(353d) A Technoeconomic Assessment of Liquid Green Hydrogen Carrier Supply Chains for Delivering Sustainable Fuel

Sustainably produced hydrogen (green hydrogen) can play a key role in the decarbonization of society, both as a chemical feedstock and as an energy carrier. The rapidly declining costs of renewable electricity generation permit affordable green hydrogen production. However, the storage and delivery costs of gaseous hydrogen pose significant barriers to its economic feasibility. These limitations may be overcome with the aid of one-way liquid green hydrogen carriers, such as ammonia and methanol, which have been frequently studied, as well as formic acid, which has received less attention. Formic acid can be produced sustainably via the electrochemical CO₂ reduction reaction with relatively high selectivity (>80% Faradaic efficiency). Ammonia and methanol both lack high performing direct electrochemical routes but can be produced sustainably by coupling green hydrogen with CO₂ hydrogenation and Haber-Bosch processes, respectively. Techno-economic assessment serves as a useful tool to evaluate each of these liquid green hydrogen carriers. To assess the economics of each carrier, a case study was constructed to deliver green hydrogen as a distributed transportation fuel. This assessment revealed the potential for formic acid produced via electrochemical CO₂ reduction to serve as an affordable means to deliver hydrogen fuel to consumers. This techno-economic assessment can also be deployed to inform researchers how to best accelerate the commercialization of green formic acid. A pathway of modest advances in green formic acid production technology was also crafted to illustrate the economic feasibility of green formic acid as a hydrogen carrier at a large scale (50,000 kg H2/day). Additional investigation also revealed that formic acid is the only green hydrogen carrier that is cheaper to produce than its fossil-based counterpart and that it also offers the safest logistics of the studied hydrogen carriers.