Propane autogas is changing the future for fleets and raising the bar for what it means to be a clean fuel. New innovations, including renewable propane technology and an ultra-low NOx (nitrogen oxide) engine are game-changers in the industry and are pushing toward near-zero emissions.

Renewable propane availability

Renewable propane will take businesses to the next level of sustainability. It has all the benefits of conventional propane: clean, affordable, and with an abundant supply on the horizon. But because it’s produced from renewable, raw materials, renewable propane is even cleaner than conventional propane — and far cleaner than other energy sources.

Renewable propane is a byproduct of the renewable diesel and jet fuel production process, which converts plant and vegetable oils, waste greases, and animal fat into fuel. The renewable fuel is currently produced in U.S. refineries in California, Texas, and Louisiana as part of their renewable diesel production systems. The process utilizes existing infrastructure which is required to produce renewable diesel. The worldwide output is currently estimated at 100MM gal. With new cellulosic sources, many experts say the entire worldwide demand can be met with renewable propane by 2040.

Renewable propane’s chemical structure and physical properties are the same as conventional propane. It behaves in the same way as propane autogas and can be used in any existing propane autogas engines, providing fleet owners the same performance and reliability they rely on. At the point of combustion, renewable propane is carbon neutral, meaning no new carbon is added to the atmosphere during combustion. It also produces fewer lifecycle carbon-dioxide emissions than traditional propane.

Most importantly, renewable propane is now available and will be a fuel that advances propane autogas well into the future.

Ultra-low NOx engine innovation

Fleets all across the country are adding ultra-low NOx engines to their propane autogas fleets. The engine is 90 percent cleaner than EPA standards, certified to the optional ultra-low NOx emissions standard as defined by the California Air Resources Board (CARB) for heavy-duty engines with 0.02 grams per brake horsepower-hour, and is certified as near-zero emissions.

The Leander Independent School District in Texas operates 127 propane autogas buses, 24 of which have the ultra-low NOx propane autogas engine. Each year, the district’s propane autogas buses reduce NOx emissions by over 130,000 pounds and particulate matter by almost 3,000 pounds when compared with the diesel buses the district replaced. See how else these engines are benefitting the district in this Roush CleanTech article.

This engine technology is profoundly important because NOx emissions are federally regulated due to their negative impact on human health and are a known trigger for issues like asthma, bronchitis, and other respiratory problems, according to the Environmental Protection Agency. This is especially significant in the school transportation industry where students are coming face-to-face with tailpipe emissions every day, but the lesson here can be translated to nearly any fleet in any industry.

The ultra-low NOx engine is proving to be an environmental and economic bonus for fleet owners in other ways. The $2.7 billion Volkswagen Mitigation Settlement includes funding for Class 4-7 medium- and heavy-duty trucks and many owners are applying and qualifying for new or replacement vehicle funding. Propane autogas ultra-low NOx engines are the most cost-effective fuel solution for reducing NOx emissions, which is the primary target of the VW Settlement.

Mitigation plans in most states are finalized and the application and awards process is well underway. For more information about state mitigation plans, visit the Propane Education & Research Council’s (PERC) Volkswagen Trust Resource Center:

These innovations are immensely important, as the future of engine fuels continues to aggressively move to zero emissions.

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