(73h) Nonthermal Plasma Assisted Catalytic Crude Oil Upgrading Under Methane

Upgrading crude oil to acceptable lighter products to improve the downstream products’ quality and to increase the topping distillate flows prior to reaching today’s refineries secures economic benefits. The conventional upgrading processes include carbon rejection and hydrogen addition technologies. In these operations, thermal or thermal catalytic cracking converts large hydrocarbon molecules into smaller, more useful molecules by subtracting carbon while rearranging the chemical bonds of the original hydrocarbon molecules. The use of ultrapure hydrogen for crude oil upgrading is undesirable given their higher cost than other “H donor” sources such as methane. The use of methane to crude oil upgrading will unfold a chance to use wasted methane, which flares or emits into the air leading to pollution and uneconomical. Challenges associated with high temperatures and pressure for these processes have urged R&D to look forward to more sustainable and effective technologies. None of the one-size-fits-all technology exists for upgrading crude oil owing to the variability in its physicochemical properties from every oil field. This creates opportunities for novel technologies to process a large range of crude oils to achieve better process efficiency. It has been witnessed over the last few decades intensive efforts of both researchers and industries to improve crude oil upgrading processing in terms of process efficiency and economics, including optimizing operating conditions and developing more effective catalysts. Yet, upgrading of crude oils, even with commercial technologies available, remains capital-intensive processing units. With economics driving the crude oil development, novel technologies are being vigorously demanded to test and pilot for commercial-scale applications.

In-liquid non-thermal plasma is a novel but feasibly promising technology for crude oil upgrading under methane. Non-thermal plasma (NTP) is among the technologies rivaling the conventional thermal upgrading of crude oil. NTP is generated by ionized gas via electric discharge and is rich in vibrationally and electronically excited molecules along with other highly active species including radicals, ions, and free electrons. Given plasma operated far from thermal equilibrium, the activated species can be generated without a noticeable increment in bulk gas temperature. Dielectric barrier discharge (DBD) is most used for plasma-catalysis as this reactor design enables effective packing of the plasma region with optimized plasma-catalyst interactions. Such DBD systems are instantly safe on/off switch, flexible, and thereby offer the potential to be coupled with renewable, intermittent energy sources such as wind or solar energy for decentralized upgrading plant, which would enhance sustainability and diminish processing costs.

This research seeks to align the aforementioned challenges and opportunities for developing a series of cost-effective and coke-resistant catalysts and determining the optimal reactor configuration and reaction conditions for non-thermal plasma assisted catalytic upgrading of a variety of crudes under methane rich gas such as natural gas for producing high value-added liquid fuel/chemicals. In order to realize catalyst design in a logical method, isotopic labeled model compounds have been engaged to study the plasma-assisted catalytic reaction mechanism, the possible plasma-catalyst synergistic effect as well as the one occurring between methane and co-reactants, and the catalyst deactivation mechanism. The optimal reactor configuration was fabricated to conduct reactions at low temperature (25-100 ^oC) and atmospheric pressure. The designed catalysts have shown the strong ability to enhance the conversion of the reactants and the selectivity of desired product. A series of material characterization and control experiments have been conducted to study the reaction mechanism and catalyst deactivation. Quantum mechanical modelling and molecular dynamic simulation have also been employed as the complimentary tools to gain a better understanding of the involved plasma-catalytic mechanism at the atomic level, thus benefiting the catalyst rational design for performance optimization. It is also worth noting that upon the establishment of a comprehensive and diverse catalyst formulation database for the NTP catalytic process including all datasets in the public domain and the evolving datasets collected from this project, predictive models have been developed to recommend optimal catalyst formulations for specific chemical reactions, powered by artificial algorithms and machine learning (ML) techniques. Furthermore, ML algorithms have been employed to guide intelligent reactor design optimization, facilitate fundamental understanding of the inherently complicated NTP-catalytic reaction mechanism, and develop adaptive control strategies to manipulate and optimize emergent, collective behavior in NTP catalytic system. The combination of ML with NTP technology opens up new avenues for advancing our understanding and harnessing the potential of NTP in chemical and energy transformations.

This research is delivering a first of this kind technology which can efficiently convert low-cost hydrocarbons to high value-added liquid fuel/chemicals at near ambient conditions, thus enabling significant breakthroughs in the field of low-cost hydrocarbons upgrading. Furthermore, the outcomes derived from this project will make positive contributions to the methane emission reduction through getting it effectively converted to high value-added liquid fuel and chemicals along with other hydrocarbons abundant in Canada with minimized energy input in a format of electricity which can be generated from renewable sources, leading to net GHG emission reduction of at least 60%. The potential valorization capability of this technology is unquestionable considering the latest market situation. We can reasonably imagine that upon successful deployment of this technology at commercial scale, the economic and environmental benefits generated from this technology will help boosting the healthy growth of green economy in terms of new hires, increased advanced manufacturing capacities, and new devices as well as new catalyst materials and high valuable liquid fuel/chemicals using the most abundant natural resources in a clean way.