Scalable heat exchanger reformer for syngas production

A heat exchanger reformer for convective steam reforming of a hydrocarbon feed, wherein the heat exchanger reformer comprises a vessel having a plate assembly section placed therein comprising of several plates separated by a gap from each other, the gap between adjacent plates providing at least alternating first and second channels between adjacent plates, which vessel comprises a first inlet at a first end of the plate assembly section for supplying a mixture of a hydrocarbon feed and steam to the first channels and causing the mixture to flow in a direction toward a second end of the plate assembly section, which vessel also comprises a second inlet close to the second end of the plate assembly for supplying hot reformer effluent as a heating gas flow to the second channels, wherein the second channels comprise a first and a second section which are connected to each other, wherein the first section is provided for conducting the hot reformer effluent in a direction towards the first end of the plate assembly counter current to the flow of the hydrocarbon feed and steam mixture in the first channels, and the second section is provided for conducting the hot reformer effluent to flow in cross direction of the first channels, which second channels are connected to a collector outlet for the reformer effluent to leave the heat exchanger reformer at the first end of the plate assembly.