Hydrothermal Carbon And Coal Gasification Of Domestic Waste And Co-combustion Characteristics

With the rapid development of the world economy and the growth of the global population,people have generated a huge amount of garbage in their lives,which has brought many problems to the environment and life.In the face of the treatment of domestic waste,people mainly burn and gasify it,which reduces the capacity and even recycles and reuses resources.However,the high water content,variety and complexity of household waste and low calorific value greatly hinder its large-scale treatment.If we mix a certain proportion of lignite with domestic waste,we can complete the co-gasification or co-combustion of domestic waste and lignite,and overcome the problem of separate treatment.In addition,the hydrothermal carbonization technology pretreatment of domestic waste can convert domestic waste into domestic waste hydrothermal carbon,so that it has a higher calorific value and changes its combustion characteristics and gasification activity.The combination of these two technologies can better dispose of household waste.Therefore,this paper conducts experimental research on the co-gasification/co-combustion technology of domestic waste hydrothermal carbon and lignite,and provides feasibility for the implementation of this technology.Compared with domestic waste,the physical and chemical properties,combustion characteristics and gasification activity of domestic waste treated by hydrothermal carbonization technology have been improved to a certain extent,and solid product hydrothermal carbon can be used as a new derivative fuel.Hydrothermal carbonization temperature 230°C The H/C and O/C atomic ratios of the prepared hydrothermal carbon enter the lignite zone,have a similar structure to lignite,and have good energy density.The combustion characteristics of domestic waste hydrothermal carbon and lignite during co-combustion were studied by thermogravimetric analyzer,and the kinetic parameters activation energy E and pre-finger factor A in the co-combustion process were calculated by Coats-Redfern method.It is found that when the heating rate increases,the thermogravimetric curve shifts to the side of the high temperature region,resulting in thermal hysteresis.With the increase of the mixing ratio of hydrothermal carbon（HC）of domestic waste,the combustion performance was enhanced,and there was a synergistic interaction in the co-combustion process,and the interaction of 40HC60L mixed samples was the most significant.The mixed combustion of hydrothermal charcoal for domestic waste and lignite can improve the slagging characteristics of lignite.The thermogravimetric gasification test of lignite（L）and HC was carried out to explore the CO₂co-gasification characteristics of the two.It is found that L gasification alone can be divided into three stages,while HC gasification alone can be divided into four stages,and the gasification reaction temperature of domestic waste hydrothermal carbon is much lower than that of lignite,and there is a significant synergistic interaction in the gasification stage of the coke mixture of the two,and the interaction of 60L40HC mixing ratio is the strongest.By calculating the kinetic parameters of the cogasification process by Flynn-Wall-Ozawa and Friedman-Reich-Levi,when 40%HC is added,the average activation energy of cogasification of mixed samples reaches a minimum value of 140.39k J/mol,so from the perspective of kinetics,it is considered that 60L40HC samples may be the most suitable mixing ratio.