The Design And Simulation Of Triethylenediamine Separation Process

Triethylenediamine is not only the most widely used but also the largest demanded polyammonia catalyst in the area of polyurethane industry. Recently, polyurethane foam develops quite rapidly, which occupies approximately 80% in the overall polyurethane products. With the application area becoming larger, the demand for catalyst triethylenediamine increases drastically. Industry catalysis research institute develops a new method of making triethylenediamine, which has a relatively higher selectivity. The researches on the design, simulation of the separation process of the reaction products and the analysis of the feasibility, are quite helpful to put this method into industrial production and realize industrialization.Software-ASPEN PLUS is an advanced software for process simulation which is produced by ASPEN Co. in America. Using this software to simulate the process, accurate unit operation models can be provided for enterprises . It can not only increase simulation efficiency but also can evaluate the operation of the original equipment and reconstruct, remodify the original equipment to reach a most excellent design.Software ASPEN PLUS is chosen as the working platform in this article, strict distillation tower operation unit is adopted. The NRTL and ELECNRTL thermod ynamic equations are used to simulate the process of separating and purifying triethylenediamine.The function of property estimation within software Aspen Plus is used to estimate the physical property of two unknown substances effectively and accurately. Consequently, reasonable technological parameters are obtained. Choosing energy consumption and equipment consumption as the objective functions, four distillation separation sequences are chosen based on the methods of direct deduction and optimization. Some important parameters such as the number of the plates, feed stage and flow rate of overhead product are studied during the simulation process. The effect of the changing of those parameters on the whole simulation process is also studied. The best separation sequence is chosen through analysis. The mass fraction of Piperazine, 2MP, NEP is 97.86% and triethylenediamine's mass fractionis 96.57% through the treatment of it.Some technical streams need to be heated while others need to be cooled. Mixing those streams together and completely using hot streams to heat cool streams to enhance the heatrecycling rate. At the same time, the separation sequence's heat integration is studied. Pinch technology and Problem Table are adopted to study heat exchange network of the separation sequence. More energy saving separation technical process is obtained. Energy saving can be reached 48.29%.