Renewable diesel is an alternative to petroleum diesel exhaust fluid. There are some differences in ingredients and production methods, but this option can deliver many of the same applications. There is one key distinction — it’s much cleaner than regular diesel and other types of biofuel.
Using eco-friendly renewable fuels is one of the most important strategies in the global fight against climate change. Renewable diesel could be the solution people have been looking for.
What Is Renewable Diesel?
Renewable diesel is a biofuel consisting of fats, oils and nonfat feedstocks. A biofuel is derived from living matter instead of nonliving sources. Through a process called hydrotreating, manufacturers mix the feedstocks with hydrogen under extreme heat and pressure to remove oxygen, nitrogen and sulfur.
The result of this process is a clean-burning hydrocarbon fuel. It has earned the name “renewable diesel” because it doesn’t rely on fossil fuels. People can make an indefinite amount of the ingredients from scratch. Here are a few reasons it’s changing the conversation around renewable fuels.
What Are Its Benefits?
1. Fewer Emissions
Renewable diesel produces fewer emissions. A 2018 National Renewable Energy Laboratory study found that it had lower levels of carbon dioxide and nitrogen oxide emissions. Ongoing analysis by fuel researchers in California has also shown that renewable diesel reduces carbon intensity by 65% compared to petroleum diesel.
Renewable diesel burns more cleanly than regular diesel for several reasons. The hydrotreating process removes oxygen, nitrogen and sulfur. It also includes lower carbon materials like waste agricultural oils and fats. Thanks to this unique concoction, the fuel produces fewer amounts of the following emissions:
- Carbon monoxide
- Carbon dioxide
- Nitrogen oxide
- Sulfur dioxide
- Benzene
- Soot
- Particulate matter
The exhaust fumes from renewable diesel may contain these substances in small amounts after internal combustion. It might not be 100% clean, but it’s still much cleaner than petroleum diesel exhaust fumes.
2.Seamless Compatibility
Although it has different ingredients, renewable diesel meets the ASTM D975 standard specifications for regular diesel. That means it can seamlessly integrate into existing diesel engine applications. Users can also safely mix renewable and regular diesel to increase their fuel supplies and boost engine performance.
Your car might not rely on diesel, but many other forms of machinery do, including the following:
- Tractor-trailers
- Airplanes
- Locomotives
- Marine vessels
- Farming equipment
- Construction equipment
- Manufacturing equipment
- Mining equipment
- Home power generators
Imagine a world where these essential machines can run on a clean and renewable fuel source. Renewable diesel could be that fuel. No changes to the machinery are necessary, making implementation a smooth process. It’s a near-identical replacement for petroleum.
3.Resilient to the Elements
Renewable diesel is also more resilient to the elements than regular diesel. Its chemical structure has no oxygen, so it performs well in cold weather. It has a cetane number between 75 and 95 that outmatches other biofuels around 50 or 60. The higher number leads to faster startups, better throttle response and less noise pollution.
Renewable diesel also has a longer shelf life than petroleum diesel. It can last up to 10 years in low humidity and temperatures slightly below 70 degrees. It might have a lower freezing point than other hydrocarbon fuels, but it still prefers a moderate environment. People can create massive stores of renewable diesel over time for emergencies.
Efficient Production Methods
Efficient production is another reason renewable diesel is more eco-friendly than petroleum. It uses fat and nonfat feedstocks instead of crude oil, allowing for a wider range of methods. Hydrotreating is the primary technique in diesel biorefineries and may use the following ingredients:
- Soybean oil
- Canola oil
- Corn oil
- Used cooking oil
- Animal fats
- Ethanol
- Wood chips
- Grass clippings
- Agricultural biomass
- Residential and commercial waste
Thanks to this diverse range of feedstocks, there are many other ways to produce large amounts of renewable diesel:
- Biological sugar upgrading: This process converts sugars to hydrocarbons through biochemical deconstruction, similar to the process of making cellulosic ethanol.
- Biomass gasification: Through gasification, biomass feedstocks get broken down into a mixture of carbon monoxide and hydrogen known as synthesis gas or “syngas.” The syngas is then catalytically converted to hydrocarbon fuel.
- Catalytic conversion of sugars: This long production method involves a chain of catalytic reactions that convert dense carbohydrate streams into hydrocarbon fuel.
- Hydrothermal processing: High pressure and moderate temperatures combine to accelerate the chemical decomposition of biomass or waste, producing an oil that can be catalytically converted to hydrocarbon fuel.
- Pyrolysis: This process decomposes organic feedstocks in the absence of oxygen, producing a liquid pyrolysis oil that can be converted into hydrocarbon fuel. It’s compatible with renewable and petroleum diesel production.
Diverse production methods are critical for integrating renewable diesel into daily life. As of 2022, the United States only has 11 domestic plants that produce about 1.75 million gallons yearly. That number must rapidly increase for renewable diesel to become the fuel of the future.
Challenges Ahead
Insufficient production is the greatest challenge facing renewable diesel’s expansion. Fortunately, the Energy Information Administration’s 2022 “Today in Energy Brief” predicts massive production increases in the coming years. A capacity of 2.4 billion gallons per year is currently under construction.
With new projects underway, production capacity could more than double by 2026. This prediction wouldn’t be surprising, as renewable diesel’s capacity has grown by 225% since 2020. The renewable diesel industry is growing rapidly, but some challenges still lie ahead:
- Meeting demand: Can manufacturers of soybean oil, canola oil and other feedstocks contribute to renewable diesel and still meet the demand from food customers?
- Agricultural conflicts: Will food shortages become a problem if soy, corn and other crops are increasingly modified for fuel production instead of nutritional value?
- Carbon intensity scores: What are the next steps for reducing the carbon intensity scores of crops that contribute to renewable diesel production?
- Leftover feedstocks: What will happen to the leftover feedstocks produced domestically due to increased renewable diesel production?
- Fuel prices: Diesel fuels are almost always more expensive than gasoline, so how would renewable diesel’s expansion impact fuel prices?
Renewable diesel’s expansion might necessitate massive changes outside the fuel industry. All producers of the various feedstocks would have to adjust their operations. Farmers would have a conflict of interest, and feedstock waste would inevitably increase. However, every challenge is an opportunity to adapt, and now is the time to do so.
Opportunities for Expanding Renewable Diesel
The greatest opportunity for expanding renewable diesel is in the automotive industry. Auto manufacturers can market renewable fuels alongside their new electric vehicles. This strategy would be the most effective for commercial cars but would also raise awareness among average consumers.
There are also untapped markets for renewable diesel, including maritime shipping, railroad transportation, aviation and electricity generation. Demand for renewable diesel in these markets can grow through policy changes, company sustainability initiatives and partnerships with environmental nonprofits.
Production materials and equipment will become more affordable as renewable diesel expands. Refinement processes will also improve, which means the fuel and agricultural industries can address their conflicting interests. Local or regional incentives can keep farmers happy. They can then afford to grow food for consumption and fuel production, increasing their chances to make profits.
Renewable Diesel’s Future Is Bright
While there are many types of biofuel, renewable diesel has the brightest future. It can immediately step in for petroleum and help many industries slash their emissions. The variety of production methods will also help accelerate its expansion and make it available to more entities. There will be some challenges along the way, but renewable diesel has a clearer path than any other type.
Frequently Asked Questions
What is renewable diesel?
Renewable diesel is a hydrocarbon biofuel that consists of fat and nonfat feedstocks, including various types of food-based oil, animal fats, ethanol, wood chips, grass clippings, agricultural biomass and common waste.
How is renewable diesel made?
Renewable diesel is made at diesel biorefineries through a process called hydrotreating. The manufacturers mix feedstocks with hydrogen under extreme heat and pressure, which removes oxygen, nitrogen and sulfur to create a clean-burning hydrocarbon.
Is renewable diesel more sustainable than regular diesel?
Renewable diesel is more sustainable than regular diesel because it has a lower carbon intensity level. The exhaust fumes also contain less nitrogen oxide, sulfur dioxide, benzene, soot and particulate matter. Renewable diesel even burns more efficiently in cold temperatures thanks to its lower freezing point.
Frequently Asked Questions
What is renewable diesel?
Renewable diesel is a hydrocarbon biofuel that consists of fat and nonfat feedstocks, including various types of food-based oil, animal fats, ethanol, wood chips, grass clippings, agricultural biomass and common waste.
How is renewable diesel made?
Renewable diesel is made at diesel biorefineries through a process called hydrotreating. The manufacturers mix feedstocks with hydrogen under extreme heat and pressure, which removes oxygen, nitrogen and sulfur to create a clean-burning hydrocarbon.
Is renewable diesel more sustainable than regular diesel?
Renewable diesel is more sustainable than regular diesel because it has a lower carbon intensity level. The exhaust fumes also contain less nitrogen oxide, sulfur dioxide, benzene, soot and particulate matter. Renewable diesel even burns more efficiently in cold temperatures thanks to its lower freezing point.