Optimizing Effective Absorption during Wet Natural Gas Dehydration by Tri Ethylene Glycol

Abstract

Effective dehydration of sales gas is the primary concern before its transmission over a long distant pipeline. The most common and efficient dehydration system is based on the counter-current absorption by TEG (Tri Ethylene Glycol). This paper deals with the problems that generally occur during the dehydration process. In a mission to find out the optimization for a troubled and unstable TEG dehydration system, this paper describes some common problems such as inappropriate TEG circulation rate, deposition waxy material formation in the internal tray assembly, higher hydrocarbon content in rich TEG, TEG loss and the solutions have been discussed with results. A simulator has been used to find out some results theoretically. Finally there were some recommendations to avoid additional problems in dehydration. I. Introduction The last 35 years have seen a remarkable growth in the contribution of gas to the world's total primary energy demand. Almost every country in the south Asia are dependent on the natural gas as it satisfies the majority if the country's demand. Natural gas from production is generally associated with crude oil and water. In a natural gas processing plant, the primary separation is occurred in the 3 phase high pressure separator where natural gas, condensate, and water are separated. However, after the primary separation substantial amount of water remains present in the wet gas that needs to be dehydrated further. It is necessary to prevent the condensation of liquid water and hydrocarbons to ensure trouble-free operation of a natural gas transmission system. There is always a risk of hydrate formation which eventually results condensate accumulation in pipeline and increase in operating pressure. Every transmission company has a sales gas criterion that includes total liquefiable and water content in the sales. Dehydration of natural gas is the removal of the water that is associated with natural gases in vapor form. The natural gas processing plant includes a dehydration system that could be either refrigeration system or countercurrent absorption system. This paper deals with the dehydration system that is driven by Tri Ethylene glycol.