• H2020
• Excellent Science
• European Research Council

Scientists part-funded by the European Research Council have identified key mechanisms of the ageing process of catalyst particles that are used to refine crude oil into gasoline. It is hoped the advance could lead to more efficient gasoline production.

The research was undertaken by scientists at the SLAC National Accelerator Laboratory, California in the United States, and Utrecht University in the Netherlands. Experiments studied so-called ‘fluid catalytic cracking’ (FCC) particles that are used to break long-chain hydrocarbons in crude oil into smaller, more valuable hydrocarbons like gasoline.

In studies, which were supported by an ERC Advanced Grant, using X-ray beams at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL), researchers studied FCC catalysts of various ages to better understand the effects of ageing. They were able to image whole catalyst particles with high resolution so they could also see the catalysts’ internal structure.

Speaking about the experiments, Bert Weckhuysen, professor of inorganic chemistry and catalysis at Utrecht University, said: “We have been able to localise the metal poisons that are a leading cause of catalyst ageing and also determine how they influence the materials. It’s been studied in the past, but not at this resolution and not on the single particle level.”

Worldwide, about 400 reactor systems refine crude oil into gasoline, and each system requires 10 to 40 tons of fresh FCC catalysts daily. Crude oil is contaminated with metals, mostly iron, nickel and vanadium and these metals accumulate in catalysts during refining and eventually deactivate them. This is particularly an issue for low quality crude oil, the largest available oil supply.

In the SSRL study, the team took a series of 2D images of catalyst particles at various angles and used software they developed to combine them into three-dimensional images of whole particles. These images show the 3D distribution of iron and nickel in catalysts of various ages.

The researchers determined that the metals quickly accumulate on the outer surface of a catalyst, blocking the crude oil molecules from travelling through catalyst pores to reach deeper into its still-active core. They also showed that some catalyst particles stick together in clusters, which disturbs the fluidity of the catalysts and lowers gasoline production yields. The Utrecht researchers are already working with companies to redesign these FCC catalysts.