National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
Biotechnol Prog. 2010 Sep-Oct;26(5):1245-51. doi: 10.1002/btpr.441.
In process integration studies of the biomass-to-ethanol conversion process, it is necessary to understand how cellulose conversion yields vary as a function of solids and enzyme loading and other key operating variables. The impact of solids loading on enzymatic cellulose hydrolysis of dilute acid pretreated corn stover slurry was determined using an experimental response surface design methodology. From the experimental work, an empirical correlation was obtained that expresses monomeric glucose yield from enzymatic cellulose hydrolysis as a function of solids loading, enzyme loading, and temperature. This correlation was used in a technoeconomic model to study the impact of solids loading on ethanol production economics. The empirical correlation was used to provide a more realistic assessment of process cost by accounting for changes in cellulose conversion yields at different solids and enzyme loadings as well as enzyme cost. As long as enzymatic cellulose conversion drops off at higher total solids loading (due to end-product inhibition or other factors), there is an optimum value for the total solids loading that minimizes the ethanol production cost. The optimum total solids loading shifts to higher values as enzyme cost decreases.
在生物质到乙醇转化过程的工艺集成研究中，有必要了解纤维素转化率如何随固含量和酶负荷以及其他关键操作变量的变化而变化。采用实验响应面设计方法，确定了固含量对稀酸预处理玉米秸秆浆酶解纤维素的影响。通过实验工作，获得了一个经验相关性，将酶解纤维素产生的单体葡萄糖产量表示为固含量、酶负荷和温度的函数。该相关性用于技术经济模型中，研究固含量对乙醇生产经济性的影响。通过考虑不同固含量和酶负荷以及酶成本下纤维素转化率的变化，该经验相关性用于更真实地评估工艺成本。只要在较高的总固含量下（由于最终产物抑制或其他因素），酶解纤维素的转化率就会下降，因此存在一个最佳的总固含量，使乙醇生产成本最小化。随着酶成本的降低，最佳总固含量向更高的值移动。
