Superacid catalysis of light hydrocarbon conversion. Final report, August 26, 1993--August 26, 1996

Abstract

Executive SummaryMotivated by the goal of finding improved catalysts for low-temperature conversion of light alkanes into fuel components or precursors of fuel components, we have investigated sulfated zirconia and promoted sulfated zirconia for conversion of butane, propane, and ethane. Catalyst performance data for sulfated zirconia promoted with iron and manganese show that it is the most active noncorrosive, nonhalide catalyst known for n-butane isomerization, and it is an excellent candidate catalyst for new lowtemperature n-butane isomerization processes to make isobutane, which can be converted by established technology into methyl t-butyl ether (MTBE).In the conversion of n-butane at temperatures as low as room temperature, ironand manganese-promoted sulfated zirconia is more than 90% selective for formation of isobutane. The additional products (propane and pentanes) result fiom disproportionation of n-butane.The advantage of the high activity of iron-and manganese-promoted sulfated zirconia catalyst is offset by the disadvantage of a lack of stability. In operation for nbutane isomerization in a flow reactor, this catalyst is deactivated rapidly, losing most of its initial activity within a few hours. However, the catalyst can be regenerated successfully at least seven times by treatment in air at 500°C.Various transition metals have been found to work as promoters of sulfated zirconia for n-butane isomerization. The combination of iron and manganese is the best known combination of promoters yet discovered. Manganese is the single promoter giving the most active catalyst initially, but the manganese-promoted catalyst rapidly loses activity in operation in a flow reactor. Iron is not as effective a promoter as manganese initially, but iron-promoted sulfated zirconia retains its activity longer in the flow reactor operation than manganese-promoted sulfated zirconia.The iron-and manganese-promoted sulfated zirconia is also a catalyst for conversion of propane and of ethane. Ethane is converted into ethylene and butanes in the presence of the iron-and manganese-promoted sulfated zirconia; propane is also converted into butane, among other products. However, the activities of the catalyst for , . . . I% 2 DISCLAIMERThii report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof. nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, m mmendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily State or ref...

The facade of scientific documentation: A case study of Richard Ofshe's analysis of the Paul Ingram case.

“…However, some of the specific details cited in Ofshe's report, which are the basis for these varied claims, are contradicted by other sources, including court transcripts (Judge F. Judge Robert Peterson, 1990) McClanahan, personal communication, August 19, 1993;Gates, 1996). Ingram was next interrogated by Detectives Vukich and Schoening, officers who had been junior to him in the sheriff department.…”