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Removal and recovery of nitrogen and sulfur compounds from coal tar fractions using supported alminium sulfate under supercritical CO{sub 2} conditions

Conference ·
OSTI ID:254787
; ;  [1]
  1. Kyushu Univ., Fukuoka (Japan); and others

Removal and recovery of nitrogen and sulfur compounds from coal tar fractions such as crude naphthalene and methylnaphthalene oils are examined using 10 wt% Al{sub 2}(SO{sub 4}){sub 3}/SiO{sub 2} as a solid acid under atmospheric or supercritical CO{sub 2} (50{degrees}C, 80 atm) conditions. Repeated use of the solid acid is achieved by purging adsorbed nitrogen compounds with higher pressure (150 atm) CO{sub 2} and methanol as an entrainer solvent, recovering effectively quinoline bases as well as purifying methymaphthalenes. Benzothiophene (BT) is dimerized over Al{sub 2}(SO{sub 4}){sub 3}/SiO{sub 2} catalyst under supercritical CO{sub 2} conditions in order to separate BT from crude naphthalene as well as to purify naphthalene. BT was more selectively dimerized under supercritical CO{sub 2} conditions (100{degrees}C, 100 atm) than in atmospheric n-octane solution at 100{degrees}C, allowing its selective dimerization and adsorption on the solid acid with selective extraction of naphthalene. Effects of supercritical CO{sub 2} conditions on the above adsorptions and reactions are discussed based on the analysis of recovered fractions and products.

OSTI ID:
254787
Report Number(s):
CONF-940813--
Country of Publication:
United States
Language:
English