TITLE:    Development of a Catalyst for Conversion of Syngas-Derived Materials to Isobutylene

AUTHOR:     Paul T. Barger and Paul R. Kurek

INST.  AUTHOR:     UOP

SPONSOR:

LANGUAGE:    English

PUB.  TYPE:     Quarterly Report

PUB.  COUNTRY:     United States of America

SOURCE:    

ABSTRACT:    The goals of this project are to develop a catalyst and process for the conversion of syngas to isobutanol.  The research will identify and optimize key catalyst and process characteristics.  In addition, the commercial potential of the new process will be evaluated by an economic analysis.

    The effects of temperature, pressure and methanol/ethanol molar feed ratio on the performance of the 2% Pt on Zn/Mn/Zr Oxide catalyst has been evaluated in a series of pilot plant tests.  Temperature has been varied from 325° to 375° C, pressure from 30 psig to 300 psig and MeOH/EtOH ratio from 10/1 to 1/1.  Raising temperature increases alcohol conversion, but reduces selectivity and productivity to the desired branched C₄ oxygenates.  The higher pressure operation shifts the product ratio from isobutyraldehyde to isobutanol.  Decreasing the feed ratio from 10/1 to 7/1 increases methanol conversion as well as selectivity to each of the iC₄ oxygenates.  However, further reduction of the feed ratio to 4/1 does not give additional improvement.  Based on these findings a pilot plant test at optimized conditions is planned using the 2% Pt on Zn/Mn/Zr oxide catalyst.

    The effect of H₂, CO and CO₂ co-feeds on the performance of the have also been evaluated using the reference catalyst. Co-feeding H₂ has very little effect, whereas CO has a deleterious effect.  CO₂ addition results in higher CO formation, but no substantial change in CO₂ selectivity.  Therefore, it appears that the use of a CO₂ recycle would not be effective for reducing the formation of carbon oxide products.

    A copper-lined reactor has been constructed that give acceptable blank activity at temperatures up to 450° C and used to evaluate the activity of the 2% Pt on Zn/Mn/Zr oxide catalyst for methanol-only conversion.  At temperatures greater than 350° C, minimal branched C₄ oxygenates are formed.  Instead, the primary products are CO and CO₂.  Therefore, this catalyst system does not appear to be promising for the conversion of methanol alone to higher alcohols.

REPORT  NUMBER:  Quarterly Report No. 17

CONTRACT  NUMBER:     DE-AC22-91PC90042