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 catalyst development found that high reaction temperature accelerated catalytic cracking rather than hydrogen transfer. 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 reactor in commercial FCC units. Catalyst properties were investigated to maximize olefin production at high reaction temperatures. A proprietary catalyst containing low acid density zeolite suppressed hydrogen transfer and maximized olefin production.
