污泥热解-自源炭重整获取高品质油气产物

Produce high quality gas & oil products from sewage sludge pyrolysis & char reforming process

利用污泥热解-自源炭重整的方式获得高品质的燃气和油,为了实现更高的气、油转化率,在600℃的重整条件下,对比了污泥在450～600℃内不同热解温度下产生的热解挥发分利用自源炭催化重整后的气、油产量与特性,同时考察了自源炭生成方式的影响。研究结果表明,550℃下污泥热解产生的热解液产量最高,同时最容易被炭催化裂解,但是因积碳使得污泥转化为气、油的产率不高。600℃下热解产生的挥发分经过重整后获得最高的气体转化率与热值,但也存在积碳问题。与一步升温到600℃的热解炭相比,不同温度下的热解炭继续被加热到600℃所获得的分步热解炭更符合连续化操作要求,但其重整效果总体上不如前者好;而热解温度在450℃时例外,450℃的热解炭继续升温至600℃并重整450℃热解挥发分,能够获得最高的气、油产率并减少碳沉积。在实际情况下的热解-重整连续化操作中推荐热解温度为450℃以及重整温度为600℃,以获得高值产物并降低对热解装置的要求。

In general,high quality gas&oil products could be obtained through a sewage sludge pyrolysis&char reforming method.In order to realize higher gas&oil conversion rate,gas&oil production and property after char catalyzing and reforming pyrolysis volatile,which was produced from sludge pyrolysis at different temperatures within 450~600℃,were compared under the same reforming temperature of 600℃.Then the effect of char yield ways was also investigated.The results showed that pyrolytic liquid gained its highest yield at the pyrolysis temperature of 550℃and it was easiest to be cracked by char catalysis.However,severe carbon deposition during the reforming process led to the relatively low yields of the final gas&oil products.The highest gas conversion rate and heat value occurred after reforming the volatile produced from sludge pyrolysis at 600℃,but the problem of carbon deposition still existed.Compared with the one-step pyrolysis char produced at 600℃,the stepwise pyrolysis chars,which were obtained by heating chars from their pyrolysis temperature to 600℃,were more coincident with the requirement of continuous operation,but had a lower reforming effect except for the one originally produced at 450℃.When the char produced at 450℃and heated up to 600℃was used to reform the pyrolysis volatile of 450℃,the highest gas&oil yield was obtained and carbon deposition could be alleviated.In practice,to run a continuous pyrolysis&reforming process for sewage sludge,pyrolysis temperature of 450℃and reforming temperature of 600℃are recommended to obtain more gas&oil products,and to reduce the quality requirement for pyrolysis facilities.