碳氮比对垃圾干化及能源化利用的影响

Influence of C/N ratio on bio-drying and energy utilization of municipal solid waste

采用自制的生物干化实验装置,以高含水率混合收集生活垃圾为研究对象,探讨了不同C/N比(15、20.7、24.6和30)对垃圾生物干化效果的影响,比较了4组干化产物的RDF产率和产品性质。结果表明,不同C/N比垃圾生物干化理化性质与脱水效果存在明显差异;低C/N比处理的pH、NH_3挥发率均大于高C/N处理。C/N比为20.7垃圾生物干化效果最佳,在这种比例下处理的含水率下降幅度、垃圾水分去除率、单位有机物脱水能力和低位热值增幅均大于其他处理组。经过12 d生物干化,不同C/N比垃圾含水率分别下降了16.5%、20.3%、13%和15.4%,干化产物低位热值同比原生垃圾增长了78.3%、114.5%、65.8%和79.0%,达到了垃圾经济性焚烧要求,其硫、氯元素含量低于0.5%,重金属的含量也在可以合理范围内,可作为RDF燃料制备原料。

The influences of different C/N ratios （15, 20.7, 24.6, and 30） on high-water-content municipal solid waste （MSW） biodrying were studied using self-made equipment, and the RDF yield and properties of four trial products were determined.The results showed that there are significant differences in the chemical properties and dewatered efficiencies between the different C/N ratios of MSW.Lower C/N ratio increased the pH and NH3 emissions of the MSW.The MSW with a C/N ratio of 20.7 led to more effective water content evaporation, higher dehydration ratio of per raw wet waste, stronger water removal capacity of per organic waste decomposition, and lower heat value （LHV） than the other experimental groups did, so it is the optimal C/N ratio for biodrying of MSW.After 12 days of bio-drying.the water content in the four trials decreased by 16.5%, 20.3%, 13%, and 15.4% for the 15, 20.7, 24.6, and 30 C/N ratios, respectively, and compared to that of the initial waste, the LHV was enhanced by 78.3%, 114.5%, 65.8%, and 79.0%, respectively.The LHVs of the four trial biodried products met the garbage incineration economic requirements, and its chlorine and sulfur contents were below 0.5%.The heavy metals content was within reasonable levels, and therefore the biodried products can be used as RDF fuel preparation feedstock.