Development of alternative fuels from coal-derived synthesis gas: Final topical report, demonstration of one-step slurry-phase process for the co-production of methanol and isobutanol

摘要

Liquid phase co-production of methanol and isobutanol (LPIBOH) was de, demonstrated at DOE's Alternative Fuels Development Unit (AFDU) in LaPorte, Texas. Methanol and isobutanol are key intermediates in a synthesis gas-based route to methyl t-butyl ether (MTBE). The technology was demonstrated in a new 18 in. slurry bubble-column reactor that was designed to demonstrate higher pressures and temperatures,higher gas superficial velocities, and lower gas hourly space velocities--all of which are conducive to obtaining optimal isobutanol yield. The integration of the new reactor into the AFDU included the addition of a high-pressure synthesis gas compressor, a high-pressure hydrogen feed source, and a closed-loop methanol- solvent absorption system to remove CO(sub 2) from the unconverted synthesis gas. These modifications were completed in January 1994. The LPIBOH run followed after a short turnaround. It employed a cesium- promoted Cu/ZnO/Al(sub 2)O(sub 3) catalyst developed in Air Products' laboratories and subsequently scaled up to a production- sized batch. Over a thirteen day campaign on simulated Shell gasifier gas, the catalyst and reactor system were tested at a matrix of pressures (750, 1300, 1735 psig) and space velocities (3000, 5000, 8200 sL/kg-hr), representing numerous first-of-a-kind run conditions for the AFDU. Inlet gas superficial velocities spanned an impressive 0.16 to 1.0 ft/sec. Stable reactor performance for a full twelve-hour data period at 1.0 ft/sec was another significant milestone for the liquid phase technology program. Apart from the catalyst deactivation, the run successfully demonstrated mixed alcohol synthesis in a slurry bubble-column reactor, as well as all of the new equipment installed for the trial. Although the full capabilities of the new oxygenates system will not be tested until future runs, the design objectives for the modifications were met with respect to the LPIBOH run.