What We’re Learning About CCUS Technology as the Industry Matures

In recent years, Carbon Capture Utilisation and Storage (CCUS) projects have moved beyond the theoretical and into real-world implementation. As engineers working in the space, we’re now seeing the industry transition from “Can this work?” to “How do we make it work reliably, efficiently, and economically at scale?”

That shift is important.

In my experience working across CCUS developments, one of the biggest lessons has been that success in CCUS often depends on making early pragmatic engineering decisions regarding technology selection.

CCUS Is Fundamentally About Managing a Waste Stream

One of the realities sometimes overlooked in CCUS discussions is that Carbon Dioxide (CO₂) is ultimately a waste product.

While this may seem self-evident, it has a significant impact on the engineering design philosophy.

Unlike hydrocarbon facilities designed to maximise production and therefore revenue, CCUS projects must carefully balance equipment reliability with economic practicality to avoid over-specification or “gold-plating”.

For example, very stringent moisture specifications can make good economic sense because they allow the pipelines to be made of carbon steel rather than more expensive corrosion-resistant materials. On the other hand, aggressively tight specifications around other impurities such as oxygen or hydrogen can create significant process configuration complexity and cost, especially for blue ammonia and other industrial-type emitters.

Finding the right balance is becoming one of the defining engineering challenges for the sector.

Why Integrally Geared Compressors Are Becoming the Preferred Choice

Compression is one of the largest technical and economic components of any CCUS facility.

To move CO₂ from near-atmospheric pressure into the supercritical phase suitable for transport and injection, the gas typically passes through multiple stages of compression. Because CO₂ undergoes a substantial reduction in volume during this process, compressor selection has a major impact on efficiency, operability, footprint, and power consumption.

Across the projects I’ve worked on, integrally geared compressors are increasingly emerging as the preferred technology for many CCUS applications.

There are several reasons for this.

First, integrally geared compressors allow each compression stage to operate at its own optimal rotational speed. That flexibility improves overall efficiency compared with traditional single-shaft barrel compressors, where all stages operate at a single speed.

That efficiency gain matters.

CCUS compression consumes a significant amount of energy, and even relatively small improvements in compressor performance can have a meaningful effect on operating costs and overall emissions intensity. In practical terms, maximising efficiency also supports overall sequestration efficiency i.e. emitting less CO₂ from burning fuel for compressing the CO₂ you were emitting in the first place!

Integrally geared designs also tend to offer a more compact footprint, which is particularly valuable for modularised developments or space-constrained facilities. Many CCUS developments are ultimately favouring water-cooled intercooling systems (over air-cooled), which are often available as a standard vendor package. From an engineering perspective, this approach provides higher compression efficiency, a more compact package arrangement, and reduced layout complexity.

Dehydration: A Bigger Conversation Than It Used to Be

Dehydration technology has also become a major area of focus in modern CCUS design.

Historically, glycol-based systems such as TEG dehydration were widely used in CO₂ pipeline applications. However, many new CCUS projects are moving toward adsorption-based dehydration systems using solid desiccants.

The reason largely comes down to long-term corrosion risk.

Glycols are hygroscopic and small amounts of carryover may slowly build up in low points of transport pipelines. Over time, they may pick up moisture and develop a range of acids that can attack carbon steel CO₂ pipelines. For offshore projects, pipeline intervention becomes more difficult and expensive. For projects converting existing and ageing hydrocarbon infrastructure, operators are understandably adopting more conservative approaches.

As a result, adsorption systems using silica gel, activated alumina, or molecular sieves are increasingly being adopted.

One interesting industry observation is that the “highest performance” option is not always the most attractive commercially. Molecular sieves, for example, can achieve extremely low moisture levels, but they also require higher regeneration temperatures and generally come with higher energy demand and operating costs.

In many CCUS applications, silica gel has proven to be a highly effective and economical solution because of its resilience to acidic environments and lower regeneration requirements. This resilience can translate to longer adsorbent life and, in some cases, more compact bed sizing, contributing to lower capital cost.

However, whilst moving away from glycol dehydration to solve one problem, it introduces another.

Adsorbents are challenged by the presence of certain impurities, such as methanol and aldehydes, which negatively influence dehydration system sizing and performance over operating life. CCUS projects must focus on managing this risk accordingly.

The Industry Is Learning Quickly

One of the most encouraging aspects of the CCUS sector today is the pace at which lessons are being shared and incorporated into new developments.

Over the past several years, we’ve seen a clear evolution in preferred configurations and equipment selection. Technologies that were once thought to be standard are now being reassessed; the industry is gaining a better understanding of what configurations and technologies are most appropriate.

This reinforces the importance of remaining technology neutral.

At Kent, we work closely with a range of Original Equipment Manufacturers (OEMs) and technology providers rather than promoting a single preferred solution. In practice, that approach allows us to focus on selecting technologies that best suit the specific project conditions rather than forcing projects toward a predetermined outcome.

That’s a healthy sign for the industry.

It shows that CCUS is maturing and builds confidence that CCUS can be delivered at the scale required to support global decarbonisation goals.

At Kent, we see that momentum continuing to build.