Co-Processing Organic Wastes in Coal–Water Slurry Gasifiers: Research Progress and Application Prospects

Co-processing organic waste in coal–water slurry (CWS) gasifiers offers high gasification efficiency and robust stabilization of hazardous substances, representing a crucial pathway for waste valorization and low-carbon chemical processing. This review systematically examines the key influencing factors, control strategies, environmental risks, and operational challenges of this technology. We compare the adaptability of various gasifier designs for handling organic waste and propose operational strategies to balance slurryability and gasification performance under complex feedstock conditions. Furthermore, this paper elucidates the mechanisms underlying adverse effects on equipment (e.g., slagging and corrosion) and emission risks induced by problematic waste components, such as high ash, alkali metals, chlorine, and heavy metals. Finally, we highlight future research directions, emphasizing the synergistic management of multi-source wastes, developing multi-scale reaction modeling, and conducting life cycle assessments (LCA) and economic evaluations to advance CWS co-processing toward highly efficient, stable, and low-carbon operations.