Modular‐scale ethane to liquids via chemical looping oxidative dehydrogenation: Redox catalyst performance and process analysis

• Published in: Journal of advanced manufacturing and processing 2019-04, Vol.1 (1-2), p.n/a
• Main Authors: Neal, Luke, Haribal, Vasudev, McCaig, Joseph, Lamb, H. Henry, Li, Fanxing
• Format: Article
• Language: English
• Subjects: Air separation; Alkenes; Catalysts; Configurations; Dehydrogenation; Economic factors; Economics; Electric power distribution; Electricity consumption; Energy consumption; Ethane; Ethylene; fuel; Gasoline; gas‐to‐liquids; Liquefaction; Liquid fuels; Liquids; Modular systems; Natural gas; natural gas liquids; Oligomerization; oxidative dehydrogenation; Redox reactions; Reinjection; Shale gas
• ISSN: 2637-403X; 2637-403X
• DOI: 10.1002/amp2.10015

The difficulties in the liquefaction and transportation of ethane in shale gas has led to significant rejection, via reinjection or flaring, of this valuable hydrocarbon resource. Upgrading this low‐value, isolated ethane into easily transportable liquid fuels is a promising solution to this supply glut. In this study, we present a modular system that can potentially be operated economically at geographically isolated gas‐processing facilities. The modular ethane‐to‐liquids (M‐ETL) system uses a chemical looping‐oxidative dehydrogenation (CL‐ODH) technology to efficiently convert ethane and natural gas liquids into olefins (primarily ethylene) via cyclic redox reactions of highly effective redox catalyst particles. The resulting olefins are then converted to gasoline and mid‐distillate products via oligomerization. CL‐ODH eliminates air separation and equilibrium limitations for olefin generation. It also simplifies the process scheme and reduces energy consumption. Here, we present experimental proof‐of‐concept data on CL‐ODH conversion of ethane to ethylene. Using the CL‐ODH performance data at 750°C, we show that a simple, single‐pass configuration can be economically viable at distributed sites. We identify that economic factors such as the capital cost, price of ethane feed, and value of electricity byproduct have strong effects on the required selling price of the liquids. It is also noted that the economic viability of the M‐ETL system is relatively insensitive to the liquid yield under a low ethane price scenario. The demand and value of electricity at distributed locations, on the other hand, can play an important role in the optimal process configuration and economics.