Co-Pelletization of Oil Sludge and Corn Straw for Improved Biomass Fuel Properties

The low ash melting temperature and high energy consumption during pelletization of biomass fuels pose significant challenges to their large-scale utilization. In this study, oil sludge was employed as an additive to corn straw in the formulation of enhanced composite pellet fuel (CPF). This study aimed to identify the optimal parameters for the copelletization process using single-factor and orthogonal experimental designs. The findings revealed that the physical and mechanical properties of the CPF were significantly influenced by the proportion of oil sludge. The optimal conditions were identified as 40% oil sludge content, 0.106 mm straw particle size, 10% moisture content, 1.5% starch content, and 60 MPa pelletization pressure. Under these conditions, the CPF exhibited significant improvements in physical and mechanical properties compared to straw pellet fuel prepared under the identical conditions. Furthermore, the quality of the optimized CPF complied with the highest standards prescribed by the Chinese and ISO biomass pellet fuel standards.