Abstract：
We propose a closed-loop pretreatment process, wherein volatiles produced during steam explosion pretreatment were recovered and reintroduced as acid catalysts into the pretreatment system. The volatiles were separated through a drastic decompression process followed by a steam explosion process and recovered as a liquified catalyst (LFC) through a heat exchanger. The LFC effectively served as an acid catalyst for hemicellulose hydrolysis, significantly decreasing residence time from 90 min to 30 min to achieve 80 % conversion yield at 170 °C. Hydrolysates with high content of lower molecular weight oligomeric sugars were obtained using LFC, and were considered advantageous for application as prebiotics. These results are attributed to the complementary features of acetic acid and furfural contained within the LFC. Computational simulation using Aspen Plus was used to investigate the effects of recycling on LFC, and it demonstrated the feasibility of the catalyst-recirculating system. A validation study was conducted based on simulation results to predict the actual performance of the proposed pretreatment system. Based on these results, the recirculating system was predicted to improve the conversion yield and low-molecular weight oligomers yield by 1.5-fold and 1.6-fold, respectively.
摘要：
我们提出了一种闭环预处理工艺，其中在蒸汽爆炸预处理期间产生的挥发物被回收并作为酸催化剂重新引入到预处理系统中。挥发物通过剧烈的减压过程和随后的蒸汽爆炸过程分离,并作为液化催化剂(LFC)通过热交换器回收。LFC有效地充当半纤维素水解的酸催化剂，在170°C下,将停留时间从90分钟显著缩短至30分钟,以实现80%的转化率。使用LFC获得具有高含量低分子量低聚糖的水解产物，并且被认为有利于用作益生元。这些结果归因于LFC中所含的乙酸和糠醛的互补特征。使用AspenPlus进行计算模拟，研究回收对LFC的影响，论证了催化剂再循环系统的可行性。基于模拟结果进行了验证研究，以预测所提出的预处理系统的实际性能。基于这些结果,预计再循环系统可将转化收率和低分子量低聚物收率提高1.5倍和1.6倍，分别。
