| The furnace gas produced in the production of yellow phosphorus contains trace hydrogen sulfide(H2S),which hinders the further utilization of yellow phosphorus tail gas due to its strong corrosivity and severe toxicity.There are many industrial methods for H2S removal,but due to the small amount of gas in yellow phosphorus production furnace,these methods have disadvantages such as high cost and complicated operation.In this paper,according to the production characteristics of phosphorus chemical enterprises,a new method of purifying hydrogen sulfide gas with yellow phosphorus and phosphate pulp was put forward.The absorption of H2S with yellow phosphorus(P4)and phosphate pulp as compound absorbent and its removal mechanism were studied.The results show that this method can effectively remove H2S from gas and has a good industrial application prospect.The main conclusions are as follows:(1)A method of purifying H2S in flue gas with P4 and phosphate pulp composite absorbent was proposed.Through investigating the effects of slurry temperature,stirring intensity,P4 concentration,phosphate solid content,H2S concentration of flue gas and flue gas flow on H2S removal effect of yellow phosphorous phosphate ore composite absorbent.In the flue gas flow rate of 300m L/min and H2S concentration of 1000-1200 mg/m3,the better reaction conditions were obtained:the slurry temperature is 65-70?,the stirring speed is 1000-1300r/min,the concentration of P4 is 2.4-4.0 g/L,the solid content of phosphate slurry is4.0-8.0 g/L,and the H2S removal efficiency reaches more than 80%.(2)The reaction mechanism of liquid phase removal of H2S by yellow phosphorous phosphate ore composite absorbent was explored.Through the characterization of the adsorption slurry and gas products,H2S is mainly induced to produce O3 through the liquid phase of P4 and O2,H2S reacts with O3 to generate SO2,which dissolves rapidly in water and further oxidizes to form H2SO4.H2SO4 mainly reacts with Ca Mg(CO3)2 in phosphate rock first,and then with Ca5(PO4)3F.The active substances O3,SO4·-and OH·,produced in the reaction process,partially oxidize H2S and HS-directly to H2SO4 and S0,and the trace Fe3+and Mn2+dissolved in phosphate ore play a key role in the formation of the active substances.(3)It is confirmed that the reaction of P4 and O2 to produce O3 is liquid phase reaction and the macroscopic kinetic equation is established.Through the design of gas-liquid reaction,it is confirmed that the main products of the reaction of P4 and O2in the liquid phase are O3 and P4O10.By controlling the key influencing factors,orthogonal experiments were designed to obtain the reaction rate,reaction order,rate constant and other parameters of the system.Based on the two-mode theory and Henry's law of liquid phase,the macroscopic kinetics model of H2S removal by ozone induced by yellow phosphorus liquid phase was obtained simultaneously.The kinetic equation of P4 reaction with O2 and the kinetic equation of P4 liquid phase induced O3absorption of H2S were obtained by using the experimental data,which provided a theoretical basis for the industrial application of yellow phosphorus liquid phase induced ozone technology. |
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