| Constructing environment-friendly and resource-saving society require the enterprises to save energy and reduce emission, improve resource utilization rate in the production process. Pyrite mineral resource is rich in China, many sulfuric acid plants use pyrite as raw material to product sulfuric acid by combustion oxidation of SO2 in the reformer. Because the oxidation conversion rate of SO2 in the reformer is not high, flue gas contains 0.30.5% of SO2 in reformer outlet. If without desulfurization dealing with the flue gas, SO2 emission would be excessive and wasted sulfur resource. Sulfuric acid plants are increasingly concerned on new technology about removal of sulfur dioxide in flue gas and recycling SO2 to sulfuric acid system,improving sulfur resource utilization.About the requirement of sulfuric acid plant's SO2 recovery, people use renewable absorbent process as sulfuric acid plant's flue gas desulfurization technology. The Cansolv method is most feazible,which is mature and used widely in coal-fired power plants. Cansolv method uses one kind of organic amine as the absorbent, which absorbs SO2 of flue gas in low temperature, desorbs SO2 from the absorption solution in high-temperature and regenerates absorbent.Firstly, through a series of single factor experiments, tested the effect of ethylenediamine concentration, initial pH value of absorption solution, the volume fraction of SO2 of flue gas, liquid gas ratio and temperature on the desulfurization rate and desorption rate,results showed the best operation process:ethylenediamine concentration C=0.3～0.4mol/L,pH=7.0～8.0,φSO2=0.3%,G/L=0.8～1.0,low temperatue is help of improving aborption rate,desorption temperature T=100～105℃.Secondly, according to the experimental results and the requirement about flue gas outlet's SO2 concentration, selected packed column as the mass transfer equipment and bulk ceramic raschig ring as packing, designed and calculated packing height and diameter of absorber and desorption tower, selected peristaltic pump as transportation equipment of absorption solution.Finally, according to the results of design calculations, manufactured absorber and desorption tower,under three conditions of inputing the air, inputing saturated water vapor and barrier gas ,studied on desulfurization rate and the relationship of SO2 concentration in desorption tower's flue gas and vacuum degree when continuous running the absorption and desorption devices.Detected various sulfur anions'concentration with titration method, explored the formation mechanism of heat stable salt and its effect factors. Studied results provided some theoretical and experimental information for ethylenediamine and phosphate solution desulfurization technology's industrial application in sulfuric acid plants. |
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