Li Xun, Shu Fengyao, He Chao, Liu Shuna, Leksawasdi Noppol, Wang Qiong, Qi Wei, Alam Md Asraful, Yuan Zhenhong, Gao Yi
Changsha University of Science and Technology Changsha 410004 China.
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640 China
RSC Adv. 2018 Mar 19;8(20):10922-10929. doi: 10.1039/c7ra13362f. eCollection 2018 Mar 16.
Saccharification of lignocellulose is a necessary procedure for deconstructing the complex structure for building a sugar platform that can be used for producing biofuel and high-value chemicals. In this study, a carbon-based solid acid catalyst derived from sodium lignosulfonate, a waste by-product from the paper industry, was successfully prepared and used for the hydrolysis of hemicellulose in corncob. The optimum preparation conditions for the catalyst were determined to be carbonization at 250 °C for 6 h, followed by sulfonation with concentrated HSO (98%) and oxidation with 10% HO (solid-liquid ratio of 1 : 75 g mL) at 50 °C for 90 min. SEM, XRD, FT-IR, elemental analysis and acid-base titration were used for the characterization of the catalysts. It was found that 0.68 mmol g SOH and 4.78 mmol g total acid were loaded onto the catalyst. When corncob was hydrolyzed by this catalyst at 130 °C for 12 h, the catalyst exhibited high selectivity and produced a relatively high xylose yield of up to 84.2% (w/w) with a few by-products. Under these conditions, the retention rate of cellulose was 82.5%, and the selectivity reached 86.75%. After 5 cycles of reuse, the catalyst still showed high catalytic activity, with slightly decreased yields of xylose from 84.2% to 70.7%.
木质纤维素的糖化是解构复杂结构以构建可用于生产生物燃料和高价值化学品的糖平台的必要步骤。在本研究中，成功制备了一种由造纸工业的废弃副产物木质素磺酸钠衍生的碳基固体酸催化剂，并将其用于玉米芯中半纤维素的水解。确定该催化剂的最佳制备条件为在250℃碳化6小时，随后用浓硫酸（98%）磺化，并在50℃下用10%过氧化氢（固液比为1:75 g/mL）氧化90分钟。使用扫描电子显微镜（SEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、元素分析和酸碱滴定对催化剂进行表征。结果发现，催化剂上负载了0.68 mmol/g的磺酸基（SOH）和4.78 mmol/g的总酸。当用该催化剂在130℃水解玉米芯12小时时，催化剂表现出高选择性，产生了相对较高的木糖产率，高达84.2%（w/w），且副产物较少。在这些条件下，纤维素的保留率为82.5%，选择性达到86.75%。经过5次重复使用后，催化剂仍表现出高催化活性，木糖产率略有下降，从84.2%降至70.7%。
