Study On Gas Phase Catalytic Effect Of Brown Gas(HHO)on Low Oxygen Combustion Of Pulverized Coal

As an effective way to reduce NO_Xemission,low oxygen combustion technology can alleviate the ecological damage and environmental pollution in the process of coal combustion.However,due to the reduction of oxygen concentration,the technology has exposed insufficient combustion,reduced combustion efficiency,and increased carbon content in fly ash,resulting in water wall corrosion and other negative effects.Brown gas itself has the advantages of easy preparation,good catalytic properties and no pollution in combustion,which avoids the defects of slagging and uneven reaction contact brought by other solid catalysts in practical application.In this paper,a small amount of Brownian gas(HHO)is introduced to improve the combustion efficiency of pulverized coal in low oxygen environment.At the same time,a reducing atmosphere is created to improve the efficiency of reducing NO_Xemission.A fixed bed micro experimental platform of brown gas pulverized coal low oxygen combustion was built.During the experiment,the principle of element conservation method was used to observe the concentration of each gas in the flue gas produced in the process of pulverized coal combustion through the flue gas analyzer,and then the solid residue after reaction was ashed by muffle furnace to observe the fixed carbon content residue after reaction,which was used as the judgment standard of pulverized coal combustion characteristics.The results are as follows:(1)Promote the rapid release of volatile matter:when the reaction temperature is 600?and the reaction atmosphere is 21%,18%and 14%oxygen concentration respectively,when1%or 2%Brown gas is added,the time for CO concentration to reach the peak value in the flue gas is advanced by 2,4 and 4 minutes respectively,and the time for CH₄concentration to reach the peak value is advanced by 3,3 and 4 minutes respectively.When 1%Brown gas is added or not added,H₂is not produced When 2%Brown gas is added,a small amount of H₂(0.12?0.22%concentration)is produced.When the reaction atmosphere is 14%oxygen concentration,with the increase of reaction temperature,the precipitation time of volatile matter does not advance after adding 1%Brown gas,but the concentrations of CO,CH₄and H₂increase by about 1%.(2)To promote the burnout of pulverized coal:when the reaction temperature is 600?,the reaction atmosphere is 21%,18%and 14%oxygen concentration respectively,and 1%Brown gas is added,the weight loss rate of pulverized coal increases by 6.41%,9.82%and0.52%respectively.The ratio of fixed carbon in solid residue decreased by 39.37%,47.16%and 0.35%respectively.After adding 2%Brown gas,the weight loss rate of pulverized coal increases by 7.02%,10.36%and 0.64%respectively.The ratio of fixed carbon in solid residue decreased by 42.67%,49.19%and 0.67%respectively.The results show that the weight loss rate of pulverized coal increases by 0.78%,1.19%and 1.81%respectively when the reaction temperature is 700?,800?and 900?.The fixed carbon content in solid residue decreased by 0.70%,1.06%and 5.29%respectively.It can be seen that in the atmosphere of higher oxygen concentration,with the addition of brown gas,the combustion of pulverized coal can be obviously promoted.When the oxygen concentration is 14%,the phenomenon of pulverized coal burnout is not obvious.In conclusion,the addition of brown gas can promote the reductive volatilization,create a strong reducing atmosphere in the furnace,inhibit the formation of NO_X,and improve the efficiency of low oxygen combustion technology to reduce NO_Xemission.At the same time,it can catalyze the combustion of pulverized coal to a certain extent and improve the burn out rate.Therefore,brown gas as a catalyst has a certain practical significance.