Phillips starts up new gasoline desulfurization unit

June 18, 2001
Phillips Petroleum Co. started up a 6,000-b/d plant using its proprietary S Zorb Sulfur Removal Technology (SRT) in April.
Phillips Petroleum Co. has started up the first commercial application of its S Zorb SRT technology in its Borger, Tex., refinery. The 6,000-b/d unit began operations in April 2001. Photograph courtesy of Phillips, Bartlesville, Okla.
Click here to enlarge image

Phillips Petroleum Co. started up a 6,000-b/d plant using its proprietary S Zorb Sulfur Removal Technology (SRT) in April.

Process advantages

Unlike hydrotreating processes, S Zorb selectively removes rather than converts sulfur-containing components. The process uses a regenerative sorbent (catalyst) that chemically attracts sulfur and removes it from gasoline blendstocks. The sorbent retains the sulfur atom while the hydrocarbon portion of the molecule is released back into the process stream. Phillips began developing this technology in 1998. Recognizing that hydrogenating olefins and aromatics reduces octane, Phillips looked for an alternative approach to hydrotreating for desulfurization. Reducing hydrogen consumption by avoiding hydrotreating can save a refinery significant operating costs, said Phillips. Hydrotreating also results in a 5-9 road octane loss vs. an expected loss of 1 road octane (or less) using S Zorb. The company says its new process reduces recombination reactions with olefins because H2S is not a product of absorption. Recombinant reactions can reintroduce 10-100 ppm of mercaptans into the desulfurized product.

Diesel desulfurization

Phillips's research and development group is developing the S Zorb process for diesel fuel, which will be similar to that for gasoline. Laboratory tests show that the new process could reduce diesel sulfur levels at lower pressures than conventional hydrotreating-275-500 psig vs. 500-2,000 psig. The company expects its diesel desulfurization technology to be available for licensing in the near future. There may be cost efficiencies, said Phil lips, associated with implementing S Zorb units for both gasoline and diesel at the same facility.