兼吸式移动床生物质热解炭化装置设计与试验

Design and Experiment of Both Updraft and Downdraft Biomass Pyrolysis Charring Device in Moving Bed

摘要:

针对目前内热式移动床生物质热解炭化试验研究平台条件不足的问题，开发了一种内加热兼吸式移动床热解炭化装置，模拟连续式热解炭化工艺，设计了供气系统、出炭系统、产物收集系统、气体净化系统、温度监控系统，以稻壳作为原料，开展了上吸和下吸式热解炭化试验，研究了停留时间和吸气方式对内热式热解炭化产物的影响。结果表明，随着停留时间的增加，上吸和下吸内热式热解炭化变化趋势基本相同，挥发分和固定碳含量均呈下降趋势，灰分含量增加，磷及氮元素含量均下降，氧元素含量上升，氢元素变化趋势不明显，热值分别从20.7MJ/kg和22MJ/kg下降到14.6MJ/kg和15.2MJ/kg；比表面积分别从0.73m2/g和0.78m2/g上升到3.84m2/g和3.95m2/g，生物炭孔隙结构得到了发展。该系统结构合理，运行稳定可靠，密封效果良好，可有效控制进气方式、进气量、保温炭化时间等试验因素。为内加热炭化工艺参数试验研究提供了重要支撑。

Abstract:

Aiming at the insufficient conditions of the current research platform for the internal heating mobile bed biomass pyrolysis carbonization test, an internal heating up and down suction mobile bed pyrolysis carbonization test device was proposed, the continuous pyrolysis carbonization process was simulated, and the gas supply system, carbon sampling collection system, product collection system, gas purification system and temperature monitoring system were designed. Using rice husk as raw material, up-suction and down-suction pyrolysis carbonization experiments were carried out to study the effects of residence time and inspiratory mode on internal thermal pyrolysis carbonization products. The results showed that with the increase of residence time, the volatile and fixed carbon contents of rice husk carbon were decreased, the ash content was increased, and the calorific value was decreased. The calorific value of rice husk carbon was decreased from 20.7MJ/kg and 22MJ/kg at 10min to 14.6MJ/kg and 15.2MJ/kg at 60min, respectively. With the increase of residence time, the content of C in rice husk carbon was decreased from 51.9% and 65.3% at 10min to 36.5% and 54.8% at 60min, respectively. The content of N element was decreased from 1.1% and 2.3% at 10min to 0.5% and 0.7% at 60min, respectively. The content of O element was increased from 46.0% and 28.7% at 10min to 61.7% and 42.2% at 60min, respectively. The change trend of H element was not obvious. With the increase of residence time, the specific surface area of up-suction and down-suction pyrolysis rice husk charcoal was increased from 0.73m2/g and 0.78m2/g at 10min to 3.84m2/g and 3.95m2/g at 60min, respectively, and the pore structure of biochar was developed. The test system had reasonable structure, stable and reliable operation, good sealing effect, and can effectively control the test factors such as air intake mode, air intake volume and heat preservation carbonization time. The development of the internal thermal pyrolysis charring platform provided an important condition support for the experimental research of internal heating charring process parameters.