Study On NO Enhanced Absorption In The Process Of Ammonia-based Wet Flue Gas Desulfurization

In WFGD(the wet flue gas desulfurization), the desulfurization efficiency ofLimestone-gypsum and ammonia-based wet flue gas desulfurization can be more than95%. Both of them are maturely developed, widely used and economical, resulting in adominant position in the desulfurization industry. Compared with Limestone-gypsum,ammonia FGD appeared late, but its desulfurization efficiency is easier to get98%,meeting the current strict emission requirements. However, although ammoniadesulfurization can obtain higher desulfurization efficiency, it cannot reach thedenitration standards. Existing methods of wet denitration mostly oxidize NO to NO2andabsorb it, but the cost of the oxidizer is very high, thus it is necessary to study how to useammonia desulfurizing solution to remove sulfur with a low-cost removal of NO.The main components of the desulfurization solution produced after ammoniadesulfurization is (NH4)2SO3,Add denitration apparatus and use (NH4)2SO3to deoxidizeNO into N2,successfully removing NO. In this Article,(NH4)2SO3has been chosen assolution to absorb NO, and its absorption characteristics of NO in a bubbling reactor willbe studied in experiments. NO is insoluble in water, hence, the NO removal efficiency ofthe desulfurization solution is very low. To improve the NO removal performance of(NH4)2SO3solution, experimental research was carried out on NO enhanced absorptionusing Feâ…¡EDTA in (NH4)2SO3solution in a bubble reaction tower in various processconditions. Simultaneously, the optimal experimental conditions have been tested, inwhich the NO removal efficiency is more than80%. Although Feâ…¡EDTA has a goodabsorption rate and capacity to NO, the higher prices and accompanying secondarypollution of EDTA limit its industrial applications. Thus,(NH4)2SO3is selected as areducing agent to explore the NO removal efficiency using a variety of complexingagents from the copper complexing agent studied not often, the cobalt complexing agentstudied popularly to the potential FeIICit. By comparing and analyzing the preparation ofabsorbing liquid, equipment corrosion and absorption performance, it is found thatFeâ…¡Cit has complex technical advantages, but relevant experimental data for NOremoval efficiency is vacant. Therefore, the absorption mechanism of Feâ…¡Cit complexingwith NO was analyzed, and some factors, such as the molar ratio of Feâ…¡to Cit, pH,reaction temperature, Feâ…¡Cit concentration, NO concentration, the gas flow rate andreactor configuration (single column or double columns) on NO removal efficiency wereinvestigated. Validated experiment was carried out under the optimum conditions in thedouble columns, the corresponding NO removal efficiency reached up to71.66%within1min. Finally, comprehensive and systematic research on Feâ…¡Cit complexation NOabsorption and regeneration was studied. This study results provide technical reference for reinforced wet denitrification based on desulfurization using ammonia solution.