Search

CN-122006401-A - Apparatus and process for low temperature regeneration of adsorbent materials

CN122006401ACN 122006401 ACN122006401 ACN 122006401ACN-122006401-A

Abstract

An apparatus and process that may be used for low temperature regeneration of an adsorption system may include feeding a low temperature regeneration gas to at least one off-line adsorber for regenerating an adsorbent material within a vessel of the off-line adsorber. The regeneration period may be set to promote regeneration of the adsorbent material without the need for high temperature regeneration to occur. Some embodiments may be configured such that post-cooling operations as the regeneration gas is fed to the adsorber may be avoided to allow embodiments to more efficiently utilize heating time.

Inventors

  • S. Gibson
  • C.R. Bongo
  • WU DINGJUN
  • Euseche Morales, J.E.

Assignees

  • 气体产品与化学公司

Dates

Publication Date
20260512
Application Date
20251110
Priority Date
20241112

Claims (20)

  1. 1. A process for operating an adsorption apparatus comprising: Feeding compressed gas to at least one first adsorber of an adsorption apparatus in an on-line state to remove one or more impurities from the compressed gas via an adsorbent material of the at least one first adsorber over a preselected purge period of time, and Feeding a regeneration gas to at least one second adsorber of the adsorption apparatus in an off-line state at a preselected regeneration temperature within a preselected regeneration low temperature range for a preselected regeneration period to heat the adsorbent material of the at least one second adsorber to the preselected regeneration temperature to regenerate the adsorbent material of the at least one second adsorber.
  2. 2. The process of claim 1, comprising: Switching the at least one first adsorber from the on-line state to the off-line state and switching the at least one second adsorber from the off-line state to the on-line state such that regeneration of the adsorbent material of the at least one second adsorber does not experience cooling before the at least one second adsorber is conditioned to the on-line state.
  3. 3. The process of claim 2, comprising: Feeding the compressed gas to the at least one second adsorber in the on-line state and the regeneration gas to the at least one first adsorber in the off-line state at a preselected regeneration temperature within the preselected regeneration low temperature range for the preselected regeneration period to heat the adsorbent material of the at least one first adsorber to a preselected regeneration temperature to regenerate the adsorbent material of the at least one first adsorber.
  4. 4. A process according to claim 3, comprising: Switching the at least one second adsorber from the on-line state to the off-line state and switching the at least one first adsorber from the off-line state to the on-line state such that regeneration of the adsorbent material of the at least one first adsorber does not experience cooling before the at least one first adsorber is conditioned to the on-line state.
  5. 5. The process of claim 3, wherein the flow rate of the regeneration gas and the preselected regeneration period are selected such that the difference between the temperature of the regeneration gas output from the adsorbent material of the at least one second adsorber in the off-line state and the temperature of the regeneration gas fed into the adsorbent material of the at least one second adsorber in the off-line state is no more than 30 ℃.
  6. 6. The process of claim 5, wherein the flow rate of the regeneration gas and the preselected regeneration period are selected such that a difference between a temperature of the regeneration gas output from the adsorbent material of the at least one first adsorber in the off-line state and a temperature of the regeneration gas fed into the adsorbent material of the at least one first adsorber in the off-line state is no more than 30 ℃.
  7. 7. The process of claim 1, wherein the preselected regeneration low temperature range is in the range of 50 ℃ to 120 ℃ and the preselected regeneration period is between 1 hour and 8 hours and less than or equal to the preselected purge period.
  8. 8. The process of claim 1, wherein the flow rate of the regeneration gas and the preselected regeneration period are selected such that the temperature of the regeneration gas when the regeneration gas is fed into the adsorbent material bed of the at least one second adsorber is no more than 30 ℃ different than the temperature of the regeneration gas when the regeneration gas is output from the adsorbent material bed.
  9. 9. The process of claim 1, wherein feeding the compressed gas to the at least one first adsorber and feeding the regeneration gas to the at least one second adsorber are performed such that a ratio of a molar flow rate of the regeneration gas fed to the at least one second adsorber to a molar flow rate of the compressed gas fed to the at least one first adsorber is between 0.1 and 0.4.
  10. 10. The process of claim 1, wherein feeding the compressed gas to the at least one first adsorber and feeding the regeneration gas to the at least one second adsorber are performed such that a ratio of a molar flow rate of the regeneration gas fed to the at least one second adsorber to a molar flow rate of the compressed gas fed to the at least one first adsorber is between 0.15 and 0.3.
  11. 11. The process of claim 1, comprising: the regeneration gas is fed through at least one regeneration gas heating device to heat the regeneration gas to a preselected regeneration temperature.
  12. 12. The process of claim 11, wherein the at least one regeneration gas heating device heats the regeneration gas with a low grade thermal waste stream as a heating medium, the low grade thermal waste stream having a temperature in the range of 50 ℃ to 140 ℃.
  13. 13. The process of claim 1, comprising: the compressed gas is fed as a heating medium to a primary regeneration gas heating device to heat the regeneration gas to a preselected regeneration temperature.
  14. 14. The process of claim 1, comprising: Feeding the regeneration gas through a primary regeneration gas heating device to heat the regeneration gas via a heating medium fed to the primary regeneration gas heating device, and The heated regeneration gas output from the primary regeneration gas is fed through a secondary regeneration gas heating device to heat the regeneration gas to a preselected regeneration temperature.
  15. 15. The process of claim 1, comprising: after removing the one or more impurities from the compressed gas, the compressed gas is cooled to a preselected heat exchanger feed temperature via an after-cooler device positioned between a heat exchanger and the first adsorber.
  16. 16. The process of claim 1, wherein the preselected regeneration low temperature range is in the range of 50 ℃ to 120 ℃.
  17. 17. An adsorption apparatus, comprising: a first adsorber adjustable between an on-line condition in which compressed gas is fed into a vessel of the first adsorber to contact a bed of adsorbent material to remove one or more impurities from the compressed gas, and an off-line condition in which regeneration gas is fed into the vessel of the first adsorber to contact the bed of adsorbent material of the first adsorber to desorb the one or more impurities from the bed of adsorbent material of the first adsorber to regenerate the bed of adsorbent material of the first adsorber, and A second adsorber adjustable between an on-line state in which the compressed gas is fed into a vessel of the second adsorber to contact a bed of adsorbent material of the second adsorber to remove one or more impurities from the compressed gas, and an off-line state in which a regeneration gas is fed into the vessel of the second adsorber to contact the bed of adsorbent material of the second adsorber to desorb the one or more impurities from the bed of adsorbent material of the second adsorber to regenerate the bed of adsorbent material of the second adsorber; At least one regeneration gas heating device positioned upstream of the first adsorber and the second adsorber to heat the regeneration gas to a preselected regeneration temperature within a preselected regeneration low temperature range for a preselected regeneration period.
  18. 18. The adsorption apparatus of claim 17, wherein the at least one regeneration gas heating device comprises a first regeneration gas heating device positioned to receive the compressed gas from a compression system as a heating medium to heat the regeneration gas and cool the compressed gas, the compression system positioned upstream of the first adsorber and also positioned upstream of the second adsorber.
  19. 19. The adsorption apparatus of claim 17, wherein the at least one regeneration gas heating device comprises a first regeneration gas heating device positioned to receive a heating medium to heat the regeneration gas and cool the heating medium, the heating medium being gas output from a heat exchanger or compressor positioned downstream of the first adsorber and also positioned downstream of the second adsorber.
  20. 20. The adsorption apparatus of claim 17, comprising: An after cooler device positioned to cool the compressed gas having the one or more impurities removed via the at least one first adsorber when the at least one first adsorber is in the on-line state to provide a heat exchanger feed at a preselected heat exchanger feed temperature, and to cool the compressed gas having the one or more impurities removed via the at least one second adsorber when the at least one second adsorber is in the on-line state to provide the heat exchanger feed at the preselected heat exchanger feed temperature.

Description

Apparatus and process for low temperature regeneration of adsorbent materials Technical Field The present invention relates to adsorbers, adsorption systems, processes for operating adsorption systems, and processes for regenerating adsorbent materials. Background The purification units typically utilize adsorbers that are typically in four different common configurations, vertical flow (vertical cross flow), horizontal, and radial. The purification unit may be configured for Temperature Swing Adsorption (TSA). Systems of TSA can be designed to remove components with high freezing points, such as ambient moisture (e.g., water vapor) and carbon dioxide (CO 2), which would otherwise freeze in downstream processing, resulting in operability problems such as plugging. Nitrous oxide (N2O), hydrocarbons, and other impurities may also be removed via front-end purification to avoid accumulation of these impurities in downstream processes. The purification unit may alternatively be configured for Pressure Swing Adsorption (PSA). Such systems may utilize a pressure cycle between low and high pressures to facilitate removal of impurities from the fluid and subsequent regeneration of the adsorbent material via release of the adsorbed impurities from the adsorbent material. Examples of adsorbers, adsorption systems, TSA systems, and PSA systems can be appreciated from U.S. patent nos. 3,531,916、4,472,178、4,541,851、4,784,672、5,137,548、5,232,474、5,425,240、5,614,000、5,759,242、5,846,295、5,855,650、5,914,455、5,917,136、6,086,659、6,106,593、6,152,991、6,471,749、6,506,236、6,599,347、6,866,075、6,984,258、7,022,159、7,225,637、7,264,651、7,285,154、7,413,595、8,206,669、8,262,783、8,268,044、8,404,024、8,518,356、8,734,571、8,814,985、9,108,145、9,199,190、9,463,434、9,631,864、9,731,241 and 11,137,205, U.S. patent application publication nos. 2011/0206581, 2011/0219950, 2019/0291078, and 2022/0001328, and canadian patent publication No. 2,357,276A. Disclosure of Invention Conventional PSA systems typically require large amounts of adsorbent material and/or short run times because the adsorbent material may not be adequately regenerated by the cyclic pressure swing utilized in such systems. In contrast, TSA systems can generally help minimize the size of the adsorber or adsorbent material bed required, and can also provide longer run times. But TSA systems also typically have significantly increased costs in terms of the energy required to heat the adsorbent material for regenerating the material. Conventionally, relatively high temperature heating is utilized to sufficiently heat the off-line adsorbent material for regenerating the material in a TSA system. This heat is typically only available for the early part of the regeneration process. This initial heating is followed by a cooling step in which the initially supplied heat is pushed through the bed of adsorbent material to desorb impurities from the bed of material, thereby regenerating the material. In conventional TSA systems, the off-line bed of adsorbent material is typically subjected to cooling to bring the bed back to or near its operating feed temperature, and then the adsorber is brought back on-line for purification to adsorb impurities to minimize the chance that heat from the regeneration process may be transferred downstream of the adsorber when the adsorber is brought back on-line. It is conventionally desirable to avoid such heat applied during the regeneration cycle being transferred downstream to other processing equipment (e.g., heat exchangers, towers, etc.), as the heat may cause instability in downstream processing, which may result in reduced yields or distillation performance for some applications (e.g., pre-purification for air separation systems, etc.). It is also conventionally desirable to avoid such heat transfer downstream applied during the regeneration cycle, as this heat may cause the temperature of the downstream equipment to exceed the maximum design temperature of the equipment. We have also found that cycling heat from a cooler on-line temperature regime to a higher regeneration temperature regime that may be suitable for regeneration of a TSA system can create significant thermal stresses on the adsorbent material and adsorber vessel. This may be a particular concern for radial adsorbers because thermal expansion of their internal components (e.g., internal screens for retaining adsorbent material, etc.) may be more difficult to manage (e.g., may be more difficult to access and more difficult to replace due to the internal configuration of such adsorbers). Thermal cycling of the adsorbent material and the vessel may result in a shortened life of the material and the body of the vessel due to thermal stresses experienced by thermal expansion and contraction that occur when the temperature changes significantly from a cooler in-line temperature to a significantly hotter regeneration temperature. Embodiments of the apparatus and process may be provided to facil