Department of Biological Systems Engineering, Washington State University, Pullman 99164-6120, United States.
Bioresour Technol. 2012 Apr;110:617-27. doi: 10.1016/j.biortech.2012.01.047. Epub 2012 Jan 28.
A two-step sequential hydrothermal liquefaction (SEQHTL) model for simultaneous extraction of polysaccharide at the first step followed by bio-oil in the second was established. The effects of reaction temperature, residence time, and biomass/water ratio on the product distribution of each SEQHTL step were evaluated. Maximum yield (32wt.%) of polysaccharides was obtained at 160°C, 20min and 1:9 biomass/water ratio. Considering the operation cost and bio-oil yield (>30%); 240°C, 20min and 1:9 biomass/water ratio was preferred as ideal SEQHTL condition for bio-oil extraction. SEQHTL always produced ∼5% more bio-oil and ∼50% less bio-char than direct hydrothermal liquefaction (DHTL). Free fatty acid content of the bio-oils exhibited a sharp decrease with increase in temperature. Comparative analysis of the energy input and net energy balance showed that SEQHTL requires ∼15% less MJ/kg bio-oil than DHTL. Energy recovery rate for SEQHTL is nearly 4% higher than the DHTL.
建立了两步顺序水热液化（SEQHTL）模型，用于在第一步同时提取多糖，然后在第二步提取生物油。评估了反应温度、停留时间和生物质/水比对每个 SEQHTL 步骤产物分布的影响。在 160°C、20min 和 1:9 生物质/水比下，多糖的最大产率（32wt.%）。考虑到操作成本和生物油产率（>30%）；240°C、20min 和 1:9 生物质/水比被优选为提取生物油的理想 SEQHTL 条件。SEQHTL 总是比直接水热液化（DHTL）多产生约 5%的生物油和少产生约 50%的生物炭。生物油中的游离脂肪酸含量随温度升高而急剧下降。能量投入和净能量平衡的比较分析表明，SEQHTL 比 DHTL 少需要约 15%的 MJ/kg 生物油。SEQHTL 的能量回收效率比 DHTL 高近 4%。
