Characteristics Of Pyrolysis Gas Of Municipal Solid Waste And Preparation Of Synthetic Gas With Catalyst

Thermal technology is one of the most promising clean energy technologies to deal with municipal solid waste?MSW?.Through pyrolysis or gasification,waste volume reduction is realized and generate secondary energy to alleviate fossil energy crisis.In this paper,based on the investigation of the thermogravimetric and pyrolysis characteristics of five typical single-component MSW?waste paper,fabric,bamboo,plastic and kitchen waste?and mixed MSW,a supported nickel-based catalyst was prepared for synthesis gas preparation.The conclusions are as follows:The raw material characteristics of single-component MSW are very different.Among them,plastics had the most C,H elements and volatile matter content,the moisture content was the lowest and the calorific value is maximum,up to 23.70KJ·Kg^-1.The waste paper had the lowest content of C,H and calorific value,which is9.34KJ·Kg^-1.The thermal weight loss process of single-component MSW can be roughly divided into several stages:drying and dehydration,precipitation of volatiles and secondary cracking.In the process from 500°C to 1000°C,the gas production of single-component MSW increased.The gas production of plastics and bamboo was obviously higher than that the other three kinds of MSW,while the gas production of fabric was the lowest.In the process of the temperature from low to high,the yield of H₂ promoted and CO₂ decreased,while the CH₄ yield showed a change of peak type.Bamboo and plastic can produce more combustible gas at high temperature,corresponding to higher gas calorific value.The distribution patterns of C,H and O of five single-component MSW are similar.Starting from 500°C to heat up,H%raised,while the change of C%and O%is opposite.The waste paper,fabric,bamboo,plastic and kitchen waste were mixed by mass ratio 2:1:1:2:2 to obtain mixed MSW.Taking single-component MSW as the reference,the elemental analysis,industrial analysis and calorific value of mixed waste are between the highest and lowest values of single-component MSW.Both the mixed MSW and the single-component MSW have three thermal weightlessness stages,but the temperature range and weight loss rate are different.The law of pyrolysis gas from mixed MSW and single-component MSW is similar.The difference between mixed MSW and waste paper and fabric is that the content of CO increases with the increase of temperature.The gas content and low heat value in gas production are between the maximum and minimum value of single-component MSW.The variation of H%in mixed wastes and single-component wastes is the same.In contrast to single-component wastes,the changes of C%and O%are the peak type,and they all reach the maximum at 600°C.A supported Ni-Fe-Mg/MPG catalyst was prepared by homogeneous precipitation method.The characterization reflects that the metal oxide particles are uniformly loaded.The particle size and specific surface area of the catalyst were 45nm and 131.66 m²·g^-1,respectively.The catalyst pyrolysis test of mixed MSW shows that the catalyst can significantly increase the pyrolysis gas production,especially the output for combustible gases,and reduce the CO₂ content.At a relatively high energy-saving and high-activity temperature?700°C?,the pyrolysis gas and combustible gas content increased by 98.8%and 208.5%respectively,especially the H₂ production increased by 525.2%,and the CO₂ removal efficiency reached 82.4%.The low heat value of gas production reaches 1786.49 KJ·m^-3,which effectively increases by 107.3%.The gas proportion in syngas is up to 96%.The life test of the catalyst showed that the Ni-Fe-Mg/MPG catalyst had excellent anti-sintering capability and still had good activity after six tests in a fixed-bed tubular furnace reactor.