A high temperature heat integration method of making carbon black. A method of making carbon black is described, including reacting a carbon black forming feedstock with hydrogen gas in a plasma reactor to produce effluent gas containing carbon black and unused hydrogen, cooling the effluent gas for further processing, and recycling the unused hydrogen back into the carbon black forming process, where the unused hydrogen gas is pre-heated in a heat exchanger to a temperature up to the reaction temperature in the reactor before being recycled into the carbon black forming process. The heat exchanger for use in such process is also described.