Supercritical hydrothermal combustion: Basic principles, characteristics, applications, and development in energy and environment

Supercritical hydrothermal combustion technology is a new homogeneous combustion technology with high potential in the fields of efficient removal of organic waste, clean utilization of conventional fossil energy, and efficient recovery of heavy oil. In this paper, the literature related to supercritical hydrothermal combustion in recent years is reviewed, focusing on evaluating the current status of experimental and numerical simulation studies on the characteristics of supercritical hydrothermal combustion, as well as the latest progress in engineering. It has been pointed out that the reduction of ignition temperature and extinction temperature is the key to promoting the application of supercritical hydrothermal combustion technology, and the consideration of the real fluid’s effects and turbulence reaction interactions can correctly reflect the combustion process. In addition, supercritical hydrothermal combustion technology, as a source of heat and reaction medium supply, can realize the efficient removal of highly concentrated organic wastewater, the clean combustion of coal, and in-situ hydrogen production, as well as the thermal recovery of heavy oil by multi-thermal fluids. At present, supercritical hydrothermal combustion forced ignition technology, reactor design guidelines, and corrosion prevention of key equipment are still the focus of future research, which is of great significance to promote the application of supercritical hydrothermal combustion technology.