Biobutanol: Savior of marine engines?

What is biobutanol?
Biobutanol is a four-carbon biologically-derived alcohol that contains nearly 90% of the energy content of gasoline. It does not phase-separate in the presence of water like ethanol which makes it well suited for recreational boats and engines. Biobutanol is also less corrosive than ethanol, which means it is more compatible with the wide variety of fuel tank and fuel system components in use in recreational boats. At up to 16.1% by volume in gasoline (iB16), biobutanol has the exact same energy content of 10 vol% ethanol fuels (E10).


How is biobutanol made?
Biobutanol is made through the fermentation of sugar from biomass sources similar to beer and wine production. Existing ethanol plants could be converted to make biobutanol using existing ethanol feed-stocks such as corn and sugar beets, or, advanced feed-stocks (cellulosic biomass) such as crop residues, wood residues, dedicated energy crops, and industrial and other wastes.


Why interest in biobutanol for recreational marine engines?
The congressionally mandated US Renewable Fuels Standard requires 36 billion gallons of renewable fuel to be blended into the gasoline supply by 2022. There is a push to increase the amount of ethanol in the fuel supply through blends such as ethanol E15. Recreational marine industry reports show significant damage to marine engines using ethanol E15 fuels. Recognizing the issues associated with higher ethanol blends such as E15, the recreational marine industry is exploring biobutanol fuel blends with very promising results. This research positions the industry as a proactive leader in finding alternative renewable fuels that are compatible with recreational marine engines and boats.


Why did BRP Evinrude demonstrate a boat powered by biobutanol fuel at the Miami International Boat Show?
The results of thousands of hours of industry testing indicate that biobutanol fuel blends are compatible with recreational marine engines. Showcasing biobutanol fuel blend in a boat will create interest in this promising renewable biofuel and allow visitors to experience this fuel first hand.


Has biobutanol caused any damage to recreational boats or engines?
Based on thousands of engine test hours, extensive industry testing and published research reports, biobutanol fuel blends resulted in no engine failures, engine runability issues or boat performance issues.


What is the difference between biobutanol, isobutanol and n-butanol?
Biobutanol is a description for biologically produced butanol which can include Isobutanol and n-butanol. Isobutanol and n-butanol are similar (same energy content and resistant to phase separation) but isobutanol has a higher octane rating than n-butanol making it more attractive for blending with gasoline. Higher octane fuels are often desirable in recreational marine engines to ensure maximum engine performance. However, both n-butanol and isobutanol have been evaluated in internal combustion engines.


How many companies are working on commercializing biobutanol?
There are many companies currently working on commercializing and developing biobutanol as a building block for renewable chemicals and/or for use as a biofuel in internal combustion engines. BRP does not endorse any specific biofuel company, but rather is focused on biofuel research that indicates compatibility with recreational marine engines.


Where can I purchase this fuel?
Large scale availability of biobutanol fuels will take some time. However, a biobutanol fuel blend is available for purchase from fuel manufactures/distributors not associated with BRP.


How long until biobutanol fuels become widely available?
Wide-scale use of biobutanol is expected to take time. The promising test results discovered in the marine industry testing program, along with support from engine and boat manufactures, will help to move the biobutanol discussion forward.


What fuel is the demo boat using?
The demonstration boat is running on a blend of 16.1 vol% isobutanol fuel (iB16) and 83.9 vol% gasoline.


Does an engine have to be altered to use this fuel?
Biobutanol (iB16) fuel blend was rigorously tested in standard marine engines with no alterations to the engine or fuel system.


Who is involved in the recreational marine biobutanol testing program?
Biobutanol research is supported by the US Department of Energy, Office of Energy Efficiency and Renewable Energy coordinated through Argonne National Laboratory. There is participation across the industry from boat and engine manufacturers as well as the National Marine Manufacturers Association (NMMA) and the American Boat and Yacht Council (ABYC).