Application of triglycol dehydration technology in Yuanba gas field purification unit

According to the wet purified gas with a water molar fraction about 0.09% and the volume flow between 96×10³ m³ and 106×10³ m³, the TEG circulation rate is between 2.50 t/h and 2.85 t/h, and the water dew point of the exported product gas is below -19 ℃, which meets the water dew point requirements. When the steam consumption of TEG reboiler was between 529 kg/h and 549 kg/h, the TEG mass fraction increased from 96.9% to 99.7% after regeneration. In order to avoid the process defects such as unstable TEG regenerative heat source, serious scaling of poor solvent post-cooled tube heat exchanger, the dehydration process was optimized: (1) The self-produced 3.8 MPa medium-pressure steam was used as heat source to ensure stable TEG regeneration temperature and make it easy to adjust. The relation curve between the steam consumption and TEG reboiler temperature was fitted to provide a reference for adjustment. (2) The direct flash process without preheating of rich TEG was adopted to reduce the preheating process of rich liquid and remove most of light hydrocarbon components in rich TEG, so as to reduce energy consumption and cost while meeting the requirements of dehydration unit. (3)The TEG lean liquid after-cooler from shell and tube heat exchanger was replaced to corrugated plate heat exchanger made of stainless steel. The heat exchanger ran smoothly for a long time and the replacement frequency of heat exchanger accessories reduced.