Modified-route chemical-to-power conversion via biomass gasification–HSOFC with waste-to-power/freshwater integration: 4E analysis for biomass selection and LS-boosting-based optimization

Abstract
This study presents an efficient modified-route chemical-to-power conversion strategy by adjusting the outlet syngas composition from biomass gasification to meet the requirements of a proton-conducting solid oxide fuel cell (HSOFC). Conventional systems cool syngas using external coolers before compression or bypass compression by feeding hot syngas directly to the fuel cell, which limits operational flexibility. To address these limitations, this system employs an advanced cascade energy recovery configuration in which syngas's thermal energy is harnessed through supercritical CO2 and ejector-based transcritical CO2 cycles, enabling both waste-to-power and syngas cooling to compression-compatible temperatures. Moreover, the HSOFC's waste heat is introduced into a multi-effect desalination (MED) system, enabling the cogeneration of freshwater and power. In addition to the novel system development, a biomass selection framework based on 4 E criteria (energy, exergy, exergoeconomic, and exergoenvironmental) is accomplished, identifying sawdust as the most suitable feedstock. Beyond parametric and sensitivity analyses, a least squares (LS)-boosting machine learning method integrated with a multi-objective grey wolf optimizer (MOGWO) is implemented to realize optimum conditions. Under the optimized settings, the entire process achieves a 37.53% exergy efficiency, with a specific cost of 11.36 $/GJ and an exergoenvironmental impact of 48.90 mPts/GJ, enhancing cost-effectiveness alongside reducing environmental impact.

Author
Mohammad Kaveh

DOI
https://doi.org/10.1016/j.ijhydene.2026.155717

ISSN
1879-3487

Publish Date: 2026-05-28