At our Mwyndy Cross site in South Wales, we operate a modular carbon dioxide removal (CDR) system based on controlled microalgal biomass production and biochar sequestration. We cultivate microalgae in closed, engineered photobioreactor units, where growth conditions (light, temperature, nutrients, mixing, and gas exchange) are actively managed and continuously monitored. During photosynthesis, the microalgae assimilate atmospheric CO₂ into organic biomass with high productivity and consistency. All biomass used within the system is purpose-grown for carbon removal, ensuring full additionality. Harvested biomass is mechanically dewatered and processed on site using slow pyrolysis in an oxygen-limited environment. This thermochemical conversion retains a high proportion of the biomass carbon in a solid, aromatic structure, producing biochar with low H/C and O/C ratios indicative of long-term chemical stability. Energy-rich process gases generated during pyrolysis are recovered and used internally, reducing external energy demand. The resulting biochar is applied to agricultural soils within the regional deployment area. Based on elemental analysis and conservative degradation modelling, the stored carbon is expected to persist for centuries to millennia, delivering durable carbon removal. Biochar handling, temporary storage, and application are controlled to maintain chain of custody and prevent diversion. Across the full system boundary, we quantify carbon removals using primary operational data, calibrated energy and mass-flow measurements, third-party laboratory analysis, and project-specific life cycle assessment. All material emissions associated with cultivation, processing, energy use, transport, and durability adjustments are conservatively accounted for and deducted to determine net CO₂ removals. Monitoring, reporting, and verification are conducted in line with recognised carbon removal standards, with independent validation and ongoing auditability. The Mwyndy Cross installation is designed to scale through replication, with additional reactor and processing modules deployed in response to confirmed demand. This enables predictable capacity growth while maintaining consistent process control, data quality, and permanence outcomes. 3rd party verified product: https://puro.earth/CORC-co2-removal-certificate/supplier-listing/nellie-mwyndy-cross-219. Additional verification provided via Isometric available upon request.

Description of Technology:

Direct Air Capture and Carbon Sequestration (DACCS), Bioenergy with Carbon Capture and Storage (BECCS), Biomass Carbon Removal and Storage (BiCRS), Biochar

Sector:

Carbon Dioxide Removal (CDR)

Type of Supplier:

Final Product Supplier

Supplier Geography:

Global

Expected Capacity (Mt/Year):

1000000 (t CO2 removed)