JERA, Japan’s largest power generator, announced on Wednesday that it had concluded a 3-month trial at its Hekinan Thermal Power Station in central Japan of co-firing ammonia and coal with 20%. The results were positive.

The utility and heavy machinery manufacturer IHI began the test on April 1 at a unit of one gigawatt (GW), in what they said was the first world-wide trial using such a large quantity of gas at a commercial plant.

JERA reported positive results, with nitrogen oxides levels no higher than when coal is fired alone. Sulphur oxides have been reduced by 20% and the generation of nitrous dioxide, which has an intense greenhouse effect, is below detection threshold.

It said that the company, which is jointly owned by Tokyo Electric Power Chubu Electric Power, confirmed that its operability was comparable when burning coal alone.

JERA, based on the results of the study, will start construction in July for commercial operation at Hekinan Power Station using ammonia fuel substitution large volume.

JERA will evaluate the impact of the recent tests on the boilers and other equipment. It aims to develop technologies that allow for the use of ammonia in the thermal power generation industry. This is expected to happen by March 2025.

When burned, ammonia is a toxic, poisonous gas that is primarily made from hydrogen from natural gas, and nitrogen from the air.

It is primarily used as a fertiliser, and as a chemical raw material. However, it can be used as low-carbon fuel for power generation or marine bunker operations.

Japan wants to increase ammonia cofiring in order to reduce its carbon footprint of power plants that run on coal, the fossil fuel with highest CO2 emissions.

Some environmentalists, however, criticize the plan because it could potentially extend the life of coal-fired plants.

BloombergNEF, an energy analyst firm, has said that ammonia and coal co-firing in Japan's electricity sector is too costly for widespread use. They also claim that even a plant using up to 50% of ammonia will still emit more carbon dioxide than a natural gas plant. (Reporting and editing by Tomaszjanowski)