Abstract: A process and apparatus for providing a carbon monoxide rich gas product. Carbon dioxide gas is partially converted in an electrolyser to obtain carbon monoxide gas and oxygen gas. A gas mixture containing at least carbon dioxide, carbon monoxide and hydrogen is withdrawn from the electrolyser. At least a part of the gas mixture is introduced into a separation system to provide a first gas or gas mixture enriched in carbon dioxide and a second gas or gas mixture enriched in carbon monoxide. The first gas or gas mixture or a part thereof is reintroduced into the electrolyser which is operated at a conversion rate for carbon dioxide 20% to 40% below a maximum conversion rate for the electrolyser.