(515e) CO2 Absorption in Amines Using SiO2 Nanoparticles in Instantaneous Regime

Nowadays, increasing levels of CO₂ in atmosphere is serious concern worldwide. This is caused due to the imbalance between the rate of emission of CO₂ and its removal. Several methods have been used to reduce the effect of these emissions, major technology being CO₂ absorption in amines. Several studies carried out earlier show that, with minute changes to the present absorptive systems, we can increase the absorption rates with would also help us in design of equipments. We have, therefore explored the application of principle of mass transfer enhancement by nanoparticles to the problem of absorptive capture of CO₂ in reactive systems.

From the literature, it is seen that concentration of solvents as well as the concentration of nanoparticles both affect the absorption rate. With optimum concentrations of both, we can achieve a state of maximum possible enhancement. For this, we have studied the effect of nanoparticles on CO₂ absorption in MEA studied in a packed column reactor in presence of Silica nanoparticles which is of interest from an industrial application point of view.

Mono Ethanol Amine (MEA) is chosen as a solvent and the parameters are adjusted to fit in to the Fast to Instantaneous regime and Instantaneous regime. Experiments are performed at different volume fractions of SiO₂ nanoparticles and concentrations of MEA. Similar experiments are conducted in capillary tube model apparatuses to check the consistency of mechanisms between both the systems.

It is observed that fewer enhancements are obtained in Instantaneous regime as compared to the Fast to Instantaneous regime. The highest possible enhancement has been found at a SiO₂ particle volume fraction of 0.6 above which agglomeration of nanoparticles is observed. The enhancement due to nanoparticles has been evaluated using some of the existing models from the literature and deviations from the experimental ones are reported. A new model has been proposed which takes in to account all the parameters in this regime and can estimate the enhancements caused due to them.