Kundu Chandan, Samudrala Shanthi Priya, Kibria Mahmud Arman, Bhattacharya Sankar
Department of Chemical Engineering, Monash University, Melbourne, 3800, Australia.
Sci Rep. 2021 May 27;11(1):11183. doi: 10.1038/s41598-021-90667-9.
Lignocellulosic biomass is an attractive renewable resource to produce biofuel or platform chemicals. Efficient and cost-effective conversion systems of lignocellulosic biomass depend on their appropriate pretreatment processes. Alkali or dilute acid pretreatment of biomass requires a high temperature (> 150 °C) to remove xylan (hemicellulosic sugar) and lignin partially. In this study, peracetic acid was used to pretreat biomass feedstocks, including hardwood and softwood species. It was found that the thermally-assisted dilute acid pretreatment of biomass conducted under the mild temperature of 90 °C up to 5 h resulted in the effective removal of lignin from the biomass with a negligible loss of carbohydrates. This thermally-assisted pretreatment achieved 90% of delignification, and this result was compared with the microwave-assisted pretreatment method. In addition, the crystallinity index (CrI), surface morphology, and chemical structure were significantly changed after the acid pretreatment. The biomass digestibility increased significantly with increased reaction time, by 32% and 23% for hardwood and softwood, respectively. From this study, it is clear that peracetic acid pretreatment is an effective method to enrich glucan content in biomass by delignification.
木质纤维素生物质是一种有吸引力的可再生资源，可用于生产生物燃料或平台化学品。木质纤维素生物质的高效且具有成本效益的转化系统取决于其适当的预处理过程。生物质的碱预处理或稀酸预处理需要高温（>150°C）来部分去除木聚糖（半纤维素糖）和木质素。在本研究中，过氧乙酸用于预处理生物质原料，包括硬木和软木种类。结果发现，在90°C的温和温度下进行长达5小时的生物质热辅助稀酸预处理，能够有效去除生物质中的木质素，而碳水化合物的损失可忽略不计。这种热辅助预处理实现了90%的脱木质素率，并将该结果与微波辅助预处理方法进行了比较。此外，酸预处理后，结晶度指数（CrI）、表面形态和化学结构发生了显著变化。随着反应时间的增加，生物质的消化率显著提高，硬木和软木分别提高了32%和23%。从这项研究可以清楚地看出，过氧乙酸预处理是一种通过脱木质素来富集生物质中葡聚糖含量的有效方法。
