Abstract: The present invention is directed to a method for producing high purity carbon monoxide. In the method, a hydrocarbon feed stock and import carbon dioxide are introduced into a reaction system containing a primary reformer and a secondary reformer. The hydrocarbon feed stock, import carbon monoxide and recycle carbon monoxide are passed through the primary reformer while being heated to a temperature sufficient to reform the feed stock into a first carbon monoxide reaction product. The first reaction product and oxygen are fed into the secondary reformer. The first reaction product is reacted in the secondary reformer in an autothermal reaction to provide a second carbon monoxide reaction product having a lower hydrocarbon level than the first reaction product. The second reaction product is removed from the secondary reformer at a second predetermined temperature and a high purity carbon monoxide is recovered from the second reaction product without the use of cryogenic separation techniques.