Compact devices for generating pure hydrogen

A hydrogen generator comprising a hydrogen membrane reactor, a fuel supply, a reaction fuel supply line, an air supply, an air supply line, a combustion fuel supply line, a tail gas supply line, a combustion by-product line for transporting combustion by-products from the combustion chamber, and a reaction product line. A membrane assembly to be joined to a reactor chamber of a hydrogen generator, which comprises a membrane; and a membrane support comprising a sintered porous metal. A reactor assembly comprising a reaction chamber containing a porous metal substrate, two membrane assemblies, a fuel supply, a reaction fuel supply line, and a tail gas supply line and a reaction product line. Methods associated with the hydrogen generator, membrane assembly and reactor assembly.