Training of Refinery Units
مهر ۱۱, ۱۴۰۳
Butane Purification
مهر ۱۱, ۱۴۰۳
Ethane Refining Unit:
The purpose of this unit is to remove carbon dioxide and water from ethane gas. The feedstock is sour ethane gas from Unit 105, and the product is dry ethane for export to petrochemical plants.
In this unit, the carbon dioxide and water present in the dry ethane, which comes from Unit 105, are removed. Carbon dioxide is eliminated in the first stage in an absorption tower using a chemical absorption process with DEA (Diethanolamine). The rich DEA obtained is regenerated in a regeneration tower and returned to the absorption tower, while ethane is finally dried using molecular sieves.
This unit consists of several main sections:
1. Absorption Section:
Before the gas enters the absorption tower, all condensates present in the gas are removed, and then the gas flows into the absorption tower. The absorption tower operates at a pressure of approximately 23.4 bar and a temperature range of 37°C to 57°C.
2. Regeneration Section:
The rich amine, after being preheated by a heat exchanger, enters the regeneration tower. This tower operates at pressures between 0.9 and 1.2 bar, with a lower temperature of approximately 130°C. The goal of this tower is to break the bonds between CO2 and the rich amine using heat.
3. Dehydration Section:
The ethane gas becomes wet in the absorption tower, and this moisture must be removed from the gas. Therefore, the gas is sent to the dehydration section, which consists of two molecular sieve towers. As the gas passes through the molecular sieve beds, moisture is absorbed, and the gas is dried. A portion of the gas is transferred for export, while about 7% of the flow rate is used for regenerating the beds; this portion is initially heated in a furnace and then enters the dryers to vaporize the absorbed water on the surface of the molecular sieve. Finally, after regeneration and drying, the gas is cooled with an air cooler and is returned to the main gas line through two compressors.
Light Amine Filtration Unit:
This unit consists of several different types of filters that are used to purify the amine from solid and liquid impurities and is very similar to the setup of Unit 101.
