Study On Fcc Process For More Propylene And Light Aromatic

As one of the most important organic chemical raw materials, the contradiction between propylene supply and demand become obviously, therefore, producing more propylene has already set severe requirements to numerous FCC units at home and abroad. The catalytic cracking process of producing more propylene and light aromatic proposed from this paper is according to the specific conditions of China’s oil resource and the characteristics of the refining units. Setting double reactors process as technology platform, using the corresponding more-produced propylene catalysts, taking the proper reaction conditions on the basis of the different natures of the oil fractions, though the optimization of process conditions to produce more propylene and light aromatic in the tow-riser.In this paper, the effect of different process conditions of three kinds of cracking raw material react in heavy oil riser reactor and gasoline riser reactor over MP3 catalyst synthesized in lab scale on the distribution of the cracking products was investigated in detail. Based on the analysis of the feeding ways in gasoline riser reactor during double reactor process, four kinds of process schemes about three cracking raw materials’simulation was performed.All of experimental results indicated that:the MP3 catalyst owed higher cracking activity、olefins selectivity and better oil raw material adaptability; the catalyst also can meet the FCC process requirements of using heavy oil as raw material to produce more propylene and light aromatic.The results of experiment show as follows:taking MP3 as FCC catalyst under the optimal process conditions, the yield of propylene can reach 18～22%in the heavy oil riser reactor; during the reaction process was carried out in the gasoline riser reactor, the yield of propylene can achieve 26～28%and 23% to C4 fraction raw material and gasoline light fraction raw material respectively, for the gasoline full fraction raw material, the yield of propylene was about 19%, under the circumstance of using C4 refining and non-refining as raw material, the yield of propylene can attain about 23% and 31% respectively. Among the productions, the yield of BTX was above 6% in the produced-gasoline which is a proper raw material for producing light aromatics, on the other hand, the hexadecane value and the freezing point of the produced-diesel was low, hence, the production can be applied to as attune components of vehicle diesel after hydrogenation treatment.