ABSTRACT
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.
ABSTRACT
Given the drawbacks of the traditional MDEA absorption process, we introduced a hydrate-based gas separation approach. Then, to study the effectiveness of this method, we performed some hydrating experiments demonstrating that energy consumption could be remarkably reduced. However, the acid components (H2S and CO2) in the product gas failed to meet the specification requirements of the sales gas. Consequently, a new technique was developed that integrated hydrate-based gas separation and chemical absorption for the sweetening of natural gas with high H2S and CO2 contents. To evaluate the performance of this new integrated method, technical comparisons based on simulation and experimental data were conducted. The results showed that the new integrated method could effectively remove sour components, which resulted in the product gas being able to meet the sales gas specifications. Additionally, the integrated technique consumed much less energy than the traditional MDEA absorption process and its amine regeneration duty was only 42% that of the MDEA method. What is more, upon an economical evaluation being performed, it was shown that the integrated technique tremendously reduced the investment and operating cost.
