Zhang Dongdong, Han Peilin, Yang Rui, Wang Hong, Lin Wei, Zhou Wanlai, Yan Zuoyi, Qi Zhiyong
Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China.
College of Chemical Engineering, Fuzhou University, Fuzhou, China.
Bioresour Technol. 2021 Dec;342:125929. doi: 10.1016/j.biortech.2021.125929. Epub 2021 Sep 13.
Superheated steam (SHS) was capable of fast and uniformly torrefying heavily loaded biomass. This work detailedly investigated the torrefied biomass in terms of fuel property and combustion behavior. The reactor chamber (300 ml) was fully loaded with pinewood pellets (160 g). Overall residence times were 20, 40 and 60 min (including preheating and holding periods) under 225, 275 and 325 °C. Biomass was estimated by elements, TG, FTIR, HHV, fuel property, combustion and pyrolysis behaviors, combustion kinetics and moisture reabsorption. Holding period as short as 2 min at 325 °C with a heating rate of 15 °C‧min was found to enhance energy density by 45% and generated homogeneous coal-like products with HHV of 26.76 MJ‧kg. Fixed carbon content increased to 64.84 wt%. The combustion activation energy increased to 79.66 kJ‧mol. Combustion indices and behaviors indicated that torrefied biomass had benign characteristics either for co-firing or as fuel. All suggests good potential of SHS torrefaction to obtain fuel alternatives.
过热蒸汽（SHS）能够快速且均匀地对高负载生物质进行烘焙。这项工作从燃料特性和燃烧行为方面详细研究了烘焙后的生物质。反应室（300毫升）中装满了松木颗粒（160克）。在225、275和325℃下，总停留时间分别为20、40和60分钟（包括预热和保温阶段）。通过元素分析、热重分析（TG）、傅里叶变换红外光谱（FTIR）、高位发热量（HHV）、燃料特性、燃烧和热解行为、燃烧动力学以及水分再吸收对生物质进行了评估。发现在325℃下以15℃·分钟的加热速率保温2分钟，可使能量密度提高45%，并生成具有26.76兆焦·千克高位发热量的均匀类煤产品。固定碳含量增加到64.84重量%。燃烧活化能增加到79.66千焦·摩尔。燃烧指数和行为表明，烘焙后的生物质无论是用于混烧还是作为燃料都具有良好特性。所有这些都表明过热蒸汽烘焙在获取燃料替代品方面具有良好潜力。
