TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The method further involves cooling the used wash solution before passing the used wash solution to regeneration, where the cooled used wash solution cools the gas comprising contaminants in the first regeneration stage. The gas comprising removed contaminants is cooled to a temperature selected to reduce the loss of water vapor from the regeneration step while minimizing the amount of re-absorption of removed contaminants into the regenerated wash solution in the first regeneration stage. After the regenerating step, the method involves passing the regenerated wash solution to reboiling; reboiling the regenerated wash solution for further removal of gaseous contaminants from the wash solution, to provide a reboiled wash solution; returning the reboiled wash solution to the contacting step, where during returning step the return wash solution is subjected to heat-exchanging with regenerated wash solution of the passing step in a first heat-exchanging step, to heat the regenerated wash solution; and heat-exchanging with used wash solution in a second heat-exchanging step, to heat the used wash solution, where in a first regeneration stage the used wash solution cools the gas comprising removed contaminants and thus minimizes water vapor loss. The method further involves withdrawing a first portion of used wash solution resulting from the second heat-exchanging step, and between the first and second heat-exchanging steps subjecting the return wash solution to heat-exchanging with the withdrawn portion of used wash solution in a third heat-exchanging step to heat the used wash solution; passing the first portion of used wash solution resulting from the third heat-exchanging step to reboiling and reboiling the portion of used wash solution for removal of gaseous contaminants from the used wash solution, to provide a reboiled wash solution, where during the passage to reboiling the first portion of used wash solution is combined with the regenerated wash solution of the step of passing regenerated wash solution to reboiling; and passing the first portion of used wash solution resulting from the third heat-exchanging step to regeneration, and regenerating the first portion of used wash solution for removal of gaseous contaminants from the used wash solution, to provide a regenerated wash solution. The regeneration involves a set of consecutive regeneration stages, where the portion of used wash solution is subjected to regeneration in a regeneration stage downstream of the stage where the used wash solution of the regenerating step is subjected to regeneration. Preferred Components: The wash solution is an amine-based wash solution. Preferred System: The regenerator is arranged for receiving used wash solution at an upper part of the regenerator. The gas purification system further comprises a third heat-exchanger for heat transfer between reboiled wash solution from the first heat-exchanger and a first portion of used wash solution from the second heat-exchanger, where the third heat-exchanger is arranged for receiving reboiled wash solution from the first heat-exchanger and for receiving a first portion of used wash solution from the second heat-exchanger. The first portion of used wash solution is 10-90%, such as 50-90%, or such as 75-90% of the used wash solution resulting from the second heat-exchanger. The second heat-exchanger is arranged for receiving reboiled wash solution from the third heat-exchanger; and the first heat-exchanger is arranged for receiving the first portion of used wash solution from the third heat-exchanger. The regenerator is arranged for receiving the portion of used wash solution from the third heat-exchanger, particularly at a bottom part of the regenerator. The second heat-exchanger is arranged for receiving reboiled wash solution from the third heat-exchanger. EXAMPLE - No suitable example given.