Release Behavior Of HCl,H₂S,NH₃ During Mulnicipal Solid Waste Pyrolysis Process

The output of mulnicipal solid waste(MSW)is rapidly increasing with the rapid development of Chinese economy,and its safety disposal has increasingly attracted the attention of researchers.In recent years,MSW disposal technology has been continuously developed and improved.Among them,pyrolysis technology has been rapidly developed as a technology to reduce,quantify,and harmless mulnicipal solid waste.However,while MSW is properly disposed of,harmful gases generated in the pyrolysis process is not only caused by atmospheric pollution,but also affect the efficiency of pyrolysis,pyrolysis products and recovering.The MSW components are complex and heterogeneous,and there is a lack of in-depth study on the precipitation rules of major pollutants generated by its pyrolysis process.Therefore,this paper summarizes the precipitation rules of several main MSW such as HC1,H2S and NH3,and provides theoretical guidance for the optimization of mulnicipal solid waste pyrolysis technology and pollution control.In this paper,MSW is divided into several different types.The pyrolysis characteristic are studied by thermogravimtric analysis.The HCI,NH3,H2S in the pyrolysis process and the changes of content of corresponding elements after the conversion of MSW into char was detected at different final pyrolysis temperatures.The experimental results show that the precipitation rates of pollutants HC1,NH3 and H2S increase with the increase of the final temperature of pyrolysis.In the pyrolysis process,the precipitaion rate of HCl is 60%-92%,and the rate of precipitation reaching the maximum at 400?,followed by a slow release rate rises again to 600? to accelerate the small amplitude;Chlorine content in char increases as the final pyrolysis temperature is lowered,at 800? chlorine content of 5%to 15%.The precipitation rate of NH3 is 25%-62%,and the precipitaion rate of NH3 is differ from the type of MSW:the NH3 precipitaion rate of unclassified waste reached the maximum at 350?,and this of plastic,kitchen and garden waste was the fastesr in the range of 600? to 800?,and this of paper waste reaches a maximum at 300? and 650?;The NH3 of fabric waste maintains a stable precipitaion rate in 300?-600?.The nitrogen content in char is the highest at 700? that the value is 41%to 50%,while lowest at 800?.The H2S precipitaion rate of MSW is 22%-53%in pyrolysis process.Plastic,kitchen waste,garden,paper,fabric waste release H2S in large quantities from 200? to 500?.At 600?,H2S almost completely precipitated,while H2S of unclassified waste released at about 800?The sulfur content in char is the lowest at 700? that the value is 27%-40%,while the highest at 600?.