Propylene Device Simulation And Optimization

As we all know, propylene is an important kind of chemical.. It is regarded as the basic raw material along with ethylene for chemical industry. A lot of other chemical products are pbtained from it through further processing. As olefin plants of large scale are always connected with downstream processing plants, how to improve the performance of C3 unit through reducing energy and material cost become the key step during the efforts to improve the general performance of ethylene mills. Some of the usual problems encountered in the operation of QILU Ethylene Plant are discussed in this paper.Recent developments in the field of ethylene production are reviewed in the first place. A number of new fixed hydrogenation process have appeared due to the emergence of new hydrogenation catalysts with excellent qualities. These technologies can simplify the production flow and reduce energy cost to a considerable degree. Base on the former hydrogenation methods, they do not need formidably large investment to replace traditional equipment as usual. However, profits from these improvements will be satisfactory.Catalytic hydrogenation integrates fraction and hydrogenation in a single column. The separate hydrogenation unit will be eliminated, thus lower the complexity of the related flow greatly. Easy operation can also be achieved. Multi-component refrigeration technology uses a kind of mixture as the medium in stead of a single component as traditional methods.Compared with traditional one, the new technique produces more levels of cold sources. Thanks to the reduction of the number of compressors, Less energy will be needed to fulfill refrigeration requirements.A mathematical model of C3 hydrogenation reactor is established. The calculation results are applied to analyze the performance of hydrogenation reactor. Lowering the reaction pressure leads to the lowering of temperature at the outlet, which diminishes the amount of green oil formed in the reactor. Recycle ratio can be lowered from 1.3 to0.8 without negative effects. These two measures have been taken in operation and have resulted in expected outcome.A mathematical model for distillation is also built to stimulate the high depropane tower and the propylene rectifier. The top pressure of depropane tower can be decreased from 1.67MPa to 1.5MPa,which leads to a lower bottom temperature.Reflux ratio should be increased lightly to make sure that the heavy component concentration is under control. The propylene rectifier can withstand higher MAPD concentration in the feed, that is to say, satisfactory product can still be got in spite of the higher concentration of MAPD than usual in the feed. So the conversion rate of hydrogenation process can be decreased further.