Abstract: An aqueous liquid sorbent suitable for use in separating a target gas from a mixture of gases in a rotating packed bed gas capture system, comprising a first amine compound, a second amine compound and water, wherein the sorbent comprises at least 16 wt % of the first amine compound and at least 51 wt % of total amine compounds, the first amine compound has a reaction rate with the target gas that is greater than the reaction rate of the second amine with the target gas, and the second amine compound has a solubility in water that is greater than the solubility of the first amine compound in water.

Abstract: Disclosed herein is a rotating packed bed, RPB, arrangement configured to provide mass transfer between a liquid sorbent and a gas, the RPB arrangement comprising: an RPB configured to provide a substantial cross-flow between a liquid sorbent and a gas; and a spray arranged to spray the liquid sorbent onto the RPB; wherein the RPB and spray are both arranged at different longitudinal positions on a gas flow path through the RPB arrangement.