Effect of heating rate on biomass liquefaction: differences between subcritical water and supercritical ethanol.
Effect of heating rate on biomass liquefaction: differences between subcritical water and supercritical ethanol.
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DOI：
10.1016/j.energy.2014.02.086
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发表时间：
2014-04
期刊：
影响因子：
9
通讯作者：
Steffen Brand;Flabianus Hardi;Jaehoon Kim;D. Suh
中科院分区：
文献类型：
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作者：
Steffen Brand;Flabianus Hardi;Jaehoon Kim;D. Suh
本研究考察了加热和冷却速率对木质纤维素生物质在亚水（亚临界水）或超临界乙醇（超临界乙醇）中液化的影响，取决于最终反应温度（250-350℃）和停留时间（1-40分钟）。升温速率是亚氢基液化的关键参数，而对超临界氢基液化的影响较小。气体、液体和固体产物的详细表征能够识别单个反应步骤，从而对取决于液化溶剂和条件的反应机制有了新的认识。与快速热解类似，水热液化由有益的一次反应（热解和水解降解）和非有益的二次反应（重组和二次裂解）组成。在scEtOH中，生物质在较高的反应温度下通过热解和醇解进行分解，而scEtOH特有的给氢反应和羟烷基化反应阻碍了反应中间体的重组。
This study investigates the influence of heating and cooling rate on liquefaction of lignocellulosic biomass in subH2O (subcritical water) or in scEtOH (supercritical ethanol), in dependency of final reaction temperatures (250–350 °C) and residence times (1–40 min). The heating rate has been identified as a crucial parameter in the subH2O-based liquefaction, whereas it has marginal influence in the scEtOH-based liquefaction. Detailed characterization of gas, liquid and solid products enables to identify the individual reaction steps, which results in a new insight into the reaction mechanisms, depending on the liquefaction solvents and conditions. Similar to fast pyrolysis, hydrothermal liquefaction consists of beneficial primary reactions (pyrolytic & hydrolytic degradation) and non-beneficial secondary reactions i.e. recombination and secondary cracking. In scEtOH, biomass was decomposed by pyrolysis and alcoholysis at relatively high reaction temperatures while the recombination of reaction intermediates are retarded by the unique reactions of scEtOH such as hydrogen donation and hydroxylalkylation.