Research on the Co-processing of Steel Rolling Sludge and Biomass

This study investigated the co-pyrolysis characteristics of steel rolling oil sludge and peanut vine biomass, as well as the distribution law of their byproducts. Steel rolling oil sludge is an oily hazardous waste with complex components that is difficult to treat, whereas biomass is high in volatile matter and renewable. Thermogravimetric analysis and tube furnace experiments were used to investigate the impact of different mixture ratios, heating rates, and pyrolysis temperatures on the pyrolysis process and products. The results showed that the pyrolysis process could be divided into three stages: the evaporation of water (from room temperature to 130°C), the breakdown of organic components (130–490°C), and the reduction of iron oxides (490–900°C).The addition of peanut vine significantly accelerated the pyrolysis reaction, decreased the activation energy, and boosted the pyrolysis efficiency. Kinetic research revealed that for the mixture samples, the pyrolysis activation energy increased with increasing heating and conversion rates, while the activation energy of pure steel rolling oil sludge decreased with increasing heating rate; in addition, the activation energy reduced with increasing peanut vine content. The analysis of pyrolysis residues showed that the metallization rate and the iron element content increased with the pyrolysis temperature, but the amount of metallic iron did not show a linear relationship with the proportion of steel rolling oil sludge. The proper amount of biomass may help with the efficient recovery of iron resources since iron has a catalytic influence on the pyrolysis of biomass. This work provides a theoretical basis for the co-disposal of biomass and steel rolling oil sludge in order to accomplish sustainable resource exploitation and environmental protection.