Technical, Economical, and Environmental Performance Assessment of an Improved Triethylene Glycol Dehydration Process for Shale Gas

We proposed an optimized triethylene glycol (TEG) dehydration approach in this work, with the aim of overcoming the drawbacks of traditional TEG dehydration method for shale gas processing and providing a more efficient, simplified, energy-saving, economical, and environmentally friendly technology dedicated for shale gas exploration. The proposed improved TEG dehydration method has less equipment and is convenient for modularization, which is of great significance and convenience to applications in the shale gas dehydration station. Additionally, it has some remarkable improvements on process optimization as well as the rational utilization of utilities. To evaluate the performance of this improved method, thermodynamics and economy were assessed in this study. The results proved that the new proposed method was an applicable and efficient technology. Moreover, in comparison to the conventional TEG dehydration method, the new method is more energy saving and economical. The energy-saving amount is especially high with a large feed capacity, and it reaches up to about 3000 MJ/h when the feed gas flowrate is 210 MMscfd. The capital cost (CapEx) and operation cost (OpEx) of the new proposed dehydration method are significantly lower, which represent only 56.9 and 47.8% those of the conventional method, respectively. Besides, sensitive analysis of the key parameters influencing system performance was performed to explore the energy-saving potential and to maximize the economic benefit. Additionally, an environmental assessment through a field-emission test was conducted, and the results showed that the new method exhibited superior environmental performance.