基于正交实验的低阶粉煤与玉米芯微波共热解研究

生物质协助低阶粉煤微波热解可改善热解产物的分布和特性,尤其是油气收率和品质。采用四因素四水平正交实验法研究了微波功率(420 W,280 W,700 W,560 W)、热解时间(30min,20min,10min,40min)、玉米芯粒径(0.250mm~0.420mm,0.177mm~0.250mm,0.841mm~1.680mm,0.420mm~0.841mm)和玉米芯添加量(10%,40%,30%,20%,质量分数)对低阶粉煤与玉米芯微波共热解中焦油收率的影响,对比分析了低阶粉煤、玉米芯单独微波热解和微波共热解的升温特性和产物特性。结果表明:影响焦油收率由主到次的因素分别为玉米芯添加量、微波功率、玉米芯粒径、热解时间。在本实验参数范围内,正交实验得到的最佳工艺条件为:微波功率700W、热解时间40min、玉米芯粒径0.841mm~1.68mm、玉米芯添加量40%,此时的半焦和气体产物收率分别为51.22%和32.17%,焦油收率达到最大,为8.85%。与低阶粉煤单独微波热解相比,微波共热解生成的焦油中轻油含量提高了11.89%,而杂原子化合物含量降低了7.09%,实现了热解焦油的轻质化和高品质化。

Microwave-assisted Co-pyrolysis of Low-rank Pulverized Coal and Corncob Using Orthogonal Test

The distribution and characteristics of pyrolysis products can be improved through biomass-assisted microwave pyrolysis of low-rank pulverized coal,especially in terms of the yield and quality of oil-gas products.In this paper,the effects of microwave power(420W,280W,700W,560W),pyrolysis time(30min,70min,10min,40min),corncob particle size(0.250mm-0.420mm,0.177mm-0.250mm,0.841mm-1.680mm,0.420mm-0.841mm)and corncob addition(10%,40%,30%,20%,mass fraction)on tar yield of co-pyrolysis of lowrank pulverized coal and corncob in microwave were studied by orthogonal experiment.The heating characteristics and product characteristics of low-rank pulverized coal and corncob pyrolysis in microwave and co-pyrolysis in microwave were comparatively analyzed.The results show that the main factors affecting tar yield are corncob addition,microwave power,corncob particle size and pyrolysis time in order.The optimum experimental conditions within the experimental range were obtained by orthogonal test,which are 700 Wof microwave power,40min of pyrolysis time,0.841mm-1.680mm of corncob particle size,40%of corncob addition.Under the optimum conditions,the semi-char and gaseous yield are 51.22%and 32.17%,respectively,and the tar yield reaches the maximum of 8.85%.Compared with the pyrolysis of low-rank pulverized coal in microwave,the content of light oil in the tar from co-pyrolysis in microwave increases by 11.89%,while the content of heteroatom compounds in tar decreases by 7.09%,which means the quality of the tar is significantly improved.