A system for producing high purity carbon monoxide and hydrogen as well as activated carbon includes a pyrolysis reactor, a gasifier, a combustion turbine, a boiler, a steam turbine, a combined cycle unit and an electrolysis unit. Liquid fuel from the pyrolysis reactor is provided to the combustion turbine. Liquid and gaseous fuels are provided to the boiler. Compressed oxygen from the electrolysis unit is provided to the combustion turbine. Electric power from the combustion turbine and steam turbine are provided to the electrolysis unit. The gasifier includes a preheat region, a gasification region, and a cooling region. CO2 and O2 are injected into the gasifier at multiple injection levels to create an isothermal gasification region to produce CO. The CO2 and O2 are preheated in a heat exchanger using the CO exiting from the gasifier prior to injection.