May 15, 2026

1)    An example of heavy oil (Source: Wikipedia), 2) Plasma treatment heavy oils using methane as an alternative for hydrocracking [1].

Bottom-of-the-barrel heavy oils, vacuum residues (VR), and bitumen represent vast, underutilized hydrocarbon resources with the potential to ensure long-term fuel independence. However, the properties of heavy oil such as high viscosity, low hydrogen-to-carbon ratios, and significant levels of impurities such as sulfur, nitrogen, and heavy metals, render conventional refining techniques insufficient for efficiently upgrading these hydrocarbons to useful fuel.

Conventionally hydrocracking is performed to upgrade heavy oils into valuable oil products. During hydrocracking, the unsaturated carbon bonds in olefinic and aromatic structures are saturated with the aid of hydrogen under high temperature and pressure. Chief among the drawbacks of hydrocracking is the high dependence on hydrogen, which is required in large quantities to saturate cracked intermediate. The production and supply of hydrogen is capital- and energy-intensive, leading to elevated operational costs and substantial carbon emissions when hydrogen is sourced from fossil fuels. Additionally, hydrocracking processes must operate under severe conditions, typically at high pressures (100–200 bar) and temperatures (650–750 °K), which necessitate specialized, high-cost reactor materials and impose necesitate maintenance burden.

This awarded project aims to utilize methane as a replacement for hydrogen in the saturation of aromatic and unsaturated hydrocarbons in heavy oils to saturated bonds at low temperatures (~300 - 500 K gas temperature) and atmospheric pressure. Methane, being abundant and inexpensive, offers a cost-effective alternative to the use of hydrogen. Our previous work [1], has been shown that methane can participate in the saturation of carbon-carbon double bonds, a reaction that is exothermic, and can proceed efficiently if methane is vibrationally excited.

In non-equilibrium plasma, particularly nanosecond-pulsed dielectric barrier discharges (DBDs), methane molecules can be activated at low temperatures (~300-500 K gas temperature) and at atmospheric pressure, creating a suitable environment for bond saturation without the need for high thermal input.

This plasma-assisted method ensures high vibrational temperatures (2000–4000 K), which are critical for activating methane molecules while minimizing overall energy costs. Compared to conventional hydrocracking, which heavily depends on hydrogen and operates at high temperatures and pressures, the proposed approach significantly reduces operational costs and infrastructure complexity by eliminating the need for external hydrogen supplies and extreme operation conditions.

1.         Liu, C.; Chernets, I.; Ji, H.-F.; Smith, J.; Rabinovich, A.; Dobrynin, D.; Fridman, A. Methane Incorporation Into Liquid Fuel by Nonequilibrium Plasma Discharges. IEEE Trans. Plasma Sci. 2017, 45, 683–690, doi:10.1109/TPS.2017.2665879.