Comparison of gas dehydration methods based on energy consumption

Abstract

This study compares three conventional methods of natural gas (Associated Natural Gas) dehydration to carry out the dehydration process and suitability of use on the basis of energy requirement. These methods are Triethylene Glycol (TEG) absorption, solid desiccant adsorption and condensation. Analyses performed were based on dehydration of Natural Gas saturated with 10³Nm³/h water content at a temperature range of -10^O C to 30^oC, and gas pressure variation between 7MPa and 20MPa. This analysis and study showed that energy required for all three processes decreases with increase in pressure, but condensation dehydration requires the least energy at high pressures. Results obtained shows that, both at high pressures and low pressures, TEG dehydration is most suitable and in cases where very low T_dew is required, solid desiccant adsorption is preferable. In conclusion, the findings in this paper will aid natural gas process design engineers to decide on what method to use base  on energy consumption and on the physical and chemical properties of the final products.

Keywords: Dehydration, Absorption, Desiccant, Condensation, Triethylene Glycol (TEG)