A method for the manufacture of polycarbonate by combining methane and inlet water to produce methanol, converting the methanol to propylene, gasoline aromatics, and gasoline olefins, converting the propylene and gasoline olefins to hydrogen, first benzene, and toluene, reacting the first benzene with propylene to form cumene, reacting the cumene with oxygen to form cumene hydroperoxide, cleaving the cumene hydroperoxide to produce acetone and phenol, reacting the phenol, additional phenol, and acetone to produce a dihydric aromatic compound, and reacting the dihydric aromatic compound with a carbonate precursor to form polycarbonate.