Techno-Economic and Environmental Assessment of a Hybrid Bioenergy System Optimized via NSGA-II: Biomass Pyrolysis, Fischer–Tropsch Synthesis, and Solar-Enhanced Power Generation

Abstract

Conventional biomass-to-fuel pathways are often plagued by low exergy efficiency, high production costs that burden consumers, and significant CO2 emissions that pollute the air. To address these challenges, this study introduces an innovative solar-assisted autothermal biomass gasification system. This energy-efficient system is combined with Fischer–Tropsch synthesis and a Rankine steam cycle. The design and simulation, performed using ASPEN Plus, show promise for biodiesel production and silent electricity generation. The unique aspect is the integrated process setup that combines concentrated solar heat with autothermal gasification, optimizing syngas usage for fuel and power generation, and utilizing a multi-objective optimization framework (NSGA-II by MATLAB) to enhance exergy efficiency, lower biodiesel production costs, and reduce CO2 emissions simultaneously— a method not documented in earlier studies. Detailed assessments, spanning energy, exergy, and economic dimensions, alongside an LCA exploring the full environmental footprint, are executed. The optimization process led to total energy and exergy efficiencies increasing from 55.91 % and 51.77 % to 57.08 % and 53.21 %, respectively. The reduction of CO2 emissions from 0.50 to 0.468 ton/MW is accompanied by an increase in net present value (NPV) from 0.5877 to 0.6078 M$/ton biomass. The cost of electricity saw a slight drop from 0.0543 to 0.0526 $/kW, while biodiesel production experienced a modest increase from 43.84 to 44.68 kg/h. The findings emphasize the proposed system’s promise as a technically sound, cost-effective, and environmentally friendly means of generating clean fuel and power.