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Biobutanol FAQ

Q: What is biobutanol and how is it made?

Biobutanol is a four-carbon alcohol produced from renewable, plant-derived energy sources in a fermentation process similar to beer and wine production. Biobutanol can be produced using existing ethanol feedstocks, such as corn and sugar beets, or advanced feedstocks (cellulosic biomass) such as crop residues, wood residues, dedicated energy crops, and industrial and other wastes. Biobutanol delivers more renewable energy content than ethanol while remaining compatible with current vehicles, boats, and infrastructure.

Q: Why interest in biobutanol for recreational marine engines?

The congressionally-mandated US Renewable Fuels Standard (RFS) requires 36 billion gallons of renewable fuel to be blended into the gasoline supply by 2022. Methods to increase renewable fuels in the gasoline supply have pri- marily focused on ethanol and higher ethanol blends such as E15. Recreation- al 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 has explored biobutanol fuel blends with very promising results. The approval of biobutanol fuel blends up to 16.1 vol percent (Bu16) for marine engines and boats positions the industry as a proactive leader in identifying renewable fuels that are more compatible with recreational marine engines and boats.

Q: How is biobutanol different from bioethanol?

Biobutanol has several characteristics which distinguish it from ethanol, mak- ing biobutanol an attractive gasoline bio component. For example:

 

  • Biobutanol is compatible with existing recreational boats and refueling infrastructure at levels significantly higher than ethanol, overcoming the impending ethanol blendwall.

  • Biobutanol is substantially less susceptible to phase separation in the presence of water than ethanol which means biobutanol behaves simi- larly to conventional non-ethanol gasoline when water is introduced to the boat fuel tank.

  • Biobutanol has an energy content that is closer to gasoline, so consumers face less of a compromise on fuel economy at higher blend ratios.  At 16.1 vol% in gasoline (Bu16), biobutanol has the exact same energy content of 10 vol% ethanol fuels (E10).

  • Biobutanol is well-suited for current boat and engine technologies. It does not require boat builders or engine manufacturers to compromise on performance to meet environmental regulations.

Q: Has biobutanol caused any damage to recreational boats or engines?

No. Based on thousands of engine and boat test hours, extensive industry testing and published research reports, biobutanol fuel blends up to 16.1 vol percent (Bu16) resulted in no engine failures, no engine runability issues and no boat performance issues.

Q: Does an engine have to be altered to use biobutanol?

No. Biobutanol fuel blends up to 16.1 vol percent (Bu16) were rigorously tested in standard marine engines and boats with no alterations to the engine or fuel system.

Q: Can biobutanol be used in an old engine?

Yes. Biobutanol fuel blends up to 16.1 vol percent (Bu16) have been tested in a variety of recreational boats powered by many different engine technologies including fuel injected four-stroke outboards, two-stroke direct fuel injection outboards, catalyst based stern-drive and inboards, non-catalyzed inboards, carbureted four-strokes, and conventional carbureted two-stroke engines.

Q: Will my boat perform differently with biobutanol?

Based on thousands of hours of testing both in the laboratory and on water, boat and engine performance is transparent between fuels such as E10 and biobutanol fuel blends up to 16.1 vol percent (Bu16). Biobutanol fuel blends behave more similarly to conventional non-ethanol gasoline, particularly when water is introduced into the boat fuel tank.

Q: Is there any significant difference in fuel economy or other operating factors that I should expect when running my boat with biobutanol fuel blends?

Thousands of hours of testing on marine engines operated both in the laboratory and operated in boats on the water indicate no negative impact on fuel economy as compared to E10. More importantly, Biobutanol does not phase separate in the presence of water which is a very desirable property, particu- larly when used as a biofuel blend for recreational boats. Fuel phase separa- tion with ethanol fuel blends such as E10 is a very common source of boat and engine related issues.  Phase separated fuels can quickly deteriorate fuel system components and can lead to catastrophic engine failure. Biobutanol fuel blends up to 16.1 vol percent (Bu16) behave similarly to conventional non- ethanol gasoline, in its resistance to phase separation, making biobutanol an excellent biofuel for recreational boats when compared to E10.

Q: Are there any different maintenance requirements in a boat using biobutanol fuel blends?

No. Comprehensive material compatibility studies indicate that biobutanol fuel blends up to 16.1 vol% (Bu16) are compatible with a variety of fuel system components typical of recreational boats. In fact, research has shown biobutanol fuel blends to be more compatible with fuel system components than ethanol. Coupled together with desirable properties including resistance to phase-separation in the presence of water and thousands of hours of successful marine industry testing means that biobutanol (Bu16) is a biofuel better suited for recreational marine engines and boats.

Q: 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. Both n-butanol and isobutanol have been evaluated in internal combustion engines.

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