Maximization Of Propylene In FCC Process By Adding ZSM-5 Additive to FCC Catalyst

FCC units are present in most refineries for production of gasoline, LPG and middle distillates, representing a conversion capacity above 14 MMBPD. FCC also plays an increasing role in residue conversion with now more than 4 MMBPD of RFCC capacity in the world and accounts for more and more of the propylene market(with more than 25% of propylene world production coming from FCC gas plants)[5].The effects of operating parameters such as reaction temperature, and ZSM-5 as FCC catalyst additive, on the distribution of the product and the yield of propylene were investigated on a bench scale fluidized bed reactor. It is the aim of this work to perform an overall analysis of the yields and selectivity of hydrocarbons obtained in the vacuum gas oil conversion over FCC and ZSM-5 catalysts .The effectiveness of ZSM-5 additive adding in FCC process was investigated. The experimented data of off gas analysis showed that, VGO cracking at high reaction temperatures of 450–550°C increases the yield of propylene. Similar behavior is observed with the addition of 10–25 wt.% ZSM-5 additive. The combination of th two effects (high temperature and ZSM-5 addition) makes the FCC unit an excellent source of light olefins for downstream petrochemical units. Higher FCC reactor temperatures (600- 650°C) would not have positive effect for increasing propylene yield.

کلیدواژه ها:

FCC ، Propylene ، Yield ، Additive ، ZSM-5