To maximize the benefit of energy utilization and to meet the demand of using liquefied petroleum gas in southern region and natural gasoline in country that has increased. PTT Public Company Limited has constructed PTT gas separation Plant unit 4 at Khanom district, Nakhon Si Thammarat province, which is the natural gas separation and processing industry, with a capacity of 230 million cubic feet per day. Construction began in 1994 and opened officially in 1996