The key difference between refining and fractional distillation is that refining distillation involves the separation of various components of petroleum, whereas fractional distillation involves the separation of hydrocarbons upon their liquefaction at different temperatures in different fractions.
Refining distillation and fractional distillation are industrial processes that are useful in the separation of different substances from mixtures.
CONTENTS
1. Overview and Key Difference
2. What is Refining Distillation
3. What is Fractional Distillation
4. Refining vs Fractional Distillation in Tabular Form
5. Summary – Refining vs Fractional Distillation
What is Refining Distillation?
Refining distillation is the refining process of petroleum which is a chemical engineering process. It usually uses other facilities that are used in a petroleum refinery in transforming crude oil into important products such as LPG (liquified petroleum gas), gasoline or petrol, diesel, kerosene, and fuel oils.
A refinery is a large industrial complex that involves a large number of processing units and auxiliary facilities, including units and storage tanks. Moreover, each of these refineries has a unique arrangement and combinations of different refining processes.
The major components in a refining distillation process include a crude oil distillation unit, vacuum distillation, naphtha hydrotreater, catalytic reforming unit, alkylation unit, isomerization unit, distillate hydrotreater, Merox, amine gas treater, fluid catalytic cracking, hydrocracking, visbreaker, and delayed coking. Besides, there are auxiliary processing units such as steam reforming, sour water strippers, utility units including cooling towers, wastewater collection systems, LPG storage vessels, and storage tanks for crude oil and finished products.
What is Fractional Distillation?
Fractional distillation is a technique useful in separating the hydrocarbon fractions in crude oil. In this process, we can separate different hydrocarbons according to the differences between their boiling points. We call this separation process “fractionation”.
When considering the process, first, we should heat the crude oil to very high temperatures and pressures. As a result, crude oil starts to vaporize. The vapor enters the fractional distillation column. There is a temperature gradient along the column (the bottom has a high temperature, and the top is cold). Since the vapor moves upwards in the column, vapor cools down. At the point where the temperature of the column is equal to the boiling point of a hydrocarbon in a vapor, that hydrocarbon tends to condense. Since the distillation column has several plates at different distances, we can collect the condensed vapor as liquids from these plates.
What is the Difference Between Refining and Fractional Distillation?
Refining and fractional distillation are two different types of distillation methods. The key difference between refining and fractional distillation is that refining distillation involves the separation of various components of petroleum, whereas fractional distillation is the separation of hydrocarbons upon their liquefaction at different temperatures in different fractions. Moreover, refining distillation involves a transformation, whereas fractional distillation involves fractionation.
Below is a summary of the difference between refining and fractional distillation in tabular form for side-by-side comparison.
Summary – Refining vs Fractional Distillation
Refining distillation is the refining process of petroleum which is a chemical engineering process, and it usually uses other facilities that are used in a petroleum refinery to transform crude oil into important products. Fractional distillation is a technique useful in separating the hydrocarbon fractions in crude oil. The key difference between refining and fractional distillation is that refining distillation involves the separation of various components of petroleum, whereas fractional distillation is the separation of hydrocarbons upon their liquefaction at different temperatures in different fractions.
Reference:
1. “Refining Process against Impurities: Oil Refining Process: Chemistry.” BYJU’S, 2 Aug. 2022.
2. Helmenstine, Anne Marie. “Learn What Distillation Means in Chemistry.” ThoughtCo, ThoughtCo.
3. “Petroleum Refining Process.” Wikipedia. Wikipedia Foundation.
Image Courtesy:
1. “Anacortes Refinery 31911” By Walter Siegmund (talk) – Own work (CC BY 2.5) via Commons Wikimedia
2. “RefineryFlow” (CC0) via Commons Wikimedia