State-owned Saudi Aramco has announced the first shipment of certified blue ammonia to Japan for co-firing in power generation at the 143,000bl/d Sodegaura refinery, owned by Japan’s Fuji Oil Company (FOC).

The ammonia was produced by Saudi chemicals firm Sabic—in which Aramco holds a 70pc majority stake—with feedstock from Aramco and shipped by Japanese shipping firm Mitsui OSK Lines. CO₂ emissions from production were captured and used in downstream applications.

Aramco previously trialled shipment of non-certified blue ammonia to Japan in 2020 and completed the first commercial shipment of certified blue ammonia to South Korea’s Lotte Chemical in late 2022.

Aramco and Sabic first received certification for blue hydrogen and ammonia production by Germany’s TUV Rheinland in August 2022. The certification requires at least 30pc of total CO₂ emissions to be chemically or minerally fixed for at least 25 years, as well as transparent accounting of lifecycle emissions to prove they are below 3.384kg of CO₂e/kg of hydrogen.

“Not only is low-carbon ammonia a means to transport lower-carbon hydrogen, it is an important energy source in its own right that can help decarbonise key sectors” Thorel, Aramco

“This [shipment] is another milestone that highlights the possibilities for low-carbon hydrogen and ammonia made from Aramco feedstock, with the potential to play a role in a lower-carbon future,” says Olivier Thorel, senior vice-president of chemicals at Aramco. “Not only is low-carbon ammonia a means to transport lower-carbon hydrogen, it is an important energy source in its own right that can help decarbonise key sectors—including power generation for both utilities and industries.”

FOC aims to reduce CO₂ emissions from its operations 20pc by 2030 compared with 2014 levels, with a particular focus on energy savings at the Sodegaura refinery.

“Japan aims to achieve carbon neutrality by 2050, low-carbon ammonia is expected to be a next-generation fuel that can contribute to the reduction of CO₂ emissions,” says Shigeto Yamamoto, representative director and president at FOC.

He adds that, in order to reduce emissions from FOC’s operations, the company is already co-firing byproduct ammonia from existing refining operations at the Sodegaura refinery’s boiler. “We plan to burn low-carbon ammonia imported this time with the cooperation of our partners in the same boiler,” he says.

Co-firing criticism

Thinktank E3G has criticised Japan’s focus on ammonia co-firing in coal-fired thermal power plants as a route to reduce emissions. It argues that a coal plant co-firing 20pc ammonia would still emit 693g of CO₂/kWh—five times the benchmark 138g of CO₂/kWh the IEA set in its Net Zero Scenario for grid emissions by 2030. Even blend rates up to 50pc would emit more CO₂ than a natural gas-fired combined-cycle power plant or adding CCS to existing power plants, the thinktank adds.

Unabated coal power must be fully phased out globally by 2040 and “promoting ammonia co-firing in coal plants increases the risk these plants stay online beyond these timelines, without any regulatory requirements to reduce emissions or shut down”, E3G says.

The thinktank also highlights that increased demand for ammonia to use in co-firing could increase emissions depending on production method. “Even with the use of blue or green ammonia, the production process of ammonia and carbon-intensive maritime transport and storage could still result in further increases in lifecycle emissions,” E3G says, noting that blue ammonia production has the additional risk of upstream methane leakage.

While the Sodegaura refinery lists restricting NOx emissions as an environmental initiative, ammonia co-firing can also increase NOx emissions depending on the blend ratio.

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Author: Polly Martin