In this article the use of gas generated in the pyrolysis of plastic waste and biomass for firing a reheating furnace was proposed as an example of effective waste management. The material used for the research was lignocellulosic biomass in the form of alder and pine chips and PP polypropylene waste, for which the content of carbon, hydrogen, nitrogen, sulfur and oxygen was determined. The research was conducted for a pusher-type metallurgical reheating furnace, fired with a mixture of natural gas and coke oven gas. The design capacity of the furnace was 80 Mg/h and the installed power of the furnace was 72.3 MW. The share of pyrolysis gas in the fuel mixture fed to the furnace was 5-15%. The chemical composition of pyrolysis gas was experimentally estimated on a test stand for solid fuels conversion in a stationary bed at a temperature of 600°C. Based on data gained from the rolling mill of one of the steel mills located in Poland, an analysis of the profitability of using pyrolysis gas for co-combustion with coke oven gas and natural gas in an industrial heating furnace was carried out. As a result, a significant benefit can be achieved, namely that the use of pyrolysis gas is an effective method of reducing the production costs of the analyzed steel company, leading to an increase in its attractiveness. Plastic waste and biomass are used as energy sources in the suggested technology, therefore using them as feedstock for the pyrolysis reactor combined with the pusher-type metallurgical reheating furnace is a potential proposal for the future.