Distributed Natural Gas Conversion with Scalable, Process-Intensified Gas Cleanup and Reactor Technologies

Shale gas is a distributed resource that is typically gathered and processed at centralized facilities. The high capital cost of the gathering, collection, and treatment infrastructure required to produce and treat shale gas results in the largest reserves (with a value high enough to justify the capital expenditure) being produced while smaller reserves are commonly avoided until the production risk is low enough to justify their production. This is particularly the case if there is any significant cleanup burden associated with these resources (ie CO₂, H₂S, etc.). One avenue to effectively utilize the smaller reserves is to treat the gas in a distributed manner and or raise its value by converting it directly to value-added products with more favorable transportation economics. For example, shale gas can be converted directly into easily transportable liquid products or pipeline spec natural gas can be produced from sour gas or acid gas. This approach is not commonly taken because traditional processing methods and approaches do not scale down efficiently to allow this to be done in an economical manner, and traditional processes do not have sufficient automation and robustness to withstand operation in the remote and sometimes harsh environments. Effective Implementation of process intensification (PI) and modular chemical process intensification (MCPI) technologies will open the door for distributed gas cleanup and conversion.

IntraMicron has developed several PI and MCPI technologies which can be applied to enable the distributed production and conversion of shale gas. Since effective gas cleanup and conditioning is required for these distributed conversion operations, IntraMicron has developed a modular, scalable catalytic desulfurization process, SourCat^TM, that was successfully demonstrated at an Eagle Ford Shale Well head site in the Fall of 2018 and is applying its Microfibrous Entrapped Sorbent (MFES) technology to modular PSA-based CO₂ separation systems for distributed acid gas treatment. Both of these technologies, which have the opportunity to supplant traditional amine-based separations followed by post treatment, are the subject of research grants from the RAPID Institute for Process Intensification. Initial TEAs have demonstrated significant cost savings for these processes compared to traditional approaches even at scales as low as 1 MMSCFD. Once contaminants are removed from the natural gas, converting it to value added components is commonly done with a series of catalytic processes that are either highly exothermic or endothermic. IntraMicron’s Microfibrous Entrapped Catalyst (MFEC) technology provides the process simplicity of a fixed bed reactor with up to 250 times the heat transfer and 10 times the mass transfer of traditional fixed bed catalyst systems. This enhanced heat transfer typically enables 20% of the catalyst to be used at similar or greater activity with improved selectivity. MFEC can be prepared with any catalyst in the appropriate size range. For highly exothermic processes the high radial thermal conductivity of MFEC enables a 16x increase in the reactor tube area (i.e 1” to 4” for FTS) to minimize part count and simplify reactor construction. Since convective heat transfer does not need to be the primary driver for reactor design, the reactors can be operated in different regimes (higher conversion, low recycle) that significantly reduce balance of plant to minimize CAPEX and OPEX. This technology has been applied to various GTL approaches and chemistries. The approach is also well suited to accommodate many of the new direct conversion chemistries that are being developed. Several scenarios for the implementation of MFEC for distributed gas conversion will be presented.