TWO STAGE DEEP NAPHTHA DESULFURIZATION WITH REDUCED MERCAPTAN FORMATION

• Main Authors: MCKNIGHT, CRAIG A, GREELEY, JOHN PETER, COOK, BRUCE RANDALL, WINTER, WILLIAM EDWARD JR, HALBERT, THOMAS RISHER, BRIGNAC, GARLAND BARRY, DEMMIN, RICHARD ALAN
• Format: Patent
• Language: English; French
• Published: 21.12.2010
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; CRACKING HYDROCARBON OILS; FUELS; LUBRICANTS; METALLURGY; MINERAL WAXES; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVEHYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, ORGASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; TECHNICAL GASES CONTAINING CARBON MONOXIDE; THEIR RELEVANT APPARATUS; TRANSPORTING

Selective and deep desulfurization of a high sulfur content mogas naphtha, with reduced product mercaptans and olefin loss, is achieved by a two stage, vapor phase hydrodesulfurization process with interstage separation of at least 80 vol. % of the H2S formed in the first stage from the first stage, partially desulfurized naphtha vapor effluent fed into the second stage. At least 70 wt. % of the sulfur is removed in the first stage and at least 80 wt. % of the remaining sulfur is removed in the second stage, to achieve a total at least 95 wt. % feed desulfurization, with no more than a 60 vol. % feed olefin loss. The second stage temperature and space velocity are preferably greater than in the first. The hydrodesulfurization catalyst preferably contains a low metal loading of Co and Mo metal catalytic components on an alumina support.