Biobutanol Fuel, Fermentation and Algae Produced Gasoline Alternative

Bio-butanol fuel can generate energy when used in internal combustion engines similar to gasoline. However, for a variety of reasons it may actually be better than gas. First, let’s talk about compatibility with existing vehicles though. The air to fuel mixture ratio is 11.2 compared to gasoline which is 14.7. The energy content of Butanol is 105,000 Btu per gallon compared to gasoline’s 114,000 Btu per gallon. This similarity between air to fuel miuxture and energy content means conversion of existing vehicles would be very simple. You can mix Butanol with gasoline in small ratios and use it in most unmodified vehicles meaning even without a direct Butanol conversion you can use it as a fuel source. This would be a great way to use an alternative fuel in your car without needing to purchase anything but the fuel.

Biobutanol Production Process

Production of biobutanol can be achieved using biomass as well as from fossil fuels. Production via the biomass route is what we refer to as biobutanol. Typically this is accomplished through fermentation of the biomass with bacterium Clostridium acetobutylicum using the A.B.E process of fermentation. This process results in acetone, butanol, and ethanol from whatever biomass crop is used. Alternatively it is possible to create biobutanol using solar energy with the help of algae or diatoms which release it as a waste product. These algae biobutanol methods hold the most hope for lowing the cost of biobutanol to be competitive with its petrostock butanol rival.

Butanol tolerates water contamination and is less corrosive than other gasoline alternatives. Additionally, because of its low vapor pressure point and a high flash point Butanol is safe to handle, transport, and use at high temperatures. There are some problems with the use of butanol as a energy source. Let’s recap both the advantages and disadvantages of butanol as a fuel.

Pros of Biobutanol Fuel

  • Can be produced using different renewable energy sources.
  • Simple conversion to adapt gasoline vehicles.
  • Safer and easier to implement than other gasoline alternatives.
  • Existing fuel infrastructure could be easily converted, biobutanol is less corrosive than gasoline.
  • More resistant to water contamination.

Negatives of Biobutanol Fuel

  • Requires a fuel flow increase in order to make up for the roughly 10% decrease in energy content compared to gasoline.
  • Some fuel systems won’t run butanol without some modification or a low ratio to gasoline.
  • Gas gauge will probably read wrong either positive or negative.
  • Exhaust from combustion of butanol is more toxic than normal.
  • Possibly more toxic than gasoline exposure.
  • Currently not cost effective when compared to producing butanol from petrostock.

The current energy landscape means that butanol will probably not be a replacement for gasoline until prices rise significantly or new technology lowers production costs. However, it is an interesting alternative fuel and a renewable one at that.



  1. Hannah Forbes says:


    I understand that there are benefits of using butanol as a renewable fuel from waste biomass but I cannot find any information about the specification for the butanol before it can be used without modifying a car engine. If butanol from fermentation is at a low concentration what is the energy requirement to remove water from the butanol mixture and how much water can be in the mixture without damaging the engine operation?

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