城市生活垃圾中有机质产气及焦化特性研究

生物质气化过程中最大的不利因素是反应过程中焦油的生成。实验以混合蔬菜为原料,在高温炉中模拟研究城市生活垃圾中有机质的热解特性,并分别以CaO和水泥生产用主要原料--石灰石为催化剂,研究焦油产物深度裂解的催化效果。实验结果表明,CaO在400～900℃的温度范围内,对焦油裂解具有明显的催化效果;石灰石在700℃以上才能起到催化作用,说明真正起催化作用的是石灰石高温分解后产生的CaO。水泥回转窑内的温度高达1000℃以上,超细的石灰石原料粉末对热解产气可起到良好的催化效果,同时还能吸附残余焦油,防止其进入后续系统,腐蚀或影响收尘器等常温设备的正常运转。热解产气分析结果表明,高温下经过石灰石催化,尽管存在CO2气体生成的不利因素,热解产气中H2、CO、CH4等可燃气体总含量平均高达60%以上,具有相当高的热利用空间。

Study on gas generation and coking character of organic matter in urban garbage

The most unfavorable factor in organic matter gasification process is the formation of tar. Using mixed vegetable, thermal de- gradeing character of the organic matter in urban garbage was simulated in high temperature furnace, and using CaO and main cement raw material limestone as catalyst, the catalysis for tar oil decomposition was studied. The results show that CaO has obvious cataly- sis effect for tar oil decomposition at 400-900 ℃, and for limestone the temperature is over 700 ℃ which proves that the real catalyst matter is CaO decomposed by limestone in high temperature. In rotary kiln the temperature is high over 1 000℃ which keeps perfect ca- talysis effect of super fine lime stone powder for the heat calcining gas generation, and at the same time absorbs remnants tar oil to pre- vent it entering following system to erode or affect normal temperature equipments. The gas generation of heat decomposition analysis results show that in despite of the unfavorable factors of CO2 generation, by catalysis effect of limestone in high temperature, the combustible content of H2,CO,CH4 in generated gas is high up to 60% which has great heat utilization space.