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Progress for high-efficiency ammonia-cogeneration plant

| By Mary Page Bailey

A process that produces anhydrous ammonia while also generating thermal power has reached a milestone toward commercialization. In January, Amec Foster Wheeler (AFW; London, U.K.; www.amecfw.com) was awarded a project development and design contract for the world’s first plant to employ Grannus LLC’s (Tucson, Ariz.; www.grannusllc.com) process, which combines ammonia production with advanced power generation. At present, AFW has completed initial front-end engineering design (FEED) work for the plant, and the project is preparing to initiate the permitting process for a site in Kern County, Calif., says Corey Smith, vice president of corporate development at Grannus. The plant, which is slated for startup in late 2017, will produce around 80,000 metric tons per year (m.t./yr) of anhydrous ammonia.

The exhaust [in the form of synthesis gas (syngas)] from a partial oxidation boiler is sent to the reaction vessel, where ammonia is produced via the Haber-Bosch process. The excess process heat from the syngas formation is used for steam co-generation, supplying electric power. According to Smith, the only raw materials required for the process are natural gas, air, electricity and limited amounts of water, making it more efficient than competing processes that employ steam-methane reformers (SMR). “The process utilizes 100% of the natural gas input as feedstock rather than utilizing a portion as fuel as in an SMR-based system,” explains Smith. Although the process can be configured for world-scale plants, the company believes that transportation and financing factors provide great opportunities for regional-scale plants, as long-haul freight can be eliminated and customers are provided with an uninterrupted product supply.