Sustainable production of fermentation-based novel proteins

Feeding the growing global population sustainably while minimizing environmental impact is grand challenge for human society. Methane-based single-cell proteins through fermentation (bio-SCP) have emerged as a promising alternative to traditional protein sources (animal and crops), addressing the significant greenhouse gas emissions from livestock production. This study explores an innovative approach to bio-SCP production using synthetic natural gas derived from biogas. The process integrates biogas production via anaerobic digestion of food waste, biogas upgrading through a series of treatments, and SCP production via aerobic fermentation of methane. Detailed process modeling reveals that the proposed design consumes 25,000 kg/h (200 Mt/y) of food waste, producing 4,269.4 kg/h (34.2 Mt/y) of SCP and valuable by-products such as biofertilizer, elemental sulfur, low-pressure steam, and nitrogen. Notably, the proposed design achieves close to 100 % energy selfsufficiency. Techno-economic analysis indicates a capital investment of $733.5 million, annual operating costs of $43.96 million, and a minimum product selling price of $1.02/kg of bio-SCP, demonstrating promising economic viability, especially with nitrogen by-product sales. A cradle-to-gate life cycle assessment highlights the environmental benefits of bio-SCP, showing significant reductions in environmental impacts compared to fossildriven SCP production. This study underscores the potential of bio-SCP in sustainable animal nutrition and greenhouse gas emission reduction.