The goal of this project is to use plasma stimulation of a light hydrocarbon resource to synthesize value-added liquid chemicals. This work will evaluate the hypothesis that the plasma will serve multiple roles in this transformative chemistry, including activation of Carbon - Hydrogen (C-H) bonds at low bulk gas temperature and pressure, providing a fast response for immediate startup and shutdown, enhancing the lifetime of the catalyst through plasma-assisted removal of surface impurities, and providing a means to activate Nitrogen (N₂) to allow for the direct formation of chemicals containing nitrogen–carbon (N-C) bonds. In addition, the project will explore the potential for exploiting these processes more broadly, by building on recent discoveries using plasma-assisted methods to convert hydrogen and N₂ feeds.

University of Notre Dame – Notre Dame, IN 46556

Flaring light hydrocarbons from wells and refineries amounts to a global, annual loss of >140 billion m³ of natural gas. Not only are valuable, non-renewable hydrocarbons misused during this process, but flaring also contributes more than 400 metric tons of CO₂ to the environment. The implementation of chemical processing technology that directly converts light gases to liquid products will relieve the strain associated with gas separations and gas compression at the source.

The project offers the opportunity to assess a potential mechanism to reduce quantities of flared gas at oil and gas production sites, where gas transport options are insufficient or do not exist, by converting the gas to energy-dense liquid products. In addition to providing a value-added pathway for use of the gas, the proposed technology will also offer environmental and economic benefits through the reduction of CO₂ emissions caused by the flaring of light hydrocarbon feeds and through the direct use of CO₂ as a soft oxidant. All of these factors offer the potential to meaningfully contribute to ensuring U.S. security and prosperity by addressing energy and environmental challenges through transformative science and technology solutions.

• Design, construction, and safe operation of three plasma-stimulated reactor systems that are leak-free and operated with reproducible experimental data collection.
• Validation and demonstration of hydrocarbon — N₂ coupling under plasma stimulation, and liquid production.
• Development of experimental procedures to identify and quantify products.
• Development and ongoing population of data structures to capture known/measured operating and performance parameters of reactors and materials. Validated through selected replication of experiments based off parameters in the database.
• Identification of surface-adsorbed intermediates from plasma stimulation using the in-situ/operando spectroscopy plasma reactor.
• Experimental evidence of product selectivity control via plasma-simulated catalysis at lower bulk temperatures than thermal catalysis.
• Identified catalysts that increase C-N bond formation from plasma-assisted catalytic reactions with various feeds.
• Methods of electrically characterizing the plasma to determine key plasma characteristics such as number of filaments, average current, and charge per filament as well as the filament lifetime of the DBD have been developed.
• A simplified version of the gliding arc has been built and is currently undergoing testing.
• Provisional patent applications have been filed.
  • 63/367,649 Plasma-Assisted Process for the Production of Liquids from Methane, 7/5/2022
  • 63/367,646 Process to Synthesize Nitrogen-Containing Liquids and Higher Molecular Weight Hydrocarbons from Shale Gas/N₂ Feeds 7/5/2022

The project entered Budget Period (BP) 3 in March 2022. Year 2 (BP2) activities were focused on evaluating process conditions to improve the selectivities of desired products and the effects of possible shale gas contaminants in the feed system on product distribution. In BP3, the project team is working on determining the appropriate catalyst to facilitate C-N coupling and/or liquid production by combining reaction performance results, in situ/operando characterization, and predictive modeling. The team is using in situ spectroscopy to identify surfaces species formed from plasma stimulation and to determine if these species participate in C-N coupling pathways. Additionally, the project team is evaluating alternative plasmas (e.g., gliding arc) to activate gas phase species to facilitate the production of liquid products..

$999,954.00

$250,044

NETL – Robert Noll (robert.noll@netl.doe.gov or 412-386-7597)
University of Notre Dame – Jason Hicks (jhicks3@nd.edu or 574-631-3661)