Yara opts for mass balance approach to low-carbon ferts

Norwegian fertilizer giant Yara is employing an internal mass balance mechanism to distribute its production of low-carbon and renewable ammonia towards finished fertilizer production.

Under the mechanism, referred to as Yara's Ammonia Transfer System, ammonia produced by Yara with a lower carbon footprint — either from renewable electricity and electrolysis or by using natural gas and carbon capture — will be handled and treated in the same manner as Yara's fossil fuel-based ammonia production. With no physical distinction between the two types of molecules, both will be held in the same tanks.

A thorough in-house carbon accounting system, referred to by Yara as Carbon Watch, will monitor overall carbon emissions from all of Yara's production ensuring that the firm is not selling more low-carbon final products than the low-carbon or renewable ammonia it has produced.

Yara will offer consumers fertilizer products made from its low-carbon ammonia with a statement of verified carbon intensity. The finished product could contain any percentage mix of renewable, low-carbon or fossil fuel-based ammonia feedstock, but the carbon intensity reduction allocation across all products will match the carbon intensity reduction achieved from Yara's low-carbon or renewable production assets. The Ammonia Transfer System and Carbon Watch have both been validated by Norwegian classification society DNV.

Yara produces renewable ammonia from its Porsgrunn plant in Norway, which it commissioned at the end of 2023 and is ramping up to 20,000 t/yr this year. Yara has also reached a final investment decision on its carbon capture and storage expansion project at its Sluiskil plant in the Netherlands, where up to 800,000 t/yr of CO2 could be captured and stored by 2026. Production from both plants will be included in the mass balance structure.

At present, Yara is applying the Ammonia Transfer System exclusively to its own production, but the firm may extend it to third-party supply in the future.

Yara has a 100,000 t/yr offtake agreement with Indian renewable energy firm Acme for renewable ammonia from its planned plant in Oman, which could supply Yara with low-carbon ammonia from 2026. The third-party supply could potentially be included in Yara's carbon accounting, the company said. The approach is being applied to finished fertilizers produced with low-carbon ammonia so far, but could be implemented for other end uses in the future.

The mass balance method avoids incurring additional emissions and costs from transporting and storing low-carbon molecules separately. This is particularly important in the fertilizer industry, where affordability is essential. It also enables low-carbon product to be phased in using existing infrastructure.

By Lizzy Lancaster