Microbial production
of 2,3-butanediol (BDO) has received
considerable
attention as a promising alternate to fossil-derived BDO. In our previous
work, BDO concentration >100 g/L was accumulated using brewer’s
spent grain (BSG) via microbial routes which was followed by techno-economic
analysis of the bioprocess. In the present work, a life cycle assessment
(LCA) was conducted for BDO production from the fermentation of BSG
to identify the associated environmental impacts. The LCA was based
on an industrial-scale biorefinery processing of 100 metric tons BSG
per day modeled using ASPEN plus integrated with pinch technology,
a tool for achieving maximum thermal efficiency and heat recovery
from the process. For the cradle-to-gate LCA, the functional unit
of 1 kg of BDO production was selected. One-hundred-year global warming
potential of 7.25 kg CO2/kg BDO was estimated while including
biogenic carbon emission. The pretreatment stage followed by the cultivation
and fermentation contributed to the maximum adverse impacts. Sensitivity
analysis revealed that a reduction in electricity consumption and
transportation and an increase in BDO yield could reduce the adverse
impacts associated with microbial BDO production.