Cleaner gas can get costly. Is it worth it?

Canadians pump more than 200 million litres of fuel into their vehicles every day, and drive a combined 325 billion kilometres each year. But compared to 20 years ago, smog-forming emissions have dropped by 90 per cent, primarily due to more efficient vehicles and cleaner fuels.

“Fuels have much less sulphur in them today,” says Peter Boag, president of the Canadian Fuels Association. “This has an impact on the effectiveness and efficiency of the vehicle’s emissions control systems.”

Sulphur is a chemical that’s found naturally in crude petroleum. Before it’s refined, crude contains some 15,000 to 18,000 parts per million (ppm) of sulphur. In the past, gasoline could still contain as much as 1,000 ppm, and in the early 1990s, Canada’s average sulphur content, at 350 ppm, was one of the highest worldwide.

Starting in 2003, government regulations reduced the allowable amount to 150 ppm, with a second phase two years later further reducing it to 30 ppm.

“Today, gasoline has only 30 ppm on average of sulphur,” Boag says. “And prior to 2007, the standard for diesel was 500 ppm, and it’s now at 15 ppm. That’s for on-road diesel, off-road, rail, and marine. All diesel now produced is what we call ultra-low-sulphur diesel, or ULSD.

“When you look at the growth of the heavy-duty vehicle segment over the last 10 to 15 years, that (sulphur) reduction has been an important part of emissions performance. ULSD has enabled new particulate filters that eliminate particulate matter, which is the visible pollutant (in diesel exhaust),” Boag says.

Removing sulphur from gasoline doesn’t affect engine performance and is strictly about the vehicle’s emissions and exhaust treatment systems.

But while low-sulphur fuels may seem like a win-win, they aren’t without their challenges. It’s expensive to take sulphur out of crude during refining, which raises the price of production. It also requires more steps, which requires more energy. While there was a net improvement in air quality linked to the removal of sulphur in fuels, there was also a rise in greenhouse gas (GHG) emissions at the refineries from the extra energy required to remove it.

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