Research And Modeling Of Phosgene Synthesis Process

The scientific name of phosgene is carbonyl chloride, it’s flavor like rotten apple. Pure phosgene is colorless, but its industrial products color is light yellow or light green. It is a strong stimulus and highly toxic, and the chemical nature very lively. It is a kind of important chemical raw material. It is widely used in the synthesis of pesticide, dye, paint, initiator, pharmaceuticals, fine chemicals, isocyanate (R-NCO), diphenyl methane diisocyanate (MDI), toluene diisocyanate (TDI), polyurethane (PU), etc. This paper focuses on mathematical modeling and optimization analysis of the phosgene synthesized, and simulation studies of phosgene refined, in order to guide the production practice of the factory.This paper studies two kinds of reaction kinetics of phosgene synthesis of chlorine and carbon monoxide, the reaction kinetics equation of I and II. Using Fortran programming and runge-kutta algorithm numerical analysis, one-dimensional homogeneous mathematical model of phosgene synthesis reactor is established. On this basis, combining the calculation equation of heat transfer coefficient and pressure, established a more complete one-dimensional homogeneous mathematical model of phosgene synthesis reactor. Establish one-dimensional homogeneous mathematical model in two reaction kinetics separately. From analysis and comparison of the calculation results (distribution of temperature and conversion rate of chlorine along the tube length), shows that the calculation of reaction kinetics equation I results more in line with the industrial production.Application of Matlab programming, Crank- Nicholson algorithm numerical analysis, based on reaction kinetics equation I of phosgene synthesis reactor, two-dimensional homogeneous mathematical model is established. To calculate the average and the center axis value of the distribution of temperature and conversion rate of chlorine along the tube length. And comparison with the calculated results of one-dimensional homogeneous mathematical model, shows that the average value of calculated results of the two-dimensional pseudo homogeneous mathematical model and the calculated results of one-dimensional homogeneous mathematical model are basically identical. In this paper, in order to solve simply, one-dimensional homogeneous mathematical model is adopted, and reaction regularity of phosgene synthesis of chlorine gas and carbon monoxide are studied.Based on the established one-dimensional homogeneous mathematical model of phosgene synthesis reactor, the various factors influencing the phosgene production are studied. Feed rate and catalyst loading density on the reaction are analyzed. Feed rate increases, catalyst loading density decreases can effectively reduce the hotspot temperature of reaction, advantageous to extend the life of the catalyst, but bad for conversion rate of chlorine, it needs to lengthen the reactor length to compensate for it in design the reactor.This paper deals with phosgene refined simulation studies, using distillation operation removal the restructuring and chlorine which may exist in phosgene. Results show that appropriate theoretical plate number is 22, the best feed pieces is 21, the best extraction location pieces is 12. On this condition, the impurity content phosgene is reduced greatly after refined.