New process designs are presented for reforming reactions of steam with hydrocarbons (such as methane, natural gas, light hydrocarbon feedstocks with one to four carbon atoms in each molecule), also for the water gas shift reaction that is of steam with carbon monoxide; also for carbon dioxide reforming of hydrocarbons (such as methane, acidic natural gas, coal gas, landfill gas, light hydrocarbon feedstocks with one to four carbon atoms in each molecule), and the combined reaction of steam carbon dioxide with same hydrocarbons. The processes employ organic polymer, organic polymer-inorganic support, and inorganic membrane permeators for species separation, with the permeators placed after the reactors where the above named reactions take place. The membranes in permeators separate selectively the H.sub.2 and CO.sub.2 species exiting from the reactors from the non-permeated reactants and products. The reject streams coming out of permeators can be recycled into the inlet of the first reactors; these reject streams can be also fed to consecutively placed steam reforming and water gas shift reactors for further conversion to H.sub.2 and CO.sub.2 products. The separated H.sub.2 and CO.sub.2 in membrane permeate and from the secondary reactions of permeator reject streams, can be used for direct methanol synthesis, feed to molten carbonate fuel cells, and other chemical syntheses; after the removal of CO.sub.2 from the mixture, pure hydrogen can be recovered and used in chemical syntheses and as fuel in fuel cells and power generation cycles.