With a growing emphasis on protecting our climate and better managing our limited resources, it is more important than ever to design effective products and systems that reduce resource use, can be reused, and are recyclable. It’s the foundation of the circular economy, where product design is done with the end in mind. Design and manufacturing of diesel engines and renewable biofuels produced from waste products are two key aspects of how diesel technology contributes to the circular economy.

According to the Environmental Protection Agency (EPA), a circular economy, as defined in the Save Our Seas 2.0 Act, refers to an economy that uses a systems-focused approach and involves industrial processes and economic activities that are restorative or regenerative by design, enable resources used in such processes and activities to maintain their highest value for as long as possible, and aim for the elimination of waste through the superior design of materials, products, and systems (including business models). It is a change to the model in which resources are mined, made into products, and then become waste. A circular economy reduces material use, redesigns materials to be less resource intensive, and recaptures “waste” as a resource to manufacture new materials and products.

Diesel Engines Are Designed for Long Useful Lives and Rebuilding

From design concepts to the assembly line, at every step diesel engines are designed for a long life; with multiple rebuilds and remanufacturing in mind. Reduced demand for raw materials, less waste created, and fewer emissions generated, coupled with greater value for customers, are the benefits of heavy-duty engine remanufacturing.

With truck engines lasting over a million miles, and engines in construction machines still on the job after thousands of hours, durability of a diesel engine is the key driver in its initial investment and the return on investment for owners. Rebuilding generally takes place when oil consumption increases and fuel economy decreases. During the course of the engine’s life, multiple rebuilds are anticipated, with complete parts and service kits readily available that will restore the engine back to its original design performance.

After a major engine failure or multiple rebuilds, customers may purchase new or remanufactured engines. Remanufactured engines are produced with precision parts, testing and quality practices just like new engines. Failed or worn engines are disassembled, cleaned, and evaluated. Core engine elements that can be preserved are machined back to original standards. Coupled with the installation of new components like cylinder liners and fuel injectors, performance is restored to the original manufactured state. Unusable components are melted down and reused for various purposes. All this occurs at a fraction of the cost of a new engine.

Since a remanufactured engine can take about 1.5 engines to produce, the recycling of parts gives at least a second life to components. Most importantly, it reduces the need for raw materials like iron ore, aluminum and other metals and materials necessary to build new parts.

The remanufacturing of diesel engines delivers substantial environmental and energy benefits to society and the customers that use the engines.Studies show that rebuilt engines need 50% less energy and only 67% of the labor required to produce new engines. The Fraunhofer Institute in Stuttgart, Germany demonstrated that the yearly energy savings by remanufacturing worldwide, equals the electricity generated by five nuclear power plants or 10.7 million barrels of crude oil. That’s equivalent to a fleet of 233 oil tankers. The yearly raw materials saved by remanufacturing worldwide would fill 155,000 railroad cars forming a train 11,100 miles long.

Remanufacturing returns end of life products back to like new operating condition, keeping waste out of landfills, through the reuse and recycling of components. Remanufacturing also reduces air pollution, by providing customers with a cost-effective option to rebuild their engine back to original performance and reducing the emissions from smelting operations if engine cores were all discarded and not rebuilt and remanufactured. The Remanufacturing Industries Council has established the American National Standard for Remanufacturing that provides a benchmark for the process of remanufacturing and specifications.

Heavy-duty engine and equipment manufacturers have long been leaders in practices central to supporting a circular economy. For example, Caterpillar, a leading manufacturer of heavy-duty and industrial engines, recycled 121 million pounds of material in its remanufacturing operations in 2021, reporting 85% less energy use, 85% less water use, and 61% lower greenhouse gas emissions. Other engine manufacturers including AGCO, Cummins, Deere, FPT, mtu/Rolls-Royce, Volvo, Isuzu and Yanmar all have similarly successful remanufacturing businesses specifically designed for their products and customers.

Renewable and biodiesel fuels are produced from waste products. Another facet of diesel engines in a sustainable and circular economy is the use of renewable and biodiesel fuels. In 2021, about 3.2 billion gallons of biodiesel fuels (biodiesel and renewable diesel) were produced in the US. Made primarily from a byproduct of soybean processing (oil), food waste and animal fats, renewable biodiesel fuels utilize these waste and processing byproducts and turn them into useable fuel. This reduces demand for petroleum-based diesel, while offering important emissions benefits in the form of up to 86% lower greenhouse gas and other emissions.

According to the Energy Information Administration, in March 2022, 527 million pounds of waste feedstocks (oils, greases, etc.) were consumed to produce biofuels, along with 988 million pounds of soybean oil used to produce biodiesel fuel. Trough established remanufacturing and rebuilding practices, as well as the expanding use of renewable biodiesel fuels, diesel technology is well established in the circular economy.

—From Diesel Technology Forum Policy Insider: https://dieselforum.org/policyinsider/how-diesel-engine-remanufacturing-and-renewable-biofuels-drive-a-circular-economy