Study On The Blending Characteristics Of Blue Carbon And Biomass

In order to relieve the strain of coal resources,it is a good solution to mix biomass in coal.Compared with other commonly used fuels in industrial coal-fired boilers,blue-coal has high fixed carbon content,high heat,low ash and low sulfur,less pollutant generation in combustion process and obvious price advantage.At present,the utilization rate of biomass is relatively low,so the mixed combustion of blue-coal and biomass can effectively make use of renewable clean energy substances,but also have certain environmental benefits.In this paper,the mixed combustion of blue-coal and biomass was studied by thermo-gravimetric experiment,kinetic analysis and numerical simulation.The combustion process of coal?blue-coal,Shenfu bituminous coal,Datong anthracite?and biomass?soybean stalk,wheat stalk?and the mixture of the two were studied experimentally under different conditions using a comprehensive thermal analyzer.The experimental results show that the combustion characteristic temperature of blue-coal decreases and the comprehensive combustion characteristic index increases with the increase of the proportion of biomass added in a certain range.When the biomass blending ratio is 50%,the ignition temperature of the mixed sample is basically close to the ignition temperature of the biomass.When the ratio of carbon to different proportion of soybean stalk is too large?more than 40%?,the combustion reaction releases less heat,so we should pay attention to the blending ratio and the mixing ratio of soybean stalk to20%-30%,the comprehensive combustion characteristic index is better.When the heating rate increases,the blending reaction of blue-coal and soybean stalk moves to the high temperature zone,and the comprehensive combustion characteristic index and burnout characteristic index increase.In order to solve the problem of high ignition temperature of blue-coal,it is possible to add combustion aids in addition to the biomass with low fire point.The combustion condition can be improved by adding combustion aids to the mixture of blue-coal and soybean stalk,but the improvement degree of different combustion aids is not the same,and the combustion characteristic temperature and activation energy of sodium citrate are greater than that of manganese dioxide.By numerical simulation of a 1.2MW experimental furnace,the simulation results show that with the increase of the proportion of soybean stalk,the volume fraction of the outlet CO₂ of the experimental furnace decreases,the average temperature of the cross section of the furnace decreases,and the volume fraction of the water vapor becomes larger.Increase the ratio of one wind to two times,when the biomass blending ratio is 30%,the CO₂ volume fraction of the outlet is the lowest,and the maximum temperature of the furnace is higher.