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Co-processing of bio-oils with conventional petroleum-based feedstocks is an attractive initial option to make use of renewable biomass as a fuel source while leveraging existing refinery infrastructures. However, bio-oils and their processing intermediates have high concentrations of organic oxygenates, which, among their other negative qualities, can result in increased corrosion issues. A range of stainless steel alloys (409, 410, 304L, 316L, 317L, and 201) was exposed at the base of the riser in a fluid catalytic cracking pilot plant while co-processing vacuum gas oil with pine-derived pyrolysis bio-oils that had been catalytically hydrodeoxygenated to 2 to 28 % oxygen. A catalyst temperature of 704C, a reaction exit temperature of 520C, and total co-processing run times of 57-75 h were studied. External oxide scaling 5-30 micrometers thick and internal attack 1-5 micrometers deep were observed in these short-duration exposures. The greatest extent of internal attack was observed for co-processing

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The fluid catalytic cracking (FCC) unit is the primary hydrocarbon conversion unit in the modern petroleum refinery. It uses heat and catalyst to convert a variety of high molecular weight feed types (eg, gas oils, cracked gas oils, deasphalted gas oils, and atmospheric/vacuum resids) into lighter, more valuable products such as gasoline, light fuel oil, and petrochemical feedstocks such as propylene and butylene. This article reviews the role of catalyst in the fluid catalytic cracking process. The design of catalyst, catalyst poisons, and the effect of catalyst on product yields and selectivity are covered. Also, the role of catalytic additives in maximizing light olefins and in controlling emissions is discussed. In addition, the importance of catalyst testing is covered, along with unconventional feedstocks and processes that are extending the role of FCC catalyst to areas beyond the original FCC process scope of converting heavy petroleum feedstocks into transportation fuels.