| China is one of the countries with phosphate rock resources in the world. It has been reported that the reserve and production of phosphate rock in Yunnan province is ranked among the top nationwide. And the yellow phosphorus production-oriented chemical industry plays an important role in the economy of Yunnan Province. Among all the phosphorus chemical industry, in the processes of production of yellow phosphorus and sodium hypophosphite, phosphine (PH3) was generated, which caused environmental pollutions and did harm to the human health. PH3was a kind of poisonous gas which could cause spontaneous combustion even explosion in air condition and hidden trouble in safety. When human was exposed to the air containing PH3, it could appear poisoning phenomenon, sometime, it even lead to death. However, PH3could also be used as an important chemical raw material. So finding a proper and effective way to handle the PH3could not only reduce environmental pollution but also improve the economic effect of phosphorus chemical industry. In this paper, the PH3was taken as research objects which generated from the preparation of sodium hypophosphite used the reaction of phosphorus slag with alkali liquor. The reaction of PH3with concentrated sulfuric acid and formaldehyde under a certain temperature was involved to prepare high value-added tetrakis (hydroxymethyl) phosphonium sulphate (THPS).THPS is a highly effective biocide, neither pollute the environment nor cause poisoning of fish and other organisms. It is now widely used in water treatment systems, cooling systems and oil systems for efficient bactericidal effect and good features.The main content of this study include:(1) design reasonable the experimental process and optimizing experiment.(2) Selection of the best catalyst for THPS synthesis from AlCl3, SnCl4, ZnCl2, MgCl2, CuCl taking phosphine conversion rate as index according to the related literature and patent.(3) Single factor experiment, in this section the effects catalyst dose, formaldehyde and sulfuric acid molar ratio, reaction temperature and the carrier gas flow rate on the PH3conversion was studied.(4) Based on the results of single factor experiments,4factors3levels orthogonal experiment was taken to optimize experiment condition. The main factors affecting the result of the experiment was concluded through a variety of analysis including intuitive analysis and variance analysis.(5) Analysis of the reaction mechanism and kinetics of THPS synthetic reaction.The results showed that:CuCl was the best catalyst for the reaction of THPS synthesis. And the best condition for THPS synthesis process was that catalyst dosage of1.0g, chemical reaction temperature of50℃, the molar ratio of sulfuric acid and formaldehyde of1:8, carrier gas flow rate of30ml/min. The reaction temperature was the main factor affecting the synthesis reaction following by carrier gas flow rate, the molar ratio of sulfuric acid and formaldehyde, catalyst dosage. THPS synthetic reaction belonged to the first order reaction, the reaction rate equation was k=164.02exp (146360/RT)... |
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