PILOT RESULTS: OXY-FIRING ON REFINERY VIABLE

Tamar Hallerman
GHG Monitor
9/6/13

Researchers behind the industry-funded CO2 Capture Project (CCP) in Brazil said this week that oxy-firing a critical portion of an oil refinery is viable “from a technical and economic standpoint.” The industry consortium behind CCP—which includes oil and gas giants like BP, Chevron and Shell—said an oxy-firing demonstration on a fluid catalytic cracking (FCC) unit on a Petrobras-owned refinery has proven to be successful, especially when compared to a post-combustion amine absorption system. “A techno-economic evaluation of the oxy-firing and post-combustion amine absorption for CO2 capture from the FCC regenerator had found that both processes are able to achieve the required specifications and recovery level,” a CCP fact sheet states. “Although the post-combustion option had a lower capital cost, the lower operational costs for oxy-firing delivered a lower overall capture cost. Oxy-firing, though challenging, was chosen as the more promising capture technology to test in an FCC unit.”

Using an oxygen supply system from Linde Gas and a CO2 recycling system from TecnoProject Latina, CCP kicked off its field demonstration in March 2011 on a pilot unit capable of processing up to 33 barrels per day of oil. Following more than a year of testing, the consortium said the demonstration confirmed that retrofitting an FCC unit with oxy-firing technology is considered “technically viable.” CCP said it achieved a “fast and smooth switch” between air and oxy-firing modes, as well as “efficient and stable operation.” But project operators did, however, find some corrosion in the unit’s recycle system due to the presence of NOx and SO2 impurities in the flue gas. “These issues were fully understood and are manageable through proper design,” the fact sheet stated. Project officials were not available for an interview as of press time.

FCC units, which are used to convert heavy oil fractions to lighter, more profitable products like liquid petroleum gas and gasoline, are the largest-emitting components of oil refineries, constituting roughly 20 to 30 percent of a typical facility’s emissions. Within an FCC unit, air is typically used to regenerate a catalyst by burning off coke deposited on the catalyst during the conversion process, but in the oxy-firing mode, the air is replaced with pure oxygen, which is subsequently diluted with recycled CO2, which “maintains thermal balance and catalyst fluidization,” according to the project fact sheet.