Search

CN-121992423-A - System and method for preparing hydrogen by electrolyzing water

CN121992423ACN 121992423 ACN121992423 ACN 121992423ACN-121992423-A

Abstract

The disclosure provides a system for producing hydrogen by electrolyzing water, which comprises an electrolytic tank, a gas-liquid pre-separator and a gas-liquid pre-separator, wherein the electrolytic tank comprises an electrode, an anode side and a cathode side, the electrolytic tank is used for generating a gas-liquid two-phase flow product under the condition that the electrode is electrified, the gas-liquid two-phase flow product is an anode two-phase flow product on the anode side or a cathode two-phase flow product on the cathode side, the gas-liquid pre-separator is coupled with the electrolytic tank and is used for carrying out pre-separation treatment on the gas-liquid two-phase flow product to obtain a pre-separation gas phase and a pre-separation liquid phase, the gas-liquid separator is coupled with the gas-liquid pre-separator through a first pipeline and a second pipeline, the gas-liquid separator receives the pre-separation liquid phase from the gas-liquid pre-separator through the first pipeline, and the pre-separation gas phase is further separated through the second pipeline to obtain a separated gas phase and a liquid phase. The present disclosure also relates to a method of producing hydrogen by electrolysis of water.

Inventors

  • WU DEFEI
  • LIU JIE
  • DAI WENSONG
  • WANG QINGCHUAN
  • ZHANG XU
  • ZHANG QI

Assignees

  • 中国石油化工股份有限公司
  • 中国石化工程建设有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (13)

  1. 1. A system for producing hydrogen from electrolyzed water comprising: An electrolysis cell (140) comprising an electrode, an anode side and a cathode side, the electrolysis cell for producing a gas-liquid two-phase flow product upon energization of the electrode, the gas-liquid two-phase flow product being either an anode two-phase flow product on the anode side or a cathode two-phase flow product on the cathode side; A gas-liquid pre-separator (130) coupled to the electrolyzer (140) for pre-separating the gas-liquid two-phase flow product to obtain a pre-separated gas phase and a pre-separated liquid phase; A gas-liquid separator (110) coupled with the gas-liquid pre-separator (130) via a first line and a second line, wherein the gas-liquid separator (110) receives the pre-separated liquid phase from the gas-liquid pre-separator (130) via the first line and the pre-separated gas phase from the gas-liquid pre-separator (130) via the second line, and further separates the pre-separated liquid phase and the pre-separated gas phase into separated gas and liquid phases.
  2. 2. The system according to claim 1, wherein a liquid phase cooler (120) is provided on the first line for cooling the pre-separated liquid phase to produce a pre-separated cooled liquid phase to be fed into a gas-liquid separator (110).
  3. 3. The system of claim 1, wherein the gas-liquid preseparator (130) is coupled with the electrolyzer (140) via a third line, the third line being of a resilient spiral structure.
  4. 4. A system according to claim 3, wherein the outlet of the third line is connected tangentially to the gas-liquid pre-separator (130).
  5. 5. The system of claim 1, wherein an ultrasonic structure is provided on the gas-liquid pre-separator (130) for emitting ultrasonic waves to the gas-liquid two-phase flow product in the gas-liquid pre-separator (130).
  6. 6. The system of any one of claims 1-5, wherein: the gas-liquid preseparator is an oxygen-side gas-liquid preseparator and is used for gas-liquid preseparation of oxygen and solution mixture at the outlet of the anode side of the electrolytic cell, and The gas-liquid separator is an oxygen side gas-liquid separator and is used for separating oxygen from a solution mixture.
  7. 7. The system of any one of claims 1-5, wherein: The gas-liquid preseparator is a hydrogen-side gas-liquid preseparator and is used for gas-liquid preseparation of hydrogen and solution mixture at the outlet of cathode side of electrolytic cell, and The gas-liquid separator is a hydrogen side gas-liquid separator and is used for separating hydrogen and a solution mixture.
  8. 8. A method for producing hydrogen by electrolysis of water, comprising: Electrolyzing the solution in an electrolytic tank to generate a gas-liquid two-phase flow product, wherein the gas-liquid two-phase flow product is an anode two-phase flow product at the anode side of the electrolytic tank or a cathode two-phase flow product at the cathode side of the electrolytic tank; enabling the gas-liquid two-phase flow product to enter a gas-liquid preseparator for preseparation treatment to obtain a preseparation gas phase and a preseparation liquid phase; The pre-separated gas phase and the pre-separated liquid phase are passed into a gas-liquid separator via different pipes for further gas-liquid separation.
  9. 9. The method of claim 8, further comprising: before the gas-liquid two-phase flow product is subjected to pre-separation treatment, the gas-liquid two-phase flow product enters a spiral elastic pipeline.
  10. 10. The method of claim 8, further comprising: ultrasonic waves are applied to the gas-liquid two-phase flow in the gas-liquid preseparator.
  11. 11. The method of claim 8, further comprising: The pre-separated liquid phase is subjected to a temperature reduction before it enters the gas-liquid separator.
  12. 12. The method of any one of claims 8-11, wherein: the gas-liquid preseparator is an oxygen-side gas-liquid preseparator and is used for gas-liquid preseparation of oxygen and solution mixture at the outlet of the anode side of the electrolytic cell, and The gas-liquid separator is an oxygen side gas-liquid separator and is used for separating oxygen from a solution mixture.
  13. 13. The method of any one of claims 8-11, wherein: The gas-liquid preseparator is a hydrogen-side gas-liquid preseparator and is used for gas-liquid preseparation of hydrogen and solution mixture at the outlet of cathode side of electrolytic cell, and The gas-liquid separator is a hydrogen side gas-liquid separator and is used for separating hydrogen and a solution mixture.

Description

System and method for preparing hydrogen by electrolyzing water Technical Field The present disclosure relates to the field of hydrogen production by electrolysis of water, and in particular to a system and a method for producing hydrogen by alkaline water electrolysis. Background The electrolysis of water to produce hydrogen is a technique for decomposing water into hydrogen and oxygen by electric energy. The basic principle is that direct current is introduced into an electrolytic tank to enable water molecules to undergo oxidation-reduction reaction on electrodes, so that hydrogen and oxygen are generated. The hydrogen gas/oxygen produced by water electrolysis is mainly four types, namely alkaline water electrolysis technology, proton exchange membrane electrolysis technology, solid oxide electrolysis technology and anion membrane electrolysis technology. Among them, alkaline water electrolysis technology has the longest history, mature technology and low cost, and is widely used at present. In the prior art, there are a number of disadvantages to alkaline electrolysis techniques. For example, as shown in FIG. 1, a prior art electrolytic water hydrogen production system is shown. First, the lye is subjected to electrolysis in the electrolytic cell 1, with an anode product (oxygen and lye mixture) being obtained from the anode side and a cathode product (hydrogen and lye mixture) being obtained from the cathode side. The anode product (oxygen and alkali liquor mixture) is led into an oxygen separation tank 2 through an anode outlet pipeline (also called an oxygen side outlet pipeline) for separation treatment, and crude oxygen and an anode side liquid phase circulation are obtained. Likewise, the cathode product (hydrogen and lye mixture) is fed into the hydrogen separation tank 3 through a cathode outlet line (also referred to as a hydrogen side outlet line) for separation treatment to obtain crude hydrogen and a cathode side liquid phase recycle. The anode-side liquid-phase circulation and the cathode-side liquid-phase circulation are then returned to the electrolytic tank 1 by the anode-side circulation pump 4 and the cathode-side circulation pump 5, respectively. However, the hydrogen in oxygen is easy to exceed standard under the conditions of high energy consumption and low load of the water electrolysis hydrogen production system. And the electrolytic cell hydrogen side outlet pipeline to the hydrogen liquid separating tank and the electrolytic cell oxygen side outlet pipeline to the oxygen liquid separating tank are all vibrated greatly. The vibration of the outlet pipeline can cause the falling off and breakage between the pipeline and the electrolytic tank and between the pipeline and the liquid separating tank, so that a great safety risk exists. Disclosure of Invention The technical scheme in the disclosure aims at the defects in the prior art, and provides a water electrolysis hydrogen production system and a method, which can solve or alleviate at least one defect in the prior art to a certain extent. A first aspect of the present disclosure provides a system for producing hydrogen from electrolyzed water, comprising: An electrolyzer comprising an electrode, an anode side and a cathode side, the electrolyzer being configured to produce a gas-liquid two-phase flow product when the electrode is energized, the gas-liquid two-phase flow product being either an anode two-phase flow product on the anode side or a cathode two-phase flow product on the cathode side; the gas-liquid preseparator is coupled with the electrolytic tank and is used for preseparating the gas-liquid two-phase flow product to obtain a preseparated gas phase and a preseparated liquid phase; A gas-liquid separator coupled with the gas-liquid pre-separator via a first line and a second line, wherein the gas-liquid separator receives the pre-separated liquid phase from the gas-liquid pre-separator via the first line and the pre-separated gas phase from the gas-liquid pre-separator via the second line, and further separates the pre-separated liquid phase and the pre-separated gas phase into separated gas and liquid phases. In a further feature, a liquid phase cooler is disposed on the first line for cooling the pre-separated liquid phase to produce a pre-separated reduced temperature liquid phase that is to enter the gas-liquid separator. In a further feature, the gas-liquid preseparator is coupled to the electrolyzer via a third line, the third line being of elastic helical construction. In a further feature, the outlet of the third pipeline is connected with the gas-liquid preseparator in a tangential direction. In a further feature, an ultrasonic structure is provided on the gas-liquid preseparator for emitting ultrasonic waves toward the gas-liquid two-phase flow product in the gas-liquid preseparator. In a further feature, the gas-liquid pre-separator is an oxygen-side gas-liquid pre-separator for pre-separating the oxygen a