Thursday, 9 August 2018

Ammonia - a renewable fuel made from sun, air, and water - could power the globe without carbon

Source: Science, 12th July 2018, by Robert F. Service

Robert F. Service reported, "(...) A green way to make ammonia - Reverse fuel cells can use renewable power to make ammonia from air and water, a far more environmentally friendly technique than the industrial Haber-Bosch process. Renewable ammonia could serve as fertilizer—ammonia's traditional role—or as an energy-dense fuel.(...) Yara is taking a first step toward greening that process with a pilot plant, set to open in 2019, that will sit next to the existing Pilbara factory. Instead of relying on natural gas to make H2, the new add-on will feed power from a 2.5-megawatt solar array into a bank of electrolyzers, which split water into H2 and O2. The facility will still rely on the Haber-Bosch reaction to combine the hydrogen with nitrogen to make ammonia. But the solar-powered hydrogen source cuts total CO2 emissions from the process roughly in half. Other projects are following suit. The state of South Australia announced plans in February to build a AU$180 million ammonia plant, again relying on electrolyzers powered by renewable energy. Slated to open in 2020, the plant would be a regional source of fertilizer and liquid ammonia, which can be burned in a turbine or run through a fuel cell to make electricity. The supply of liquid energy will help stabilize the grid in South Australia, which suffered a debilitating blackout in 2016. (...)"