不同混合比催化剂对生物质热解特性的影响

Influence of catalysts of different mixing ratio on biomass pyrolysis characteristics

基于更加深入的了解生物质催化热解行为,对稻秆进行脱灰预处理(水洗和酸洗),分析灰成分中金属元素在热解过程的作用,同时尝试将K2CO3与白云石进行不同比例掺混,添加到酸洗样中,研究不同混合比催化剂对生物质热解的影响规律。试验结果表明,脱灰预处理在一定程度上阻碍了生物质的热解,水洗样在300℃附近出现肩状峰,即对生物质三组分结构上产生一些影响;而添加金属盐对生物质热解有一定促进作用,其中添加7%K2CO3试样在650℃附近热解焦产率最低,添加白云石试样在720℃以后表现出催化作用且最大失重速率随白云石比例增加而增大,当K2CO3与白云石混合比例为7∶3时,生物质热解速率最大为-0.004 5/s,且热解焦产率最小,表现出更好的催化活性。

In order to understand the behavior of hiomass catalytic pyrolysis, the rice straw was washed with 7 % acids （HC1） and distilled water, respectively. The catalysis effects of alkaline earth metallic on pyrolysis characteristics of pretreated biomass were analyzed with K2CO3 , dolomite （CaCO3· MgCO3 ） and their mixture of different mixing ratio addition. The test results show that acid wash can hinder biomass pyrolysis and the DTG curve of water washed sample occurs shoulder shape peak at about 350 ℃ which means water washing can change the structure of three com- ponent of biomass. Alkaline earth metallic compounds addition can promote biomass pyrolysis, which added 7 % K2CO3 specimen in 650 ℃ nearby pyrolysis coke etc rate minimum, added dolomite specimen in 720 ℃ showed maximum catalysis and weightlessness rate increased with dolomite proportion increases, the mixture shows better catalytic activity with the largest rate of biomass pyrolysis and the lowest char Production when the mixing ratio is 7 ： 3 and got the highest pyrolysis rate （ -0. 004 5/s）.