Modeling and analysis of carbon capture from biogas by high pressure water scrubbing
Author
Shoikat, Moinul Hossain
Term
4. term
Education
Publication year
2026
Submitted on
2026-06-01
Abstract
This thesis examines whether high pressure water scrubbing is a practical and viable method for carbon capture, utilization and storage (CCUS) in Denmark. Today, this technology is mainly used to upgrade biogas into biomethane, while the separated CO2 is typically released to the atmosphere. The aim of the study is to assess whether the process can deliver very high-purity CO2 that meets carbon capture specifications, while also producing biomethane of sufficient quality for injection into the Danish national gas grid. Initial process calculations show that the system can capture CO2 with a purity of 99.81 %, which is suitable for commercial use, and that methane (CH4) recovery is close to the current industry average. However, the purity of methane at 77 % is lower than Danish industry requirements, although further optimization is expected to improve this. The economic analysis indicates that the process can generate revenue, has a payback period of 4.95 years, which is shorter than the industry average, and a high return on investment (ROI of about 60 %), suggesting that the process is profitable. From an environmental perspective, the process reduces CO2 emissions, methane losses and the use of environmentally hazardous solvents. Overall, high pressure water scrubbing appears to be a technically robust, economically attractive and environmentally sound solution for biomethane upgrading and CO2 valorisation in Denmark.
Denne specialerapport undersøger, om højtryks-vandvask (high pressure water scrubbing) er en realistisk metode til karbonfangst, udnyttelse og lagring (CCUS) i Danmark. I dag bruges metoden typisk til at opgradere biogas til biomethan, mens CO2’en ofte blot udledes til atmosfæren. Formålet med studiet er at vurdere, om processen kan levere CO2 i meget høj renhed, som opfylder kravene til karbonfangst, samtidig med at man opnår tilstrækkelig kvalitet af biomethan til indførsel i det danske naturgasnet. De første beregninger viser, at processen kan fange CO2 med en renhed på 99,81 %, hvilket vurderes egnet til salg, og at metan (CH4) kan genvindes på et niveau tæt på branchegennemsnittet. Dog er metanrenheden på 77 % lavere end de krav, der normalt stilles i Danmark, men yderligere optimering vurderes at kunne forbedre dette. En økonomisk analyse viser, at processen kan skabe indtægter, har en kortere tilbagebetalingstid (4,95 år) end branchegennemsnittet og et højt afkast (ROI på cirka 60 %), hvilket peger på, at processen er rentabel. Miljømæssigt mindsker processen udslip af CO2 og metan samt behovet for brug af miljøskadelige opløsningsmidler. Samlet set fremstår højtryks-vandvask som en teknisk robust, økonomisk attraktiv og miljømæssigt bæredygtig løsning til opgradering af biomethan og udnyttelse af CO2 i Danmark.
[This abstract has been rewritten with the help of AI based on the project's original abstract]
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