Ethane recovery from natural gas

In 2005, Project on “Plant for ethane and NGL recovery from natural gas” with a capacity of 3.0 billion m³/year for LLC Orenburggazprom, aimed at reconstruction of the operating plant, was completed.

After reconstruction, the plant produces the following market products (per year) ethane fraction - 169 - 193 thousand tons.

• LPG - 70 - 144 thousand tons
• stripped natural gas - 2.77 - 2.82 billion m³

The plant enables to increase ethane production volume at Helium plant due to application of modern technologies. The recovery rates of target products are as follows: ethane – 94% and NGL up to 99.5%.

The gas processing technology is based on application of the following methods:

• gas pre-cooling by recovery of backflow cold and using of source gas as a heat-transfer fluid in the demethanizer
• adiabatic gas expansion in a turbo-expander
• absorption of target components by liquid methane
• separation and rectification of liquid hydrocarbons
• adsorption refining of ethane fraction from H₂S and CO₂ and LPG from mercaptans

The external cooling cycle is used only at ethane fraction production stage.

In accordance with the adopted processing technology, the production facility includes the following process units:

• source gas measuring point
• ethane and LPG recovery plants
• propane cooling unit
• fired heater unit
• flare system
• booster compressor workshop
• end products cleaning plant
• auxiliary departments including nitrogen storage, compressed air receivers, etc.

The major part of the equipment is manufactured at Russian factories. The share of imported equipment is about 10%.