A portable containerised apparatus for producing hydrogen and graphene from a hydrocarbon source, the apparatus comprising: a plasma reactor system configured to produce hydrogen and graphene from a process gas comprising hydrocarbons; an inlet for receiving a feed stream comprising hydrocarbons from the hydrocarbon source and means for supplying the process gas to the plasma reactor system; a hydrogen outlet for removing hydrogen from the containerised apparatus and/or hydrogen storage means within the containerised apparatus, and means for providing a hydrogen-containing output gas from the plasma reactor system to the hydrogen outlet and/or the hydrogen storage means; and a graphene outlet for removing graphene-containing solids from the containerised apparatus and/or graphene storage means within the containerised apparatus, and means for providing graphene-containing solids from the plasma reactor system to the graphene outlet and/or the graphene storage means. Also provided is a method of producing hydrogen and graphene using such an apparatus.