微波辅助气流床煤气化工艺研究
Process study on microwave-assisted entrained flow gasification
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摘要: 为寻求一种对煤种及汽氧比无任何特殊要求的煤气化工艺,采用微波为辅助热源,以吸波剂为传热介质,以低温低压饱和水蒸气为单一气化剂对无烟煤、烟煤、褐煤进行气流床煤气化。结果表明,在正交试验的最佳工艺条件下,以流量为2.2 L/s、158.7℃饱和水蒸气为气化剂,800 W微波功率下,75 g无烟煤与MnO2基吸波剂以质量配比3∶1混匀后在直径10 mm反应器中的稳定气流床气化温度为1 966℃,完全气化时间为10.7 s,单位质量煤气化微波能耗仅为114.2 kJ/kg,所制水煤气中CO和H2的含量为94.1%。当稳定气化温度为1 742℃时,所制水煤气中CO2体积分数仅为0.8%,本工艺的高温环境对变换反应进行了有效抑制。无烟煤、烟煤、褐煤所制水煤气组成随煤与吸波剂配比变化曲线均按CO、CO2、N2、H2、O2、CH4的顺序顺时针旋转,小管径反应器具有更快的气化速度及更低的能耗。Abstract: In order to seek a kind of coal gasification process without any special requirements,such as the type of coal or the ratios of the water vapour and oxygen,the low-temperature low-pressure saturated steam was used as the single gasification agent,and microwave was used as an entrained flow auxiliary heat source,absorbing agent was used as the heat transfer medium for the gasification of anthracite,bituminous and lignite.The results were as follows,under optimum conditions of the orthogonal experiment,75 g anthracite was mixed with MnO2-based absorbing agent in accordance with the mass ratio of 3∶1.The mixture was gasified in the 800 W microwave power when the 158.7 ℃ steam flow was 2.2 L/s,and the stable gasification temperature was 1 966 ℃,the complete gasification time was 10.7 s.The microwave energy consumption per unit mass was only 114.2 kJ/kg,the content of hydrogen and carbon dioxide in the water gas made from the above conditions was 94.1%.When the stable gasification temperature was 1 742 ℃,the CO2 concentration was only 0.8%.A high temperature environment effectively inhibited the converting reaction.The composition-ratio curves of three typical water gas were rotated clockwise order by CO、CO2、N2、H2、O2、CH4.The small diameter gasification reactor had a faster speed and lower microwave power consumption.