Towards a Low-Carbon and Circular Oyster Processing Industry: Carbon Footprint Assessment and Mitigation Strategies in China

The development of the oyster processing has increased interest in reducing in carbon footprint and finding productive uses for discarded shells. This study assessed the carbon footprints of major oyster processing pathways and oyster shell valorization. Electricity consumption and packaging materials are the primary contributors to processing emissions. Under the integrated mitigation scenario combining packaging optimization, improvements in processing efficiency, changes in the electricity mix, and adjustments in transportation distance product carbon footprints could be reduced by 54-86% by 2050. Beyond processing, we find that valorizing oyster shells into soil amendments, calcium carbonate, and coarse aggregates shows lower carbon footprints than conventional production systems. Whether oyster shell valorization has a lower carbon footprint than landfill disposal depends on transport distance, making localized collection and valorization essential. By extending the assessment boundary from oyster processing to shell valorization and quantifying the potential of mitigation strategies, this study provides a scientific basis for aligning China’s oyster processing industry with low-carbon and circular economy principles.