两段式固定床反应器中焦油脱除的实验研究

Experimental study on tar destruction in a two stage fixed-bed reactor

通过两段式固定床反应器实验,研究了热裂解、部分氧化和炭层转化三种方法对焦油脱除的效果,并研究了生物质种类、反应温度、停留时间、生物质焦的粒径及种类等因素对热解焦油的脱除和转化规律。结果表明,随着温度的升高,三种脱除方法中焦油生成量下降,且降幅逐渐减小,实验过程中无论采取何种方法,都难以将焦油完全脱除;部分氧化和炭层转化对焦油的脱除效果都较相同温度条件下的热裂解要好,且在焦油脱除效果上,炭层转化>部分氧化>热裂解;联合部分氧化和炭层转化可达最高的焦油脱除效率,三种生物质热解焦油经1 000℃联合脱除后产量分别为,稻秆0.43%、玉米秆0.61%和杉木屑1.15%,转化率分别达到98.28%、97.23%和96.29%;相同实验条件下稻秆的热解焦油最容易脱除,这与其物料中含氧量较高有关;生物质焦种类对焦油的脱除效果影响较小。

Methods of thermal cracking,partial oxidation and char bed conversion on tar destruction has been investigated by a two stage fixed-bed reactor,effects of fuel type,temperature,residence time,char particle size and char type on tar destruction are considered.The result indicates that tar conversion efficiency increase with the second stage reactor temperature increasing in all three kinds of conversion methods.Partial oxidation and char bed conversion is more effective in tar destruction compared to thermal cracking.Associated with partial oxidation and thermal cracking,char bed can get least tar yield.Three kinds of biomass tar yield in the experimental condition of 1 000 ℃ is： rice straw 0.43%,corn straw 0.61% and fir sawdust 1.15%,and the corresponding tar conversion efficiency is 98.28%,97.23% and 96.29% respectively.Tar yield content of each conversion methods are decreasing with reactor temperature increase.It is really difficult to removal all tar completely in these experiments due to complex tar composition and experimental conditions.The results also show that biomass tar destruction feasibility are： rice straw corn strawfir sawdust,and on obvious diversity is obtained between different char species on tar destruction.