【Q&A Question 187】2017.07.06
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This post was last edited by liuquan1100 on 2017-8-7 22:08. [Q&A Question 187] 2017.07.06: What is the difference between fractionation and distillation? The reference answers will be visible after responding; points are awarded by identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Note: For questions of the type \"one question per day,\" if a person replies continuously for a month, that is, posts more than 30 times, their score will be assigned as 2 points, which is the lowest possible score. Click once to reply; if multiple replies are made, points will be awarded as appropriate, as deleting posts is also a waste of time. Both fractional distillation and distillation achieve separation through vaporization and condensation. Distillation uses partial vaporization or partial condensation to separate the mixture to achieve a certain degree of purity ； Distillation, on the other hand, uses multiple vaporizations and condensations to achieve a higher degree of purity in the separation of mixtures. Scoring criteria: 2 Wealth points for incorrect attempts; 3–8 points for *incomplete* answers. 10 Wealth points for correct answers, provided along with a detailed explanation; 15–20 Wealth points if the answer is correct but lacks sufficient details. Please score according to these criteria. Note: If there are editing records after answering, only points will be awarded to those who participated. For continuous malicious spamming, 2 points will be deducted each time, with no upper limit. Pure numbers, pure emojis, or random letters that have no relation to the answer are all considered malicious spamming; points will start to be deducted after three warnings. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html Petrochemical Zone – “Creative Ideas for Energy Saving” campaign (the second phase is in full swing) http://bbs.hcbbs.com/thread-1666758-1-1.html (Source: Haichuan Chemical Industry Forum)
Distillation is a physical process; no new substances are formed, only the existing substances are separated. The main difference between distillation and fractional distillation is that distillation involves only one process of vaporization and condensation; the substances obtained are generally quite pure. For example, distilled water is produced by using natural water, while anhydrous ethanol is obtained by adding quicklime to industrial alcohol and then distilling it ； Fractionation involves multiple successive processes of vaporization and condensation; the substances obtained are still mixtures, only with different boiling point ranges. For example, when petroleum is subjected to atmospheric and vacuum fractionation, several fractions with varying boiling point ranges can be obtained.
Fractionation is the process of separating mixtures that contain two or more substances; it is a simple and rough method of separation with low precision； Distillation is a process that separates mixtures of multiple components through repeated heating and cooling
The distillation process and the fractional distillation process are essentially the same; in organic and inorganic chemistry, fractional distillation is generally used, while in the principles of chemical engineering and physical chemistry, distillation is the term applied. In industry, distillation is utilized to separate several substances with similar boiling points
Fractionation: The boiling ranges of the various products are wide, and there are significant differences in boiling points among the different components; therefore, the fractionation process involves gradual vaporization and gradual condensation, resulting in a relatively coarse separation process. Distillation: The boiling ranges of the various products are narrow, and the boiling points of the different components are close to each other; therefore, the distillation process involves multiple stages of vaporization and condensation, resulting in a very precise separation process.
Fractionation, also known as distillation, involves multiple contacts between the vapor and liquid phases under the condition of providing reflux, thereby enabling mass and heat transfer between the phases and allowing for the effective separation of the various components in a volatile mixture. The principle of distillation is based on the different boiling points and relative volatilities of components in a mixture. Under certain conditions, each component in the mixture establishes its own equilibrium between the vapor and liquid phases. The unbalanced vapor and liquid phases undergo heat exchange; part of the vapor condenses and part of the liquid vaporizes, thereby achieving separation of the vapor and liquid phases.
Fractionation: The boiling ranges of the various products are wide, and there are significant differences in boiling points among the different components; therefore, the fractionation process involves gradual vaporization and gradual condensation, resulting in a relatively coarse separation process. Distillation: The boiling ranges of the various products are narrow, and the boiling points of the different components are close to each other; therefore, the distillation process involves multiple stages of vaporization and condensation, resulting in a very precise separation process.
Fractionation: The boiling ranges of the various products are wide, and there are significant differences in boiling points among the different components; therefore, the fractionation process involves gradual vaporization and gradual condensation, resulting in a relatively coarse separation process. Distillation: The boiling ranges of the various products are narrow, and the boiling points of the different components are close to each other; therefore, the distillation process involves multiple stages of vaporization and condensation, resulting in a very precise separation process.
Fractionation is for separation and recovery, while distillation is for separation without recovery
Both fractional distillation and distillation achieve separation through vaporization and condensation. Distillation uses partial vaporization or partial condensation to separate the mixture to achieve a certain degree of purity ； Distillation, on the other hand, uses multiple vaporizations and condensations to achieve a higher degree of purity in the separation of mixtures.