Experimental Study On Reducing The NO_x From Fluid Catalytic Cracking Gas By Coal Burning

The flue gas emissions from the regenerator of a fluid catalytic cracking（FCC）unit makes up the largest part of the total refinery pollutions. is characterized bycontaining large quantity of dust, high temperature（600℃⁷00℃）,complexcomponent,therefore, to seek suitable denitration process has been the focus ofresearch.This paper simulated the flue gas emission from FCC catalyst regenerationprocess and analyse the flue gas composition, select charcoal as a reducing agent.Theeffects of reaction temperature, space velocity, NO_xinlet concentration, oxygencontent and other operation conditions on the efficiency of NO_xreduction of charcoal,experiment found that the reduction efficiency decreases with the temperatureincreases, but higher than600℃the efficiency tends to be stable; the reductionefficiency decreases with the space velocity increases, NO_x removal rate is above80%between5000h-1⁷000h-1. The efficiency is not affected under the experimentalconditions of the imported NO_xconcentration (500mg m-3⁹00mg m^-3) and oxygen（5%⁸%, volume fraction）. The addition of oxygen can promote carbon gasificationat low temperature, resulting in the surface of carbon material to produce more carbonactivity and surface activity of C （O） compounds, while the carbon activity andsurface activity of C （O） compound in the presence of both in favor of NO reductionreaction, The results of comprehensive experimental show the NO_xremoval efficiencycan reach95%at700℃、6%O2、5000h^-1,This paper studies the effect of carbonreduction denitration process in the presence of SO2, found it has little effect onefficiency at high temperature. The content of CO of outlet flue gas is increased dueto incomplete combustion of carbon, oxygen content is decreased due to the samereason, CO can be burning in hood to removing and recycling the energy; Accordingto the calculation of carbon wastage and design of FCC catalyst regeneration flue gasdenitration process. According to the carbon and NO heterogeneous reductionreaction to establish a macroscopic kinetic equation mathematical model, calculate thereaction activation energy （Ea） and pre-exponential factor （k0） through theexperimental data, thus we get the reaction rate equation:-(dC_NO/dt)=263.77.exp(-（23255.92/RT）C_NO^0.98The carbon reduction method is applied in a Hunan paint factory denitration project, the results show through the commissioning and operation: The denitrationefficiency can reach above95%through controling the carbon reduction bedtemperature and space velocity, reach the discharge standards. The technologicalprocess and equipment was simple, convenient to operation, the carbon materialabundantly available, the cost of treatment is low, products for CO₂and N₂, withoutthe secondary pollution.