Disclosed are methods of reduction of chlorine in pyrolysis products derived from a mixed plastics stream. Methods may comprise: (a) causing pyrolysis of a plastic feedstock to produce a first stream of C1-C4 gaseous hydrocarbons and light gas olefins and a second stream comprising the remaining pyrolysis components. The second stream and hydrogen gas may be fed into a hydrocracker to produce a third stream of gaseous C1-C4 hydrocarbon gases and a fourth stream comprising the remaining hydrocracker components. The fourth stream may be fed to either (i) a steam cracker to produce a fifth stream comprising C1-C4 gaseous hydrocarbons and light gas olefins, a sixth stream comprising C6-C8 hydrocarbons and a seventh stream comprising hydrocarbons heavier than C8; or (ii) a fluidized catalytic cracker to produce an eighth stream comprising C1-C4 gases and light gas olefins and a ninth stream comprising hydrocarbons that are C5 or greater.