A method for producing a chemical reaction is provided. This method includes providing at least two helical tubes, wherein the helical tubes comprise: a first axis and a second axis; wherein the first axis and the second axis are normal to each other; a cross-sectional shape of a predetermined contour; and an inlet end and an outlet end. The method includes reforming a first gas stream and a second gas stream into a third gas stream in the presence of a catalyst. The method includes surrounding a heat source with the helical tubes are, and operating the tube with an average catalyst temperature of above 500 F. An apparatus for producing a chemical reaction is also provided. This apparatus comprises at least two helical tubes, wherein the helical tubes comprise: a first axis and a second axis; wherein the first axis and the second axis are normal to each other; a cross-sectional shape of a predetermined contour; an inlet end and an outlet end, wherein the helical tubes contain a catalyst capable of reforming a first gas stream and a second gas stream into a third gas stream. The helical tubes are designed to surround a heat source, and the tube operates with an average catalyst temperature of above 500 F.