城市生活垃圾中聚乙烯塑料流化床气化

引言 城市生活垃圾气化熔融作为新一代的高效低污染垃圾热处理技术,在国外已有一定发展,如Thermoselect技术[1,2]、Siemens技术[1,3]、荏原技术[4]、RCP技术[1]等.上述技术中气化温度大多控制在550～650℃,但根据垃圾组分含量不同,反应条件也随之变化.因此,非常有必要进行垃圾单组分气化研究.我国城市生活垃圾中塑料大约占总质量的8%～20%,见表1.PE大约占塑料类垃圾的50%,其发热量高达43000 kJ·kg-1,所以有效气化PE极具意义.

Fluidized bed gasification of PE plastic in municipal solid waste

In order to develop municipal solid waste(MSW) gasification and melting technology with low emission and high efficiency for developing countries, the optimum conditions of ployethylene plastic gasification were studied.Polyethylene(PE) plastic widely existing in MSW was gasified in a fluidized bed. The study was focused on the characteristics of PE gasification at different excess air ratios(EAR) (0.2—0.8) and temperatures (400—700℃).The highest gasification efficiency reached 72% in the above experiments when temperature was 700℃ and EAR was 0.2,and the low heating value(LHV) of product gas was up to 10000 kJ•m^-3, the yield was 3.1 m³•kg^-1 and the conversion efficiency of C was 80%. The conversion efficiency of C could be increased up to about 100% if temperature was maintained at 700℃ and EAR was over 0.4 (or temperature at 600℃, and EAR over 0.8).Then the reaction process and mechanism of PE gasification were proposed by analyzing the characteristics of product gas.