Department of Chemical and Biomolecular Engineering, Olin Hall, Cornell University, Ithaca, New York 14853, USA.
Biotechnol Bioeng. 2012 Jun;109(6):1499-507. doi: 10.1002/bit.24417. Epub 2012 Jan 7.
Most biomass pretreatment processes for monosaccharide production are run at low-solid concentration (<10 wt%) and use significant amounts of chemical catalysts. Biphasic CO(2) -H(2) O mixtures could provide a more sustainable pretreatment medium while using high-solid contents. Using a stirred reactor for high solids (40 wt%, biomass water mixture) biphasic CO(2)-H(2) O pretreatment of lignocellulosic biomass allowed us to explore the effects of particle size and mixing on mixed hardwood and switchgrass pretreatment. Subsequently, a two-temperature stage pretreatment was introduced. After optimization, a short high-temperature stage at 210°C (16 min for hardwood and 1 min for switchgrass) was followed by a long low-temperature stage at 160°C for 60 min. Glucan to glucose conversion yields of 83% for hardwood and 80% for switchgrass were obtained. Total molar sugar yields of 65% and 55% were obtained for wood and switchgrass, respectively, which consisted of a 10% points improvement over those obtained during our previous study despite a 10-fold increase in particle size. These yields are similar to those obtained with other major pretreatment technologies for wood and within 10% of major technologies for switchgrass despite the absence of chemical catalysts, the use of large particles (0.95 cm) and high solid contents (40 wt%).
大多数用于生产单糖的生物质预处理工艺都是在低固含量（<10wt%）下进行的，并使用大量的化学催化剂。两相 CO(2)-H(2)O 混合物可以提供一种更可持续的预处理介质，同时使用高固含量。在高固含量（40wt%，生物质水混合物）下使用搅拌反应器进行两相 CO(2)-H(2)O 预处理木质纤维素生物质，使我们能够探索颗粒大小和混合对混合硬木和柳枝稷预处理的影响。随后，引入了两段式预处理。经过优化，在 210°C 下进行短暂的高温段（硬木 16 分钟，柳枝稷 1 分钟），然后在 160°C 下进行长时间的低温段 60 分钟。硬木的葡萄糖到葡萄糖转化率为 83%，柳枝稷为 80%。分别获得木本和柳枝稷的总摩尔糖收率为 65%和 55%，尽管粒径增加了 10 倍，但比我们之前的研究提高了 10 个百分点。这些收率与其他主要木材预处理技术获得的收率相似，与柳枝稷的主要技术收率相差不到 10%，尽管没有使用化学催化剂，使用了大颗粒（0.95 厘米）和高固含量（40wt%）。
