Pyrolysis of Waste and Wood in Reactors to be Integrated in Cement Plants─Characterization and Comparison with Benchmark Oils

Pyrolysis of waste and biomass can be integrated into cement plants to supply energy to the cement processes through char and light gases while producing pyrolysis oil as an additional revenue stream. This study investigated the feasibility of applying waste and biomass pyrolysis in cement plants through laboratory (0.5 kg/h) and pilot scale (6 kg/h) experiments using sand and cement raw meal (CRM) as fluid bed materials. The resulting pyrolysis oils were analyzed and compared to benchmark oils, including commercial pyrolysis oils from wood and plastic and marine fuels. Laboratory experiments achieved oil yields of up to 57 wt % for beech wood and 60 wt % for refuse-derived fuel (RDF) waste. The type of fluid bed material had a minimal impact on oil quality. However, shifting from beech wood to RDF waste led to significant changes, including reduced water content and total acid number (TAN), increased viscosity and heating value, and higher chlorine content due to the presence of plastic fractions in the waste. Pilot scale pyrolysis yielded oils with lower oxygen and chlorine contents and lower TAN compared to lab-scale oils, attributed to higher temperatures, oxygen ingress, and the presence of calcined raw meal during pilot tests. The produced oils were evaluated for marine fuel applications using the ISO 8217:2024 standard, analyzing properties such as the water content, TAN, calorific value, flash point, chlorine content, viscosity, and evaporation characteristics. Pilot plant waste-derived oils showed potential as maritime fuel blends, while beech wood-based oils exhibited inferior properties, such as high TAN and low flash points. Results indicate that high-plastics-content waste enhances the suitability of the oil for use as marine fuel, requiring only minor post processing, while high-biomass-content waste will require further upgrading for marine applications.