阅读说明：本技术 一种用微乳液制备硫酸氧钒溶液的方法 (Method for preparing vanadyl sulfate solution by using microemulsion ) 是由 李鸿乂 郭赟 元一衡 于 2019-08-21 设计创作，主要内容包括：本发明公开一种用微乳液制备硫酸氧钒溶液的方法。该工艺过程是在常温下进行的,能耗低。避免了传统的多级逆流萃取和多级逆流反萃取,得到的VOSO4溶液杂质含量低,生产过程微乳液可循环利用,无废水外排,是高效绿色可循环的工艺。(The invention discloses a method for preparing vanadyl sulfate solution by using microemulsion. The technological process is carried out at normal temperature, and the energy consumption is low. The traditional multi-stage countercurrent extraction and multi-stage countercurrent back extraction are avoided, the obtained VOSO4 solution is low in impurity content, the microemulsion can be recycled in the production process, no wastewater is discharged, and the process is efficient, green and recyclable.)

1. A method for preparing vanadyl sulfate solution by using microemulsion is characterized by comprising the following steps:

obtaining the vanadium-containing solution containing sodium metavanadate, and adjusting the pH value to 2.5-14;

preparing microemulsion by using Aliquat 336, isoamylol, n-heptane and mixed solution of NaOH and NaCl;

mixing the microemulsion with the solution obtained in the step 1) according to the volume ratio of 1:1-5, oscillating for extraction, standing for layering, wherein the upper phase is a microemulsion phase, the lower phase is a water phase, and separating the microemulsion phase from the water phase;

mixing the upper micro-emulsion phase (loaded micro-emulsion phase) in the step 3) with a sulfuric acid solution according to the ratio of 1:0.5-3, oscillating for washing, standing for layering, and separating the micro-emulsion phase from the water phase;

the concentration of the sulfuric acid solution is 1-3;

obtaining VOSO by A or B method₄Solution:

a: preparing a mixed solution of sulfuric acid and sulfurous acid;

mixing the loaded microemulsion phase obtained by washing in the step 4 with the mixed solution in the step according to the ratio of 1-3:1, standing for layering, wherein the upper phase is the microemulsion phase, and the lower phase is VOSO₄Solution, separating micro-emulsion phase from water phase;

b: mixing the loaded microemulsion phase obtained by washing in the step 4 with sulfuric acid solution, and introducing SO₂Standing for layering, wherein the upper phase is microemulsion phase, and the lower phase is VOSO₄And (3) separating a microemulsion phase from a water phase.

2. The method for preparing vanadyl sulfate solution with microemulsion according to claim 1, wherein:

neutralizing and washing the microemulsion obtained in the step 5, standing and layering after washing, and separating a microemulsion phase from a water phase to obtain a lower phase VOSO₄And (3) solution.

3. A process for preparing vanadyl sulfate solutions from microemulsions according to claim 1 or 2, characterized in that:

and 7, carrying out internal water phase restoration on the microemulsion obtained after the reaction is finished, wherein the restored microemulsion can replace the microemulsion in the step 2 for recycling.

4. The method for preparing vanadyl sulfate solution with microemulsion according to claim 1, wherein: in the step 1, the concentration of vanadium in the vanadium-containing solution is 1-35 g/L;

if the silicon content in the solution is less than or equal to 300mg/L, desiliconization is not needed, and if the silicon content exceeds 300mg/L, desiliconization is needed.

5. The method for preparing vanadyl sulfate solution with microemulsion according to claim 1, wherein: step 2) in the microemulsion:

the concentration of Aliquat 336 is: 1-45% (w/w)

The concentration of isoamyl alcohol is: 10-30% (w/w)

The concentration of n-heptane was: 30-80% (w/w)

The concentration of NaOH is: 0.1-1mol/L

The concentration of NaCl was: 0.1-1mol/L

6. The method for preparing vanadyl sulfate solution with microemulsion according to claim 1, wherein: step 5), before standing and layering, continuously introducing SO into the reactor₂。

7. The method for preparing vanadyl sulfate solution with microemulsion according to claim 2, wherein:

in step 6), the solution used for neutralization washing is NaOH solution.

8. The method for preparing vanadyl sulfate solution with microemulsion according to claim 3, wherein:

in the step 7, the concentration of NaOH and NaCl in the mixed solution is 0.1-1 mol/L.

Technical Field

The invention relates to preparation of materials related to an all-vanadium redox flow battery, in particular to vanadyl sulfate electrolyte.

Background

An all vanadium redox flow battery (VFB for short) is a novel pollution-free chemical energy storage power supply and has the characteristics of long service life, deep charging and discharging, and easiness in operation and maintenance. The VFB is mainly applied to the fields of energy storage systems of large-scale renewable energy power generation such as wind power generation, solar power generation and the like, peak shaving balance load of power plants and the like. VFB adopts sulfuric acid solutions of vanadium ions with different valence states as electrolytes, usually, a positive electrolyte adopts a tetravalent vanadium ion solution, and charging is oxidized into a pentavalent vanadium ion solution; the negative electrolyte adopts trivalent vanadium ion solution, and is charged and reduced into divalent vanadium ion solution, so that the preparation of tri-valent and quadrivalent vanadium ion solution is of great importance to the actual field operation. The electrolyte is not only an energy carrier of the battery, but also a reaction active substance, determines the capacity and specific energy of the battery, and directly influences the charge-discharge efficiency, the service life and other performances of the vanadium battery.

Vanadyl sulfate (VOSO)₄) The solution is used as a positive electrode electrolyte and is reduced into V³⁺VFB was composed as the negative electrolyte. Thus, a VOSO corresponding to the preparation of the electrolyte is obtained₄Solutions are of great significance. Preparation of VOSO at present₄The main raw material is V₂O₅. The adopted reducing agents comprise organic reducing agents, such as oxalic acid, tartaric acid, sucrose, ethanol, formic acid, acetic acid and the like; and also H₂S and Fe²⁺As a reducing agent. The organic reducing agent has problems of weak reducing ability, slow reaction speed and CO₂Gas generation, large consumption of reducing agent, high cost, and difficult removal of the reducing agent when the reducing agent is excessive; h₂S has good reducibility and high reaction speed, but H has high reaction speed under the reaction condition₂The S gas has low solubility in water and high toxicity, and is not easy to control in use; fe²⁺Iron ion impurities are introduced as a reducing agent, so that purification is not easy to realize and VOSO is influenced₄Yield and purity of, to VOSO₄Is unfavorable as an electrolyte.

Disclosure of Invention

The invention aims to provide a method for preparing vanadyl sulfate solution by using microemulsion, which is characterized by comprising the following steps:

obtaining a vanadium-containing solution containing sodium metavanadate, and adjusting the pH value to 2.5-14;

preparing microemulsion by using Aliquat 336, isoamylol, n-heptane and mixed solution of NaOH and NaCl;

mixing the microemulsion with the solution obtained in the step 1) according to the volume ratio of 1:1-5, oscillating for extraction, standing for layering, wherein the upper phase is a microemulsion phase, the lower phase is a water phase, and separating the microemulsion phase from the water phase;

mixing the upper micro-emulsion phase (loaded micro-emulsion phase) in the step 3) with a sulfuric acid solution according to the ratio of 1:0.5-3, oscillating for washing, standing for layering, and separating the micro-emulsion phase from the water phase;

the concentration of the sulfuric acid solution is 1-3;

obtaining VOSO by A or B method₄Solution:

a: preparing a mixed solution of sulfuric acid and sulfurous acid, wherein the volume ratio of the sulfuric acid solution to the sulfurous acid solution in the raw materials is (1-3) to (1-3); the concentration of the sulfuric acid is 1-10mol/L, and the concentration of the sulfurous acid is 1-5% (w/w);

mixing the loaded microemulsion phase obtained by washing in the step 4 with the mixed solution in the step according to the ratio of 1-3:1, standing for layering, wherein the upper phase is the microemulsion phase, and the lower phase is VOSO₄Solution, separating micro-emulsion phase from water phase;

b: mixing the loaded microemulsion phase obtained by washing in the step 4 with a sulfuric acid solution according to a ratio of 1-3:1, and introducing SO₂Standing for layering, wherein the upper phase is microemulsion phase, and the lower phase is VOSO₄Solution, separating micro-emulsion phase from water phase;

sulfuric acid solution and SO₂The volume ratio of the gas is 1: 1-50; the concentration of the sulfuric acid solution is 1-10 mol/L;

further, 6) neutralizing and washing the microemulsion obtained in the step 5, standing and layering after washing, and separating a microemulsion phase from a water phase to obtain a lower phase VOSO₄And (3) solution.

Further, 7) carrying out internal water phase restoration on the microemulsion obtained after the reaction is finished, wherein the restored microemulsion can be used for replacing the microemulsion in the step 2) for recycling.

Further, in the step 1), the concentration of vanadium in the vanadium-containing solution is 1-35 g/L;

if the silicon content in the solution is less than or equal to 300mg/L, desiliconization is not needed, and if the silicon content exceeds 300mg/L, desiliconization is needed.

The desiliconization step is as follows: firstly, regulating the pH value of the vanadium-containing solution to 9-10, adding aluminum sulfate according to the Al/Si molar ratio of 0.9 for desiliconization, and regulating the pH value of the desiliconized solution to 2.5-8.

Further, step 2) in the microemulsion:

the concentration of Aliquat 336 is: 1-45% (w/w)

The concentration of isoamyl alcohol is: 10-30% (w/w)

The concentration of n-heptane was: 30-80% (w/w)

The concentration of NaOH is: 0.1-1mol/L

The concentration of NaCl was: 0.1-1mol/L

Further, in step 5), continuously introducing SO into the reactor before standing and layering₂。

Further, in step 6), the solution used for neutralization washing was a 4 to 6mol/L NaOH solution, and the washing phase ratio O/a was 1: 1-3.

Further, in the step 7), the concentration of NaOH and NaCl in the mixed solution is 0.1-1 mol/L.

The invention provides a new clean and efficient production mode, solves the problems of the prior art, and prepares VOSO from the microemulsion₄The new process can solve the problems of the existing process, and belongs to the technology of environmental protection, high efficiency and energy saving.

Drawings

Figure 1 is a process flow diagram.

Detailed Description

The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.

A method for preparing vanadyl sulfate solution by using microemulsion is characterized by comprising the following steps:

obtaining a vanadium-containing solution containing sodium metavanadate, and adjusting the pH value to be 2.5-14, preferably 2.5-8.