Advantages and disadvantages of liquid-solid extraction method

Liquid-solid extraction, also known as solid-liquid extraction, has the following advantages and disadvantages:

First, advantages

1, widely used.

The application fields of solid-liquid extraction are more and more extensive, such as extracting edible oil from plant seeds, extracting Chinese herbal medicine preparations from various plants, producing instant coffee, food seasonings and food additives.

2, the solvent is easily available

Solid-liquid extraction method is to use solvents to dissolve soluble substances in solid substances and separate them. Water is the most commonly used solvent for liquid-solid extraction.

Second, disadvantages: First of all, raw materials should be pretreated.

Almost all solid-liquid extraction requires pretreatment of raw materials, which are generally crushed into fine particles or sheets. The useful component (solute) in the material is dispersed in the insoluble solid (carrier), and the solvent and solute must pass through the pores of the carrier before the solute can be transferred to the solution outside the solid.

Liquid-liquid extraction:

Liquid-liquid extraction is a process of separating and extracting components in liquid mixtures with solvents. The selected solvent which is immiscible (or slightly miscible) with the liquid mixture is added, and the purpose of separation or extraction is achieved by using the solubility difference of its components in the solvent. For example, benzene is used as solvent to separate phenol from coal tar, and isopropyl ether is used as solvent to recover acetic acid from dilute acetic acid solution.

This is done in the laboratory with instruments such as a separatory funnel. It is industrially carried out in packed tower, sieve plate tower, centrifugal extractor and spray extractor. Used in organic chemistry, petroleum, food, pharmacy, rare elements, atomic energy and other industries.