我国南方某生活垃圾填埋场存量垃圾直接开挖掺烧中试

A PILOT-SCALE STUDY OF DIRECT EXCAVATION AND CO-INCINERATION OF EXISTING MUNICIPAL SOLID WASTE IN A LANDFILL IN SOUTHERN CHINA

为探讨存量生活垃圾开挖装运的作业效率以及直接掺烧对垃圾焚烧厂的工况影响,以我国南方某邻近垃圾焚烧厂的填埋场为对象进行了中试研究。结果表明:该填埋场的存量垃圾成分以约占56%的橡塑类为主,湿基低位热值为5037 kJ/kg。中试处理的存量垃圾填龄为4~8年,开挖装运效率可达到141 t/h。在50%的掺烧比例下,为维持炉膛热负荷,焚烧量提高了22%,达到设计处理负荷的104%,飞灰和炉渣产生率则同步升高了38%,未对烟气污染物的达标排放和飞灰炉渣的处理利用造成影响。维持垃圾充分燃烧无须提高二次风量和启用助燃,烟气处理无须启用干法脱酸,但脱氮负荷明显增大,熟石灰和氨水使用量分别增加了41%和194%,二噁英的毒性当量浓度为0.062,0.034 ng-TEQ/m^(3),可进一步降低二噁英的排放浓度。

In order to investigate the efficiency of excavation and load and transportation of the existing municipal solid waste(MSW)from the landfill,and the influence of direct co-incineration of existing MSW on the working condition of an MSW incineration plant,a pilot-scale study was conducted on the landfill adjacent to the MSW incineration plant in southern China.The results showed that the essential component of the existing MSW in the whole landfill was about 56%of rubber-plastic,and its lower heating value was 5037 kJ/kg in the wet base.The age of the existing MSW in the pilot-scale area was 4 to 8 years and the efficiency of excavation,load and transportation of the existing MSW could reach 141 t/h.At the co-incineration ratio of 50%,the incineration amount was increased by 22%and reached 104%of the designed value,to maintain the furnace’s thermal load.At the same time,the generation ratios of fly ash and slag were all increased by 38%,and the standardized emission of flue gas pollutants as well as the treatment and utilization of fly ash and slag were not affected.It was still not necessary to increase the volume of the secondary air or introduce assist incineration to maintain the sufficient incineration of MSW.For the treatment of flue gas,it was not necessary to enable the process of dry deacidification but the denitrification load was significantly increased.Consumption of slaked lime and liquid ammonia was increased by 41%and 194%,respectively.The emission concentrations of dioxin were 0.062 and 0.034 ng-TEQ/m^(3) of toxicity equivalency quantity,which can be further decreased.