In conventional shift converter designs, the process gas travels axially through the catalyst bed. In contrast, in axial-radial flow converters, the process gas travels axially and radially through the catalyst bed. This results in increased conversion efficiency and reduced pressure drops through the process. This measure is applicable to all types of feedstocks and to both CO shift converters and ammonia synthesis converters.

 Before the renovation at the ammonia plant of Guizhou Chitianhua Group Co., Ltd., the process gas in the shift converter was travelling axially through the catalyst bed. After the renovation, the process gas travels axially and radially through the catalyst bed and the size of the catalyst granules is reduced to 3x5mm. The result was improved conversion efficiency and increased catalyst lifetime (Jigang, 2004)