Add heat, reduce risk

Carbon capture is a complex technology. Can you help simplify it for me?

Carbon capture is an energy demanding technology, whether we use cryogenics, amines, or hot potassium carbonate. In the case of amines, to separate CO₂ from the amine solution, you need to be able to heat it until the CO₂ gas stream and the liquid solvent can be recovered. The overall amount of energy needed to strip CO₂ from the solvent is very large.

Depending on the facility, there might be available energy present. Being able to integrate that existing excess energy from the facility into the capture unit improves the capital expenditure (CAPEX) and operating expenditure (OPEX) of the project, as well as being significant from a sustainability perspective.

This type of medium to high temperature heat needed is usually not available at cement plants. Can you explain how to overcome this challenge?

That's right. If you were establishing a carbon capture plant on, for example, a biomass or waste-to-energy power plant, you would instantly have access to high temperature steam that could be used as a heat source for the carbon capture unit. At a cement plant, there are other streams at a lower temperature. That is where innovative technologies such as a waste heat recovery unit can help collect the energy from that low temperature stream so it can be used in the carbon capture process.

There are also more advanced solvents available now. What kind of advantages do they offer?

There are widely used amine types, like MEA, that have been used for many years, but now there are new advanced types available that include more complex chemicals to capture more CO₂ per unit volume. They have a lower degradation rate, meaning that the carbon capture is more effective while less amines are lost during operation. Usually, the amine solution needs to be replenished continuously, meaning that the new types of amines can help reduce the operational expenditure even though they might cost more initially. Many of these are proprietary amines, so independent testing is not always possible, and it is necessary to rely on the data sheets provided by the manufacturers.