Mechanical strength evolution of biomass pellet during chemical looping gasification in fluidized bed
Mechanical strength evolution of biomass pellet during chemical looping gasification in fluidized bed
复制标题
DOI：
10.1016/j.fuproc.2021.106951
复制
发表时间：
2021-10
影响因子：
7.5
通讯作者：
Shen Wang;Xianglei Yin;Kolja Jarolin;Timo Dymala;Jiale Xu;Shangyi Yin;M. Dosta;Tao Song;S. Heinrich;Laihong Shen
中科院分区：
文献类型：
--
作者：
Shen Wang;Xianglei Yin;Kolja Jarolin;Timo Dymala;Jiale Xu;Shangyi Yin;M. Dosta;Tao Song;S. Heinrich;Laihong Shen
由于生物质颗粒粒径大、比表面积小，在化学链气化（CLG）过程中，颗粒的破碎对内部挥发分的脱除速率和转化率起着至关重要的作用。为了研究生物质颗粒在CLG过程中的机械强度变化规律，建立了一个可任意控制气化时间的鼓泡流化床气化反应器。选用不同灰分的木屑和稻壳颗粒作为燃料。在不同条件下收集了720多个经历不同气化时间（15 ~ 180 s）的生物质样品。结果表明，在CLG过程中，炭样的多孔脆性结构是一个从表面到内部结构逐渐演化的过程。单轴压缩试验表明，试样破碎峰值压缩力的降低主要取决于包括内骨架和外表皮在内的整体碳结构的消耗和破坏。载氧体通过孔隙和/或裂纹的渗透以及挥发分快速释放而产生的内部超压是内部碳骨架断裂和磨损的显著促进因素。建立了相应的热损伤模型来预测CLG过程中球团的机械强度。
Due to a large particle size and a small specific surface, biomass pellet fragmentation during Chemical looping gasification (CLG) process plays a critical role in the internal devolatilization rate and its conversion. To investigate the mechanical strength evolution of biomass pellet during CLG process, a gasification reactor of bubbling fluidized bed capable of controlling the gasification time arbitrarily is established. Sawdust and rice-husk pellets with different ash content are selected as fuels. More than 720 biomass samples undergoing different gasification time ranging from 15 s to 180 s are collected at different conditions. A porous and brittle morphology of char samples is revealed to be a gradual evolutionary process from the surface to the internal structure during CLG process. Uni-axial compression test shows that the reduction of the peak compressive force for crushing the samples mainly depends on the consumption and destruction of the overall carbon structure including internal skeleton and external epidermis. The penetration of oxygen carrier through pores and/or cracks and the internal overpressure because of rapid volatiles release are the remarkable boosts to the breakage and attrition of the internal carbon skeleton. A corresponding thermal-damage model is developed to predict the mechanical strength of pellet during CLG process.