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.