Development Of New Chelated Iron Desulfuring Agent And Desulfurization Technology

At present good functional desulfurization agent is not conducive to industrial large-scale promotion because of high price. The research selects out a chelated-irondesulfurization system, it is able to have good stability under alkaline conditions, highsulfur capacity, and it can be beneficial to be used in large-scale industrial applications.Based on theory of oxidation-reduction potential, chelated iron desulfurization systemhas been screened. To screen out the best system is mixed desulfurization system ofPBTCA (2-phosphonic acid, butane-1,2,4-tricarboxylic acid)/EDTA (ethylenediaminetetraacetic acid) with the ratio of4/1under laboratory conditions. To test the sulfur contentin my own designed desulfurization tower, the sulfur capacity of this complexing irondesulfurization system can reach to0.845g/L. It is equel to common high efficiencydesulphurization on the aspects of sulfur capcity but it has low expent. To test theregeneration condition in my own designed regeneration tower，it is10.9L desulfurizationfluid regeneration rate was more than95percent in the blast volume of400L, about10.15m~3air/kg sulfur, compared to the previously design tower of13m~3air/kg sulfur is stilllowe21.92%. What’s more, the complex system can easily regenerate, because addedauxiliary oxygen carrier to it. Desulfurization-regeneration system continuously operated700min, the output concentration of hydrogen sulfide is still less than2mg/m~3,desulfuration efficiency is still more than99percent. When measuring sulfur content, thesystem didn’t regenerate running600min the output concentration of hydrogen sulfidereached to10mg/m~3. To treat the coking desulfurization decyanation waste with thismethod in order to recycle sodium thiosulfate, sodium thiocyanate or to recoverthiocyanate ion to produce cuprous thiocyanate. After evaporation, liquid-solid phaseseparation, mixing content of sodium thiocyanate solution, cooling and crystallizationprocess, product containing sodium thiocyanate is equal or greater than90percent isrecycled, the recovery rate of sodium thiocyanate is82.3percent, sodium thiosulfatecontent of the filter residue reached to85percent. To recycle effluent thiocyanate ion toproduce cuprous thiocyanate, the cuprous thiocyanate content was99.1percent at theoptimal conditions,,Chelated-iron system which has been studied mainly include ferrisulphas,ethylenediamine tetraacetic acid, organic phosphate2-phosphonic acid, butane-1,2,4-tricarboxylic acid, compared to the888, MSQ, ADA desulfurizers etc in the market, moreeconomical and more competitive in the market. Screened desulfuration was higher sulfurcapacity and better regeneration performance. Industrial desulfurization-regenerationsystem has been simulated, To obtain the optimal operating conditions of thedesulfurization system has a solid theoretical foundation and good guide in industrialproduction.