Reviewer-2-Does-Geoengineering

Take on a podcast episode from Reviewer 2 does geoengineering, originally published Sat, 04 Ap. Listen: https://podcasters.spotify.com/pod/show/reviewer2geoengineering/episodes/Sustaera---electric-DAC-e3heke1 TL;DR Sustaera embeds Joule heating directly into a monolithic sorbent structure using a carbon-based resistor — no steam, no gas-phase heat transfer. Claims >90% heating efficiency in a 3.4L lab prototype. Sorbent is alkali carbonate on alumina, not amine: claimed 18,000–24,000 cycles (~3 years) before 30% degradation forces recoating. If real, that’s a meaningful operating-cost lever. Full adsorption/desorption cycle in 30–45 minutes; desorption at just 80°C, ramping in seconds. Host pushes back hard on whether this actually meshes with curtailed-power economics — worth hearing both sides. Manufacturing piggybacks on catalytic-converter production lines. Buried at the end of the episode, but arguably the most important claim. technology readiness level (TRL) 5 (1 t/yr indoor), raising $8.6M for a first 500–750 t/yr outdoor unit against $700/t pre-purchases from Stripe and Shopify. Andrew of Reviewer 2 Does Geoengineering interviews Corey Sanderson, CTO and co-founder of Sustaera, the North Carolina direct air capture (DAC) startup that spun out of incubator Sustion in 2021. It’s a proper technical grilling — sorbent chemistry, desorption physics, cycle economics — from a host who knows his physisorption from his chemisorption. Episode here. ...

Take on a podcast episode from Reviewer 2 does geoengineering, originally published Thu, 16 Ap. Listen: https://podcasters.spotify.com/pod/show/reviewer2geoengineering/episodes/Avantium-Engineering-Sorbents-for-DAC---Wessels-e3i16mo TL;DR Avantium sells high-throughput sorbent testing rigs (€350k–€1M) to DAC developers including Climeworks and Shell; 150+ units deployed, mostly for catalysis. Central claim: no standardized DAC sorbent test protocol exists — labs routinely publish one or two adsorption/desorption cycles as “results.” Plausible and underdiscussed. Wessels says early cycles show large variation, so single-cycle data is essentially noise. Real deployment means thousands of cycles. Avantium just joined the NIST Carbon Dioxide Removal consortium to push standardized breakthrough-curve protocols. Worth tracking. Claimed 4x reduction in sorbent time-to-market via 16-channel parallel testing. Vendor number, but customer-testimonial-backed. Andrew from Reviewer 2 does geoengineering interviews Rudolf Wessels, Director of Technology and Innovation at Avantium R&D Solutions, the Amsterdam-based Shell spin-out (founded 2000, publicly listed) better known for its plant-based PEF polymer. The DAC-relevant part: Avantium’s R&D Solutions unit builds parallel testing hardware that lets sorbent developers run identical adsorption/desorption experiments across multiple channels simultaneously. Episode here. ...

Take on a podcast episode from Reviewer 2 does geoengineering, originally published Fri, 15 Ma. Listen: https://podcasters.spotify.com/pod/show/reviewer2geoengineering/episodes/Viridas-Pressurised-DAC--El-Sayed-e3jct2c TL;DR Viridas pitches “pressurized DAC”: compress incoming air to ~70 bar so CO2 partial pressure jumps from ~400 ppm to ~2.8%, shrinking contactors ~70x. Sorbent is a cheap aqueous ammonia + alkali carbonate mix (carbamate formation + bicarbonate buffer), regenerated thermally at ~90–110°C. Sensible chemistry, nothing exotic. Core thesis: solvent R&D is hitting thermodynamic limits; the real lever is CAPEX, attacked by retrofitting gas-turbine turbomachinery as compressor/expander. Claimed round-trip efficiency target: ~97–98% (vs ~70% for current compressed-air energy storage). That’s the whole ballgame and it’s not demonstrated. No technoeconomic assessment shared, no pilot, no funding disclosed, Gmail contact address. Treat as concept-stage. The host of Reviewer 2 Does Geoengineering interviews Ahmed El-Sayed, co-founder of Viridas Technologies, about a pressurized DAC concept built around retrofitted gas-turbine machinery. The episode is recorded walking through a Cambridge park, which means a non-trivial fraction of the runtime is ice cream and hawthorn commentary — the substantive technical content is maybe 35 minutes. ...