Renewable Hydrogen from Seafood Shell Waste for Long-term Energy Storage on Islands

This study explores the potential of renewable seafood shell waste for sustainable energy conversion and longterm storage, particularly for isolated communities. Despite its rich chitin and protein composition, seafood shell waste is often neglected. The research evaluates and compares three advanced gasification technologies: biomass gasification, plasma gasification, and chemical looping, to convert seafood shell waste into syngas and H2. The study uses validated Aspen Plus models to optimize feedstock blending ratios and operational parameters. Results show that feedstocks high in lobster and shrimp shells yield higher H2 outputs and improved syngas quality compared to clam-dominated blends. For instance, biomass gasification at 1200 ◦C yielded approximately 500 kg/h of H2 from pure lobster or shrimp feeds, while plasma gasification at 4500 ◦C achieved yields near 730 kg/ h. Plasma gasification, when integrated with fuel cell conversion and heat recovery systems, can generate over 10,000 kWh during a 6-hour peak period, enough to power over 1100 single-detached homes. Its levelized cost of hydrogen (LCOH) varies from $5.72-$8.37/kg H2, making it less expensive than chemical looping and biomass gasification. Plasma gasification also has the lowest global warming potential (GWP) at 6 kg CO2e/kg H2. Combining plasma gasification with carbon capture and storage may reduce GWP to 0.3 kg CO2e/kg H2 and can be further explored. These findings underscore the technical and economic viability of converting seafood shell renewable waste into H2, advancing sustainable energy transitions, and supporting net-zero goals.