There are currently approximately 50 million tonnes of hydrogen produced annually. This figure is expected to rise over the coming decades with the growth of a hydrogen economy. Hydrogen is currently and predominately used in industry to produce ammonia, hydrogenation of fats and pharmaceutical manufacture. All of these industries will continue to use hydrogen gas, so there will be an increased demand on the volume of hydrogen produced each year if the hydrogen economy is to succeed as an alternative form of energy. Consequently, hydrogen would need to be sourced from more than a single production pathway, and yet be sustainable. Each production pathway has unique benefits and disadvantages, such as cost of production and the purity of hydrogen produced. As a result, new sustainable methods of producing hydrogen are being researched for optimisation and commercialisation. In this article, the authors examine traditional and new routes to production techniques and costs that are associated with them.Published versio
