There is a global quest for the vehicle fuels of the future. Oil prices are fluctuating, and with growing concern over the climate effects of fossil fuels, the search is on for products with lower carbon dioxide emissions. Biogas, electricity and ethanol are the commercialized alternatives. Now, Swedish consumers can choose diesel and gasoline containing tall oil, a renewable resource.
Diesel based on forestry feedstock
A couple of years ago, a new process to make diesel from tall oil was developed by the Swedish oil company Preem in collaboration with the forest industry. The feedstock is a residual product from the pulp industry. The fuel was released in 2011 under the name of Evolution Diesel, and is marketed as a regular diesel with 30 percent less carbon dioxide emissions compared to the conventional Swedish MK1 diesel. This made Sweden the first country to use forest industry residue in regular diesel.
The emission comparison considers the entire chain of production, and is based on a “well-to-wheel” analysis, an approach to life cycle assessments well established in the fuel industry.
The same properties as regular diesel
Most biodiesels are blended with petroleum diesel. Evolution Diesel is different, as it’s produced through a hydrogenation process, where fossil petroleum and renewable tall oil are refined together. The gasified oil is heated to about 300 degrees Celsius and hydrogen is added. The mixture is then fed into the biorefinery together with the tall oil. The hydrogen reacts with the oxygen and sulfur present in both substances, removing these unwanted elements. The diesel is then processed in a SynSat reactor, to reduce the content of harmful aromatic hydrocarbons. Finally, 7 percent RME (rapeseed methyl ester, made from renewable rapeseed oil) is added, resulting in a fuel with 32 percent renewable content.
Due to the hydrogenation step, the diesel is molecularly identical to regular fossil diesel. No engine conversion is required, and the fuel works in any diesel engine, without affecting service requirements or engine behaviour. Performance, fuel consumption and price are the same; the only difference is reduced emissions.
The next step: forestry-based gasoline
“Now, Sweden will be the first country to make gasoline partly from tall oil. Preem’s Evolution Gasoline will be the most environmentally friendly standard gasoline on the market and contains 10 percent renewable energy – twice as much as other gasoline on the market”, says Morten Bendz, responsible for Preem’s stations.
“We are proud to have developed a gasoline partly made from forest residue. It will help reduce transports impact on climate change. Today, 97 percent of all vehicles are gasoline or diesel powered, and that number is most likely to stay up for a long time ahead. If Sweden wants to reduce its dependence on fossil fuels, it will be necessary to make diesel and gasoline from renewable raw materials”, Morten says.
Lower carbon dioxide emissions
Preem’s Evolution Gasoline is a regular 95-octane petrol with 5 percent ethanol and 5 percent tall oil. The tall oil is refined together with the fossil raw materials, like in the diesel process. The ethanol is mixed into the fuel.
”Evolution Petrol reduces the carbon dioxide emissions by 8,4 percent compared to a 100 percent fossil petrol. Compared to low-admixture standard petrol, with a 5 percent ethanol content, the reduction is 4,9 percent. The ethanol in Evolution Petrol has extra-high carbon savings – 90 percent carbon dioxide reduction instead of the normal 70 percent.
Combined with the five percent tall oil content, this adds up to a carbon dioxide reduction of 13 600 tons. This is equivalent to the emissions from approximately 5,500 automobiles per year”, Morten says.
“In the summer of 2015 the new gasoline will be sold at 40 Preem stations in Helsingborg, Malmö and Halmstad. This autumn, however, we will start selling the gasoline on more stations. It can be used in all gasoline vehicles, and can be mixed with all other kinds of gasoline. It also has the same effect and the same price as regular gasoline. We will continue to develop our fuel products and give them more renewable contents”, says Morten Bendz.
The article was published in September 2015