What are the characteristics of fractionation?

Question 1: What are the characteristics of fractionation? Distillation and fractionation are both methods to separate liquid mixtures.

Distillation and fractionation both make use of the different boiling points of the components in the liquid mixture. By controlling the temperature and heating, a part of the substance is vaporized, then condensed and liquefied and collected, and the other part is left in the original device.

Distillation and dry distillation are both physical processes, which do not produce new substances, but only separate the original substances.

The main difference between distillation and fractionation is that distillation only evaporates and condenses once, and the separated substances are generally pure. For example, distilled water is made of natural water, and anhydrous ethanol is distilled after adding quicklime to industrial alcohol.

Fractionation requires many times of continuous vaporization and condensation, and the separated substances are still mixtures with different boiling points. For example, after atmospheric and vacuum distillation of petroleum, a variety of fractions with different boiling points can be obtained.

There is no essential difference between distillation and fractionation. It is in this sense that fractionation is the application of distillation principle.

Dry distillation is a processing method of decomposing wood and coal by strengthening heat under the condition of isolating air. After dry distillation, the composition and aggregation state of raw materials will change, and there are solid, gaseous and liquid substances in the products.

Charcoal, wood tar and wood gas can be obtained by dry distillation of wood;

Coke, coal tar, crude ammonia and coke oven gas can be obtained by dry distillation of coal. Dry distillation is a chemical process.

Question 2: The difference between fractionation and distillation, and dry distillation. Distillation: Using the different boiling points of substances, the substances with low boiling points are first gasified and then condensed into liquid, so as to separate and purify the substances.

Fractionation: distillation is carried out for many times by using the principle of distillation to separate out various substances. For example, the fractionation of petroleum.

Dry distillation: the process of isolating air and strengthening heat, causing complex physical and chemical changes and decomposition of substances. For example, dry distillation of coal.

The biggest difference

Distillation and fractionation are physical changes.

Dry distillation is a chemical change.

Question 3: You still can't log in to Baidu mp3 after registration. Why? How to fill in the domain name? MP3 can log in without a user name and password.

As long as your computer can surf the internet, it's OK!