Mass transfer efficiency for CO2 capture using soda solutions
Narayanasamy, Mohankumar (2021)
Diplomityö
2021
School of Engineering Science, Kemiantekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2021110954433
https://urn.fi/URN:NBN:fi-fe2021110954433
Tiivistelmä
The global emissions from transportation division and the demand for synthetic fuels to diminish emissions is anticipated a mammoth growth in the upcoming years. To offset the emissions produced in biogenic processes is to capture the maximum CO2 gas which is produced during the processes and utilizing it in the production of e-fuel, which will boost the efficiency and ameliorates the plan of becoming carbon neutral by 2035 as proposed by Finnish Government’s climate policy.
In this thesis various methods for CO2 capture, methods used to measure mass transfer rates of flue gas, acceleration techniques of mass transfer rates in gas absorption and approaches in optimizing the process will be reviewed. Absorption based post-combustion capture technology developed by VTT (Enhanced soda scrubbing process) were experimented using a high-performance bubble generation device at pilot scale container using synthetic gas mixtures at various experimental setup. Since the absorption rates of gas were unknown more exact measurements were performed to determine the gas absorption rates so that it can be used in future scale up and for more rigorous performance evaluation. The gas bubble images were recorded by high-speed camera which is useful in determining the average bubble size.
Enhanced soda scrubbing process for carbon capture was tested, it is observed that the absorption rate and capacity is higher when compared to water, due to chemical reaction the absorption of the pollutant gas is ten times higher, higher delay time after the bubble producing device was not effective, with vertically mounted bubble producing device promising results were achieved at realistic conditions. Capture efficiency of 90% was achieved at 1 bar pressure without regeneration and an optimal L/G ratio 1.25 was identified which produces best results as trade-off between input energy power and mass transfer rate. Nevertheless further investigation and experiments are necessary to achieve better results and technoeconomic evaluation of tested technology is needed.
In this thesis various methods for CO2 capture, methods used to measure mass transfer rates of flue gas, acceleration techniques of mass transfer rates in gas absorption and approaches in optimizing the process will be reviewed. Absorption based post-combustion capture technology developed by VTT (Enhanced soda scrubbing process) were experimented using a high-performance bubble generation device at pilot scale container using synthetic gas mixtures at various experimental setup. Since the absorption rates of gas were unknown more exact measurements were performed to determine the gas absorption rates so that it can be used in future scale up and for more rigorous performance evaluation. The gas bubble images were recorded by high-speed camera which is useful in determining the average bubble size.
Enhanced soda scrubbing process for carbon capture was tested, it is observed that the absorption rate and capacity is higher when compared to water, due to chemical reaction the absorption of the pollutant gas is ten times higher, higher delay time after the bubble producing device was not effective, with vertically mounted bubble producing device promising results were achieved at realistic conditions. Capture efficiency of 90% was achieved at 1 bar pressure without regeneration and an optimal L/G ratio 1.25 was identified which produces best results as trade-off between input energy power and mass transfer rate. Nevertheless further investigation and experiments are necessary to achieve better results and technoeconomic evaluation of tested technology is needed.