Abstract:

With the development of society and urban expansion, the disposal pressure of sewage sludge and waste plastics is increasing, while pyrolysis has received widespread attention as a means of resourceful disposal of organic solid waste. In this paper, the effects of temperature and PVC on the distribution of the three-phase products of sludge pyrolysis and their properties were investigated by conducting co-pyrolysis experiments of sewage sludge (SS) and waste polyvinyl chloride plastic (PVC) at 500—900℃. The results showed that with increasing temperature the yield of biochar decreased while the yield of bio-gas increased, and the yield of bio-oil decreased after the first increasing. Meanwhile, the content of CH₄ and CO in bio-gas increased while the content of CO₂ decreased. The carbon number of organic matter in bio-oil decreased with increasing proportion of hydrocarbon and aromatic organic matter increased. The pore structure of biochar surface became irregular and the functional groups decreased. Compared with sludge pyrolysis alone, the addition of PVC increased the yield of bio-gas while decreasing the yield of biochar, and the production of bio-oil would be suppressed at higher temperatures. Furthermore, the added PVC was benefit to improve the quality of bio-gas and increase the content of heavy components bio-oil at high temperature, and enrich the oxygen-containing functional groups of biochar with increasing surface irregularity.

Key words: sewage sludge, polyvinyl chloride, co-pyrolysis, three-phase products, blending ratio

摘要：

伴随着社会发展和城市扩张，生活污泥和废塑料的处置压力越来越大，同时热解作为一种资源化处置有机固体废弃物的手段受到普遍关注。本文通过开展生活污泥（SS）和废聚氯乙烯塑料（PVC）在500~900℃共热解实验，探究了温度和PVC掺混比对热解三相产物分布及其性质的影响。结果表明：伴随温度的升高，热解的固相产率下降，气相产率上升，液相产率先上升后下降；与此同时，热解气中的CH₄和CO含量上升，CO₂的含量下降；热解油中有机物含碳数减小，烃类和芳香类有机物比例增大；热解炭表面孔隙结构变得不规则，官能团减少。与污泥单独热解相比，PVC的加入会在降低产炭率的同时提高产气率，且高温下将抑制液相产物的产生。除此之外，PVC有利于提升热解气品质，提高高温热解油中重质组分的含量，并在增大热解炭表面不规则程度的同时使其含氧官能团更为丰富。

关键词: 污泥, 聚氯乙烯, 共热解, 三相产物, 掺混比