Case 10 Gas Separation Plant in Thailand

Thailand s sole producer of methane, propane, and LNG/NGL is operating at least four gas separation plants. From these state-owned sites, the company supplies more than 90% of its production to the domestic market. A small percentage of NGL is exported. 

The various plants each have a daily input capacity of natural gas of 220-350 MMcfd. All operate 24 hours a day, providing an estimated total daily production capacity of 1,000 MMcf of methane, 1,450 t of ethane, 1,414 t of propane, 2,670 t of LPG and 5,700 bbl of NGL. 

A vital part of the process system for each of the plants includes a turboexpander-compressor set. This turbomachinery string has two main functions. The first function reduces the pressure and temperature of the incoming gas to facilitate separation of the methane. The second function raises the pressure of the methane after it leaves the fractionation tower and is transferred directly to the customers through an underground pipeline. 

The oldest of the various systems was commissioned when the plant first opened in 1985 it has been operating continuously 24 hours a day. The turboexpander-compressor set has proved its durability, requiring only lube oil skid maintenance prior to its first overhaul after many years of operation. 

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