Optimization and techno-economic-environmental assessments of a biomass-powered multi-generation plant for hydrogen and freshwater production

This study investigates a novel biomass-powered multi-generation plant designed to produce electricity, heating, cooling, hydrogen, and freshwater. The plant's performance was analyzed using a multi-objective optimization approach, focusing on its exergoeconomic and exergoenvironmental aspects. The thermoeconomic analysis was conducted using the Specific Exergy Costing (SPECO) approach, while the thermodynamic evaluation was based on exergy analysis. For the exergoenvironmental evaluation, the Eco-indicator 99 was employed as a practical instrument to assess the environmental performance of the plant. Key variables, including gasification temperature, combustion pressure and temperature, and injected steam temperature, were adjusted to improve efficiency. In the base case, the plant generated 2806 kW of net power, 239.4 kW of heating, 1725 kW of cooling, 20 kg of hydrogen per day, and 3.6 cubic meters of freshwater per hour. The gasifier and heat exchanger were identified as the primary sources of inefficiency, contributing to significant exergy losses. Moreover, the cumulative product exergy unit and the exergoenvironmental impact per exergy unit of all products are computed at 0.083 $/kWh and 28.59 mpts/kWh respectively. Optimization efforts demonstrated that cost and environmental impact decreased in optimal performance of the plant. These trade-offs underscore the importance of balancing economic and environmental factors. This research offers valuable insights into the potential of biomass-powered systems for sustainable multi-generation applications.