褐煤与大豆荚共热解的产物特性分析

Characteristic Analysis of Co-pyrolysis Products of Lignite and Soybean Pod

利用自制的低温热解装置研究褐煤与大豆荚共热解的产物特性,考察大豆荚掺混比和催化剂Fe_2O_3对热解产物特性的影响。通过FT-IR、GC-MS、SEM-EDX和UV-vis分析共热解产物的性质,并将半焦用于亚甲基蓝吸附实验。研究结果表明:掺混比30%时,共热解焦油的产率达到最大值11.98%,比煤焦油产率增加44.86%,与计算值的正偏差最大(0.8%),同时,大豆荚的添加有促进焦油生成的协同作用。大豆荚的添加有利于共热解焦油中含氧杂环的断裂,使共热解焦油中直链烷烃增多,芳香族化合物减少,使重质组分转化为轻质组分,从而提高焦油品质;同时,大豆荚的添加使共热解半焦的含氧基团增加,微观形貌变粗糙。而Fe2O3的加入使共热解焦油中酚、醇类物质增加;加Fe_2O_3共热解半焦的褶皱更加明显。共热解半焦对亚甲基蓝的吸附率为33.62%,比煤半焦的吸附率提高8.84%,加Fe_2O_3共热解半焦的吸附率为55. 57%,比共热解半焦提高65.29%。

The characteristics of co-pyrolysis products of lignite and soybean pod were studied by using homemade carbonization apparatus and the influences of different soybean pod ratios and blending Fe2O3 in lignite on the yields were also studied.The characteristics of co-pyrolysis products were analyzed by FT-IR,GC-MS,SEM-EDX and UV-vis,meanwhile,the char was used to study the adsorption of methylene blue.The results showed that the yield of pyrolysis tar rose to 11.98%with the blending ratio of 30%,which was increased by 44.86%compared to lignite pyrolysis alone and reached the most-positive deviation to the theoretical values(0.8%)and the results indicated that the addition of soybean pod had synergistic effect of promoting the production of tar.The addition of soybean pod could facilitate the breakage of oxygen-containing heterocycles,increase the number of straight-chain alkanes and reduce of aromatic compounds in co-pyrolysis tar.It could also enhance the quantity of oxygen-containing groups and the surface roughness of co-pyrolysis char.Blending of Fe2O3 increased the phenols and alcohols content in co-pyrolysis tar,and the folds of the char were more obvious.The methylene blue removal rate of co-pyrolysis char reached 33.62%,which was risen by 8.84%compared with that of coal char.And the removal rate of co-pyrolysis char with Fe2O3 reached 55.57%,which was risen by 65.29% compared with that of co-pyrolysis char.