RDF热解前后表面结构变化的研究

INVESTIGATION ON CHANGES OF SURFACE STRUCTURE OF RDF BEFORE AND AFTER PYROLYSIS

对城市生活垃圾衍生燃料(RDF)及其在不同温度及时间下快速热解生成半焦的比表面积和孔容积的变化进行了分析研究。实验结果发现RDF热解时比表面积及孔容积先随热解温度升高而降低,然后随反应程度的加深而增大,在约550℃时出现极大值,而后由于产生结焦等原因再次降低。研究表明RDF热解半焦孔结构与煤焦孔结构变化有一定的相似性。此外对RDF及半焦孔结构分布的分形特征进行了初步分析。

The changes of specific surface area (SSA) and pore volume (PV) of refuse derived fuel (RDF) and its char produced at different pyrolysis temperatures or on different retention times are investigated in this paper The experiment results show that the SSA and PV of RDF vary with the reaction temperature during rapid pyrolysis and its characteristic is the same as that of coal coke Increasing the temperature, the SSA and PV of RDF char decrease in the beginning, then raise quickly between 350℃ and 550℃ and step down in the end The maximum value is appeared near 550℃ Medium pore volume amounts to about 50 per cent of the total pore volume The SSA sum of micro pore and medium pore almost makes up the total SSA of RDF and its char, and they are nearly the same in the quantity The PV and SSA of micro pore increase rapidly during pyrolyzing at 350℃ or at 650℃ in the beginning Micro pore expands to medium pore and medium pore to large pore after pyrolysis temperature increased or pyrolysis extent deepened Furthermore, the fractal feature of pore structure of RDF and its char is also discussed The effect of temperature and pyrolysis yield on fractal dimension are investigated in this paper