Alternative ammonia production processes and the use of renewables

The Haber-Bosch synthesis of ammonia is an energy-intensive process that uses coal or natural gas as a fuel and feed. Direct electrochemical nitrogen reduction represents a potential alternative to the Haber-Bosch process that can be less polluting. This alternative route to ammonia from dinitrogen is not likely to require the same large capital investments as does the Haber-Bosch process, thus suggesting a distributive production structure of ammonia relative to the existing ammonia industry. In addition, the flexibility borne from the use of electrochemistry yields technologies that are better fit for the use of renewable energy sources that supply intermittent electricity. We show that under certain scenarios, at levels of efficiency (as determined by the required overpotential and the Faradaic efficiency) that might reasonably be achieved, direct electrochemical nitrogen reduction would be a sustainable and economically viable alternative to the Haber-Bosch process.