When a carbon capture company needed technology that could handle exceptional pressure conditions, traditional valves proved too expensive and difficult to scale. Halton’s solution: use heavy-duty isolation dampers instead.
Initially, the challenge seemed straightforward. A company developing direct air capture (DAC) technology required isolation components for its system. But when Halton’s sales team looked at the requirements more carefully, it became apparent that this customer case was anything but ordinary.
“They needed components that could maintain absolutely zero leakage under extreme negative pressure of almost 100,000 pascals. This is not something you see every day,” says Fraser Campbell, Halton’s Sales Manager for heavy industry in North America.
The requirement of 100,000 pascals is equivalent to 1 bar of negative pressure (or 14.5 psi). For comparison, a car tyre typically holds about 2 bars of pressure.
“Our standard test for isolation dampers covers pressures up to 10,000 pascals, so clearly we were in an interesting territory,” Fraser recalls. “Even the smallest leak would compromise the entire system’s efficiency.”
Capturing carbon from thin air
Direct air capture does exactly what it sounds like: it removes CO₂ directly from the surrounding air. Unlike capturing carbon at power stations, where CO₂ levels in flue gases can reach 5–15 percent, ambient air contains only about 0.04 percent of CO₂.
To capture CO₂ from such dilute concentrations, you need to move large volumes of air through specialised materials. Modern DAC systems increasingly utilise metal-organic frameworks (MOF). These are synthetic, highly porous, powder-like materials with an exceptional capacity for CO₂ absorption.
In the customer’s project, isolation was necessary to separate two distinct ductwork systems. The first duct system delivers highly pressurised air into the MOF filter. As air passes through the MOF, it captures CO₂ molecules within its nano-sized pores.
A second duct system is used to blow heated air onto the MOF. This releases the CO₂, which is then pressurised and stored. The cycle of capturing and releasing CO₂ is repeated continuously. A large DAC facility can include dozens of these ductwork systems operating simultaneously.
“The dampers work like doors in the system,” Fraser explains. “You have two loops, one bringing ambient air in, one managing the extraction. The key is to keep the two systems strictly isolated despite the enormous pressure.”
The case for scaling
In current DAC facilities, industrial valves are used to control pressure. However, scale presents a challenge here. A single duct’s diameter ranges from 2 to 2.5 metres. A valve of this size can cost hundreds of thousands of dollars. The enormous weight would complicate installation, and the lead times for such large valves could be lengthy.
“When you’re testing in a lab, you can use a small valve,” Fraser notes. “But when you scale up by a factor of 1,000, suddenly the economics change completely.”
That’s where Halton saw an opportunity. What if, instead of one massive valve, you used several isolation dampers in parallel? Four CID-01 dampers can be combined to handle the same airflow as a single large valve, but at a fraction of the cost and weight.
The CID-01 was originally designed for nuclear and industrial applications requiring zero leakage. Its construction is robust: 3 mm steel casing, continuous stainless steel shafts, and closed-cell pad seals. But could it handle the extreme vacuum conditions of DAC systems?
“Our R&D team took the challenge and tweaked the CID-01 slightly here and there. With the new design, we started rigorous testing with negative pressure. It turned out the damper achieved 95kPa on the negative pressure test. The customer said okay, this is enough.”
Switching from valves to dampers offers many benefits beyond cost savings. Installation is faster. The modular approach enables incremental scaling. Dampers can be manufactured at multiple Halton facilities worldwide, decreasing lead times and transportation costs. This is particularly important when a single DAC facility may require dozens of isolation components.
Ready when you are
“We’ve demonstrated that our dampers can work in these applications. We’ve proven the concept and refined the design, and we are discussing with several potential customers in the DAC space. It’s a question of when the market conditions align,” Fraser says.
“In reality, for a new technology such as DAC, sustained government funding is crucial. We hope to see more of that around the globe to help get more of these facilities up and running.”
The long-term outlook remains promising. The International Energy Agency projects that carbon capture capacity must increase more than 100-fold by 2050 to meet climate targets. Direct air capture can play a vital part on the road to a net-zero world.
More information
Toni Setänen
toni.setanen@halton.com
Segment Director, Heavy Industry
