Dehydration of isobutanol to isobutene in a slurry reactor

Technical Report · Tue Feb 01 04:00:00 EST 1994

DOI:https://doi.org/10.2172/171265· OSTI ID:171265

Latshaw, B E

The April 1990 Alternative Fuels Proposal to the Department of Energy involved the development of new technology, based on the liquid phase process, for conversion of coal-derived synthesis gas to oxygenated hydrocarbon fuels, fuel additives, and fuel intermediates. The objective of this work was to develop a slurry reactor based process for the dehydration of isobutanol to isobutene. The isobutene can serve as a feedstock for the high octane oxygenated fuel additive methyl tertiary-butyl either (MTBE). Alumina catalysts were investigated because of their wide use as a dehydration catalyst. Four commercially available alumina catalysts (Catapal B, Versal B, Versal GH, and Al-3996R) were evaluated for both activity and selectivity to the branched olefin. All four catalysts demonstrated conversions greater than 80% at 290 C, while conversions of near 100% could be obtained at 330 C. The reaction favors low pressures and moderate to low space velocities. A yield of 0.90 mole isobutene per mole reacted isobutanol or better was obtained at conversions of 60--70% and higher. From 75 to 98% conversion, the four catalysts all provide isobutene yields ranging from 0.92 to 0.94 with the maximum occurring around 90% conversion. At low conversions, the concentration of diisobutyl ether becomes significant while the concentration of linear butenes is essentially a linear function of isobutanol conversion. Doping the catalyst with up to 0.8 wt % potassium showed a modest increase in isobutene selectivity; however, this increase was more than offset by a reduction in activity. Investigations using a mixed alcohols feed (consistent with isobutanol synthesis from syngas) demonstrated a small increase in the C4 iso-olefin selectivity over that observed for a pure isobutanol feed. 55 refs.

• Research Organization: Air Products and Chemicals, Inc., Allentown, PA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC22-91PC90018
• OSTI ID: 171265
• Report Number(s): DOE/PC/90018--T11; ON: DE96003944
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
10 SYNTHETIC FUELS
2-METHYLPROPANOL
2-METHYLPROPENE
ALUMINIUM OXIDES
CATALYTIC EFFECTS
CHEMICAL FEEDSTOCKS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
DEHYDRATION
DOPED MATERIALS
ETHERS
EXPERIMENTAL DATA
FUEL ADDITIVES
LIQUID PHASE METHANOL PROCESS
MODIFICATIONS
SYNTHESIS
THERMODYNAMICS