SASKATOON, Sask. — Oil refining is the backbone of the Canadian energy sector, with the industry producing over two million barrels per day of refined petroleum products. But treating crude oil to produce useful gas products comes with challenges.
In a new study, Dr. Ajay Dalai and Simon Kwao from the University of Saskatchewan’s College of Engineering, have improved our understanding of a key process known as hydrotreating, making it possible for refineries to run with fewer interruptions.
The researchers looked at a problem in oil refining called fine particle deposition. Fines are tiny solid particles that build up on the catalysts inside reactors that are used to clean gas oils made from bitumen. As these particles accumulate, they gradually block the flow of oil, increase pressure, and force the reactor to eventually shut down.
Using the Canadian Light Source at USask, Dalai and Kwao discovered that fines collect first in the hottest part of the reactor and then spread to cooler areas. In the hottest zone, the particles react chemically with the catalyst particles, damaging it and reducing its ability to remove impurities. In the cooler zones, the particles mainly form physical blockages, and catalyst performance declines only after large deposits built up over time.
“There was no way we could know what is changing in the catalysts without the use of the synchrotron light source. So, when we went in, it was with an open mind, to look at the material and see are there chemical changes, are there physical changes,” says Dalai.
What they’ve learned, says Dalai, can help engineers design better reactors, choose operating conditions that reduce buildup, and extend catalyst life. The team’s results are published in the journal Industrial & Engineering Chemistry Research.
“This could lower maintenance costs, reduce unexpected shutdowns, and improve the efficiency of producing cleaner fuels from heavy oil.”
Dalai and Kwao hope their findings can help the industry operate safely, and for longer. In some cases, understanding the importance of operating temperature could double the uninterrupted operating time at refineries from about a year to two years.
“We've been able to identify ways to prolong the use of these reactors, and by doing that we'll be able to reduce the cost of the end product for consumers,” says Kwao.
— Submitted by Canadian Light Source Communications
