Design and Simulation of Dehydration Columns in Khangiran Gas Refinery

Natural gas as one of the most important energy sources is usually saturated with water when produced from the gas well. Water vapor increases the corrosive power of natural gas, especially in presence of sour gases. Of the various possible methods of drying the natural gas, using silica gel as an adsorbent is considered in this work because of its capability in providing very low dew points. The design procedure has been presented and analyzed here for four dehumidification columns that are used for dew point control of 260 MMSCFD of natural gas and the effect of various parameters has been investigated. A spreadsheet has also been presented that can be used for process simulation. The results of the hydraulic design procedure show an error of about 5 percent in adsorbent bed height and almost no error in the column internal diameter as compared with actual values.