Ammonia is one of the largest industrial chemicals with an annual production of over 190 million metric tons/year in 2017. Eighty percent of ammonia is used as fertilizer with the other 20 % for industrial uses. Ammonia is produced from the reaction of hydrogen and nitrogen where essentially all of the hydrogen is produced from fossil fuel sources, mostly natural gas. While the nitrogen comes from air, energy is expended in either compressing air to the required pressure for the ammonia synthesis reaction or in an air liquefaction facility that produces high purity nitrogen.
Ammonia production accounts for 1% of the total energy consumed world wide and 1% of the CO2 emissions. As such it is the largest industrial greenhouse gas emitter. Hydrogen can also be produced by the electrolysis of water and if the electric power required for the electrolysis is obtained from renewable resources, such as solar, wind or biomass, rather than from fossil fuels, there will be no CO2 emissions and such “Green” hydrogen can be used to produce “Green” ammonia.
Siemens is one of several companies offering commercially proven electrolysis and is involved in a number of Green Ammonia demonstration projects. One is a £1.5 million pilot project at the Rutherford Appleton Laboratory in Oxfordshire, England, designed to produce 30 kg/day of ammonia. Fifty percent of the pilot project is funded by Innovate UK, a UK government funding agency. A second pilot project started up earlier in 2018 at the Fukushima Renewable Energy Institute– AIST (FREA) in Japan with a capacity of 20 kg/day of ammonia.
Siemens is also one of several companies collaborating on a demonstration plant off the island of Goeree-Overflakkee in the Netherlands. Proton Ventures, the Dutch mini-ammonia plant developer, is leading the consortium consisting, in addition to Siemens, Yara, the international fertilizer producer, Van Iperen, a specialty fertilizer producer, and the Van Peperstraten Group, a local sustainable agricultural producer. The Green Ammonia project is based on using tidal power to supply electricity to a Siemen’s 25 MWe electrolyzer to produce hydrogen for 20,000 mt/yr of ammonia. The demonstration plant is scheduled to begin operations in January, 2020.
ThyssenKrupp also has commercially proven electrolysis technology and recently announced its “advanced water electrolysis” which uses renewable electricity to produce carbon-free hydrogen and is involved in a number of Green Ammonia projects.
One such project is a demonstration plant in Port Lincoln, Australia, being developed by Hydrogen Utility (H2U), an Australian hydrogen infrastructure firm. This is a US$95 million project with a ThyssenKrupp 30MW water electrolyser generating more than enough hydrogen to produce 50 metric tons/day of ammonia. The excess hydrogen will feed a 10 MW hydrogen-fired gas turbine and a 5MW hydrogen fuel cell to provide power to the local electrical grid. Intermittent renewable resources including solar arrays provide the energy for the demonstration plant. Integrating its water electrolysis technology with its Uhde’s ammonia synthesis technology, Thyssen Krupp claims the overall energy efficiency to be 10 MWh per ton of ammonia, roughly equivalent to 36 GJ/mt (34.1 MMBtu/mt) equal to the global average efficiency for natural gas to ammonia plants.
In addition to its participation in the Goeree-Overflakkee pilot project, Yara’s Australian subsidiary, Yara Pilbara Fertilizer, has a green ammonia demonstration project near its Pilbara Western Australia 850,000 metric ton/year ammonia plant scheduled to begin production in 2019. Electricity is being provided by a 2.5 MW solar array. Yara is also collaborating with Nel Hydrogen Electrolyser, a division of Norwegian company Nel ASA, in the development of a green fertilizer project in Norway. At the date of this announcement, no details were provided about either the location of the project or its capacity. It is being funded by a grant under Norway’s “PILOT-E scheme for the development and realization of a green fertilizer project.”
Yet another demonstration project is taking place in Morocco. The OCP Group, the Moroccan company and world’s largest exporter of phosphate fertilizers and a significant user of ammonia in its finished fertilizer products such as mono and di ammonium phosphates (MAP and DAP) has a partnership with the Moroccan Institute for Research in Solar Energy and New Energies (IRESEN). Plans are to duplicate a green hydrogen pilot plant that is at an advanced stage of construction at the Fraunhofer Institute in Leuna, Germany at IRESEN’s Green Energy Park in Ben Guerir, Morocco. An ammonia synthesis unit will be added to produce green ammonia.
Success in these and other green ammonia projects leading to implementation of commercial world scale facilities should result in a significant reduction in carbon emissions. According to a recently published McKinsey report, “Decarbonization of Industrial Sectors: the next frontier,” the fossil-fuel-based ammonia industry currently generates 0.5 gigatons of annual CO2 emissions. With no changes in technology and assuming the historical growth rate of the ammonia fertilizer and industrial sectors continues, annual CO2 emissions would increase to 1.7 gigatons by 2050. Replacing the fossil fuel feedstocks with green hydrogen from renewable-fueled electrolysis could reduce the projected 2050 annual CO2 emissions from ammonia production as much as 1.3 gigatons.