A structured body for heating gas

A structured body arranged for heating a feed gas, said structured body comprising a first macroscopic structure and a second macroscopic structure, each extending in a longitudinal direction from a first end to a second end, where said first end forms an inlet to said first and second macroscopic structures for said feed gas and said second end forms an outlet for heated gas, said first and second macroscopic structure comprising a three-dimensional network structure, wherein the network structure forms flow paths allowing the feed gas to flow from said first end to said second end, the network structure being formed by a metallic material being electrically conductive, wherein the second macroscopic structure is arranged at least partly circumferentially around the first macroscopic structure, and wherein the first and second macroscopic structures are electrically connected at the second end.