Research may help fuel big changes in oil refining

By Costa Maragos Posted: March 31, 2016 6:00 a.m.

(l-r) Daniel Markewich, undergraduate and Dr. Allan East, professor of Theoretical Chemistry, show their solution to a ‘vexing mystery’ in petroleum refining chemistry.
(l-r) Daniel Markewich, undergraduate and Dr. Allan East, professor of Theoretical Chemistry, show their solution to a ‘vexing mystery’ in petroleum refining chemistry. Photo by Trevor Hopkin - U of R Photography.

A supercomputer on campus is helping fuel the potential for big changes in the way crude oil is refined.

It has helped a U of R research team, led by Dr. Allan East, Professor of Theoretical Chemistry, to solve a vexing mystery in petroleum refining chemistry - and that is how molecules rearrange in the middle of the entire process of oil refining.
“It’s hard to improve something if you don’t know how it works. Once you know how it works you have a much better shot at improving it. We believe we’ve accomplished that on the theory side. We’ve figured out how it works,” explains East.

The discovery has  been published in the peer reviewed Journal of Organic Chemistry and reported in the Feb. 15 issue of the American national chemistry newsmagazine Chemical and Engineering News. East was the lead on this research along with undergraduate students Daniel Sandbeck, Daniel Markewich, and former M.Sc. candidate Abrha Wagaye.

Petroleum refining is a high-temperature process, using a lot of energy to produce energy. For instance, temperatures of 500 to 700 Celsius are used in a stage called fluid catalytic cracking, a process to crack the thick tars from Alberta’s oil sands into gasoline.

Here’s the challenge: to find the magic catalyst that will refine oil at much lower temperatures, while maintaining product distribution control. Such a scenario would mean major energy savings and less pollution.

“The heating step in refining of oil is really done in two main stages,” explains East. “The first is a distillation step which separates the oil into fractions, which are thick tar, liquids and gases. The second stage is when you start to crack the tars and the thick stuff to get octanes. That second heating stage triggers a chemical reaction. Once it starts there’s a cascade of reactions that happens at that point.”

Within that cascade, “the role of protonated cyclopropane (PCP) structures in carbocation rearrangement is a decades-old topic that continues to confound,” notes the research paper.

East’s research has solved this last mystery about the reaction cascade. His new theory explains, for instance, how molecule-branching steps proceed. Such steps affect the octane rating of fuels.
“Now, in theory there’s a chance of designing a catalyst that can steer the cascade and block some pathways and encourage other pathways, with the bottom line being producing gasoline at much lower temperatures,” says East.

Enter that supercomputer, located in a temperature controlled room in the U of R’s Administrations Humanities building. That computer was used to perform many simulations to help build the new theory, and then for targeted calculations to test the theory and determine molecular energies for each observed step.

The research team’s final challenge was to find a way to present its numerous results in an understandable way.  

“This was very satisfying, to be able to present this research to fellow scientists with their reaction being, aha,” says East.

Other researchers are now applying the theory to larger-scale simulations.

Should East’s theory be found to improve large-scale simulations, the hope is that engineers and others along the line will find new catalysts with it.

We’ll keep you posted.

The research was funded by the National Science and Engineering Research Council, the Canada Foundation for Innovation, the Government of Canada and CiaraTech (Canada) for its supercomputer funding.

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