(182a) Electricity-Carbohydrate-Hydrogen (ECHo) Cycle for Sustainability

We wish to suggest the electricity-carbohydrate-hydrogen (ECHo) cycle for sustainable development. In this energy conversion cycle, electricity is a universal energy carrier; hydrogen is a clean electricity carrier; and carbohydrate is a high-energy density hydrogen carrier (14.8 H2 mass%) or a high-electricity storage carrier (~10 MJ electricity output/kg sugar) or a source for food, feed, liquid biofuels, and renewable materials. Each element of this cycle can be converted to the other reversibly & efficiently depending on resource availability, needs, and costs. To fill the gaps in this cycle, carbon dioxide can be biologically fixed by electricity or hydrogen for producing carbohydrate. These artificial photosynthesis processes are designed according to the design principles of synthetic biology, knowledge in the literature, and thermodynamics analysis; however, the validation experiments and its innovation require collaborative efforts from biologists, chemists, electrochemists, and engineers. Implementation of artificial photosynthesis on a large scale would solve numerous sustainability challenges, such as food production, CO2 utilization, electricity storage, transportation fuel production, fresh water conservation, wildlife habitat restoration, or maintaining a small closed ecosystem for space travel and the survival of humankind.