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CN-121971957-A - Energy-saving triethylene glycol dehydration system

CN121971957ACN 121971957 ACN121971957 ACN 121971957ACN-121971957-A

Abstract

The invention belongs to the technical field of natural gas dehydration, and discloses an energy-saving triethylene glycol dehydration system, wherein raw material gas is introduced into an absorption tower to remove water from triethylene glycol lean solution, the formed dry gas is introduced into a dry gas purification separator to separate liquid, high-efficiency dehydration is realized, the formed product gas is divided into two parts, one part of the product gas is delivered to the outside after being depressurized, the other part of the product gas enters an expander to apply work and drive a generator to generate power without external energy input, the energy-saving and environment-friendly requirements are met, a reboiler is arranged at the bottom of a regeneration tower, a generator is electrically connected with the reboiler, the triethylene glycol rich solution formed in the absorption tower is sequentially introduced into a coil pipe at the top of the regeneration tower to be heated, the flash evaporation is carried out in a flash evaporator, the lean rich solution heat exchanger exchanges heat with the hot triethylene glycol lean solution, distilled water in a rectifying column at the middle part of the regeneration tower is regenerated into hot triethylene glycol lean solution, and the hot triethylene glycol lean solution is introduced into the lean solution heat exchanger to exchange with the triethylene glycol rich solution, and the energy utilization rate is improved.

Inventors

  • Lou juan
  • CHEN JIAN
  • WANG YU
  • LIU ZIPENG
  • LIU JIAN

Assignees

  • 博思特能源装备（天津）股份有限公司
  • 北京东方华智石油工程有限公司

Dates

Publication Date
20260505
Application Date
20260311

Claims (10)

  1. 1. An energy efficient triethylene glycol dehydration system comprising: The dehydration assembly comprises an absorption tower (11) and a dry gas purification separator (12), wherein raw gas is introduced into the absorption tower (11) to remove water from triethylene glycol lean solution, the formed dry gas is introduced into the dry gas purification separator (12) to separate liquid, and the formed product gas is divided into two streams, wherein one stream of product gas is subjected to depressurization and then is conveyed outwards; The power generation assembly comprises an expander (21) and a generator (22) which are connected, wherein the other strand of product gas enters the expander (21) to do work and drives the generator (22) to generate power; the regeneration assembly comprises a regeneration tower (31), a flash evaporator (32) and a lean-rich liquid heat exchanger (33), wherein a coil (311) is arranged at the top of the regeneration tower (31), a rectifying column (312) is arranged at the middle part of the regeneration tower (31), a reboiler (313) is arranged at the bottom of the regeneration tower (31), a generator (22) is electrically connected with the reboiler (313), triethylene glycol rich liquid formed in the absorption tower (11) is sequentially introduced into the coil (311) for heating, flash evaporation is carried out in the flash evaporator (32), heat exchange is carried out between the lean-rich liquid heat exchanger (33) and hot triethylene glycol lean liquid, and distilled water in the rectifying column (312) is regenerated into the hot triethylene glycol lean liquid, and the hot triethylene glycol lean liquid is introduced into the lean-rich liquid heat exchanger (33) for heat exchange with the triethylene glycol rich liquid.
  2. 2. The energy-saving triethylene glycol dehydration system according to claim 1, wherein the absorption tower (11) is provided with a gas inlet and a liquid inlet, the liquid inlet is positioned above the gas inlet, the raw material gas is introduced into the gas inlet, and the triethylene glycol lean solution is introduced into the liquid inlet.
  3. 3. An energy efficient triethylene glycol dehydration system according to claim 1 wherein the dehydration assembly further comprises a filter separator (13) arranged upstream of the absorber tower (11), the filter separator (13) being for filtering impurities in the feed gas.
  4. 4. An energy efficient triethylene glycol dehydration system according to claim 1 wherein the dehydration assembly further comprises a gas-liquid heat exchanger (14) arranged between the absorber column (11) and the dry gas purification separator (12), the dry gas exchanging heat with the hot triethylene glycol lean liquid in the gas-liquid heat exchanger (14).
  5. 5. An energy-efficient triethylene glycol dewatering system according to claim 1, characterized in that the top of the absorption tower (11) is provided with a wire mesh mist catcher for removing glycol droplets larger than 5 μm in the dry gas.
  6. 6. The energy-efficient triethylene glycol dehydration system of claim 1 wherein the product gas output after depressurization is 10% -20%.
  7. 7. An energy-efficient triethylene glycol dehydration system according to claim 1, wherein the liquid return port of the dry gas purification separator (12) communicates with a coil (311) in the regeneration tower (31).
  8. 8. An energy-efficient triethylene glycol dehydration system according to claim 1 wherein the bottom of the regeneration column (31) is in communication with a buffer tank (34), said hot triethylene glycol lean solution is stored in said buffer tank (34), and said buffer tank (34) is in communication with said lean rich solution heat exchanger (33).
  9. 9. The energy-saving triethylene glycol dehydration system according to claim 4, wherein a circulating pump (35) is arranged between the lean-rich liquid heat exchanger (33) and the gas-liquid heat exchanger (14), the circulating pump (35) is used for pumping the hot triethylene glycol lean liquid into the gas-liquid heat exchanger (14), and the generator (22) is electrically connected with the circulating pump (35).
  10. 10. The energy-saving triethylene glycol dehydration system according to claim 4, further comprising a triethylene glycol storage tank (36), wherein the triethylene glycol storage tank (36) stores a triethylene glycol lean solution, a liquid supplementing pump (37) is arranged between the triethylene glycol storage tank (36) and the gas-liquid heat exchanger (14), the liquid supplementing pump (37) is used for pumping the triethylene glycol lean solution into the gas-liquid heat exchanger (14), and the generator (22) is electrically connected to the liquid supplementing pump (37).

Description

Energy-saving triethylene glycol dehydration system Technical Field The invention relates to the technical field of natural gas dehydration, in particular to an energy-saving triethylene glycol dehydration system. Background In the traditional natural gas triethylene glycol dehydration process, wet raw material gas is dehydrated into product gas through an absorption tower, and the ethylene glycol-rich solution is recycled through high-temperature rectification in a regeneration system. The energy consumption and the emission problems of the existing dehydration process are outstanding, the reboiler is used as core heat source equipment of a regeneration system, direct combustion of external fuel is usually relied on for heat supply, primary energy is continuously consumed, tail gas such as carbon dioxide is discharged, green low-carbon production requirements are difficult to meet, dehydrated high-pressure product gas is required to be reduced in pressure by a throttle valve before being output, the process causes waste of pressure energy contained in the high-pressure product gas, and the energy utilization efficiency of the whole system is low. Disclosure of Invention The invention aims to provide an energy-saving triethylene glycol dehydration system which can efficiently dehydrate and recover the pressure energy of product gas, does not need external energy input, is energy-saving and environment-friendly, and meets the requirements of green low carbon. To achieve the purpose, the invention adopts the following technical scheme: An energy efficient triethylene glycol dehydration system comprising: the dehydration assembly comprises an absorption tower and a dry gas purification separator, raw material gas is introduced into the absorption tower to remove water from triethylene glycol lean solution, the formed dry gas is introduced into the dry gas purification separator to be separated into two streams, and one stream of product gas is subjected to depressurization and then is output; The power generation assembly comprises an expander and a generator which are connected, and the other strand of product gas enters the expander to do work and drives the generator to generate power; The regeneration assembly comprises a regeneration tower, a flash evaporator and a lean-rich liquid heat exchanger, wherein a coil is arranged at the top of the regeneration tower, a rectifying column is arranged at the middle part of the regeneration tower, a reboiler is arranged at the bottom of the regeneration tower, the generator is electrically connected with the reboiler, triethylene glycol rich liquid formed in the absorption tower is sequentially introduced into the coil for heating, flash evaporation is carried out in the flash evaporator, heat exchange is carried out between the lean-rich liquid heat exchanger and hot triethylene glycol lean liquid, and distilled water in the rectifying column is regenerated into the hot triethylene glycol lean liquid, and the hot triethylene glycol lean liquid is introduced into the lean-rich liquid heat exchanger for heat exchange with the triethylene glycol rich liquid. Preferably, the absorption tower is provided with a gas inlet and a liquid inlet, the liquid inlet is positioned above the gas inlet, the raw material gas is introduced into the gas inlet, and the triethylene glycol lean solution is introduced into the liquid inlet. Preferably, the dehydration module further comprises a filter separator disposed upstream of the absorption tower, the filter separator being used for filtering impurities in the raw gas. Preferably, the dehydration assembly further comprises a gas-liquid heat exchanger arranged between the absorption tower and the dry gas purification separator, and the dry gas exchanges heat with the hot triethylene glycol lean solution in the gas-liquid heat exchanger. Preferably, a wire mesh mist catcher is arranged at the top of the absorption tower and is used for removing glycol liquid drops with the size larger than 5 mu m in the dry gas. Preferably, the product gas which is externally delivered after depressurization accounts for 10-20%. Preferably, the liquid return port of the dry gas purification separator is communicated with a coil pipe in the regeneration tower. Preferably, the bottom of the regeneration tower is communicated with a buffer tank, the hot triethylene glycol lean solution is stored in the buffer tank, and the buffer tank is communicated with the lean-rich solution heat exchanger. Preferably, a circulating pump is arranged between the lean-rich liquid heat exchanger and the gas-liquid heat exchanger, the circulating pump is used for pumping the hot triethylene glycol lean liquid into the gas-liquid heat exchanger, and the circulating pump is electrically connected with the circulating pump. Preferably, the energy-saving triethylene glycol dehydration system further comprises a triethylene glycol storage tank, wherein the triethylene glycol