With the expansion of domestic canola crush capacity in Western Canada, the term “renewable diesel” is being mentioned much more frequently. Many growers are familiar with biodiesel, but the two are different and not interchangeable.
Although they can come from the same feedstocks, such as vegetable oil, the process of making them is different. Ian Thomson, president of Advanced Biofuels, defines the three types of fuel in the following ways:
Biodiesel is the original. It’s made through a simple biochemical process (i.e, esterification) creating a fuel that can be ‘dropped in’ up to 20 per cent. Biodiesel is chemically different from diesel, and blended typically at lower blend levels in winter. Biodiesel is handled differently in cold weather but extensive cold-climate use in the U.S. in Minnesota and elsewhere shows it can be done.
Renewable diesel is also called hydrogenation-derived renewable diesel in Canada (HDRD) and is made with a thermal chemical process in facilities that look a lot like an oil refinery, but are standalone production facilities. The fuel is chemically almost identical to diesel fuel, and can be produced at varying low temperature ratings. It can be 100% dropped in, meaning that it is fully compatible with our vehicles and existing infrastructure.
Co-processed renewable diesel (and gasoline, jet) is the most recent innovation in renewable fuels. Veg oils/fats are literally fed into one of several places in an oil refinery, and are ‘co-processed’ at around 5 per cent (10 per cent max) feed rate with crude oil. This occurs in a traditional oil refinery, which requires it to add some additional tank infrastructure, and which requires some change and more careful use of catalysts. The resulting product is a hydrocarbon (as is HDRD) chemically indistinguishable from the fossil fuel. Depending on where in the refinery the biomass is introduced, the renewable content ends up in the diesel fuel, gasoline, or jet fuel.
This interest in renewable diesel is not just a Canadian thing, either.
“As the country [United States] has moved towards a push for cleaning burning transportation and heating fuels, its brought biodiesel and renewable diesel into the light,” said National Biodiesel Association CEO, Donnell Rehagen, on a recent episode of AgriTalk.
The Canadian government’s Clean Fuel Standard looks to encourage the production of renewable diesel, which has the canola industry and processors encouraged by the demand.