Design and Economic Analysis of a Thermochemical Lignocellulosic Biomass-to-Butanol Process

A novel continuous
lignocellulosic biomass-to-butanol process using
a thermochemical route and a mixed-alcohol synthesis catalyst has
been developed. The process was designed and modeled using Aspen Plus
and consists of major process steps such as biomass drying; indirect
steam gasification; syngas cleanup and conditioning; mixed-alcohol
synthesis over a modified methanol catalyst; alcohol separation; and
utilities including cooling water, steam, and power generation. A
heat integration analysis was also carried out, resulting in an energy-sufficient
process with no requirement for external hot utilities and net power
production. A technoeconomic analysis was carried out using results
of the Aspen Plus model, equipment cost estimates, and discounted
cash flow analysis, with an assumption of nth-plant
costs and financing resulting in a minimum butanol selling price (MBSP)
of $0.83/L. Different plant and cost parameter scenarios were rigorously
explored using a sensitivity analysis.