Oil refining
Current technology
Oil refining is a general name for many processes and technologies:
- Oil rectification: Separation of oil into fractions by rectification;
- Oil separation: Removal of impurities and separation into constituent components;
- Thermal processes: Thermal cracking, visbreaking, coking, pyrolysis;
- Catalytic processes: Catalytic cracking, alkylation, polymerization;
- Hydrotreating and hydrocracking to purify and improve the quality of petroleum products;
- Catalytic reforming of high-octane gasoline production;
- Isomerisation for winter fuel and other products;
- GTL (Gas-to-liquid) technologies for the conversion of natural gas into liquid synthetic products.
All these processes use certain catalysts including PGMs, nickel, copper and cobalt.
Palladium-based catalysts have proven highly effective in key areas of oil refining and petrochemicals. For instance, they are widely used as hydrogenation catalysts for oil fractions, which serve as feedstocks for the production of base oils in lubricants, as well as white oils for the medical and polymer industries. Selective hydrogenation catalysts for unsaturated hydrocarbons in petrochemical processes are also well known.
Market
Despite the decarbonisation trend, the demand for catalysts in the petrochemical industry will not decline as dramatically as that of catalytic converters for car exhaust gas neutralisation.
Moreover, the same trend to reduce greenhouse gas emissions will push petroleum producers to look for new, more energy-efficient types of catalysts, where palladium may have an advantage over other catalysts.
Challenges of current technology
In general, the oil refining industry is quite old and there is a strong preference for technology and catalysts.
Nevertheless, there is still room for improving seemingly long-established processes. Catalyst fabricator companies consistently offer custom catalysts depending on the customer’s preferences, which creates a favourable environment for the development and implementation of palladium-based catalysts.
Positive impact of palladium
A palladium catalyst can compete with different groups of catalysts thanks to its many attractive properties.
Compared to a metal catalyst made from platinum, palladium will be more cost-effective, as its density is half that of platinum. Relative to catalysts made of more expensive PGMs such as iridium, palladium may simply be a cheaper substitute, without significant degradation in catalytic properties, unless resistance to high temperatures is required.
The use of palladium can significantly enhance both productivity and service life by improving catalytic efficiency and stability. For instance, palladium-based catalysts often exhibit higher activity and selectivity in various reactions compared to other metals. This results in faster reaction rates and better product yields over longer periods without substantial loss of activity.
A palladium-doped nickel catalyst may also have greater selectivity compared to catalysts based solely on nickel and other metals.
It is also worth noting that palladium is the most active catalyst for hydrogenating unsaturated and aromatic hydrocarbons. For a long time, nickel was the primary catalyst for hydrogenation, but for many processes this approach has become outdated due to the obvious advantages of palladium: high activity, selectivity, and operational stability.
To find out more about the catalytic qualities of palladium see – Chemistry.
To find out more about palladium catalysts, see the following scientific publications:
Smulders, L. C., van de Minkelis, J. H., Meeldijk, J. D., Tang, M., Liutkova, A., Cheng, K., … & de Jong, K. P. (2023). Steering the metal precursor location in Pd/zeotype catalysts and its implications for catalysis. Chemistry, 5(1), 348-364. DOI: https://doi.org/10.3390/chemistry5010026
Bauer, F., Ficht, K., Bertmer, M., Einicke, W. D., Kuchling, T., & Gläser, R. (2014). Hydroisomerization of long-chain paraffins over nano-sized bimetallic Pt–Pd/H-beta catalysts. Catalysis Science & Technology, 4(11), 4045-4054. DOI: https://doi.org/10.1039/C4CY00561A
Busto, M., Benitez, V. M., Vera, C. R., Grau, J. M., & Yori, J. C. (2008). Pt-Pd/WO3-ZrO2 catalysts for isomerization-cracking of long paraffins. Applied Catalysis A: General, 347(2), 117-125. DOI: https://doi.org/10.1016/j.apcata.2008.06.003