Study On Simulation And Optimization Of Coal Tar Distillation Separation Process

Coal tar is a major byproduct of coking, and its composition is very complex. Itmainly contains polycyclic aromatic hydrocarbons, which is also immensely valuableorganic chemical raw materials. It is reported that some of polycyclic aromatichydrocarbons in coal tar have certain irreplaceable in the field, such aspharmaceuticals, pesticides, dyes, synthetic fibers and high temperature materials. Onthe whole, coal tar processing technologies in domestic is relatively backward.Atmospheric distillation processes is a mainly technology, which is divided intoone-tower process and two-tower process. Correspondingly, an atmospheric-vacuumprocess is usually employed in abroad, which can not only obtain coal tar productswith full range and multi-species, but also improve the quality of coal tar pitch.Due to the complexity of coal tar system, the previous studies were limited tothe traditional experimental methods. With the development of scientific andtechnological progress and computer technology, some advanced simulation methodswere used to study coal tar separation process. In this work, Universal Aspen Plusprocess simulation software is adopted in simulating coal tar distillation process.In this paper, based on100,000tons/year of coal tar devices in the tar plant ofchemical factory of Anshan Iron and Steel Group Company, Aspen Plus processsimulation software is employed to establish a model for coal tar distillation system, amethod of combining real components and virtual components is used to characterizecoal tar conventional components, and the appropriate thermodynamic methods andalgorithms are selected to solve these equations. By the analysis of the simulationresults, it was found that the calculation results of the model was very close to theactual production index, which verified the reliability of simulation model. The modelbasically reflects the law of coal tar distillation process and can be used for theseparation process of coal tar.On this basis, the simulation and optimization of the main separation units in thecoal tar distillation process was further researched. Firstly, the effects of temperature, pressure on the first evaporator and the secondary evaporator were investigated.Especially, the attentions focused on the operation conditions of anthracene tower andfraction tower. And, on the basis of material balance, the effects of the feed location,reflux ratio and lateral line production location on the separation process and productpurity, energy consumption and composition content were discussed. The resultscould provide an improved basis and theoretical guidance for the practical industrialproduction.