Abstract:
The overall economic performance of biodiesel production can be improved by reducing the cost
of methanol required for the transesterification process. Gasification integrated with Fischer-
Tropsch synthesis provides an alternative route to biomass conversion. In this study, a thermodynamic
model of steam gasification of Jatropha curcas L. (Euphorbiaceae) seedcake and Fischer-
Tropsch synthesis of the syngas is developed to forecast the production of bio-methanol using
Aspen Plus. The combined effects of the gasification temperature, steam flow rate, and off-gas
recycling percentage were investigated using a response surface methodology to pinpoint the
optimal operating conditions. The results showed that a gasification temperature of 820 C, steam
flow rate of 740 kg/h and off-gas recycle fraction of 0.6 were the optimum operating conditions
for producing the highest amount of bio-methanol (53.13 wt.%). An initial capital investment of 7.4
million dollars and a minimum production price of bio-methanol of $0.91/L was determined.
Integrating the bio-methanol production process in biodiesel plants reduces the cost of producing
biodiesel by 26.36%. The environmental impact analysis showed that the process had an overall
effect of 10 potential environmental impacts/kg of bio-methanol generated. Utilizing optimized
process parameters may improve the process’ competitiveness on a commercial scale and improve
sustainability in the biorefinery process.
