ENGINES & EMISSIONS
The Fastest Path to Emissions Reduction for Heavy-Duty Diesel Engines Make the most of current technology and alternative fuels.
by Julie Blumreiter, ClearFlame Engine Technologies
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The Challenge Diesel engines are critical to world economies. However, they contribute to local air pollution, and the burning of fossil fuels is currently the largest contributor to greenhouse gas emissions from human activities. Projections suggest that even with a growing number of alternatives, only 25% of new, heavy-duty trucks in 2035 will be rated for zero tailpipe emissions. This leaves the remaining 75% to rely on
CLEARFLAME ENGINE TECHNOLOGIES
olutions are needed that can mitigate the 4.8 gigatons of annual carbon dioxide (CO2) emissions generated globally from heavy-duty sectors that use diesel fuel. These include on-road transportation and off-highway equipment. While electrification helps curb tailpipe emissions of light-duty, medium-duty and short-range transportation, largescale deployment for heavy-duty and off-highway sectors is still decades away. These industries need solutions for decarbonization today to help meet global climate goals. fossil fuel unless other alternatives are developed. Additionally, the number of heavy-duty vehicles on the market continues to increase, with nearly 359,000 Class-8 vehicles expected in production in 2022. The size of the diesel emission problem and the wide range of applications in which these engines are used have created a search for decarbonization solutions across the heavy-duty industry. One question often asked is: How fast can we get to zero emissions?
Figure 1. Emission reduction trajectories associated with limiting warming below 1.5°C based on the starting year. Solid black lines show historical emissions while dotted lines show emissions constant at 2018 levels.
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OEM Off-Highway | JULY/AUGUST 2022
Framing the question in this way creates a single, acceptable outcome— only the solutions with perfect, zero emissions are the ones worth implementing. However, if all the diesel emissions were cut in half today, the industry would have twice as long to find the quickest path to zero emissions. Perhaps a better question is: How quickly can we reduce emissions? This way, the industry can prioritize progress toward that perfect future without discounting provisional solutions that can help get the industry there sooner. In stronger words, focusing exclusively on zero tailpipe emission solutions impedes the progress the industry can make and needs to be making by deploying midterm solutions that offer significant emissions reductions today.
Key Considerations Four key factors should be considered when assessing emissions reduction for on- and off-highway applications: • Life-cycle emissions as the primary metric—Reducing life-cycle greenhouse gas (GHG) emissions is essential for lowering atmospheric
