CN114772834A - A kind of hydrogen production acidic water recycling device and method - Google Patents

Abstract

The invention provides a hydrogen production acid water recycling device, which comprises: a mixing tank, a membrane separator and an evaporation dryer; the mixing tank is connected with an acid water inlet pipeline and an alkali liquor inlet pipeline, and is also connected with a mixed liquor outlet pipeline; the inlet end of the membrane separator is connected with the mixed liquid outlet pipeline, and a concentration outlet pipeline is also arranged on the membrane separator; the inlet of the evaporation drier is communicated with a concentration outlet pipeline. The invention also provides a method for recycling the hydrogen-producing acidic water, which comprises the following steps: step S001: introducing acidic water containing carbonate and bicarbonate into a mixing tank, simultaneously introducing alkaline liquor containing hydroxyl into the mixing tank, stirring and neutralizing to generate a carbonate solution and a bicarbonate solution; step S002: introducing the carbonate and bicarbonate solution into a membrane separator for membrane separation to obtain concentrated carbonate and bicarbonate solution; step S003: and (3) introducing the concentrated carbonate and bicarbonate solution into an evaporation drying device to obtain carbonate and bicarbonate crystals.

Description

A kind of hydrogen production acidic water recycling device and method

technical field

The invention belongs to the field of petrochemical industry, and in particular relates to a hydrogen-producing acid water recycling device and method.

Background technique

The hydrogen production unit owned by Yanchang Petroleum started construction in February 2013 and was handed over in October 2013. This unit is a supporting device for the diesel hydrogenation unit. Desulfurization part, steam reforming part, shift reaction and heat recovery part, steam production system part and PSA purification part, etc. The raw material refining part adopts the method of ZnO for fine desulfurization to carry out the raw material purification, and the transformation part adopts the hydrocarbon-steam reforming method. Hydrogen and product parts adopt PSA purification and purification process to produce hydrogen. The hydrogen production capacity of the hydrogen production unit is 20,000 standard/hour. The designed raw materials are catalytic dry gas, hydrogenated dry gas and natural gas. The product is industrial hydrogen with a purity of more than 99.9 mol%. The hydrogen produced is mainly supplied to the diesel hydrogenation unit. After the by-product acid water is stripped, the carbon dioxide-containing gas reacts with steam and feed gas into the reformer again, and the undissolved CO ₂ in the influent water is finally mixed with hydrogen fuel gas through PAS pressure swing adsorption analysis and mixed with hydrogen fuel gas as reformer fuel and then discharged to the atmosphere middle. All of the above methods still end up producing large amounts of acidic water, while also having high CO ₂ emissions.

SUMMARY OF THE INVENTION

The present invention proposes a hydrogen-producing acid water recycling device and method, which are used to overcome the above-mentioned problems or at least partially solve or alleviate the above-mentioned problems.

The present invention proposes a hydrogen-producing acid water recycling device, comprising:

a mixing tank, the mixing tank is connected with an acid water inlet pipeline and an lye water inlet pipeline, and the mixing tank is also connected with a mixed liquid outlet pipeline;

a membrane separator, the inlet end of the membrane separator is connected with the mixed liquid outlet pipeline, and the membrane separator is also provided with a concentration outlet pipeline;

An evaporative dryer, the inlet of the evaporative dryer is communicated with the concentration outlet pipeline.

The hydrogen-producing acid water recycling device of the present invention also has the following optional features.

Optionally, the membrane separator is further provided with a return water pipeline, and the return water pipeline leads back to the mixing tank.

Optionally, the membrane separator is also provided with a fresh water inlet pipeline.

Optionally, a first circulating pump is connected to the mixed liquid outlet pipeline.

Optionally, it also includes a buffer tank, the membrane separator is also provided with a concentration buffer pipeline, the inlet of the buffer tank is connected to the concentration buffer pipeline, and the outlet of the buffer tank is passed through the pipeline. The evaporative dryer.

Optionally, a second circulating pump is further provided on the pipeline between the buffer tank and the evaporative dryer.

The present invention also proposes a method for a hydrogen-producing acid water recycling device, which is implemented by the hydrogen-producing acid water recycling device described in any one of the above, including the following steps:

Step S001: the acidic water containing carbonate and bicarbonate is passed into the mixing tank, while the alkali lye containing hydroxide is passed into the mixing tank and stirred and neutralized to generate carbonate and bicarbonate solution;

Step S002: passing the carbonate and bicarbonate solutions into the membrane separator and separating the concentrated carbonate and bicarbonate solutions by membrane;

Step S003: Pass the concentrated carbonate and bicarbonate solutions into an evaporative drying device to obtain carbonate and bicarbonate crystals.

In step S001, the alkali solution is sodium hydroxide.

The hydrogen-producing acidic water recycling device and process of the present invention neutralize and convert acidic water containing relatively high _CO into sodium bicarbonate or sodium carbonate solution, and the solution can be directly used as a product out of the device, or can also be prepared into sodium bicarbonate or sodium bicarbonate by membrane separation. Sodium carbonate crystals solve the problem of acid water discharge in hydrogen production units, and also reduce environmental CO ₂ emissions.

Description of drawings

FIG. 1 is a schematic structural diagram of an embodiment of the hydrogen-producing acid water recycling device of the present invention.

In the above picture: 1 mixing tank; 2 acid water inlet pipeline; 3 lye water inlet pipeline; 4 mixed liquid outlet pipeline; 5 membrane separator; 6 concentrated outlet pipeline; 7 evaporation dryer; 8 return water pipeline 9 fresh water inlet pipeline; 10 first circulating pump; 11 buffer tank; 12 concentrated buffer pipeline; 13 second circulating pump; 14 return water bypass.

Detailed ways

Example 1

Referring to FIG. 1, an embodiment of the present invention provides a hydrogen production acid water recycling device, including: a mixing tank 1, a membrane separator 5 and an evaporative dryer 7; the mixing tank 1 is connected with an acid water inlet pipeline 2 and the lye water inlet pipeline 3, the mixing tank 1 is also connected with a mixed solution outlet pipeline 4; the inlet end of the membrane separator 5 is connected with the mixed solution outlet pipeline 4, and the membrane separation The device 5 is also provided with a concentration outlet pipeline 6 ; the inlet of the evaporative dryer 7 is communicated with the concentration outlet pipeline 6 .

The acid water containing higher _CO2 produced by the hydrogen production device is led to the mixing tank 1 through the acid water inlet pipeline 2, and the sodium hydroxide solution is introduced through the lye water inlet pipeline 3 at the same time, and the mixing tank 1 is provided with anti-acid. The alkali-corrosion stirring impeller is used to agitate the sodium hydroxide solution and the acid water to neutralize the acid-base corrosion-proof stirring impeller. The wall of the mixing tank 1 is equipped with a pH detector to control and adjust the pH in the device; through the pH parameter adjustment and control, carbonic acid is generated. Sodium hydrogen or sodium carbonate solution, the solution can be directly used as a product out of the device. The reaction formula is as follows:

H ⁺ +HCO ₃ ^- +NaOH=NaHCO ₃ +H ₂ O

2H ⁺ +CO ₃ ^2- +NaOH=NaCO ₃ +2H ₂ O

Sodium bicarbonate or sodium carbonate solution is injected from the top of the membrane separator 5 through the mixed liquid outlet pipeline 4. The upper layer of the filter membrane in the membrane separator 5 is a sodium bicarbonate or sodium carbonate solution with a higher concentration, which is different from that in the membrane separator 5. The mixed liquid outlet pipeline 4 connected to the upper area of the filter membrane is communicated with the evaporative dryer 7, and the high-concentration sodium bicarbonate or sodium carbonate solution separated by the membrane separator 5 can be passed into the evaporative dryer 7 to prepare carbonic acid. Sodium hydrogen or sodium carbonate crystals.

Example 2

Referring to FIG. 1 , on the basis of Embodiment 1, the membrane separator 5 is further provided with a return water pipeline 8 , and the return water pipeline 8 leads back to the mixing tank 1 .

The lower area of the filter membrane in the membrane separator 5 is connected to the return water pipeline 8, and the return water pipeline 8 is connected to the mixing tank 1. If the membrane fails, the water separated by the filter membrane of the membrane separator 5 can be returned to the mixing tank. In the tank 1, it can also be discharged to other places through the return water bypass 14 on the return water pipeline 8.

Example 3

Referring to FIG. 1 , on the basis of Example 1, the membrane separator 5 is further provided with a fresh water inlet pipeline 9 .

The membrane separator 5 can also pass fresh water through the fresh water inlet pipe 9 to clean the concentration outlet pipe 6 .

Example 4

Referring to FIG. 1 , on the basis of Embodiment 1, a first circulating pump 10 is connected to the mixed liquid outlet pipeline 4 .

The first circulating pump 10 on the mixed liquid outlet pipeline 4 can pump the mixed liquid in the mixing tank 1 to the membrane separator 5 .

Example 5

Referring to FIG. 1 , on the basis of Embodiment 1, a buffer tank 11 is also included, the membrane separator 5 is further provided with a concentration buffer pipeline 12 , and the inlet of the buffer tank 11 is in phase with the concentration buffer pipeline 12 . connected, the outlet of the buffer tank 11 leads to the evaporative dryer 7 through a pipeline.

After passing the sodium bicarbonate or sodium carbonate solution into the evaporative dryer 7, use steam to evaporate with heat to obtain sodium bicarbonate or sodium carbonate crystals, because the evaporative dryer 7 can only pass a certain amount of high-concentration sodium bicarbonate or Therefore, the concentrated buffer tank 11 is set to temporarily store sodium bicarbonate or sodium carbonate solution.

Example 6

Referring to FIG. 1 , on the basis of Embodiment 5, the pipeline between the buffer tank 11 and the evaporative dryer 7 is further provided with a second circulating pump 13 .

The second circulating pump 13 can pass the high-concentration sodium bicarbonate or sodium carbonate solution stored in the buffer tank 11 into the evaporative dryer 7 .

Example 7

The embodiment of the present invention also proposes a method for recycling acid water for hydrogen production, which is implemented by the recycling device for producing acid water for hydrogen production described in any of the above embodiments, and includes the following steps: Step S001: The acidic water of hydrogen radical is passed into mixing tank 1, and the alkali lye containing hydroxide radical is passed into mixing tank 1 simultaneously and is stirred and neutralized to generate carbonate and bicarbonate solution; Step S002: carbonate and bicarbonate are The salt solution is passed into the membrane separator 5 to separate the concentrated carbonate and bicarbonate solution from the membrane; Step S003: pass the concentrated carbonate and bicarbonate solution into the evaporative drying device 7 to obtain carbonate and bicarbonate Salt crystals.

The main components of the acid water for hydrogen production are: CO, CO ₂ , CH ₄ , N ₂ , H ₂ O, among which the CO ₂ (wt%) content is about 11%, the flow rate of the acid water into the device is 14t/h, the temperature is 70°C, the alkali The liquid is fed with 30% NaOH solution at room temperature, the feeding amount is about 3.5t/h, the temperature after mixing is about 60 °C, and it is mixed in the mixing tower for about 20 minutes and discharged, and the discharge rate is controlled at 17.5t/h, and is separated by a membrane separator. , the separation rate of the membrane is 98%, which can be filtered and concentrated several times to obtain a concentrated solution of about 30% NaCO ₃ at 40 ° C. The concentrated solution of NaCO ₃ enters the dryer heated by steam, and the dryer is equipped with a stirrer to prevent NaCO ₃ Agglomeration, under the constant stirring of the stirrer, the _NaCO3 concentrated solution in the dryer evaporates to obtain _NaCO3 crystal powder, which can be packaged in a woven bag with a moisture-proof lining.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims. Components and structures not described in detail in this embodiment belong to well-known components and common structures or common means in the industry, and will not be described one by one here.

Claims (8)

1. a hydrogen-producing acid water recycling device, is characterized in that, comprises: A mixing tank (1), the mixing tank (1) is connected with an acid water inlet pipeline (2) and an lye water inlet pipeline (3), and the mixing tank (1) is also connected with a mixed liquid outlet pipeline (4); A membrane separator (5), the inlet end of the membrane separator (5) is connected with the mixed liquid outlet pipeline (4), and the membrane separator (5) is also provided with a concentration outlet pipeline (6). ); An evaporative dryer (7), the inlet of the evaporative dryer (7) is communicated with the concentration outlet pipeline (6). 2. The hydrogen-producing acid water recycling device according to claim 1, characterized in that, the membrane separator (5) is also provided with a return water pipeline (8), and the return water pipeline (8) leads back to The mixing tank (1). 3 . The hydrogen-producing acid water recycling device according to claim 1 , wherein the membrane separator ( 5 ) is further provided with a fresh water inlet pipeline ( 9 ). 4 . 4. The hydrogen-producing acid water recycling device according to claim 1, characterized in that, a first circulating pump (10) is connected to the mixed liquor outlet pipeline (4). 5. The hydrogen-producing acid water recycling device according to claim 1, characterized in that it further comprises a buffer tank (11), and the membrane separator (5) is also provided with a concentration buffer pipeline (12), so The inlet of the buffer tank (11) is connected with the concentration buffer pipeline (12), and the outlet of the buffer tank (11) is connected to the evaporative dryer (7) through a pipeline. 6. The hydrogen-producing acid water recycling device according to claim 5, wherein the pipeline between the buffer tank (11) and the evaporative dryer (7) is also provided with a second circulating pump ( 13). 7. A method for recycling and utilizing hydrogen-producing acid water, characterized in that, adopting the hydrogen-producing acid water recycling device described in any one of claims 1 to 6 is implemented, comprising the following steps: Step S001: the acidic water containing carbonate and bicarbonate is passed into the mixing tank, while the alkali lye containing hydroxide is passed into the mixing tank and stirred and neutralized to generate carbonate and bicarbonate solution; Step S002: passing the carbonate and bicarbonate solutions into the membrane separator and separating the concentrated carbonate and bicarbonate solutions by membrane; Step S003: Pass the concentrated carbonate and bicarbonate solutions into an evaporative drying device to obtain carbonate and bicarbonate crystals. 8. The method for recycling acidic water for hydrogen production according to claim 7, characterized in that, in step S001, the lye is sodium hydroxide.

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