Enzyme enhanced CO2 absorption rate-based modeling and pilot plant validation

Amongst the different process configurations for CO2 capture from power plant flue gases, post combustion absorption technique is the most mature technology and has the greatest potential to be used in the near future since it can be retrofitted to conventional (fossil) fuel burning power plants.

For CO2 capture from flue gases the most crucial factor is the absorbent, since it has to selectively absorb CO2 at very low partial pressure. Amine Solvents such as e.g. MEA have drawn high interest in this field, because they have high reactivity towards CO2 and are able to bind it chemically.

Chemical reaction of the CO2 enhances the physical mass transfer and is good for the absorption step. Nevertheless, this chemical binding is a big disadvantage in the regeneration of the solvent, where the bound CO2 has to be released. This step comprises the biggest energy requirement of the total process. Solvents with high mass transfer and reaction kinetics usually need higher energy for regeneration, whereas solvents with low energy requirement show very poor kinetics and mass transfer.

In this project the application of enzymes as kinetic promoter in the carbon capture process is to be investigated. The enzyme, a carbonic anhydrase, one of the fastest enzymes known and an enzyme present in humans and other organisms to handle CO2 will be supplied by Novozymes. In the first step of the project a good enzyme-solvent system will be determined by intensive screening. In the next stage, the mass transfer and reaction kinetics of the enzyme and solvent will be investigated.

The project will be rounded off with pilot plant experiments validating a robust mathematical model and demonstrating the technical feasibility for the process.

Supervisor: Assoc. Prof. Nicolas von Solms, nvs@kt.dtu.dk

Co-supervisor: Prof. John Woodley, jw@kt.dtu.dk

Co-supervisor: Ass. Prof. Philip Loldrup Fosbøl, plf@kt.dtu.dk