Emission Control Technologies in Modern Engines: A Comprehensive Guide

Emission control technologies in modern engines have become increasingly sophisticated, with a focus on reducing greenhouse gas (GHG) emissions and improving overall engine efficiency. The Environmental Protection Agency (EPA) has set new standards to control refueling emissions from incomplete medium-duty vehicles, and battery durability and warranty. These standards are based on EPA’s assessment of the suite of available control technologies for those pollutants, some of which are effective in controlling both GHGs and criteria pollutant emissions.

Tier 3 and Tier 4 Locomotive Emission Standards

One such technology is the use of Tier 3 and Tier 4 locomotive emission standards, which are the highest efficiency and performance standards currently available. The Washington State Department of Commerce has partnered with the Puget Sound Clean Air Agency (PSCAA) to produce a Priority Climate Action Plan (PCAP), which includes increasing the number of locomotive engine conversions to Tier 3 and Tier 4 locomotive emission standards.

The PCAP also plans to pilot a hydrogen fueling station and engine conversions which will look to replace diesel-powered emissions entirely for a certain percentage of locomotives. This additional work in the measure would have further impacts on GHG reductions in the region. Costs will vary depending on the development of technology and supply chain. Additional funding from CPRG would allow the facility to expand from its current rate of 1-2 engine conversions per year to an additional 4-6 engine conversions per year and add hydrogen refueling capacity.

The new locomotive repair and maintenance shop would also incorporate, wherever possible, all sustainable development and design practices. These include strategies that promote minimal environmental impact, advanced energy efficiencies, reduced water consumption, practical landscaping, and other green technologies that would be of particular interest and focus. Maintenance ease and the economical operation of the facility would also be essential to the project build. The new facility could also meet nationally recognized standards for energy efficiency and pursue LEED Certification.

Quantifiable GHG Emissions Reductions

Table 18 shows the estimated cumulative GHG reductions for Tier 3 and Tier 4 locomotive engines. With funding from CPRG, the number of converted locomotives to either Tier 3 or Tier 4 could be more than 35 by 2030. Additional shop space, staff, and apprentices could cut the timeline of this work in half and allow for an additional 4-6 conversions a year (instead of the average 1 to 2). By 2050, POVA staff could complete an estimated 150-200 locomotive conversions, thus directly impacting at least 1% of the total North American Fleet, which as of 2020 was estimated to have around 38,450 locomotives in total with over 26,000 of them being diesel-powered.

Multi-Pollutant Emissions Standards for Model Years 2027 and Later

Another technology that is being widely used is Multi-Pollutant Emissions Standards for Model Years 2027 and Later. This standard is established to control refueling emissions from incomplete medium-duty vehicles, and battery durability and warranty. This standard is based on EPA’s assessment of the suite of available control technologies for those pollutants, some of which are effective in controlling both GHGs and criteria pollutant emissions.

Advanced Gasoline Engines and Electrification

In addition to these technologies, the use of advanced gasoline engines, improvements to tailpipe controls, additional electrification of gasoline powertrains, and electric powertrains are also being used to reduce emissions. EPA’s modeling provides information about several potential compliance paths manufacturers could use to comply with the standards, based on multiple inputs and assumptions. EPA’s central analysis shows that both within the product lines of individual manufacturers and for 10 of 1181 different manufacturers across the industry, manufacturers will make use of a diverse range of technologies, including advanced gasoline engines (reducing engine-out emissions), improvements to tailpipe controls, additional electrification of gasoline powertrains, and electric powertrains.

The use of advanced gasoline engines can significantly reduce engine-out emissions, leading to lower overall emissions. Improvements to tailpipe controls, such as the use of catalytic converters and particulate filters, can further reduce emissions from the vehicle’s exhaust. Additionally, the electrification of gasoline powertrains, including the use of hybrid and plug-in hybrid systems, can help to reduce emissions by utilizing electric motors and batteries to supplement the internal combustion engine.

Electric powertrains, on the other hand, offer the potential for zero-emission driving, as they do not produce any direct emissions from the vehicle. The increased adoption of electric vehicles, powered by renewable energy sources, can contribute significantly to the reduction of GHG emissions and the improvement of air quality.

In conclusion, the use of emission control technologies in modern engines is a critical step towards reducing GHG emissions and improving overall engine efficiency. The EPA’s new standards and the use of Tier 3 and Tier 4 locomotive emission standards, hydrogen fueling station and engine conversions, advanced gasoline engines, improvements to tailpipe controls, additional electrification of gasoline powertrains, and electric powertrains are all examples of technologies that are being used to achieve this goal. These technologies not only help in reducing emissions but also promote minimal environmental impact, advanced energy efficiencies, reduced water consumption, practical landscaping, and other green technologies.

References:
– The Williams Companies Inc. CDP Climate Change Questionnaire 2023
– Washington CPRG PCAP
– EPA’s Proposed Rule for Light-Duty Vehicle Greenhouse Gas Emission Standards for Model Years 2024-2026