasse after EPH pretreatment under different temperature

温度/℃	酸度/mol/L	时间/min	纤维素保留率/%	半纤维素去除率/%	木质素去除率/%	残渣保留率/%	酶解率/%
70	0.05	60	97.89	1.06	3.41	95.23	18.89
90	0.05	60	92.72	28.16	22.77	78.09	29.73
110	0.05	60	90.47	76.70	90.33	48.54	72.79
130	0.05	60	87.04	100.00	92.68	40.17	76.15

表2 不同有机溶剂预处理甘蔗渣的酶解率比较

Table 2 Comparison of enzymatic hydrolysis of sugarcane bagasse with different Organic solvent pretreatment

有机溶剂	催化剂	温度/℃	时间/min	酶解率/%	参考文献
乙二醇苯醚	硫酸	110	60	89.71	本文
乙二醇苯醚/丙酮/水	硫酸	125	120	74.52	Li 等^[19]
60 %乙醇	FeCl₃	160	60	93.80	Zhang 等^[20]
水/乙醇/乙酸乙酯/甲酸	甲酸	159	40	84.50	Suriyachai 等^[21]
甘油	硫酸	200	15	70.00	Pascal等^[22]

图1 原料（a, c）和预处理残渣（b, d）的SEM图

Fig. 1 SEM images of the raw material (a, c); pretreated residue (b, d)

图2 原料和预处理残渣的红外光谱图

Fig. 2 FTIR spectrum of the raw material and residue

图3 原料和预处理残渣的X射线衍射谱图

Fig. 3 X-ray diffraction pattern of the raw material and residue

图4 CEL (a)和(c)、EPHL (b)和(d)的二维HSQC NMR谱中的侧链区域（δC/δH 45-95/2.5-6.0）和芳香族区域（δC/δH 95-140/6.0-8.5）

Fig. 4 Side chain region (δC/δH 45–95/2.5–6.0) and aromatic region (δC/δH 95–140/6.0–8.5) in 2D HSQC NMR spectra of CEL(a) and(c), and EPHL(b)and(d).

表 3 CEL和EPHL二维HSQC核磁共振光谱中芳香族和脂肪族区域的半定量分析

Table 3 Semi-quantitative analysis of aromatic and aliphatic regions in the 2D HSQC NMR spectra of CEL and EPHL

木质素结构单元和基本连接键	CEL	EPHL
S (%)	30.78	20.96
G (%)	69.22	79.04
S/G	0.445	0.265
β-O-4 (%)	53.82	19.71
β-β (%)	7.12	4.41

图5 CEL和EPHL芳香区域和侧链区域的基本连接键及木质素结构单元

Fig. 5 Main interunit linkages and lignin subunits of aromatic and side chain regions of CEL and EPHL

图6 CEL和EPHL的红外光谱图

Fig. 6 FTIR spectrum of the CEL and EPHL

图7 乙二醇苯醚预处理物料平衡图

Fig. 7 Mass balance analysis of EPH pretreatment

参考文献 38

1	Liu W, Ning C X, Li Z, et al. Revealing structural features of lignin macromolecules from microwave-assisted carboxylic acid-based deep eutectic solvent pretreatment[J]. Industrial Crops and Products, 2023, 194: 116342.
2	Shen G N, Yuan X C, Cheng Y, et al. Densification pretreatment with a limited deep eutectic solvent triggers high-efficiency fractionation and valorization of lignocellulose[J]. Green Chemistry, 2023, 25(20): 8026-8039.
3	Constant S, Wienk H L J, Frissen A E, et al. New insights into the structure and composition of technical lignins: a comparative characterisation study[J]. Green Chemistry, 2016, 18(9): 2651-2665.
4	Zeng Y N, Zhao S, Yang S H, et al. Lignin plays a negative role in the biochemical process for producing lignocellulosic biofuels[J]. Current Opinion in Biotechnology, 2014, 27: 38-45.
5	Madadi M, Elsayed M, Song G J, et al. Biphasic lignocellulose fractionation for staged production of cellulose nanofibers and reactive lignin nanospheres: a comparative study on their microstructures and effects as chitosan film reinforcing[J]. Chemical Engineering Journal, 2023, 465: 142881.
6	Zhu J J, Zhang H, Jiao N X, et al. Fractionation of poplar using hydrothermal and acid hydrotropic pretreatments for co-producing xylooligosaccharides, fermentable sugars, and lignin nanoparticles[J]. Industrial Crops and Products, 2022, 181: 114853.
7	Rajan K, Kim K, Elder T J, et al. Ionic-liquid-assisted fabrication of lignocellulosic thin films with tunable hydrophobicity[J]. ACS Sustainable Chemistry & Engineering, 2022, 10(27): 8835-8845.
8	Wu R J, Li Y Z, Wang X D, et al. In-situ lignin sulfonation for enhancing enzymatic hydrolysis of poplar using mild organic solvent pretreatment[J]. Bioresource Technology, 2023, 369: 128410.
9	Han S M, Wang R Z, Wang K, et al. Low-condensed lignin and high-purity cellulose production from poplar by synergistic deep eutectic solvent-hydrogenolysis pretreatment[J]. Bioresource Technology, 2022, 363: 127905.
10	Tsegaye B, Balomajumder C, Roy P. Organosolv pretreatments of rice straw followed by microbial hydrolysis for efficient biofuel production[J]. Renewable Energy, 2020, 148: 923-934.
11	Wang B, Sun D, Wang H M, et al. Green and facile preparation of regular lignin nanoparticles with high yield and their natural broad-spectrum sunscreens[J]. ACS Sustainable Chemistry & Engineering, 2019, 7(2): 2658-2666.
12	Smit A, Huijgen W. Effective fractionation of lignocellulose in herbaceous biomass and hardwood using a mild acetone organosolv process[J]. Green Chemistry, 2017, 19(22): 5505-5514.
13	Zhang Q, Dai C X, Tan X S, et al. Biphasic fractionation of lignocellulosic biomass based on the combined action of pretreatment severity and solvent effects on delignification[J]. Bioresource Technology, 2023, 369: 128477.
14	Chen J Z, Tan X S, Miao C L, et al. A one-step deconstruction-separation organosolv fractionation of lignocellulosic biomass using acetone/phenoxyethanol/water ternary solvent system[J]. Bioresource Technology, 2021, 342: 125963.
15	Meng X Z, Pu Y Q, Li M, et al. A biomass pretreatment using cellulose-derived solvent Cyrene[J]. Green Chemistry, 2020, 22(9): 2862-2872.
16	Sluiter A, Hames B, Ruiz R, et al. Determination of. structural carbohydrates and lignin in biomass[J]. Laboratory analytical procedure, 2008, 1617(1): 1-15.
17	Salem K S, Kasera N K, Rahman M A, et al. Comparison and assessment of methods for cellulose crystallinity determination[J]. Chemical Society Reviews, 2023, 52(18): 6417-6446.
18	Ioelovich M, Morag E. Effect of cellulose structure on enzymatic hydrolysis[J]. BioResources, 2011, 6(3): 2818-2835.
19	Li W H, Tan X S, Miao C L, et al. Mild organosolv pretreatment of sugarcane bagasse with acetone/phenoxyethanol/water for enhanced sugar production[J]. Green Chemistry, 2023, 25(3): 1169-1178.
20	Zhang H D, Zhang S S, Yuan H Y, et al. FeCl₃-catalyzed ethanol pretreatment of sugarcane bagasse boosts sugar yields with low enzyme loadings and short hydrolysis time[J]. Bioresource Technology, 2018, 249: 395-401.
21	Suriyachai N, Champreda V, Kraikul N, et al. Fractionation of lignocellulosic biopolymers from sugarcane bagasse using formic acid-catalyzed organosolv process[J]. 3 Biotech, 2018, 8(5): 221.
22	Pascal K, Ren H Y, Sun F F, et al. Mild acid-catalyzed atmospheric glycerol organosolv pretreatment effectively improves enzymatic hydrolyzability of lignocellulosic biomass[J]. ACS Omega, 2019, 4(22): 20015-20023.
23	Jeong S Y, Lee J W. Optimization of pretreatment condition for ethanol production from oxalic acid pretreated biomass by response surface methodology[J]. Industrial Crops and Products, 2016, 79: 1-6.
24	Li S X, Li M F, Yu P, et al. Valorization of bamboo by γ-valerolactone/acid/water to produce digestible cellulose, degraded sugars and lignin[J]. Bioresource Technology, 2017, 230: 90-96.
25	Song G J, Sun C H, Hu Y, et al. Construction of anhydrous two-step organosolv pretreatment of lignocellulosic biomass for efficient lignin membrane-extraction and solvent recovery[J]. Journal of Physics: Energy, 2023, 5(1): 014015.
26	Pan Z Y, Liu X Y, Zhang Z Y, et al. Low-temperature pretreatment by AlCl₃-catalyzed 1, 4-butanediol solution for producing 'ideal' lignin with super-high content of β-O-4 linkages[J]. International Journal of Biological Macromolecules, 2023, 253(Pt 6): 127306.
27	del Río J C, Lino A G, Colodette J L, et al. Differences in the chemical structure of the lignins from sugarcane bagasse and straw[J]. Biomass and Bioenergy, 2015, 81: 322-338.
28	Nge T T, Tobimatsu Y, Takahashi S, et al. Isolation and characterization of polyethylene glycol (PEG)-modified glycol lignin via PEG solvolysis of softwood biomass in a large-scale batch reactor[J]. ACS Sustainable Chemistry & Engineering, 2018, 6(6): 7841-7848.
29	Fan D, Xie X Y, Li C X, et al. Extraction of noncondensed lignin from poplar sawdusts with p-toluenesulfonic acid and ethanol[J]. Journal of Agricultural and Food Chemistry, 2021, 69(37): 10838-10847.
30	Wu Y L, Cheng J R, Yang Q, et al. Solid acid facilitated deep eutectic solvents extraction of high-purity and antioxidative lignin production from poplar wood[J]. International Journal of Biological Macromolecules, 2021, 193(Pt A): 64-70.
31	Zijlstra D S, de Santi A, Oldenburger B, et al. Extraction of lignin with high β-O-4 content by mild ethanol extraction and its effect on the depolymerization yield[J]. Journal of Visualized Experiments, 2019(143): 30663678.
32	Varanasi P, Singh P, Arora R, et al. Understanding changes in lignin of Panicum virgatum and Eucalyptus globulus as a function of ionic liquid pretreatment[J]. Bioresource Technology, 2012, 126: 156-161.
33	Shen X J, Wen J L, Mei Q Q, et al. Facile fractionation of lignocelluloses by biomass-derived deep eutectic solvent (DES) pretreatment for cellulose enzymatic hydrolysis and lignin valorization[J]. Green Chemistry, 2019, 21(2): 275-283.
34	Ji H R, Song Y L, Zhang X, et al. Using a combined hydrolysis factor to balance enzymatic saccharification and the structural characteristics of lignin during pretreatment of Hybrid poplar with a fully recyclable solid acid[J]. Bioresource Technology, 2017, 238: 575-581.
35	Suzuki K, Katayama K, Sumii Y, et al. Vibrational analysis of acetylcholine binding to the M₂ receptor[J]. RSC Advances, 2021, 11(21): 12559-12567.
36	Yao L, Yoo C G, Meng X Z, et al. A structured understanding of cellobiohydrolase I binding to poplar lignin fractions after dilute acid pretreatment[J]. Biotechnology for Biofuels, 2018, 11: 96.
37	Madadi M, Bakr M M A, Song G J, et al. Co-production of levulinic acid and lignin adsorbent from aspen wood with combination of liquid hot water and green-liquor pretreatments[J]. Journal of Cleaner Production, 2022, 366: 132817.
38	Madadi M, Zahoor, Song G J, et al. One-step lignocellulose fractionation using acid/pentanol pretreatment for enhanced fermentable sugar and reactive lignin production with efficient pentanol retrievability[J]. Bioresource Technology, 2022, 359: 127503.

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