Test Bed for Purification and Liquefaction of CO₂

It is becoming increasingly important to utilize the CO₂ found in flue gases and generated in biochemical processes (e.g. ethanol and biogas production), either for CCU (Carbon Capture and Usage) or for CCS (Carbon Capture and Storage).

Negative Emissions

If the used raw materials are of biogenic origin and the CO₂ is permanently stored, this is called BECCS (BioEnergy with Carbon Capture and Storage) and leads to so-called negative emissions. BECCS and negative emissions are a necessity if we are to be able to reach set global targets for net zero emissions. At Swedish national level, there is a target of capturing and storing 1.8 million tonnes of CO₂ by 2030. The level is then expected to increase to 3-10 million tonnes by 2045. Regardless of which levels are reached in the end, these are large volumes, and new systems are required to be built up in a short time.

Tailor-made Purification

There is a lot of research about capturing CO₂ from flue gases, but very little attention has been paid to subsequent purification in combination with liquefaction of CO₂. This is where our test bed comes in.

The needed degree of purity of the CO₂ product depends on what it is to be used for, and in the case of CCS, extensive purification is required with respect to certain components, e.g. the oxygen content may not exceed 10 ppm, while some other components are not regulated at all. If the CO₂ product is to be used in industry (CCU), other specifications may apply, but regardless of which, the gas needs some type of purification / conditioning after capture from flue gases or from biochemical processes.

With the test bed, we can test and verify the purification of CO₂ flows of different origin and for different applications, in order to reach the specifications set by the end user. This may provide valuable information for investment decisions for upscaling to full scale.

We Can Come to You

The pilot plant is mobile and placed in a standard 20-foot container, which makes it easy to move around to host plants with different CO₂ streams. It consists of compressor, activated carbon filter, gas dryer, pre-liquefaction chiller, distillation column and buffer storage for liquid CO₂, and can be extended with further purification steps. Product quality is monitored with a gas analyzer (IR and electrochemical sensors) and external analyses as needed.

The test bed is largely automated and is modular so that different unit operations can be bypassed to simplify the purification and be able to purify the CO₂ flow to good-enough quality to be able to lower CAPEX and OPEX in full scale. The test bed is built to be able to process a wide range of gas streams from different sources, which provides high flexibility and enables the operation in conjunction with other test beds, e.g. our test bed for capturing CO₂.

The test bed is available from autumn 2023.