1. Preparation: Crude oil, a complex mixture of hydrocarbons, is heated to a high temperature in a furnace to vaporize its components.
2. Introduction: The vaporized crude oil is introduced into the bottom of the fractionating column, which contains a series of horizontal trays or plates.
3. Condensation and Separation: As the vapor rises up the column, it encounters cooler temperatures at different levels. Each component in the crude oil has a specific boiling point, and when the vapor reaches a temperature below its boiling point, it condenses back into a liquid. Different components condense at different heights in the column.
4. Trays or Plates: The trays or plates inside the column are designed to increase the contact surface area between the rising vapors and the condensed liquids. This allows for better separation and prevents mixing of different components.
5. Reboiling and Recycling: Some of the condensed liquids on the trays may still contain lighter components. To ensure complete separation, these liquids are partly re-vaporized by flowing them back down the column. This process helps in further separating the components and sending them to their respective sections of the column.
6. Product Withdrawal: At specific heights in the column, there are outlets or draw-off points where the separated components are withdrawn as different fractions. These fractions are further processed or sent to storage tanks.
7. Cooling: At the top of the fractionating column, a condenser cools and collects the lightest components that vaporized at the lowest temperatures. These typically include gases such as methane and ethane.
By manipulating the temperature and pressure inside the column, the various components of crude oil are separated based on their different boiling points. This process allows refineries to obtain different products with specific properties and compositions from a single source of crude oil.
