Green e-fuel production requires a carbon source that is both RFNBO-compliant and available at scale over the long term. Point-source CO₂ loses eligibility under the RFNBO Delegated Acts in 2041. Biomass-based CO₂ is constrained by land-use competition and regulatory uncertainty.  

Atmospheric CO₂ is subject to neither an eligibility deadline nor land-use constraints, making it the only feedstock that can support genuinely resilient e-fuel supply chains. Greenlyte's LiquidSolar™ platform is built on this premise.

 The platform is a fully integrated, electrochemical process that co-produces green CO₂ and green hydrogen as co-located feedstocks from a single process, using only air, water and the power of renewable electricity. The tech operates through three integrated steps:

1. continuous absorption of atmospheric CO₂ into a potassium carbonate solution, 2. crystallisation into solid potassium bicarbonate - concentrating CO₂ by more than 600,000-fold relative to ambient air - and 3. simultaneous electrochemical release of CO₂ and generation of H₂ at purities above 99%, confirmed by an independent institution. The crystallisation step is architecturally significant: the resulting solid buffer decouples the energy-low capture phase from the energy-intensive release, enabling desorption to be scheduled around renewable electricity availability. Intermittency becomes an operational cost lever rather than a constraint.

Validation evidence spans multiple development stages. The technology reached TRL 5–6 at Greenlyte's pilot plant in Essen in 2025 (5 t CO₂/year) and has since advanced to TRL 7 at the LiquidSolar SNG plant in Duisburg (40 t CO₂/year), operational since early 2026. Across all facilities, Greenlyte has accumulated over 15,000 operating hours.

Scale-up is achieved through a modular architecture: larger capacities are reached by adding standardised units rather than scaling individual components. The transition from pilot to demonstration scale at the LiquidSolar SNG plant in Duisburg, operational since Q1 ‘26, yielded critical engineering insights, particularly around electrochemical stack stability under variable renewable input, bicarbonate crystallisation kinetics at continuous operation, and system integration for co-location with downstream synthesis.

These learnings directly inform the next deployment: a commercial-scale plant at Chempark Marl, targeting approximately 1,400 t CO₂/year, designed for integration into an existing industrial chemical infrastructure. The first module will be built until Q4 ‘26 with additional units coming in 2027 as well as an e-methanol synthesis unit. 

On regulatory fit: atmospheric CO₂ qualifies as a valid carbon source under the RFNBO framework (Commission Delegated Regulation 2023/1184 and 2023/1185), making downstream e-fuels eligible for certification under ReFuelEU Aviation and FuelEU Maritime - with eligibility that does not expire.

Ongoing R&D with RWTH Aachen University, Zentrum für Brennstoffzellentechnik and the Max Planck Institute for Chemical Energy Conversion targets electrochemical stack performance, system integration and techno-economic optimisation.

Development is further advanced through collaboration with industrial partners across the e-fuel value chain, such as Lufthansa Group, Grisemann or Uniper.