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Test Results Show Biobutanol Performs Similarly to Unleaded Gasoline

1-butanol is less volatile than ethanol, and butanol-gasoline blends are less volatile than ethanol blends. Adding a fraction of butanol to an ethanol blend brings down the volatility. Click to enlarge. Source: BP

New fuel testing results on bio-derived 1-butanol presented by DuPont and BP at the SAE World Congress indicate that biobutanol has proven to perform similarly to unleaded gasoline on key parameters, based on ongoing laboratory-based engine testing and limited fleet testing.

According to BP Biofuels program manager Frank Gerry, biobutanol formulations meet key characteristics of a “good” fuel, including high energy density, controlled volatility, sufficient octane and low levels of impurities.

He described early testing data that indicate that biobutanol fuel blends at a nominal 10 vol% level perform very similarly to unleaded gasoline fuel. Additionally, the energy density of biobutanol is closer to unleaded gasoline.

Butanol does not phase-separate in the presence of water, unlike ethanol. With a lower oxygen content than ethanol, higher volumetric concentrations of butanol could be blended into gasoline while still adhering to oxygen limits. Fuel testing also has proven that biobutanol does not phase separate in the presence of water, and has no negative impact on elastomer swelling.

Combined with ethanol in gasoline blends, butanol can bring down the vapor pressure of the fuel.

Fuel Properties
Property Ethanol 1-Butanol Gasoline
1 Blend values of alcohol octane numbers and vapor pressure.
2 Summer / Winter specifications.
Sp. Gravity 60/60 F 0.794 0.814 0.720 - 0.775
Heating Value [MJ/l] 21.1 - 21.7 26.9 - 27.0 32.2 - 32.9
RON 106 - 1301 941 95
MON 89 - 1031 80 - 811 85
Rvp@ 5% / 10% [psi] 311 / 201 6.41 / 6.41 < 7.8 / 152
Oxygen [%wt] 34.7 21.6 < 2.7



Warren Heath

Engineer-Poet, I agree with you wholeheartedly, but as you said, we've lost so much time & resources that could have given us economical direct Biomass Gasification or waste CO2 or even atmospheric CO2 to alcohols, that countries like China with rapidly growing demand for liquid fuels are fast tracking methanol production with coal to methanol, which can produce methanol for $0.50 per gallon.

Dr George Olah, the Nobel Prize winning chemist, has a brilliant method for methanol production from CO2 plus Water & Electricity (could be all green), with a kind of reverse methanol fuel cell, but is getting zero government funding. There are lots of places where remote green electricity plus waste or atmospheric or volcanic CO2 could be used to produce methanol, such Iceland's vast geothermal reserves, or remote hydro or tidal power plants, or solar stations in the deserts, or Wind Farms in extreme wind areas - even fluctuating wind is no problem - methanol will store peak wind energy.

Max Reid

I guess Methanol has 50 % the energy content of gasolene compared to 73 % in Ethanol and 95 % in Butanol.

Thats a big problem. Any comments ?.

Warren Heath

Max Reid, when you can burn Methanol at double the efficiency of gasoline, then same size fuel tank, burn in a series hybrid with high efficiency generator and double the range again for the same size fuel tank. Other than that, to get a clean burning fuel, that costs less than gasoline per btu of energy (costs $1 per gallon & can be made for $.50 per gallon), meets ultra-low emissions vehicle standards, and even if burned in a standard ICE flexfuel vehicle, so what, double the size of an el-cheapo plastic fuel tank. Try burning H2 or other compressed gases and see how difficult, bulky, expensive, and inconvenient that is.


Olah's system is very slick (neat chemistry), but it has the unique problem of collecting CO2 as well as the general problem of getting all the energy to reduce it.  IMHO, this is a long-term prospect (30+ years).


DuPont is not the only patent holder:


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