Major technological breakthroughs designed to reduce the carbon footprint of diesel engine emissions may not be coming any time soon.
“I don’t know of any new technology coming down the pipe,” said Harvey Chorney of the Prairie Agricultural Machinery Institute in Winnipeg.
“I think they (equipment manufacturers) have gone as far as they can in terms of reducing the emissions on diesel engines,” he said.
From Tier 1 to Tier 4, the emission quality of diesel engines has steadily improved.
Electronics were introduced into Tier 1 engines about 15 years ago to help control fuel-to-air ratios injected into engines. Before this, engine fuel ratios were mechanically controlled.
“Tier 1 immediately eliminated the thick, black smoke after starting,” Chorney said.
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A few years later, Tier 2 improved on Tier 1.
Then Tier 3 engines with larger cooling systems were introduced, which were designed to enable engines to operate at hotter temperatures.
“The idea of running engines hotter was to get a cleaner burn. So in order to meet those requirements, they were trying to optimize the fuel-to-air ratios and run them very hot so they would essentially burn cleaner.”
He said engine performance recovery happened between tiers 3 and 4 with urea being injected, which significantly improved engine efficiency.
Under those systems, a chemical reaction takes place in the exhaust system that combines nitrous oxide with the extra nitrogen from urea, resulting in only nitrogen and oxygen coming out, as well as a significantly cleaner exhaust.
Introduced in 2011, Tier 4, as well as subsequent improvements, saw more focus on the exhaust and the use of urea while burning less fuel and operating under lower engine temperatures.
Chorney compares the progression to the introduction of catalytic converters on motor vehicles during the mid 1970s.
“When they started doing treatments on the exhaust pipes with the catalytic converters, all of a sudden the efficiency started coming back again. That’s the same analogy that happened in the diesel emission categories.
“They kind of choked the engines down to try and meet (emissions targets) between Tier 1, 2 and 3 and then they realized the only way they can meet Tier 4 was treatments on the exhaust,” he said.
“It was very expensive, which is why they held off as long as they did, but when they did that, they improved the efficiencies of the engines back again. So that’s where the fuel consumption came back.”
In the future, he said engine installation efficiency will improve by reducing pan sizes and by having smaller cooling packages.
However, he said engine improvements are not necessarily motivated by the need to reduce carbon but by the race to stay competitive.
“It’s driven by competition in that they want to take cost out, which probably means the price of the machines is not going to go down, but they may not increase as fast as they’ve been doing.
“But the other thing that’s going to happen is there’s going to be an efficiency gain. There’s going to be more useful work done for a litre of fuel burnt.”
Chorney said while manufacturers were tasked with the burden of trying to meet aggressive targets for reducing greenhouse gas emissions on farm, farmers ultimately incurred the expense.
“Manufacturers have added the cost of these systems into the units. In order to capture the cost the farmer got the benefit of having the lower emissionized engine, but they paid for the cost.”
He said farmers pay for their initial machine and also for the ongoing costs of adding urea in their units and setting up an on-farm urea filling station.
“All of those costs were incurred and no benefits from a farm perspective have come back. There has been a lot of contribution by the farms and really not much trumpeting in terms of (the general public) perceiving any benefits by it,” he said.
Chorney said farmers have been doing their part for the past 15 years to reduce their carbon footprints.
“Now, talks about a carbon tax that starts from zero and in the meantime, farmers have incurred considerable expenses on farm.”
Unlike other businesses, Chorney said farmers are unable to pass the costs of lower emission machines on to their customers.