Abstract

Results from the comparative analysis of the energy and economic efficiencies of the torrefaction reactors (or low-temperature pyrolysis reactors) with the heat of the heating gas supplied directly to the processed biomass are presented. Upright reactors of two types are considered, viz., reactors with a bed of dense biomass moving by gravity towards the heating gas flow and fluidized-bed reactors. Advantages and drawbacks of the different types of torrefaction reactors are discussed. Criteria for the evaluation of the torrefaction reactors' energy efficiency have been defined based on the data of experimental research conducted on a pilot power-engineering plant at the Joint Institute for High Temperatures, Russian Academy of Sciences, equipped with a moving-bed reactor and the results of numerical modeling of a fluidized-bed reactor. The conditions for creating the thermal effect of the hemicellulose decomposition reaction and the mechanism that restricts the increase in the biomass temperature during the self-heating by the exothermic reaction heat are considered. The analysis performed has shown that a moving-bed reactor with a controlled exothermic biomass destruction reaction has the highest energy efficiency and the best criteria for estimating the financial and commercial efficiency of the investments. Conclusions have been made that moving-bed reactors are preferable for small-scale production for which granulated biomass (biomass pellets) is the optimal feedstock, while fluidized-bed reactors and fine-dispersed feedstock materials are more suitable for large-scale production.

中文翻译：

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生物质的低温热解反应器效率比较

摘要

给出了对焙烧反应器（或低温热解反应器）的能量和经济效率与直接供应给处理过的生物质的加热气体热量进行比较分析的结果。认为有两种类型的立式反应器，即具有通过重力向加热气流流动的致密生物质床的反应器和流化床反应器。讨论了不同类型的焙烧反应器的优缺点。根据在俄罗斯科学院高温联合研究所的试验动力工程工厂进行的实验研究数据，确定了焙干反应堆能效的评估标准，该工厂配备了移动床反应堆和流化床反应器数值模拟的结果。考虑了产生半纤维素分解反应的热效应的条件和通过放热反应热来限制自加热期间生物质温度升高的机理。进行的分析表明，具有受控的放热生物质破坏反应的移动床反应器具有最高的能源效率和最佳的标准，可用于估算投资的财务和商业效率。得出的结论是，对于颗粒状生物质（生物质颗粒）是最佳原料的小规模生产，移动床反应器是优选的，而流化床反应器和细分散的原料则更适合大规模生产。