Butanol can be made greener by the research of a Japanese institute, who developed an energy-saving biobutanol with a density of at least 80 percent. They derived their biobutanol from a 1 percent concentrated butanol and used a zeolitic separation membrane.
Being derived from biomass sources, biobutanol’s overall carbon emissions are zero, since the carbon dioxide it emits when burned is reabsorbed by the next biofuel crops. Unlike ethanol, which has a relatively smaller energy density (27 MJ/kg), biobutanol has 34 MJ/kg and has the same cost per calorific value. Moreover, biobutanol is easier to store and the tanks don’t have to have special designs. It doesn’t mix with water, like ethanol, which is a plus.
The biomass can be used more effectively, because the microorganisms that can produce biobutanol can use a sugar (named C5) which the ones involved in the production of ethanol can’t.
Even more, the energy required to collect butanol decreases by 50 to 70 percent because the researchers synthesized a silicalite separation membrane with a high alcohol permselectivity. They also could collect high density butanol from low-density butanol, which let increased productivity.