INVISTA Performance Technologies (IPT) and Koch-Glitsch announced 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 10ppm sulphur 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 commercialised by China Petroleum University-Beijing (CUPB) and Hebei Refining Technologies (HRT) – utilises a proprietary solvent to extract sulphur and aromatics from mid-cut FCC naphtha (C6/C7). The sulphur-rich extract is sent to the FCC hydrotreater for sulphur removal while the olefin rich raffinate with less than 10ppm sulphur 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-sulphur, olefin-rich, mid-cut FCC naphtha can also be utilised as feed for other processes to further increase its value.
“Refineries worldwide are facing the challenge of ever decreasing total sulphur limits in the gasoline pool,” said Christoph Ender, Koch-Glitsch senior vice president of global sales and business development. “Expanding our partnership with INVISTA Performance Technologies 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 sulphur 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 sulphur species are thiophenic. The ExoS solvent is formulated to extract the thiophenic sulphur from the mid-cut naphtha for further processing in the hydrotreater. The process utilises a series of extraction and distillation columns optimised to recover more than 90% of the olefins in the raffinate and more than 95% of the sulphur in the extract.
“We are excited to add the ExoS technology to our expanding refinery portfolio,” said Mike Massa, INVISTA Performance Technology licensing director. “The refining industry no longer has to accept significant octane loss to meet mandatory sulphur limits. The ExoS process provides an option to preserve octane, and optimise the hydrotreater design and operation.”
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