Chundawat Shishir P S, Pal Ramendra K, Zhao Chao, Campbell Timothy, Teymouri Farzaneh, Videto Josh, Nielson Chandra, Wieferich Bradley, Sousa Leonardo, Dale Bruce E, Balan Venkatesh, Chipkar Sarvada, Aguado Jacob, Burke Emily, Ong Rebecca G
Department of Chemical and Biochemical Engineering, Rutgers-State University of New Jersey;
Department of Chemical and Biochemical Engineering, Rutgers-State University of New Jersey.
J Vis Exp. 2020 Apr 18(158). doi: 10.3791/57488.
Lignocellulosic materials are plant-derived feedstocks, such as crop residues (e.g., corn stover, rice straw, and sugar cane bagasse) and purpose-grown energy crops (e.g., miscanthus, and switchgrass) that are available in large quantities to produce biofuels, biochemicals, and animal feed. Plant polysaccharides (i.e., cellulose, hemicellulose, and pectin) embedded within cell walls are highly recalcitrant towards conversion into useful products. Ammonia fiber expansion (AFEX) is a thermochemical pretreatment that increases accessibility of polysaccharides to enzymes for hydrolysis into fermentable sugars. These released sugars can be converted into fuels and chemicals in a biorefinery. Here, we describe a laboratory-scale batch AFEX process to produce pretreated biomass on the gram-scale without any ammonia recycling. The laboratory-scale process can be used to identify optimal pretreatment conditions (e.g., ammonia loading, water loading, biomass loading, temperature, pressure, residence time, etc.) and generates sufficient quantities of pretreated samples for detailed physicochemical characterization and enzymatic/microbial analysis. The yield of fermentable sugars from enzymatic hydrolysis of corn stover pretreated using the laboratory-scale AFEX process is comparable to pilot-scale AFEX process under similar pretreatment conditions. This paper is intended to provide a detailed standard operating procedure for the safe and consistent operation of laboratory-scale reactors for performing AFEX pretreatment of lignocellulosic biomass.
木质纤维素材料是植物衍生的原料，如作物残渣（例如玉米秸秆、稻草和甘蔗渣）以及专门种植的能源作物（例如芒草和柳枝稷），这些原料大量可得，可用于生产生物燃料、生物化学品和动物饲料。嵌入细胞壁中的植物多糖（即纤维素、半纤维素和果胶）极难转化为有用的产品。氨纤维膨胀（AFEX）是一种热化学预处理方法，可提高多糖对酶的可及性，以便水解成可发酵糖。这些释放出的糖可以在生物精炼厂中转化为燃料和化学品。在此，我们描述了一种实验室规模的间歇式AFEX工艺，用于在不进行任何氨循环的情况下以克级规模生产预处理生物质。该实验室规模的工艺可用于确定最佳预处理条件（例如氨负载量、水负载量、生物质负载量、温度、压力、停留时间等），并生成足够数量的预处理样品，用于详细的物理化学表征以及酶促/微生物分析。在相似的预处理条件下，使用实验室规模的AFEX工艺预处理的玉米秸秆经酶水解后可发酵糖的产量与中试规模的AFEX工艺相当。本文旨在为进行木质纤维素生物质AFEX预处理的实验室规模反应器的安全和一致操作提供详细的标准操作程序。
