EAGER: Catalytic oligomerization of methane using solid super acids

Louisiana State University, Baton Rouge LA

Investigators

Abstract

The growth of shale resources has resulted in increased flaring of natural gas, especially methane - its chief constituent - due to poor economics of collecting and transporting gas from remote and distributed sources such as shale deposits. Technologies are needed that can convert methane to transportable liquid fuels and chemicals at the well-head and at smaller scale than typically utilized in refinery or petrochemical complexes. Processes that can effect the direct conversion of methane are particularly appealing based on manufacturing simplicity, more favorable economics, and scalability. This project is an exploratory study to investigate a process for converting methane gas to longer chain hydrocarbons utilizing solid acid catalyst technology compatible with field-based modular chemical manufacturing (MCM) facilities. This EAGER project explores the feasibility of direct methane oligomerization utilizing a solid superacid catalyst based on the binary Lewis/Bronsted (L/B) superacid H+/(AlBr4)-. The superacid catalyst approach is based on a posited reaction mechanism that first transfers a proton from the acid catalyst to the methane to make a (CH5)+ species, in contrast to the usual hydrogen abstraction mechanism that inevitably results in high coking tendency. Although preliminary work by the investigators has suggested the superacid based oligomerization chemistry works in the gas phase, a practical application will require a supported version of the catalyst. Thus, the proposal focuses on the synthesis, characterization, and catalytic performance evaluation of supported versions of both the simple AlCl3 and AlBr3 solid acid catalysts and the binary (L/B) solid super acid catalyst derived from reacting HBr with the supported AlBr3 solid acid catalyst. Successful completion of the project would set the stage for more detailed mechanistic investigations as well as optimization of support and metal(M)-halide(X) combinations. Ultimately, supported superacid catalyst technology could represent an efficient and lower capital cost alternative to current practices for utilizing the huge amount of methane resources from shale gas. The award is co-funded by the NSF/ENG Office of Emerging Frontiers and Multidisciplinary Activities.