INVISTA Performance Technologies (IPT; Wichita, Kan.; www.invista.com) and Koch-Glitsch (Wichita, Kan.; www.koch-glitsch.com), affiliates of Koch Industries Inc., announced today an expansion of their partnership to offer the proprietary ExoS technology to customers. The technology allows refineries to generate an olefin rich C6/C7 raffinate with less than 10 ppm sulfur that bypasses the FCC naphtha hydrotreater for direct blending.
With eight units in commercial operation and seven units in the design and construction phase, the technology is commercially proven to deliver value by preserving octane and reducing hydrotreater size, operating expenditures, and capital expenditures when installed with a new hydrotreater. As a revamp, the technology preserves octane number, lowers operating expenditures, and frees up hydrotreater capacity and hydrogen availability.
The ExoS process technology – developed and commercialized by China University of Petroleum-Beijing (CUPB) and Hebei Refining Technologies (HRT) – utilizes a proprietary solvent to extract sulfur and aromatics from mid-cut FCC naphtha (C6/C7). The sulfur-rich extract is sent to the FCC hydrotreater for sulfur removal while the olefin-rich raffinate with less than 10 ppm sulfur is sent directly to the blending pool. This reduces the hydraulic load on the hydrotreater and avoids the saturation of the high-octane number olefins. Alternatively, this low-sulfur, olefin-rich, mid-cut FCC naphtha can also be utilized as feed for other processes to further increase its value.
“Refineries worldwide are facing the challenge of ever decreasing total sulfur limits in the gasoline pool,” said Christoph Ender, Koch-Glitsch senior vice president of global sales and business development. “Expanding our partnership with IPT to offer ExoS will provide our customers with a valuable solution that is easier to operate, lower in cost, and more environmentally friendly to stay ahead of the sulfur curve versus hydrotreating alone.”
Approximately 40 wt% of the olefins in full range naphtha are in the mid-cut (C6/C7) and approximately 90 wt% of the sulfur species are thiophenic. The ExoS solvent is formulated to extract the thiophenic sulfur from the mid-cut naphtha for further processing in the hydrotreater. The process utilizes a series of extraction and distillation columns optimized to recover more than 90% of the olefins in the raffinate and more than 95% of the sulfur in the extract.
IPT is the technology licensing group within Invista. IPT provides the resources and know-how to deliver world-scale technology for licensing to a growing portfolio of technologies in the polyester, polyurethane, nylon and refining value chains. Koch-Glitsch is a global leader in developing, engineering, designing, and manufacturing a complete line of mass transfer and separations technology equipment for the chemical, petrochemical, refining, and gas processing industries.