Sustainable Ammonia Production from Sun, Air and Water

There is an ever growing demand for ammonia production that already reached globally 200 million tons per year by 2018 and is forecasted to increase to over 350 million tons per year by 2050 [1]. The application segment is dominated by the fertilizer industry, since the most important fertilizer and the world’s most widely produced chemical is urea. Ammonia is synthesized via the Haber-Bosch process, for which the required hydrogen and nitrogen are currently provided by using fossil fuels. This work proposes a novel approach to produce ammonia from the raw materials water and air only by utilizing solar energy…


Creating a Redox Materials Database for Solar-Thermochemical Air Separation and Fuels Production

Converting heat from renewable sources into other forms of energy is considered an essential factor in the reduction of greenhouse gas emissions. For instance, high temperatures can be reached using concentrated solar power (CSP), and the thus-captured energy can be converted into so-called solar fuels via thermochemical processes. These consist of the partial reduction of a redox material, usually a metal oxide, at high temperatures following the exothermic re-oxidation of this material at a lower temperature level using steam or CO2, which are thus converted into hydrogen or carbon monoxide, respectively. These two gases can be combined to generate syngas…


Future Ammonia Technologies: Plasma, Membrane, Redox

I wrote recently about two pathways for ammonia production technology development: improvements on Haber-Bosch, or electrochemical synthesis. Last week, I covered some of these Haber-Bosch improvements; next week, I'll write about electrochemical processes. This week, I want to write about some innovations that don't fit this two-way categorization: they don't use electrochemistry and they don't build upon the Haber-Bosch process, and that might be the only thing that links them.


Thermochemical energy storage with ammonia and implications for ammonia as a fuel

This seminar presents recent advances in ammonia-based thermochemical energy storage1 (TCES), supported by an award from the US Department of Energy SunShot program. The goal of SunShot is to “reduce the total installed cost of solar energy systems to $.06 per kWh by 2020.” Within the arena of concentrating solar thermal power, Sunshot has established goals for each subsytem, including reducing the cost of the energy storage subsystem to $15 per kWht of stored energy and enabling working fluid temperatures greater than 600°C, consistent with advanced, high performance power blocks. Schematic of an NH3-based thermochemical energy storage system. In ammonia-based…


A Green Ammonia Economy

Ammonia has a high volumetric hydrogen density of 107.3 kg H2 per cubic meter, because it is easily liquefied by compression below 0.86 MPa at 20° C. The vapor pressure of liquefied ammonia is similar to propane. Moreover it has a high gravimetric hydrogen density of 17.8 mass% compared with the solid state hydrogen storage materials. It is noteworthy that ammonia can be synthesized from hydrogen in large scale manufacturing by Haber–Bosch process at 400-600° C and 20-40 MPa. Therefore, liquid ammonia is one of the most promising methods for storing and transporting hydrogen. CO2 free hydrogen (ammonia) will be…