A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel （RDF）. The CaO dechlorination model obtained by the thermal g...A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel （RDF）. The CaO dechlorination model obtained by the thermal gravity analysis （TGA） is coupled to investigate the process of CaO dechlorination. An Eulerian-Eulerian method is adopted to simulate the gas-solid flow and self-developed chemical reaction modules are used to simulate chemical reactions. Flow patterns, gasification results and dechlorination efficiency are obtained by numerical simulation. Meanwhile, simulations are performed to evaluate the effects of Ca/Cl molar ratio and temperature on dechlorination efficiency. The simulation results show that the presence of bubbles in the gasifier lowers the CaO dechlorination efficiency. Increasing the Ca/Cl molar ratio can enhance the dechlorination efficiency. However, with the temperature increasing, the dechlorination efficiency increases initially and then decreases. The optimal Ca/Cl molar ratio is in the range of 3. 0 to 3. 5 and the optimal temperature is 923K.展开更多
Study on behavior of chlorine contained in oval-shaped densified refuse derived fuel (d-RDF) prepared from municipal solid waste in pyrolysis was carried out by means of temperature-programmed electrical furnace, and ...Study on behavior of chlorine contained in oval-shaped densified refuse derived fuel (d-RDF) prepared from municipal solid waste in pyrolysis was carried out by means of temperature-programmed electrical furnace, and the gas evolving from pyrolysis was investigated by FTIR. De-HCl rate was calculated by determining the emission fraction of HCl in the flue gas and the fraction of Cl left in the pyrolysis residue. The results show that Cl in the d-RDF releases primarily in the form of HCl during the pyrolysis, and the initial releasing temperature of HCl enhances with the increase of heating rate. Meanwhile, the higher the end temperature of pyrolysis, the more the Cl released. De-HCl rate is about 70% when the end temperature of pyrolysis is around 600℃. Besides, mechanism of Cl release is dis-cussed.展开更多
A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature...A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature. The physicochemical property of RDF was tested. Orthogonal experiment method was used to optimize the process parameters using dropping strength (mechanical strength) and thermal stability of the RDF as indices for quality of RDF. The result shows that the mixture of MSW and coal with a total moisture ranging from 5% to 17% can be easily compressed into RDF briquettes at a pressure above 70 MPa. When the briquetting pressure is higher than 100 kN and moisture content is about 10%, the qualified RDF can be obtained. The orthogonal experiment shows that the moisture can greatly affect the mechanical strength of RDF, while all the technique parameters have no obvious influence on thermal stability of RDF. The optimal parameters are a shaping pressure of 106 MPa, a moisture content of 10%, and a coal content of 20%.展开更多
In this paper,refuse derived fuel(RDF)and bituminous coal were co-fired to investigate the particulate matter(PM)yields and the interaction between the inherit minerals in a lab-scale drop tube furnace(DTF).The PM1-10...In this paper,refuse derived fuel(RDF)and bituminous coal were co-fired to investigate the particulate matter(PM)yields and the interaction between the inherit minerals in a lab-scale drop tube furnace(DTF).The PM1-10 yields during the co-firing of coal and RDF dramatically decreased by 16.29%~28.5%of the combustion of coal alone.In addition,methane auxiliary combustion inhibited the PM_(1) yields by 7.95%at air atmosphere.The Si-rich minerals in coal interreacted with the organic alkali(earth)metals in RDF,massively generating sticky particles with high liquid amount of K-Al-Si and Ca-Al-Si,promoting the transformation of fine grains into coarser mode.Moreover,it was proved that both methane auxiliary combustion and co-firing can reduce the emission of fine particles.The additional heat accelerated the burn of the char at the early stage of combustion,providing adequate time for the interaction between the inorganic species.Through thermodynamic equilibrium calculations of 1500~3000 fly ash grains,it was found that co-firing increased the formation of sticky particles by 64.8%~70.3%,resulting in a significant enhancement in capturing fine particles and Na,K vapor.Therefore,the co-firing of coal with RDF offers a promising approach to realize the harmless and resourceful treatment of municipal solid waste(MSW),and inhibit land resource losses caused by landfill.展开更多
NO_x formation behaviors of two kinds of RDF (Refuse Derived Fuel) samples with different N content were studied using a fluidized bed combustor. The results show that RDF samples are easily to be combusted in the flu...NO_x formation behaviors of two kinds of RDF (Refuse Derived Fuel) samples with different N content were studied using a fluidized bed combustor. The results show that RDF samples are easily to be combusted in the fluidized bed reactor and the combustion process is stable without external energy. The distribution of NO_x contents depends on the temperature distribution along the height of the fluidized bed. Under the same operation conditions, the higher nitrogen content in the RDF sample leads to higher NO_x concentration in the flue gas. Both the extra air ratio and the injection of secondary air can affect the NO_x formation characteristics, especially for the RDF with high nitrogen content.展开更多
基金The National Natural Science Foundation of China(No.51476032)
文摘A three-dimensional numerical model verified by previous experimental data is developed to simulate the fluidized bed gasification of refuse derived fuel （RDF）. The CaO dechlorination model obtained by the thermal gravity analysis （TGA） is coupled to investigate the process of CaO dechlorination. An Eulerian-Eulerian method is adopted to simulate the gas-solid flow and self-developed chemical reaction modules are used to simulate chemical reactions. Flow patterns, gasification results and dechlorination efficiency are obtained by numerical simulation. Meanwhile, simulations are performed to evaluate the effects of Ca/Cl molar ratio and temperature on dechlorination efficiency. The simulation results show that the presence of bubbles in the gasifier lowers the CaO dechlorination efficiency. Increasing the Ca/Cl molar ratio can enhance the dechlorination efficiency. However, with the temperature increasing, the dechlorination efficiency increases initially and then decreases. The optimal Ca/Cl molar ratio is in the range of 3. 0 to 3. 5 and the optimal temperature is 923K.
基金Project supported by Foundation of Education Department of Jiangsu Government for Commercialization of High Technology Developed by Universities
文摘Study on behavior of chlorine contained in oval-shaped densified refuse derived fuel (d-RDF) prepared from municipal solid waste in pyrolysis was carried out by means of temperature-programmed electrical furnace, and the gas evolving from pyrolysis was investigated by FTIR. De-HCl rate was calculated by determining the emission fraction of HCl in the flue gas and the fraction of Cl left in the pyrolysis residue. The results show that Cl in the d-RDF releases primarily in the form of HCl during the pyrolysis, and the initial releasing temperature of HCl enhances with the increase of heating rate. Meanwhile, the higher the end temperature of pyrolysis, the more the Cl released. De-HCl rate is about 70% when the end temperature of pyrolysis is around 600℃. Besides, mechanism of Cl release is dis-cussed.
基金Foundation of Education Departmentof Jiangsu Government for Commercialization of High Technology Developed in Universities
文摘A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature. The physicochemical property of RDF was tested. Orthogonal experiment method was used to optimize the process parameters using dropping strength (mechanical strength) and thermal stability of the RDF as indices for quality of RDF. The result shows that the mixture of MSW and coal with a total moisture ranging from 5% to 17% can be easily compressed into RDF briquettes at a pressure above 70 MPa. When the briquetting pressure is higher than 100 kN and moisture content is about 10%, the qualified RDF can be obtained. The orthogonal experiment shows that the moisture can greatly affect the mechanical strength of RDF, while all the technique parameters have no obvious influence on thermal stability of RDF. The optimal parameters are a shaping pressure of 106 MPa, a moisture content of 10%, and a coal content of 20%.
基金supported by Major Program of National Natural Science Foundation of China(5217060506)Shanghai Pujiang Program(22PJ1405900).
文摘In this paper,refuse derived fuel(RDF)and bituminous coal were co-fired to investigate the particulate matter(PM)yields and the interaction between the inherit minerals in a lab-scale drop tube furnace(DTF).The PM1-10 yields during the co-firing of coal and RDF dramatically decreased by 16.29%~28.5%of the combustion of coal alone.In addition,methane auxiliary combustion inhibited the PM_(1) yields by 7.95%at air atmosphere.The Si-rich minerals in coal interreacted with the organic alkali(earth)metals in RDF,massively generating sticky particles with high liquid amount of K-Al-Si and Ca-Al-Si,promoting the transformation of fine grains into coarser mode.Moreover,it was proved that both methane auxiliary combustion and co-firing can reduce the emission of fine particles.The additional heat accelerated the burn of the char at the early stage of combustion,providing adequate time for the interaction between the inorganic species.Through thermodynamic equilibrium calculations of 1500~3000 fly ash grains,it was found that co-firing increased the formation of sticky particles by 64.8%~70.3%,resulting in a significant enhancement in capturing fine particles and Na,K vapor.Therefore,the co-firing of coal with RDF offers a promising approach to realize the harmless and resourceful treatment of municipal solid waste(MSW),and inhibit land resource losses caused by landfill.
文摘NO_x formation behaviors of two kinds of RDF (Refuse Derived Fuel) samples with different N content were studied using a fluidized bed combustor. The results show that RDF samples are easily to be combusted in the fluidized bed reactor and the combustion process is stable without external energy. The distribution of NO_x contents depends on the temperature distribution along the height of the fluidized bed. Under the same operation conditions, the higher nitrogen content in the RDF sample leads to higher NO_x concentration in the flue gas. Both the extra air ratio and the injection of secondary air can affect the NO_x formation characteristics, especially for the RDF with high nitrogen content.
