Development of High Severity FCC Process for Maximizing Propylene Production —Catalyst Development and Optimization of Reaction Conditions—

Abstract

A new hydrocarbon conversion process called High Severity FCC (HS-FCC) has been developed to maximize propylene production in oil refineries. HS-FCC propylene yield was maximized using a combination of three factors; catalyst properties, reaction conditions and reactor design. Optimization of reaction conditions and cata- lyst development found that high reaction temperature accelerated catalytic cracking rather than hydrogen trans- fer. As a result, olefin/paraffin ratio of the product was higher at high reaction temperatures. Short contact time suppressed undesirable reactions such as hydrogen transfer and thermal cracking. High catalyst/oil (C/O) ratio accelerated catalytic cracking over thermal cracking, which also accelerated at high reaction temperatures. High C/O ratio is necessary to maintain high reaction temperature by transferring enough heat from regenerator to reac- tor in commercial FCC units. Catalyst properties were investigated to maximize olefin production at high reac- tion temperatures. A proprietary catalyst containing low acid density zeolite suppressed hydrogen transfer and maximized olefin production.