What is a supercritical substance, and what is a supercritical state?

There are three phases of any substance--- gas, liquid, and solid. The point where the three phases coexist in equilibrium is called the three-phase point. The point where the liquid and gas phases are in equilibrium is called the critical point.

The temperature and pressure at the critical point are called the critical temperature and critical pressure. Different substances require different pressures and temperatures at their critical points. A state that is above the critical temperature and pressure and close to the critical point is called a supercritical state.

will disappear. Definition of supercritical fluid.

If you increase the temperature and pressure to observe the change of state, it will be found that if you reach a specific temperature and pressure, the interface between liquid and gas will disappear The point is called the critical point, and near the critical point, there will be a sharp change in the physical properties of all fluids such as the density, viscosity, solubility, heat capacity, and dielectric constant.

Liquids with temperature and pressure above the critical point are called supercritical fluids

Fluid, abbreviated as SCF). For example, when the temperature and pressure of water rise to a critical point (t=, p=

MPA), it is in a new fluid supercritical state that is different from the gaseous state and different from the liquid and solid state, and the water in this state is called supercritical water.

Properties of supercritical fluids.

Supercritical fluids disappear due to the separation between liquids and gases, and are non-condensable gases that do not liquefy even if the pressure is increased. The physical properties of supercritical fluids are both liquid and gaseous. It is still basically a gaseous state, but it is a dense gaseous state unlike ordinary gases.

Its density is two orders of magnitude greater than that of ordinary gases, and it is similar to that of liquids. Its viscosity is smaller than that of liquids, but its diffusion rate is faster than that of liquids (about two orders of magnitude), so it has better fluidity and transfer properties. Its dielectric constant changes sharply with pressure (e.g., an increase in dielectric constant is conducive to the dissolution of some substances with high agglomerate polarity).

In addition, depending on the pressure and temperature, this physical property changes.

The solubility of a substance in a supercritical fluid is greatly affected by pressure and temperature. Heating and depressurization (or both) can be used to separate and precipitate the dissolved substances in the supercritical fluid to achieve the purpose of separation and purification (it has the functions of both distillation and extraction of two spikes).For example, under high pressure conditions, the supercritical fluid is in contact with the material, and the high-efficiency components in the material (i.e., solute) are dissolved in the supercritical fluid (i.e., extraction).

After separation, the pressure of the solute-dissolved supercritical fluid is reduced, and the solute is precipitated. If there is more than one active ingredient (solute), a step-by-step depressurization can be taken to precipitate a variety of solutes step by step. There is no phase change during the separation process and the energy consumption is low.

A supercritical state is a state in which a substance is above a critical temperature and pressure.

Ultra-lead consequence critical (SC).

Supercritical units and ultra-supercritical units of thermal power plants refer to the pressure of working fluid in the boiler. The working fluid in the boiler is water, and the critical pressure of water is: , the critical temperature is; At this pressure and temperature, the density of water and steam is the same, it is called the critical point of water, the working fluid pressure in the furnace is lower than this pressure, Huaipei is called subcritical boiler, greater than this pressure is supercritical boiler, the steam temperature in the furnace is not less than 593 or the steam pressure is not less than 31 MPa is called ultra-supercritical.

At present, in engineering, it is often referred to as ultra-supercritical above 25MPa.

The supercritical unit of thermal power plant and the supercritical unit of supercritical unit refer to the pressure of the working fluid in the boiler. The working fluid in the boiler is water, and the critical pressure of the water is as follows: , the critical temperature is; At this pressure and temperature, the density of water and steam is the same, which is called the critical point of water, and the pressure of the working fluid in the furnace is lower than this pressure, which is called the subcritical boiler

What does the state of the ant be a supercritical fluid sail to tease and bury?