Green Ammonia Production and Integration in Multigeneration Systems: A Review

The widespread proliferation of ammonia through the Haber–Bosch process resulted in an agricultural revolution, being responsible for worldwide population growth and substantial improvement of global quality of life. Now, with the worldwide shift away from non-renewable resources and fossil fuels, ammonia has emerged as a solution to a global crisis once again, leveraging its properties as a viable carrier for the proposed fuel of the future, hydrogen, and also being feasible as a fuel on its own merits. However, the current state of the ammonia industry relies on fossil fuel reforming to procure the required feedstock, and so an alternative route must be explored, wherein ammonia can be produced entirely from renewable sources, in terms of both material feed and power. This paper will provide an overview of the current state of the ammonia industry, particularly highlighting the production of ammonia from renewables, known as “green ammonia”, and will also provide a preliminary review of the literature relating to the integration of ammonia generation systems to power and other multigeneration schemes, for increased efficiency, as well as explore the various processes used, such as biological, electrochemical, and catalytic conversion.