BENZOL-UMWANDLUNG IN EINEM VERBESSERTEN VERFAHREN ZUR AUSREICHUNG VON KOHLENWASSERSTOFFEN

• Main Authors: HILBERT, TIMOTHY, LEE, TREWELLA, JEFFREY, CHARLES, BORGHARD, WILLIAM, STERN, COLLINS, NICK, ALLEN, DURAND, PAUL, PIERCE
• Format: Patent
• Language: German
• Published: 15.07.2004
• Edition: 7
• Subjects: CHEMISTRY; CRACKING HYDROCARBON OILS; FUELS; LUBRICANTS; METALLURGY; MINERAL WAXES; PEAT; PETROLEUM, GAS OR COKE INDUSTRIES; 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

Low sulfur gasoline is produced from an olefinic, cracked, sulfur-containing naphtha by treatment over an acidic catalyst, preferably an intermediate pore size zeolite such as ZSM-5 to crack low octane paraffins and olefins under mild conditions with limited aromatization of olefins and naphthenes. A benzene-rich co-feed is co-processed with the naphtha to reduce the benzene levels in the co-feed by alkylation. This initial processing step is followed by hydrodesulfurization over a hydrotreating catalyst such as CoMo on alumina. In addition to reducing benzene levels in the combined feeds, the initial treatment over the acidic catalyst removes the olefins which would otherwise be saturated in the hydrodesulfurization, consuming hydrogen and lowering product octane, and converts them to compounds which make a positive contribution to octane. Overall liquid yield is high, typically at least 90 percent or higher. Product aromatics are typically increased by no more than 25 weight percent relative to the combined feeds and may be lower than the feed.