Heterogeneous catalytic process for alcohol fuels from syngas. Twelfth quarterly technical progress report, October--December 1994

The principal objectives of this project are to discover and evaluate novel heterogeneous catalysts for conversion of syngas to oxygenates having use as fuel enhancers, to explore novel reactor and process concepts applicable in this process, and to develop the best total process for converting syngas to liquid fuels. The authors have prepared an improved version of 10-DAN-54, a Zn/Cr/Mn spinel oxide promoted with Pd and K. This material (16-DMM-68) has acceptable elemental analysis for the expected composition and possesses the desired high surface area of >80 m{sup 2}/g. The catalyst has extra added potassium vs. the standard catalyst, 10-DAN-54, as previous work had indicated that more potassium is required for optimal performance. In tests under standard conditions (400 C, 1,000 psi, GHSV = 12,000, syngas ratio = 1), this catalyst shows a selectivity to total alcohols of 84% and produces > 100 g/kg/hr of isobutanol with a MeOH/i-BuOH mole ratio = 4.7. The authors have tested 16-DMM-68 at temperatures above 400 C and pressures up to 1,500 psi (GHSV = 12,000, syngas ratio = 1). At 440 C and 1500 psi, this catalyst shows a selectivity to total alcohols of 64% and produces 179 g/kg/hr of isobutanol with a MeOH/i-BuOH mole ratio = 2.2. This is their best overall performance to data. The catalyst operates at syngas conversions up to 28% with good selectivity to total alcohols due to the extra added alkali. This performance can be compared with 10-DAN-54, which could only operate up to 20% conversion before hydrocarbon formation became a serious inefficiency