Steel hardware for the carbon removal industry

Sector brief

Carbon removal moved from pilots into commercial fleets between 2023 and 2026. Three technology families share one supply-chain need: heavy steel hardware, fabricated to a structural standard, welded to a documented procedure, painted for outdoor service, and shipped to a site that may be a quarry, a concrete recycler, a port, or a geothermal field.

The three families we are set up to serve:

• Carbon mineralisation. CO2 is bound permanently into calcium-rich waste such as crushed demolition concrete, steel slag, or bottom ash. The mineralisation product is calcite, locked into the aggregate. The hardware footprint is a reaction vessel or silo, gas dosing skid, instrumentation, and a small operator cabin, retrofitted onto existing recycling plants.
• Direct air capture (DAC). Modular CO2 collector containers stacked into arrays. Each collector is a sealed steel envelope housing a sorbent stack, fans, valves, and heat-exchange piping. The plant scales by adding modules rather than redesigning the whole site.
• Carbon capture and storage (CCS). Capture skids attached to flue stacks at cement, steel, energy-from-waste, and biogas plants. Compression, liquefaction, and intermediate storage tanks bridge to truck, rail, or pipeline transport to a sequestration site.

All three depend on serial production of fabricated steel envelopes, frames, vessels, and skids. That is what our line in Bánovce nad Bebravou does, under the same welding and steel-execution discipline we run for European defense work.

Reference customer

Neustark AG, Switzerland

Neustark AG, an ETH Zurich spin-off founded in 2019, is the European reference for carbon mineralisation at commercial scale. The company operates a growing network of storage sites across Switzerland and into Germany, binding CO2 into demolished concrete that would otherwise re-enter the construction supply chain unmineralised.

We signed an NDA with Neustark AG in September 2025 to develop carbon mineralisation silo hardware. Project specifics, drawings, and unit counts sit under that agreement and we do not publish them. What the relationship signals to the rest of the cleantech market is the type of work we are cleared to do: structural steel hardware for a customer whose product is permanent CO2 removal, on a timeline and quality envelope that match the customer's certification path.

Compliance and procurement path

The cleantech buyer set is heterogeneous: deep-tech startups, large industrial corporates, EPC contractors, and increasingly project-finance vehicles funded against verified carbon-removal credits. The common thread is that every site needs documentation that survives auditing by the credit issuer, the insurer, and the host-country regulator. Our default documentation envelope covers that.

• EN 1090-1 EXC2 execution for structural steel (frames, envelopes, supports, skid bases).
• ISO 3834-2 welding at production-level, the same standard that feeds our NATO AQAP 2110 line.
• ISO 9001 and ISO 14001 quality and environmental management.
• EN ISO 9606 welder qualifications (MAG 135 and adjacent).
• EN ISO 8501 Sa 2.5 surface preparation and documented paint thickness for outdoor exposure.
• EN 10204 3.1 material certificates on structural steel.
• FARO Arm Prime 10 3D measurement on critical geometry, recorded per unit.

For projects that involve flammable carrier gases, methanation by-products, biogas tie-ins, or heated sorbent systems, ATEX zoning is set by the technology integrator. We fabricate the steel envelope to the integrator's hazardous-area classification (HAC) and integrate certified penetrations, gland plates, and grounding studs to the agreed drawing.

The AQAP 2110:2017 quality system we operate for defense work overlaps directly with what a Series B or Series C carbon-removal company asks for during a hardware supplier audit. Lot traceability, weld procedure qualification, material certs, and surface preparation records are produced as a matter of course, not as a special-case deliverable.

Typical hardware configurations

We do not publish customer drawings. The configurations below are the recurring formats we are set up to build for the cleantech sector.

• Mineralisation silos and reaction vessels. Vertical or horizontal sealed steel vessels, single or multi-chamber, with feed and discharge ports, CO2 injection bosses, instrumentation taps, inspection hatches, and external structural framing. Painted for outdoor service at recycling plants and quarries.
• Gas dosing and instrumentation skids. Welded base frame, perimeter handrails for service access, cable trays, removable side panels, hot-dip galvanizing on request for coastal or wet sites.
• DAC-style modular collector envelopes. ISO 20 ft or 40 ft envelope geometry, or buyer-specified footprint. Reinforced floor and ceiling for sorbent stacks and fan modules, sealed roof, vent and louvre cut-outs to the customer drawing, RAL exterior to buyer livery.
• Operator and electrical cabins. PIR sandwich envelope, internal split for control cabinets and operator desk, AC unit, electrical distribution to PN-HD 60364. Cabin-side instrumentation pass-throughs to the process skid.
• CCS skid platforms and transport frames. EN 1090 EXC2 steel platforms for capture skids, intermediate liquid CO2 storage saddles, and lifting frames for craneable transport of compression modules.
• Custom builds. B2B work for cleantech OEMs runs through our standard custom path: customer drawings, our engineering review for manufacturability, weld procedure qualification, production, paint, FARO inspection, and EXW or DAP handover.

Engagement model

Three of our four engagement models apply directly to cleantech work.

1. Custom build to spec. Your engineering drawings, our review and production. This is how most cleantech hardware projects are structured. Engineering-review feedback is delivered in days, not weeks, and is treated as a billable line where heavy redesign is required.
2. Subcontract under prime. EPC contractors and integrators frequently want a European steel fabricator under their prime contract for a specific work package: vessels, frames, skid bases, or modular envelopes. We deliver to the prime's QA chain, with EN 1090 EXC2 and ISO 3834-2 as the baseline.
3. Framework with periodic call-offs. For customers scaling a fleet of identical or near-identical units across multiple sites, a multi-year framework with locked pricing and reserved production slots is the most efficient structure. This is the structure we already operate at scale on our defense framework.

The fourth model (catalog purchase) is rarely the right fit for cleantech hardware, because nearly every project involves a custom envelope or skid base. We will still ship a standard ISO 20 ft or 40 ft as a starting envelope where that makes sense.

Lead times

• Custom build to spec: 10 to 16 weeks from engineering sign-off.
• Hot-dip galvanizing or extended outdoor coating systems add 1 to 2 weeks.
• Framework call-offs: as agreed in the framework. Pricing locked, slot reserved against the production calendar.
• NDA in 24 hours from first contact where the project warrants it.

Why a defense-grade line fits cleantech

Carbon-removal hardware sits at industrial sites for 15 to 25 years, often outdoors, and is increasingly inspected against issuer requirements of voluntary or compliance credits. The steel envelope is part of the durability story for the carbon claim itself.

Our hall runs one welding standard (ISO 3834-2), one structural execution class (EN 1090 EXC2 capability), and one paint specification (Sa 2.5 with documented thickness). Switching between a defense container, a fire-rescue sanitary module, and a cleantech mineralisation silo is a process change on the shop floor, not a capability change.

FAQ

Why is Neustark AG named here when the project is under NDA? Both parties agreed at NDA signing in September 2025 that the existence of the relationship and the generic activity (carbon mineralisation silo hardware) can be referenced. Project specifics, drawings, unit counts, pricing, and timelines remain confidential.

Are you a hardware-only supplier, or do you integrate process equipment? Hardware-only. We build the steel envelope, the structural frame, the skid base, the operator cabin, and the painted, certified, FARO-measured deliverable. Process integration, instrumentation calibration, sorbent loading, valve commissioning, and software belong to the cleantech customer or their nominated process integrator. We design and fabricate to that integrator's interface drawing.

Do you handle ATEX-rated builds? We fabricate the steel structure to the customer's hazardous-area classification, integrate certified penetrations and bonding points, and provide weld and inspection records suitable for the integrator's ATEX declaration. The system-level ATEX certification is the integrator's responsibility because it covers the assembled hardware including process equipment we do not supply.

What documentation ships with each unit? Per-unit dossier: weld procedure specification and weld procedure qualification record (WPS / PQR) for the relevant joints, EN 10204 3.1 material certificates, paint thickness report against the agreed coating system, FARO geometric inspection record, CSC plate where applicable, warranty terms, and a multilingual operator and handling manual. Programme-level dossiers add full lot traceability and welder qualifications per EN ISO 9606.

How does AQAP 2110 help a cleantech customer? AQAP 2110 is a NATO quality assurance standard. The reason it matters to a carbon-removal buyer is operational, not military: it forces a documented chain from raw steel to handover, including lot traceability, deviation handling, and per-unit inspection records. Carbon-removal projects are increasingly audited against issuer protocols (Puro.earth, ICVCM-aligned methodologies, EU CRCF) that ask for exactly this kind of supply-chain evidence on the durable hardware.

What is the smallest and largest unit you can ship? The smallest practical envelope is a skid frame or small reaction vessel that fits on a single truck without escort. The largest single weldment is bounded by our 14-metre robotic welding track and the gauge of our press brake (DURMA AD-S 60400, 400 ton, 6050 mm). Larger structures are built as bolted or site-welded sub-assemblies.

Do you ship outside Europe? Yes. We are a Slovak entity with EXW Bánovce as the default Incoterm, and we routinely arrange DAP and DDP into Switzerland, Germany, Czech Republic, Austria, France, the United Kingdom, and (under separate processes) the United States. Cleantech customers based outside Europe typically engage us for the hardware envelope and handle local installation through a regional integrator.

Can you white-label hardware under our brand? Yes. Buyer livery (RAL code, decals, regulatory placards) is set at the customer engineering-review stage. The unit ships in the buyer's livery with the buyer's nameplate. Our nameplate sits on the structural element only where required by EN 1090.