(360e) Triptane Production in a Pilot Reactor: Opportunities and Challenges in Scaling High Octane Gasoline Technology Beyond the Bench

Authors: 
Hensley, J. E., National Renewable Energy Laboratory
Ruddy, D. A., National Renewable Energy Laboratory
Marie-Rose, S., Enerkem
Christensen, E., National Renewable Energy Laboratory
Luecke, J., National Renewable Energy Laboratory
Nash, C., National Renewable Energy Laboratory
Schaidle, J. A., National Renewable Energy Laboratory
The homologation of dimethyl ether (DME) over catalysts like copper on beta zeolite (Cu/BEA) opens a potential new market for bio-gas, bio-methanol, methanol, and natural gas by enabling the production of non-aromatic high-octane gasoline blendstocks like 2,2,3-trimethylbutane (triptane, research octane value 112), for which there is significant demand. Process and economic models suggest that the yield of high-octane paraffins is a key driver of market viability for this process. A decade of laboratory research has elucidated reaction mechanisms, kinetics, optimal operating conditions, preferred catalyst formulations, and methods to improve catalyst lifetime and selectivity to triptane. This bench-scale data is insufficient to inform decisions to commercialize the technology, however, because liquid fuel can only be produced in milliliter quantities – far from the quarts and gallons required for industry-standard (ASTM) testing and validation. Furthermore, the catalysts’ performance in the presence of impure feed streams and process-scale hydrodynamics must be understood. We have recently conducted pilot-scale studies of triptane production over Cu/BEA, starting with bio-methanol, to produce gallons of high-octane isoparaffinic fuel. In this presentation, we will highlight some of our successes and learnings from increasing the size of our catalytic reactor by 1000x. In addition, we will discuss some of the unexpected impacts to fuel composition and will show data for several performance metrics of gasoline prepared by blending conventional gasoline with our high-octane product. Finally, we will comment on the next steps for this technology.