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Green ammonia plant proposed for Orkney

Eneus Energy recently announced that it intends to build a green ammonia plant in Orkney, Scotland. Eneus describes itself as a “project developer and technology integrator for green ammonia,” and this announcement marks the first public disclosure of a site from its “portfolio” of projects under development. Orkney has been a net energy exporter since 2013, with wind, tidal, and wave energy generation far exceeding local demand; the islands have also been producing green hydrogen for some years. If this latest project moves ahead, the 11 ton per day green ammonia plant would be powered by two new wind turbines, each of 4.2 MW capacity, expanding the existing Hammars Hill wind farm and providing the island with a scalable solution for renewable energy storage and distribution that does not require grid transmission.

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Comparative Technoeconomic Analysis of Conventional and Absorbent-Enhanced Ammonia Synthesis

Ammonia is the second-most produced synthetic chemical and the main precursor for nitrogen-based fertilizer. In 2015, 160 million tons were produced globally, and global demand is expected to grow 1.5% annually until 2050 [1]. However, traditional ammonia production uses natural gas or coal as its hydrogen source, and as a result, is also responsible for more than 1% of global GHG emissions and 5% of global natural gas consumption [2]. Clearly, a more sustainable ammonia production scheme is needed. One such alternative is obtain hydrogen from electrolysis powered by wind- or solar-derived electricity. It has been proposed to perform this…

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Ammonia Absorption and Desorption in Ammines

While adsorption onto solids is a common separation process, absorption into solids is much less often used. The reason is that absorption is usually assumed ineffective because it includes very slow solute diffusion into the solid. An exception may be the separation of ammonia from nitrogen and hydrogen using ammines, especially at temperatures close to those used in ammonia synthesis. There, ammonia can be selectively absorbed by calcium chloride; nitrogen and hydrogen are not absorbed. The kinetics of ammonia release seem to be diffusion controlled. The kinetics of absorption are consistent with a first order reaction and diffusion in series,…

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Lower Pressure Ammonia Synthesis

Ammonia is a very important chemical, mainly produced through the Haber-Bosch process. This process requires high temperature (>400 °C) and pressure (>150 bar) in order to ensure fast kinetics and high conversions, respectively.1 As a result, ammonia synthesis is known to be very complex and energy-intensive.2 To alleviate the complexity and energy requirements of ammonia synthesis, and to reduce the CO2 emissions, we are proposing an innovative reaction-absorption process to synthesize carbon-free ammonia in small plants.3 This green ammonia can be synthesized in wind-powered plants, with hydrogen from electrolysis of water and nitrogen from pressure swing adsorption of air.4 In…

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Design Optimization of a Distributed Ammonia Generation System

Distributed ammonia generation located near farms is a promising alternative to the current practice of large-scale, centralized production. This production mode would reduce the need for transportation of ammonia over long distances currently caused by the mismatch between production and consumption locations. In addition, a small-scale ammonia synthesis process could more easily take advantage of distributed power generation based on wind or sunlight to reduce energy costs and lessen the dependence on fossil fuels. Distributed, renewables-based fertilizer production would largely insulate farmers against market uncertainty while also increasing the sustainability of the agricultural supply chain. However, a technically proven, economically…