水的临界温度（Tc=374℃）和临界压力（Pc=22.1MPa）以上的区域称为“超临界水”。尽管超临界水具有极高的反应性和 溶解能 力，但需要使用昂贵的耐腐蚀合金作为设备材料。 相对而言，普通不锈钢材料可用于180-250℃的过热水，因此用 途广泛。使用 过热水的高分解力和溶解力来液化和溶解固体或分解有害物质的过程称为“水热处理”，而利用过热水的催化 能力合成有价值的 材料的过程被称为“水热合成”。水热处理在环境治理方面主要有如下表所示的用途。

表 水热处理的用途例

水的状态图

Detailed introduction:

The area above the critical temperature (Tc=374℃) and critical pressure (Pc=22.1MPa) of water is called "supercritical water". Although supercritical water has extremely high reactivity and dissolving power, it requires the use of expensive corrosion-resistant alloys as equipment materials. Relatively speaking, ordinary stainless steel materials can be used for superheated water at 180-250°C, so it has a wide range of uses. The process of using the high decomposition and dissolving power of superheated water to liquefy and dissolve solids or decompose harmful substances is called "hydrothermal treatment", and the process of using the catalytic ability of superheated water to synthesize valuable materials is called "hydrothermal" synthesis". Hydrothermal treatment mainly has applications as shown in the following table in terms of environmental governance.