Thermo-gravimetric-analysis(TGA) was used to analyze the combustion characteristics of an oil shale and semi-cokes prepared from it.The effect of prior pyrolysis and TGA heating rate on the combustion process was stud...Thermo-gravimetric-analysis(TGA) was used to analyze the combustion characteristics of an oil shale and semi-cokes prepared from it.The effect of prior pyrolysis and TGA heating rate on the combustion process was studied.Prior pyrolysis affects the initial temperature of mass loss and the ignition temperature.The ignition temperature increases as the volatile content of the sample decreases.TG/DTG curves obtained at different heating rates show that heating rate has little effect on ignition temperature.But the peak of combustion shifts to higher temperatures as the heating rate is increased.The Coats-Redfern integration method was employed to find the combustion-reaction kinetic parameters for the burning of oil shale and oil shale semi-coke.展开更多
In a test rig,pulverized semi-coke was preheated to 850℃in a circulating fluidized bed(CFB)and then cornbusted at 1100℃in a down-fired combustor(DFC).Experiments were conducted to reveal the effects of three seconda...In a test rig,pulverized semi-coke was preheated to 850℃in a circulating fluidized bed(CFB)and then cornbusted at 1100℃in a down-fired combustor(DFC).Experiments were conducted to reveal the effects of three secondary air nozzle cases(co-axial jet,top circular jet and wall circular jet)on the NO emission.The results show that the optimized secondary air nozzle can reduce NO emission.O_2 concentration profile is the major factor affecting NO generation and emission,which is led by the secondary air nozzle.The lower O_2 concentration led to the generation of lower initial NO.The NO emission at the exit of the DFC was reduced from 189 to 92mg/m^3(@6%O_2)with the decrease of initial generation.The peak of NO at 100 mm below the nozzle should be attributed to the oxidization of NH_3 in the syngas,rather than the oxidization of fuel-N in the char.The low and well-distributed O_2 concentration contributes to the reduction of initial NO,which helps to reduce the NO emission.The combustion effieiencies of the eases of the co-axial jet,the top circular jet,and the wall circular jet are97.88%,98.94%and 98.74%,respectively.展开更多
基金Project CPEUKF08-04 support by the Key Laboratory of Coal Processing and Efficient Utilization, Ministry of Education of China
文摘Thermo-gravimetric-analysis(TGA) was used to analyze the combustion characteristics of an oil shale and semi-cokes prepared from it.The effect of prior pyrolysis and TGA heating rate on the combustion process was studied.Prior pyrolysis affects the initial temperature of mass loss and the ignition temperature.The ignition temperature increases as the volatile content of the sample decreases.TG/DTG curves obtained at different heating rates show that heating rate has little effect on ignition temperature.But the peak of combustion shifts to higher temperatures as the heating rate is increased.The Coats-Redfern integration method was employed to find the combustion-reaction kinetic parameters for the burning of oil shale and oil shale semi-coke.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA07030100)
文摘In a test rig,pulverized semi-coke was preheated to 850℃in a circulating fluidized bed(CFB)and then cornbusted at 1100℃in a down-fired combustor(DFC).Experiments were conducted to reveal the effects of three secondary air nozzle cases(co-axial jet,top circular jet and wall circular jet)on the NO emission.The results show that the optimized secondary air nozzle can reduce NO emission.O_2 concentration profile is the major factor affecting NO generation and emission,which is led by the secondary air nozzle.The lower O_2 concentration led to the generation of lower initial NO.The NO emission at the exit of the DFC was reduced from 189 to 92mg/m^3(@6%O_2)with the decrease of initial generation.The peak of NO at 100 mm below the nozzle should be attributed to the oxidization of NH_3 in the syngas,rather than the oxidization of fuel-N in the char.The low and well-distributed O_2 concentration contributes to the reduction of initial NO,which helps to reduce the NO emission.The combustion effieiencies of the eases of the co-axial jet,the top circular jet,and the wall circular jet are97.88%,98.94%and 98.74%,respectively.
