EAGER: Catalytic oligomerization of methane using solid super acids

页岩资源的增长导致天然气的燃烧增加，尤其是其主要成分甲烷，原因是从页岩矿床等偏远和分散的来源收集和运输天然气的经济性很差。需要能够将甲烷转化为可运输的液体燃料和化学品的技术，其井口规模小于炼油厂或石油化工综合体通常使用的规模。基于制造简单、更有利的经济性和可伸缩性，可以实现甲烷直接转化的工艺特别有吸引力。该项目是一项探索性研究，旨在探索一种利用与现场模块化化学制造设备兼容的固体酸催化剂技术将甲烷气体转化为长链烃的过程。该项目旨在探索基于二元Lewis/B(L/B)超强酸H+/(AlBr4)-的固体超强酸催化甲烷直接齐聚的可行性。超强酸催化剂方法基于假定的反应机理，即首先将质子从酸催化剂转移到甲烷中生成(CH5)+物种，而通常的氢提取机理不可避免地导致高结焦倾向。尽管研究人员的初步工作表明，基于超强酸的齐聚化学在气相中起作用，但实际应用将需要有载体版本的催化剂。因此，本研究的重点是简单的AlCl3和AlBr3固体酸催化剂的负载型以及HBr与负载型AlBr3固体酸催化剂反应得到的二元(L/B)固体超强酸催化剂的合成、表征和催化性能评价。该项目的成功完成将为更详细的机械调查以及优化支撑物和金属(M)-卤化物(X)组合奠定基础。最终，支持的超强酸催化剂技术可能代表着一种高效且更低的资本成本替代方案，以取代目前从页岩气中利用大量甲烷资源的做法。该奖项由NSF/ENG新兴前沿和多学科活动办公室共同资助。

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.