The Diesel Technology Forum has released a new primer on potential strategies for upgrading existing diesel engines in both on and off-road equipment.
The whitepaper, Retrofitting America’s Diesel Engines, describes the various advantages and strengths of the “five Rs” of emissions reduction: rebuild, refuel, retrofit, repower and replace:
Rebuild. After 3 or 4 years, rebuilding some core engine components to manufacturers’ original specifications can return emissions performance to the original design levels. Some manufacturers also have options to improve emissions beyond the original performance levels.
Refuel. Use of Ultra-low Sulfur Diesel (ULSD)can lower emissions, as can some other renewable fuels and fuel products such as biodiesel and emulsifiers.
Retrofit. The installation of exhaust emissions control technologies such as particulate filters, oxidation catalysts, exhaust gas recirculation (EGR), selective catalytic reduction (SCR) devices, and lean NOx catalysts (LNCs).
Repower. Replacing the older engine in diesel-powered equipment with a new or newer diesel engine can dramatically reduce emissions.
Replace. Replacing entire vehicles or equipment may be the best option for some of the oldest, heaviest emitting vehicles or equipment due to technological feasibility and cost considerations.
The paper also provides an overview of funding sources for various types of projects, as well as case studies of sample retrofit projects.
Diesel retrofit is highly cost-effective, but one size does not fit all. As noted earlier, several studies have proven that diesel retrofits are extremely cost effective. Some equipment may not be candidates for emissions control devices, but could potentially have emissions reduced through repowering with a newer, cleaner diesel engine. In other cases, engines may be only a few years old and already have some emissions control technology, but can have emissions reduced through selective use of ULSD.
Each retrofit case is unique in terms of its business and its technological environment, but in most cases, a retrofit, broadly defined as one of the 5 Rs, can reduce diesel emissions for virtually all diesel vehicles and equipment purchased before 2007.