Supercritical water oxidation (SCWO) is an effective, promising technology for destroying almost all kinds of organic waste with the advantage of high removal efficiency and low residence time, and without producing pollutant byproduct. The chemical energy of organic pollutants can be considered as an emerging renewable energy source. As a high-temperature and pressure process, an immense energy demand is required in the pressurization and preheating sections. On the other side, the reactor effluent has a great potential for energy recovery because of the great amount of heat released during the SCWO reaction combined with the previous energy input. Thus, SCWO is not only an organic waste treatment process but also an energy conversion and utilization system. The application of SCWO has been extended to the clean, efficient utilization of low-quality fuels such as high-sulfur coal, heavy oils, and biomass instead of conventional combustion, hydrothermal spallation drilling in geothermal energy production, and heavy oil recovery. However, energy consumption cost is still rather high in the actual process due to insufficient equipment performance, unreasonable energy system integration, and selection of an anti-corrosion and salt plugging reactor. Thus, a systematic, in-depth analysis on energy conversion and utilization in SCWO is conducted for the first time in the paper. The mechanism of exergy destruction analyses indicates that reducing enthalpy change and energy level difference are critical to reducing energy consumption. Suggestions on improving energy efficiency are proposed in the preheating stage, chemical exergy release, and reactor design.

超临界水氧化（SCWO）具有去除效率高、停留时间短、不产生污染物副产物的优点，是一种有效的、有前途的技术，可用于破坏几乎所有类型的有机废物。有机污染物的化学能可视为一种新兴的可再生能源。作为高温高压过程，加压和预热部分需要巨大的能源需求。另一方面，由于 SCWO 反应过程中释放的大量热量与先前的能量输入相结合，反应器流出物具有很大的能量回收潜力。因此，SCWO不仅是一个有机废物处理过程，也是一个能量转换和利用系统。SCWO的应用已经扩展到清洁、高效利用高硫煤、重油、生物质等低质燃料代替常规燃烧，地热能生产中的热液散裂钻探和重油回收。但由于设备性能不足、能源系统集成不合理、防腐防盐塞反应器的选择等，在实际过程中能耗成本仍然较高。因此，本文首次对SCWO中的能量转换与利用进行了系统、深入的分析。火用破坏机理分析表明，减小焓变和能级差是降低能耗的关键。在预热阶段、化学火用释放和反应器设计方面提出了提高能效的建议。