CN110820008A - A water electrolysis cell using organic liquid to absorb hydrogen - Google Patents

Abstract

The invention provides a water electrolysis cell that utilizes organic liquid to absorb hydrogen, and the water electrolysis cell that utilizes organic liquid to absorb hydrogen comprises: a membrane electrode, an anode cavity, a cathode cavity, an anode solution, and an organic liquid hydrogen storage material; wherein, the membrane In the cavity on both sides of the electrode, the upper part is gas, and the lower part is liquid. Both sides of the membrane electrode are immersed in the liquid and are in contact with the liquid. The liquid in the cathode side cavity is an organic liquid hydrogen storage material. The cathode and anode of the membrane electrode are respectively connected with the negative electrode of the DC power supply Connect to positive. The invention can effectively reduce the cost of the device, simplify the equipment, and utilize the exothermic heat of the hydrogenation reaction of the organic liquid to provide the heat required for water electrolysis, thereby improving the energy utilization rate and operation efficiency of the system.

Description

A water electrolysis cell using organic liquid to absorb hydrogen

technical field

The present application relates to the field of environmental protection, and in particular, to a water electrolysis cell that utilizes organic liquid to absorb hydrogen.

Background technique

At present, the hydrogenation reaction of organic liquid hydrogen storage materials needs to be completed in a special hydrogenation reactor. When using organic liquids to store hydrogen produced by water electrolysis, two sets of equipment, a water electrolyzer and a hydrogenation reactor, are required, which are bulky and have low efficiency.

Therefore, combining the water electrolyzer with the organic liquid hydrogenation device can effectively reduce the cost of the device, simplify the equipment, and use the exothermic heat of the organic liquid hydrogenation reaction to provide the heat required for water electrolysis, and improve the system energy utilization and operating efficiency.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a water electrolysis cell that utilizes organic liquid to absorb hydrogen, and uses a set of integrated equipment to complete the hydrogen production reaction of electrolysis water and absorb hydrogen at the same time. The invention discloses a water electrolysis cell which utilizes organic liquid to absorb hydrogen, so as to solve the problems of large volume and low operation efficiency of the prior art equipment.

The invention discloses a water electrolysis cell utilizing organic liquid to absorb hydrogen, comprising: membrane electrode, anode cavity, cathode cavity, anode solution, and organic liquid hydrogen storage material; wherein:

In the chambers on both sides of the membrane electrode, the upper part is gas, the lower part is liquid, the two sides of the membrane electrode are immersed in the liquid and are in contact with the liquid, and the liquid in the cathode side chamber is organic In the liquid hydrogen storage material, the cathode and anode of the membrane electrode are respectively connected with the cathode and the anode of the DC power supply.

The membrane electrode is composed of electrode catalysts and porous current collectors supported on both sides of a high temperature proton exchange membrane, and the membrane component is phosphoric acid doped PBI.

The anode cavity contains liquid, which is an aqueous phosphoric acid solution.

The melting point of the organic liquid hydrogen storage material in the cathode side cavity is not higher than 70°C, and the materials that can be used include but are not limited to ethyl carbazole, propyl carbazole, methyl indole, ethyl indole, Benzyltoluene, benzyltoluene and mixtures thereof.

A water pump connected to the anode cavity, an organic liquid delivery pump connected to the cathode cavity, and an organic liquid outlet valve installed below the liquid level of the cathode side cavity.

An anode pressure sensor, an anode blow-off valve, a cathode pressure sensor and a cathode blow-off valve are respectively installed on the gas sides of the anode and the cathode.

The anode cavity and the cathode cavity are filled with inert gas.

The hydrogen absorption chemical reaction of the water electrolysis cell using organic liquid to absorb hydrogen gas is carried out on the cathode side of the membrane electrode. Compared with the prior art, the present invention has the advantages of combining the water electrolyzer with the organic liquid hydrogenation device, which can effectively reduce the cost of the device, simplify the equipment, and utilize the exothermic heat of the organic liquid hydrogenation reaction to provide the required water electrolysis. heat, improve system energy utilization and operating efficiency.

Description of drawings

In order to illustrate the technical solutions of the present application more clearly, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, without creative work, the Additional drawings can be obtained from these drawings.

Figure 1 is a structural diagram of a water electrolysis cell that utilizes organic liquids to absorb hydrogen.

The symbols in the above figures are as follows:

1—membrane electrode; 2—anode chamber; 3—cathode chamber; 4—phosphoric acid aqueous solution; 5—organic liquid hydrogen storage material; 6—water pump; 7—organic liquid delivery pump; 8— — organic liquid outlet valve; 9 — anode pressure sensor; 10 — anode vent valve; 11 — cathode pressure sensor; 12 — cathode vent valve.

Detailed ways

Referring to FIG. 1 , it is a structural diagram of a water electrolysis cell using organic liquid to absorb hydrogen.

A water electrolysis cell using organic liquid to absorb hydrogen provided by this application may specifically include the following structures: a membrane electrode 1, an anode cavity 2, a cathode cavity 3, an aqueous phosphoric acid solution 4, an organic liquid hydrogen storage material 5, a water pump 6, an organic Liquid delivery pump 7 , organic liquid outlet valve 8 , anode pressure sensor 9 , anode vent valve 10 , cathode pressure sensor 11 , cathode vent valve 12 .

In practical applications, the electrolytic cell is heated to 110-160 °C; both the anode cavity and the cathode cavity are filled with inert gas, the pressure difference between the two sides of the cavity is kept below 50kPa, and the pressure of the anode side cavity 2 should be higher than the current temperature. Saturated water vapor pressure to prevent boiling of the water in the solution.

The cost of argon gas is low, so argon gas is used in the anode cavity and the cathode cavity.

Under the action of the current, the water in the phosphoric acid aqueous solution 4 is electrolyzed, the anode of the membrane electrode 1 generates oxygen and rises above the liquid level, and merges into the gas in the upper part of the anode cavity 2; the cathode cavity 3 generates hydrogen, and the hydrogen is stored with the organic liquid. The hydrogen material 5 undergoes a hydrogenation reaction under the action of the catalyst of the membrane electrode 1 to generate a hydrogenated organic liquid.

The water pump 6 replenishes water to the anode cavity 2 according to the consumption of electrolyzed water, and maintains the concentration of the phosphoric acid aqueous solution 4 constant. The organic liquid delivery pump 7 injects the unhydrogenated organic liquid into the cathode cavity 3 at a certain rate, and the hydrogenated organic liquid flows out from the outlet valve 8 at a certain rate to keep the amount of organic liquid in the cathode cavity 3 stable.

Phosphoric acid doped PBI is selected as the high temperature proton exchange membrane, the anode catalyst can be selected as Ir, and the cathode catalyst can be selected as Pt. Electrons rely on proton conduction on the proton exchange membrane. In order to improve the conduction efficiency, the proton exchange membrane is acidified with phosphoric acid. In order to further continuously acidify the proton exchange membrane, the liquid in the anode cavity adopts phosphoric acid aqueous solution 4 with a concentration of 1-2 mol/L.

The pressure control system discharges the gas by controlling the pressure regulating valves 10 and 12, adjusts the pressure difference between the two sides of the cavity to be less than 50kPa, and controls the maximum working pressure of the cavity 2 and 3 to be less than 3MPa.

The melting point of the organic liquid hydrogen storage material in the cathode side cavity is not higher than 70°C, and the materials that can be used include but are not limited to ethyl carbazole, propyl carbazole, methyl indole, ethyl indole, Benzyltoluene, benzyltoluene and mixtures thereof. The hydrogenation reaction temperature of N-ethylcarbazole is relatively low, about 110℃-120℃, and the melting point is just right, the reaction rate is high, 1 ethylcarbazole molecule can load 12 H atoms, 1 to 2 Complete hydrogenation can be achieved within an hour, so N-ethylcarbazole is used as the organic liquid hydrogen storage material 5 in the cathode cavity 3 .

Before the device was started, the gas sides of the anode cavity 2 and cathode cavity 3 were replaced with Ar gas, the entire electrolytic cell and the liquid on both sides were heated to 130 °C, and the pressure on both sides of the cavity increased to keep the phosphoric acid aqueous solution from boiling.

For the direct current applied to the monolithic membrane electrode, the voltage should not exceed 1.7V. Membrane electrode 1, the anode part generates oxygen and flows into the anode gas side, the cathode generates hydrogen and reacts with ethylcarbazole under the action of a catalyst to generate hydrogenated ethylcarbazole, and the unreacted hydrogen in the cathode part will flow into the cathode gas side.

As the electrolysis reaction progresses, excess oxygen at the anode and excess hydrogen at the cathode will be discharged through their respective air release valves 10 and 12 to ensure that the pressure of the anode cavity 2 and the cathode cavity 3 is maintained at about 2MPa, and the pressure difference between the two poles is not more than 50kPa. The water pump 6 continuously supplies water to the anode to supplement the consumption of the electrolysis reaction. As the degree of hydrogenation of ethylcarbazole in the cathode chamber 3 increases, the organic liquid outlet valve 8 is opened intermittently to remove the organic liquid 5 with a relatively high degree of hydrogenation in the cathode chamber 3, and at the same time, the organic liquid delivery pump 7 is turned on to replenish the The organic liquid of hydrogen keeps the total amount of organic liquid in the cathode cavity 3 constant.

Through the above process, the electrical energy input to the electrolytic cell is converted into hydrogen, and is stored in ethylcarbazole through the hydrogenation reaction that occurs in situ on the electrode to obtain hydrogenated ethylcarbazole.

A kind of water electrolysis cell that utilizes organic liquid to absorb hydrogen gas provided by the present invention has been described in detail above. In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above examples are only used to help understanding The method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be It is construed as a limitation of the present invention.

Claims (7)

1. A water electrolytic cell for absorbing hydrogen gas with an organic liquid, comprising: the membrane electrode, the anode cavity, the cathode cavity, the anode solution and the organic liquid hydrogen storage material; wherein:

the upper part of the two side cavities of the membrane electrode is gas, the lower part of the two side cavities of the membrane electrode is liquid, the two sides of the membrane electrode are immersed in the liquid and are contacted with the liquid, the liquid in the cathode side cavity is an organic liquid hydrogen storage material, and the anode and the cathode of the membrane electrode are respectively connected with the cathode and the anode of a direct current power supply.

2. The water electrolytic cell for absorbing hydrogen by using organic liquid as claimed in claim 1, wherein the membrane electrode is composed of a high temperature proton exchange membrane, both sides of which are loaded with electrode catalyst and porous current collector, and the membrane component is phosphoric acid doped with PBI.

3. The electrolytic cell of claim 1, wherein the liquid in the anode chamber is phosphoric acid aqueous solution.

4. The electrolytic cell of claim 1, wherein the organic liquid hydrogen storage material in the cathode side chamber has a melting point of no higher than 70 ℃.

5. A water electrolyser for absorbing hydrogen with organic liquids as in claim 1 further comprising a water pump connected to the anode chamber and an organic liquid delivery pump connected to the cathode chamber, and an organic liquid outlet valve mounted below the liquid level in the cathode side chamber.

6. A water electrolyser for absorbing hydrogen with organic liquids as claimed in claim 1 wherein the gas sides of said anode and said cathode are fitted with an anode pressure sensor, an anode bleed valve and a cathode pressure sensor, respectively, a cathode bleed valve.

7. The electrolytic cell of claim 1 wherein the anode chamber and the cathode chamber are filled with an inert gas.