Experimental Study Of Recycled No Reduction In Oxy-fuel Combustion

Capturing CO2 from conventional coal-fired power plant is very costly because of its relatively low concentration in the flue gas. One option to reduce the cost of gas separation is to increase CO2 concentration in the flue gas by eliminating nitrogen before combustion and recycling part of the flue gas. This scheme is known as O2/CO2 recycle combustion. It has been investigated that the recycled NO has a significant effect on the final emission of NOx in the O2/CO2 recycle combustion.In this research, chars were prepared in a simulator of high-temperature entrained flow reaction (SHEFR) which can simulate the environment of real oxy-fuel combustion. Then a drop tube furnace (DTF) was used to simulate coal combustion by separating the gas-phase reaction and coal-char reaction. Also, the char combustion characteristics and combustion dynamic parameters have been studied by Thermal Gravimetric Analysis.The influence of O2/CO2 ratio,excess air ratio and temperature on the volatile-N or fuel-N transformation during the oxy-fuel combustion have been studied. Also, the comprehensive effect of volatile-N and fuel-N on the recycled NO reduction has been studied.