There
has been an increasing interest in the conversion of biomass
to biofuels, energy, and chemicals due to an increase in meeting environmental
demands and price and decrease in the potential availability of crude
oil. Among the biofuels postulated as viable alternatives due to their
physicochemical characteristics is butanol. Given its high energy
content, it is projected as a potential substitute for ordinary gasoline.
However, butanol production process through fermentation of lignocellulosic
material has shown some disadvantages. Another way of producing butanol
is by reduction of volatile fatty acids (from waste streams of organic
matters) with hydrogen. An effluent with a high content of water and
butanol is obtained. In that sense, thermodynamic interactions make
the separation process challenging. On the other hand, current policies
and needs have guided the proposals for chemical processes to meet
various sustainability metrics, for example, high profit margins and
low environmental impact, with inherent safety and robust operation
in the presence of disturbances. With this in mind, this work proposes
purification schemes to obtain butanol of high purity, from a butanol–water
mixture, in the compositions generated by reduction of volatile fatty
acids, using pervaporation, pressure swing distillation, and azeotropic
distillation. Comparing the results obtained, the pervaporation scheme
turned out to be the most promising alternative as it presents reductions
in all the “green” indicators (compared to the other
purification alternatives) in percentages between 27 and 52%. The
general indices for such alternative were 0.0392 ($/kgbutanol), 0.0066 (ecopoints/kgbutanol), 8274, 2.772 × 10–04 (probability/year), and 0.4281 $/kgbutanol regarding the total annual cost, ecological indicator 99, condition
number, individual risk, and minimum selling price, respectively.