Peak-demand buffering via hydrogenation heat-to-power conversion in liquid organic hydrogen carrier systems

Renewable electricity is intermittent, motivating flexible buffering technologies. This study evaluates a thermally integrated system that recovers the exothermic heat of toluene hydrogenation in liquid organic hydrogen carrier (LOHC) systems and converts it into electricity for potential peak-demand buffering. Hydrogenation was carried out at 150–250 ℃ over Ru/Al 2 O 3 and Pt/Al 2 O 3 catalysts; Pt/Al 2 O 3 gave higher methylcyclohexane (MCH) selectivity and better thermal stability. A process model was built in Aspen Plus for a hydrogen processing capacity of 1,000 kg/h, and raising the steam pressure from 5 to 50 bar increased the net power output from 1,612 to 2,271 kW. A techno-economic analysis (TEA) using a stacked cost–revenue framework was applied to two configurations. In the co-production case (Case A), MCH is the primary product and the recovered heat yields electricity as a co-product, so the economics are set mainly by the MCH value. In the closed-loop case (Case B), electricity is the only product, giving a baseline levelized cost of electricity (LCOE) of 0.51 $/kWh against an industrial benchmark of 0.09 $/kWh; lowering the dehydrogenation energy cost is the key lever toward grid parity. A life cycle assessment (LCA) gives 0.24–0.33 kg CO 2 -eq/kWh, below the grid average, provided that dehydrogenation energy use and material losses are controlled. LOHC facilities could therefore act not only as hydrogen-storage units but also as distributed power nodes that support grid flexibility.