Experimental Research On Co-pyrolysis Of Biomassand Coal In Rotary Equipment

In today's global energy crisis,it is particularly important to use clean energy to solve the crisis.As a kind of clean renewable energy,biomass has the characteristics of reserves,renewable,environmental friendly and so on.It is a good alternative to traditional energy.As the traditional energy,coal still occupies the main energy consumption.However,there will be a variety of pollution and environmental problems in the process of coal combustion and utilization.Therefore,it is particularly important to develop the clean utilization technologies of coal.Pyrolysis is a kind of way to use coal resources clean.Co-pyrolysis of biomass and coal is a kind of energy utilization way that can make use of clean energy environmental friendly.Co-pyrolysis of biomass and coal in rotary equipment is a new way of co-pyrolysis.It can achieve dynamic co-pyrolysis of biomass and coal,with controllable reaction time.In this paper,corn straw molding material,cotton stalk forming material and HongShan coal as raw materials were researched through TGA and rotary equipment.Using tebau GmbH STA409PC TGA,this paper take a thermogravimetric analysis of the co-pyrolysis of raw materials.According to thermogravimetric data,the pyrolysis dynamics analyses of pyrolysis process is taken with the method of the Coats–Redfern.Experiments show that there is synergistic effect in the co-pyrilysis process,and the activation energy of co-pyrolysis is lower than the activation energy of individual pyrolysis.According to the characteristics of raw materials and experimental requirements,a rotary pyrolysis experimental platform is designed and built.The reaction part of the experimental platform was selected by using the spiral transport device.The main parameters are that:the inner diameter is 100mm,the length is 1000mm,the pitch is40mm,the radial gap is 30mm,and the electric heating power is 6kW.The rate of material treatment in the experimental platform is 3.84-13.9kg/h,and the reaction time of the material can be controlled between 10-14min.The co-pyrolysis experiments of biomass and coal are carried out on the completed experimental platform.The effects of the reaction time,the mixing ratio and the reaction temperature on the components of the thermal gas are analyzed.The experimental results show that:The content of CO,CO₂ and C_nH_m in pyrolysis gas all decreases with the increase of temperature.The content of H₂ and CH₄ increases with the increase of temperature,and the calorific value of pyrolysis gas increases with the increase of temperature.The co-pyrolysis of cotton stalk with coal and corn straw with coal have the same trend of pyrolysis gas and heat value.The content of CO,CO₂ and H₂ decreas with the content of coal increasing,the content of CH₄,C_nH_m and the heat value increas with the content of coal increasing.With the increase of reaction time,the content of CO₂,CH₄ and C_nH_m decreases,but at the same time,the content of CO and H₂ increases,and the calorific value of pyrolysis increases slightly with the increase of reaction time.On the basis of the calculation of material heat absorption and the numerical simulation of fluidized bed combustion intensity,the possibility of coupling between fluidized bed combustion furnace and rotary pyrolysis experimental device is discussed.The results of calculation and simulation show that fluidized bed combustion furnace can achieve high intensity combustion.The lowest thermal power is 9.2kW,and the maximum heat absorption power of pyrolysis is 2.7kW.Therefore,the coupled pyrolysis process of fluidized bed combustion furnace and rotary pyrolysis device can be realized.