Performance analysis, techno-economic and life cycle assessment of Jatropha curcas L. (Euphorbiaceae) seedcake gasification and Fischer-Tropsch integrated process for bio-methanol production

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.