Tips for carbon dioxide recovery and utilization
Understanding carbon dioxide recovery and utilization
With carbon taxes on the rise, more stringent regulations enacted all of the time and the planet warming, many companies face two important questions. Does it make sense to recover the CO2 we produce? If yes, how can I do that? The answer to these questions is carbon dioxide recovery and utilization. But what does that mean? Let’s look.
Carbon dioxide (CO2) is a biproduct of many industrial processes. It is also a gas that is responsible for climate change. In the past, it was just blasted into the air. Now, however, there are technologies available that allow us to “capture” CO2 and to liquify (and reuse) it or “sequester” it (usually underground) so that it cannot escape into the air.
The first question of whether it makes sense to take advantage of these technologies can be answered with a resounding “Yes!” There are financial and moral incentives to use carbon capturing.
On the one hand, it’s the right thing to do. Allowing the carbon dioxide you produce to simply vanish into the atmosphere only makes the challenge of addressing climate change more daunting. Capturing the carbon, however, is becoming also good for business.
In the EU, the carbon tax is €90 per ton while, depending of the source, it could cost much less than that to capture the CO2.
That brings us to the second question: How can I do this in the most effective and efficient manner?
Different types of carbon dioxide recovery and utilization
The answer to that question is: “That depends.”
There are a variety of factors that determine which is the optimal carbon dioxide recovery and utilization technology.
One key question is how much CO2 is produced in a given industrial process. If it’s a lot, for example in the production of cement, steel or biogas, then recovering the carbon dioxide can be relatively easy.
If not a lot of CO2 is being produced, i.e., if the carbon dioxide content of the emissions is low (like direct air carbon capture), then it becomes more difficult.
In other words: If the emissions contain a lot of CO2, then they are in general better suited for carbon capture.
How does carbon capture work?
We will focus on one of the most common CO2 capture technolgies: amine scrubbing.
The process begins by filtering out the contaminants from the CO2-rich emission stream. Most processes that create CO2, also generate sulfur and nitrogen-based compounds, which must be removed early in the process to avoid damaging components further down the process.
The next step in recovering carbon dioxide is to extract it out of the emission stream. This is done using a CO2 adsorbing liquid medium known as an amine-solution which is at the heart of this carbon-capture technique.
In the following step, this solution is pumped to a stripper as a carbon dioxide-rich fluid. As the name indicates, the stripper strips (removes) the CO2 from that liquid. This is normally done using heat, and the result is a CO2-rich gas and a low-CO2 liquid.
In a final step, the gas has to be compressed so that it can be liquified, captured or used for another process.
This is where Atlas Copco comes in. We provide state-of-the-art CO2 compressors and dryers. Their outstanding quality, reliability and efficiency not only help you do your part for the environment but also cut your costs.
In certain sectors, carbon capture can be quite lucrative. Mainly, those are the ones that produce a lot of emissions with a high carbon dioxide content. They include the coal chemical and power plant sectors, the petrochemical sector and steel and cement producers.
flue gas chart process of co2
Choosing the optimal carbon capture technology
There are different carbon capture technologies to choose from. The most common is using adsorption by chemical solvents. This is used for large-scale carbon dioxide recovery and utilization. Here, following amine scrubbing to capture the carbon dioxide, a CO2-rich solution is regenerated in the scrubber at temperatures of 100-120 °C. The resulting highly concentrated carbon dioxide steam is released and later dried.
Another, increasingly popular process is cryogenic separation, which works similar to distillation. The flue gasses are dried and compressed at 10 bar before being cooled in stages.
Both of these can simply be added to an existing production plant, which is a key advantage.
What all of these processes have in common is that a compressor is needed. Otherwise, the captured CO2 will not be easy to transport, use or store.
While the carbon dioxide discovery and utilization technologies can be complicated, the compression process is fairly simple. However, you will still need a special CO2 compressor to reliably get the job done.
For example, in order to prevent the corrosion that can be caused by carbonic acid. That is why the compressor should rely on components made from stainless steel or another corrosion-resistant material.
But whatever your compression needs are, one thing is for sure: Atlas Copco will have a solution. With compressors specifically designed for CO2 compression, we can help you take an important step toward carbon dioxide recovery and utilization.
