Fluidized bed separation method and device for methanol-to-olefins quenched water

Patent metadata

Field	Value
Publication number	US-12466753-B2
Application number	US-202018245575-A
Country	US
Kind code	B2
Filing date	Sep 17, 2020
Priority date	Sep 17, 2020
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Disclosed are a fluidized bed separation method and device for methanol-to-olefins quenched water. The method may subject quenched water to liquid-solid separation via a micro-cyclone separator. The method may also subject clear liquid from the micro-cyclone separator to a secondary separation via a fluidized bed separator, then sending the same to an olefin separation device, then recovering some waste heat of the quenched water, and then returning the same to a quenching tower after performing heat exchange. The method may also regenerate a separation medium by reversely feeding stripping tower purified water or quenched water, so as to release catalyst particles absorbed by the separation medium. The method may also send a catalyst slurry concentrated by the micro-cyclone separator and the fluidized bed separator to a filter-press unit for filter-press dehydration, so as to recover a catalyst.

First claim

What is claimed is:

1 . A fluidized bed based separation method for methanol-to-olefins quench water, comprising the following steps:
(a) subjecting quench water from a quench tower to liquid-solid separation by a microcyclone separator to remove large particles of catalyst entrained in the quench water; (b) subjecting supernate from the microcyclone separator to secondary separation by a fluidized bed separator to remove residual particles in the quench water which is then sent to an olefin separation device as a low-temperature heat source to recover part of residual heat of the quench water, and then returned to the quench tower after heat exchange; (c) after a period of time of continuous operation of the fluidized bed separator, regenerating a separating medium in the fluidized bed separator by back-feeding purified water from a stripping tower or the quench water to release catalyst particles adsorbed by the separating medium, wherein the stripping tower is communicated with the fluidized bed separator; and (d) sending concentrated catalyst slurries from the microcyclone separator and the fluidized bed separator to a pressure filtration unit for dewatering by pressure filtration to recover the catalyst.

2 . The method of claim 1 , wherein the method further comprises the following steps:
(i) removing large catalyst particles from a product gas obtained by reacting a methanol raw material in a fluidized bed reactor, and then sending the product gas to the quench tower for washing and cooling, while washing fine catalyst powder entrained in the product gas into the quench water; (ii) sending the product gas washed and cooled by the quench tower to a water washing tower for washing, recooling and removal of oil-wax substances condensed in the product gas; (iii) discharging a portion of washing water obtained after the washing in the water washing tower to the stripping tower for stripping organic matter in the washing water to obtain a stripped product, a part of which is subjected to wastewater treatment, and a remaining part of which is used for regeneration of the separating medium in the fluidized bed separator; and (iv) cooling the quench water and the washing water by recovering heat, and reusing them by circulating in the quench tower and the water washing tower, respectively.

3 . The method of claim 2 , wherein in step (i), a solid particles content of the quench water is 0.1-5.0 g/L, and an average particle diameter of the solid particles is 0.5-50 μm, before being subjected to the liquid-solid separation.

4 . The method of claim 1 , wherein after the liquid-solid separation in step (a), an average particle diameter of the catalyst in the quench water is reduced to 5 μm or less; after the secondary separation in step (b), a catalyst content in the quench water is reduced to 10 mg/L or less; and a separation precision of the fluidized bed separator is D 85 =0.1 μm.

5 . The method of claim 1 , wherein a pressure loss of the microcyclone separator is 0.15-0.30 MPa; and a pressure loss of the fluidized bed separator is 0.02-0.30 MPa.

6 . The method of claim 1 , wherein the fluidized bed separator is operated at a set pressure difference, and the separating medium is cleaned and regenerated by further introducing nitrogen or steam to the fluidized bed separator to fluidize the separating medium to an ebullient state.

7 . A fluidized bed based separation device for methanol-to-olefins quench water, comprising:
a quench tower, a microcyclone separator in communication with the quench tower for liquid-solid separation of quench water to remove large particles entrained in the quench water; a fluidized bed separator in communication with the microcyclone separator for secondary separation of supernate from the microcyclone separator to remove residual particles in the quench water; an olefin separation unit as a low-temperature heat source which receives the quench water; and a pressure filtration unit in communication with the fluidized bed separator for dewatering concentrated catalyst slurries separated from the microcyclone separator and the catalyst slurries concentrated from the fluidized bed separator by pressure filtration to recover the catalyst, wherein the device further comprises: a fluidized bed reactor for reacting a methanol raw material therein; the quench tower in communication with the fluidized bed reactor for washing and cooling a product gas obtained by the reaction in the fluidized bed reactor after large catalyst particles are removed, while washing fine catalyst powder entrained in the product gas into the quench water; a water washing tower in communication with the quench tower for washing and recooling the product gas washed and cooled by the quench tower, and removing oil-wax substances condensed in the product gas; and a stripping tower in communication with the water washing tower for stripping a portion of washing water obtained by the washing in the water washing tower; wherein the stripping tower is communicated with the fluidized bed separator, and water for regeneration of a separating medium in the fluidized bed separator is purified water from the stripping tower.

8 . The device of claim 7 , wherein the device further comprises a residual heat recovery unit in communication with the fluidized bed separator for recovering heat from supernate of the quench water which is cooled for reuse.

9 . The device of claim 7 , wherein one or more granular separation media are in the fluidized bed separator, wherein a material of the separation media is an organic or inorganic material capable of adsorbing molecular sieve catalyst particles; and a three-phase cyclone separator is disposed at a top of the fluidized bed separator to form a cyclone field to enhance a regeneration effect of the separating medium, and, at the same time, achieve recovery of separation media particles during a regeneration by fluidization.

Assignees

• Univ East China Science & Tech
• Shanghai Huachang Env Prot Co Ltd
• Sinopec Guangzhou Eng Co Ltd

Inventors

• Wang Hualin
• Lv Wenjie
• Chen Jiangi
• Liu Yu
• Shi Lei
• Qiao Ligong
• Zhang Jie
• Chang Guoping
• Dang Zhihong
• Ji Yujie
• Ma Hongpeng
• Cui Xin
• Sang Weichi
• Wang Jinsong

Classifications

• C02F2303/16

  Regeneration of sorbents, filters · CPC title

• C02F2303/10

  Energy recovery · CPC title

• C02F2103/18

  from the purification of gaseous effluents · CPC title

• C02F11/122

  using filter presses (C02F11/123 takes precedence) · CPC title

• C02F1/38

  by centrifugal separation · CPC title