Ethane Separation Unit
مهر ۵, ۱۴۰۳
Aspen Hysys Simulation of MEROX Unit
مهر ۵, ۱۴۰۳
Purpose and Feedstock Specifications
The NGL Gas Separation Unit is designed to produce propane, butane, and C5+. Incoming feedstock consists of C3+ from Unit 105, with a pressure of 21.8 bar and a temperature of 93 degrees Celsius. Final products include propane, which is sent to Unit 114; butane, directed to Unit 115; and C5+, which goes to Units 103 and 110.
Separation Process
This unit contains two main distillation columns for the separation of propane and butane. Liquid propane, liquid butane, and C5+ are separated through a distillation process in these two columns. The separated C5+ is mixed with the gas condensates from Unit 103, and then the sweetened butane and propane are exported.
Key Components of the Unit
The unit comprises two major sections:
- Propane Column (Depropaniser)
- Butane Column (Debuthaniser)
Due to the vapor pressure differences of the various C3+ components, heat is utilized for their separation. The feedstock enters the 21st tray of the propane column, which has 32 trays. This column is equipped with a reflux drum and a reboiler.
Operating Conditions of the Propane Column
- Lower Temperature: 138 degrees Celsius
- Lower Pressure: 21.6 bar
- Upper Pressure and Temperature: 21.3 bar and 62.5 degrees Celsius
In the reboiler, low-pressure steam is used for heating. The propane gas exits from the top of the column and is condensed in an air cooler, subsequently being sent to the reflux drum to enhance product purity.
Transfer to the Butane Column
C4+ is transferred from the bottom of the propane column to the butane column. The feed for this column enters through the 17th tray (which has 28 trays). Other operations are similar to those of the propane column.
Operating Conditions of the Butane Column
- Lower Temperature: 130 degrees Celsius
- Upper Temperature: 62.5 degrees Celsius
- Pressures: 7.2 bar and 5.7 bar
Butane is cooled with seawater down to 40 degrees Celsius. Additionally, C5+ is cooled in an air cooler down to 60 degrees Celsius before being sent to Unit 103.
