Keey Aerogel — Green Silica Aerogel from Construction Waste

Product · Building Envelope

Product · InnDex 35 · Evidence provided · High specification risk

Ultra-low-density silica aerogel (98% air) made from construction waste using recycled CO2 and ethanol.

Keey converts demolition waste into silica aerogel for thermal insulation in building envelopes. The closed-loop production process substitutes recycled CO2 and ethanol for virgin materials, targeting lower embodied energy and carbon than conventional aerogel synthesis. A pilot plant has operated since 2022; Series A funding (€18M, Jan 2025) supports scaling to commercial production in France's Grand Est region.

Keey converts demolition waste into ultra-low-density silica aerogel insulation using a closed-loop process that substitutes recycled CO2 and ethanol for the virgin inputs of conventional aerogel synthesis, targeting both the thermal performance advantages of aerogel and a substantially lower embodied-carbon footprint. The combination of feedstock circularity and aerogel's inherent thermal properties addresses two persistent problems in building envelope innovation simultaneously, and the €18M Series A in January 2025 provides some evidence of investor confidence in the scale-up pathway. The pilot plant has operated since 2022, which is a modest but real operational track record. The gaps that matter most for specification are the absence of any published EPD, independent LCA, or durability and moisture-performance data — the carbon benefit claims are unvalidated, and no named building or field deployment has been disclosed. Aerogel's inherent brittleness and handling complexity add site-labour considerations that are not addressed in available materials, and demolition-waste feedstock consistency across geographies is an undemonstrated supply-chain assumption. The product is interesting enough that a specifier working on a project with aggressive embodied-carbon targets and budget for early-adopter risk should open a dialogue with Keey; it is not yet in a position for mainstream specification without independent performance certification.

Strengths

• Diverts construction demolition waste from landfill as feedstock, closing a material loop
• Claims reduced embodied carbon and production energy vs. conventional aerogel (virgin silica, supercritical drying)
• Ultra-low thermal conductivity (98% air) enables thinner high-performance envelope insulation
• Closed-loop recycled CO2 and ethanol reduce virgin input dependency

Considerations

• Aerogel is brittle and fragile; requires robust mechanical protection and careful handling on site, adding labor and assembly complexity (moderate)
• High cost per unit volume typical of aerogel; likely premium vs. foam/mineral wool, limiting market adoption in cost-sensitive segments (moderate)
• No disclosed EPD, independent LCA, or durability/moisture performance data; claims of carbon benefit remain unvalidated (high)

Risks

• Pilot-stage process (2022–2025); scaling to commercial volumes may encounter yield loss, cost overruns, or quality variance not apparent at pilot scale (high)
• Supply chain for consistent demolition waste feedstock not yet demonstrated; geographic variability in waste composition may limit reproducibility (moderate)
• No named buildings or real-world deployment data disclosed; thermal/hygric performance in situ and long-term durability unproven (high)
• Recycled CO2 and ethanol sourcing and loop closure efficiency not detailed; risk of greenwashing if recycled inputs are marginal or energy-intensive (moderate)
• Regulatory approval (building code listing, fire rating, moisture classification) for European markets not confirmed; may delay commercialization (moderate)

Performance

• Thermal resistance: Silica aerogel (~98% air); λ not published
• Fire resistance (EV battery): Delays thermal runaway spread 5–10 min; withstands 1,000°C
• Series A raised: €18M (Jan 2025)
• Pilot plant operational: Since 2022, Habsheim, Alsace

Reality check

Funding and pilot plant status are verified via Tech.eu (Jan 2025, Bpifrance SPI 2, WIND). Founding date (2015) and location (Alsace) are stated. However, no named customers, production volumes, third-party LCA, EPD, or performance data (thermal conductivity, cost vs. conventional aerogel, carbon payback period) are publicly available. The claim of 'major European clients' is unverified. The closed-loop process and waste feedstock are plausible but unaudited. No evidence of regulatory approvals (CE mark, building codes) or durability/field data.

#aerogel #thermal_insulation #circular_economy #construction_waste #low_carbon #closed_loop_production

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