A process for the production of liquid acid, comprising the steps of: feeding liquid acid with a first concentration into a gas purification; passing a gas through the gas purification such that a second concentration of the liquid acid is reached; withdrawing the liquid acid from the sump of the gas purification, where in the gas purification sump is divided by a partition wall into a first and a second section. The concentration of the liquid acid collected in the first section is adjusted to the first concentration. The liquid acid with the first concentration from the first section is at least partially fed back into step and the liquid acid with the second concentration collected in the second section is at least partially withdrawn as product.