Carbon dioxide chemical absorption using methylpiperidines aqueous solutions

- A methyl group placed away the N group shows the better behavior.
- 3-Methylpiperidine reaches better regeneration results than monoethanolamine.
- 3-Methylpiperidine is a suitable solvent for carbon dioxide chemical absorption.

Present research work has centered on the improvement of carbon dioxide chemical absorption with piperidine aqueous solutions changing the solvent to reach better solvent characteristics and avoid certain negative items such as high toxicity and corrosion. This aim will be obtained by using solvents with an additional methyl group in the molecule in different parts of piperidine, and analyzing the effect upon carbon dioxide absorption behavior. The carbon dioxide absorption rate has been analyzed under different operation conditions (gas flow-rate and amine concentration) and type of solvent using a semicontinuous gas-liquid contactor (batch for liquid phase and continuous for gas phase). Also carbon dioxide loading was determined for each solvent in relation with reaction mechanism between carbon dioxide and each amine. The regeneration process was carried out for the best solvent using a treatment with calcium hydroxide avoiding the high temperatures in stripping methodology reaching better results that the best available technique.

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