Carbon credit purchasing consortium Frontier, which counts Google and Meta as founding members, has awarded $2 million in R&D grants to two zero-carbon lime companies.

The grants were awarded to UK-based Leilac and Swedish firm SaltX. According to Frontier, the grants will support the scaling of zero-carbon lime, which it claims could become a low-cost feedstock for several carbon removal applications, namely Ocean Alkalinity Enhancement (OAE).

Traditional lime production is highly carbon-intensive, with limestone heated in fossil-fueled calciners, releasing CO2 from combustion and the chemical reaction. The two companies backed by Frontier aim to decarbonize the process through electric calcination, which removes combustion emissions and enables more efficient CO2 capture.

UK firm Leilac was formed from environmental technology firm Calix in 2014, following the patenting of its indirect heated calcination technology. Leilac’s indirect heating system works by converting limestone into alkaline material using renewable electricity while capturing concentrated CO2. The output can be used for carbon removal or to counter ocean acidification.

It announced its first pilot project in 2016 with Heidelberg Materials in Belgium. Since then, it has secured funding from the European Union’s (EU) Horizon 2020 program, leading to the opening of the pilot plant in 2019.

The company has also signed deals with Direct Air Capture firm Heirloom, and in 2023 saw its planned zero emissions lime plant in the UK pass the due diligence phase of the UK Government’s carbon capture funding scheme.

The deal with Frontier will support Leilac in producing OAE materials for testing and in conducting an engineering study to develop the lowest-cost solutions for producing zero-carbon lime for OAE.

“We look forward to working with Frontier, building on the solutions we are developing to reduce the cost and carbon emissions from cement and lime production. By enabling flexible electric heating and efficient capture of unavoidable process carbon dioxide, Leilac’s patented technology aims to produce the materials needed to seize this opportunity at the lowest possible cost,” said Daniel Rennie, Leilac CEO.

Headquartered in Stockholm, SaltX’s low-carbon lime solution comprises electric arc calciners that use plasma torches to heat limestone above 4,000°C (7,232°F), producing high-purity quicklime and concentrated CO2 suitable for carbon removal use cases such as ocean alkalinity enhancement and mineral looping DAC.

The $1.5m investment from Frontier is expected to support the construction of its first industrial pilot plant in Mo i Rana, Norway, with a planned capacity of 40,000 tons per year, scheduled for the first half of 2026.

“The pilot plant in Mo i Rana remains our primary focus and a critical step toward the industrialization of our technology. Support from Frontier, with the ambition to accelerate scale-up in response to long-term market demand for higher volumes, is an important recognition of the technology’s potential. Together with our partners, we now look forward to taking the next step toward commercial large-scale deployment,” said Lina Jorheden, CEO of SaltX Technology.

The investment is the latest deal signed by Frontier in the carbon removal space. Earlier this month, the consortium signed two pre-purchase agreements totaling $3.05m with early-stage carbon removal firms, Pronoe and Cella.

Frontier inked several carbon removal deals in 2025, including a $44.2m deal with Canadian biowaste carbon-capture and storage firm Nulife GreenTech for 122,000 tons of CO2 between 2026 and 2030, in December.

The month before, it signed an agreement with biogas carbon capture firm Reverion to remove 96,000 tons of CO2 between 2027 and 2030. As part of the deal, Frontier buyers will pay Reverion $41m.