阅读说明：本技术 基于orp值计算湿法脱硫浆液液相含硫(iv)物质含量的方法 (Method for calculating liquid-phase sulfur (IV) containing substance content of wet desulphurization slurry based on ORP value ) 是由 房孝维 何育东 李兴华 陶明 余昭 吴晓龙 宦宣州 何仰朋 孟令海 李楠 王韶晖 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种基于ORP值计算湿法脱硫浆液液相含硫(IV)物质含量的方法,包括：针对脱硫浆液液相中发生的各氧化还原反应,确定各反应标准电极电位；针对脱硫浆液液相中发生的各氧化还原反应,根据能斯特方程,确定反应电极电位与氧化态及还原态物质浓度的关系；计算脱硫浆液实测ORP值,确定脱硫浆液的实测ORP值与其含硫(IV)物质含量的对应关系；根据脱硫浆液的实测ORP值与其含硫(IV)物质含量的对应关系确定湿法脱硫浆液液相的含硫(IV)物质含量,该方法能够准确测定湿法脱硫浆液液相含硫(IV)物质含量。(The invention discloses a method for calculating the liquid-phase sulfur (IV) containing substance content of wet desulphurization slurry based on ORP value, which comprises the following steps: determining the potential of each reaction standard electrode aiming at each redox reaction generated in the desulfurization slurry liquid phase; determining the relation between the reaction electrode potential and the concentration of the oxidation state and reduction state substances according to the nernst equation aiming at each oxidation-reduction reaction in the desulfurization slurry liquid phase; calculating an actual measurement ORP value of the desulfurization slurry, and determining a corresponding relation between the actual measurement ORP value of the desulfurization slurry and the content of sulfur (IV) containing substances; and determining the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry according to the corresponding relation between the measured ORP value of the desulphurization slurry and the content of the sulfur (IV) containing substances of the liquid phase of the wet desulphurization slurry, wherein the method can accurately determine the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry.)

1. A method for calculating the liquid phase sulfur (IV) containing species content of a wet-desulfurization slurry based on the ORP value, comprising:

determining the potential of each reaction standard electrode aiming at each redox reaction generated in the desulfurization slurry liquid phase;

determining the relation between the reaction electrode potential and the concentration of the oxidation state and reduction state substances according to the nernst equation aiming at each oxidation-reduction reaction in the desulfurization slurry liquid phase;

determining the corresponding relation between the measured ORP value of the desulfurization slurry and the content of sulfur (IV) containing substances according to the measured ORP value of the desulfurization slurry;

and determining the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry according to the corresponding relation between the measured ORP value of the desulphurization slurry and the content of the sulfur (IV) containing substances.

2. The method for calculating the content of sulfur (IV) containing substances in the liquid phase of a wet desulfurization slurry based on the ORP value of claim 1, wherein the sulfur (IV) containing substances in the liquid phase of the wet desulfurization slurry comprises H₂SO₃、HSO₃ ^-And SO₃ ^2-。

3. The method for calculating the liquid-phase sulfur (IV) containing species content of a wet-desulfurization slurry based on the ORP value of claim 1, wherein the following redox reactions occur in the liquid phase of the desulfurization slurry:

。

4. the method for calculating the liquid-phase sulfur (IV) containing species content of a wet-desulfurization slurry based on the ORP value of claim 1, wherein each reaction electrode potential E₁、E₂、E₃、E₄、E₅And E₆The relationship with the concentration of the oxidized and reduced species is:

。

wherein R is a gas constant, n is the number of transferred electrons, F is a Faraday constant, T is the slurry temperature,andthe standard electrode potentials of the reactions are respectively.

5. The method for calculating the liquid phase sulfur (IV) containing species content of a wet flue gas desulfurization slurry based on ORP value of claim 4, wherein the measured ORP value E of the slurry is_total＝E₁+E₂+E₃+E₄+E₅+E₆。

6. The method for calculating the liquid-phase sulfur (IV) containing species content of a wet-desulfurization slurry based on the ORP value of claim 4, wherein H₂SO₃、HSO₃ ^-And SO₃ ^2-And HSO₄ ^-And SO₄ ^2-The following relationships exist:

Technical Field

The invention belongs to the technical field of chemistry, and relates to a method for calculating the content of sulfur (IV) containing substances in a wet desulphurization slurry liquid phase based on an ORP value.

Background

At present, the flue gas desulfurization of a thermal power plant mostly adopts a wet desulfurization process, air blown by an oxidation fan is used for oxidation, the oxidation-reduction reactions in a liquid phase are represented by formulas (1) to (6), the reactions are all conversion from sulfur (IV) containing substances to sulfur (VI) containing substances, and the sulfur (IV) containing substances involved in the liquid phase reaction in the reaction process comprise: h₂SO₃、HSO₃ ^-And SO₃ ^2-The sulfur (VI) containing substance being predominantly H₂SO₄、HSO₄ ^-. The reaction all takes place in the liquid phase, O₂It is necessary to dissolve from the gas phase into the liquid phase before the reaction takes place.

The content of sulfur (IV) containing substances in the slurry liquid phase can reflect the oxidation degree of the slurry, and can be used for accurately guiding an oxidation fan so as to ensure the quality of gypsum.

However, the prior art can not measure the content of sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for calculating the content of sulfur (IV) containing substances in the liquid phase of wet desulphurization slurry based on ORP value, which can accurately determine the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry.

In order to achieve the above object, the method for calculating the liquid-phase sulfur (IV) containing material content of the wet-process desulfurization slurry based on the ORP value according to the present invention comprises:

determining the potential of each reaction standard electrode aiming at each redox reaction generated in the desulfurization slurry liquid phase;

determining the relation between the reaction electrode potential and the concentration of the oxidation state and reduction state substances according to the nernst equation aiming at each oxidation-reduction reaction in the desulfurization slurry liquid phase;

determining the corresponding relation between the measured ORP value of the desulfurization slurry and the content of sulfur (IV) containing substances according to the measured ORP value of the desulfurization slurry;

and determining the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry according to the corresponding relation between the measured ORP value of the desulphurization slurry and the content of the sulfur (IV) containing substances.

The sulfur (IV) containing species of the wet desulfurization slurry liquid phase comprise H₂SO₃、HSO₃ ^-And SO₃ ^2-。

The following redox reactions take place in the liquid phase of the desulfurized slurry:

potential E of each reaction electrode₁、E₂、E₃、E₄、E₅And E₆The relationship with the concentration of the oxidized and reduced species is:

wherein R is a gas constant, n is the number of transferred electrons, F is a Faraday constant, T is the slurry temperature,andthe standard electrode potentials of the reactions are respectively.

Measured ORP value E of slurry_total＝E₁+E₂+E₃+E₄+E₅+E₆。

H₂SO₃、HSO₃ ^-And SO₃ ^2-And HSO₄ ^-And SO₄ ^2-The following relationships exist:

the invention has the following beneficial effects:

when the method for calculating the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry based on the ORP value is specifically operated, firstly, the corresponding relation between the actually measured ORP value of the desulphurization slurry and the content of the sulfur (IV) containing substances is determined, and then the content of the sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry is determined according to the corresponding relation between the actually measured ORP value of the desulphurization slurry and the content of the sulfur (IV) containing substances.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following embodiments of the present invention will be clearly and completely described in the following embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all embodiments, and are not intended to limit the scope of the disclosure of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The method for calculating the liquid-phase sulfur (IV) containing substance content of the wet-process desulfurization slurry based on the ORP value comprises the following steps:

1) determining standard electrode potential E of each reaction aiming at each oxidation-reduction reaction generated in the desulfurization slurry liquid phase^θ；

2) Determining the relation between the reaction electrode potential and the concentration of the oxidation state and reduction state substances according to the nernst equation aiming at each oxidation-reduction reaction in the desulfurization slurry liquid phase;

the sulfur (IV) containing species comprises H₂SO₃、HSO₃ ^-And SO₃ ^2-。

The ORP value is obtained from the following 6 redox reactions occurring in the liquid phase of the desulfurized slurry:

the relationship between the potential of each reaction electrode and the concentration of the substances in the oxidation state and the reduction state is as follows:

wherein R is a gas constant, n is the number of transferred electrons, F is a Faraday constant, and T is the slurry temperature.

3) Determining the corresponding relation between the measured ORP value of the desulfurization slurry and the content of sulfur (IV) containing substances;

measured ORP value E of slurry_total＝E₁+E₂+E₃+E₄+E₅+E₆。

Obtaining ORP value and H₂SO₃、HSO₃ ^-And SO₃ ^2-The one-to-one correspondence of the contents is then determined according to the ORP value and H₂SO₃、HSO₃ ^-And SO₃ ^2-And determining the content of sulfur (IV) containing substances in the liquid phase of the wet desulphurization slurry according to the one-to-one correspondence relationship of the contents.

Note that, according to the weak acid dissociation equilibrium constant, H₂SO₃、HSO₃ ^-And SO₃ ^2-And HSO₄ ^-And SO₄ ^2-The following relationships exist: wherein, when T is 298.15K at normal temperature, Ka₁、Ka₂And Ka'₂Respectively, are 1.23X 10^-2、5.6×10^-8And 1.02X 10^-2Ka value according to Δ G under very high temperature conditions_dissCalculated as-RTlnKa,. DELTA.G_dissIs the change in gibbs free energy during acid dissociation.

SO₄ ^2-Concentration ofWherein, K_spIs a solubility product constant, the solubility product being in the temperature range from 273.15K to 348.15K, in terms of K_sp(T)＝-1.307×10^-4+9×10^-7·T-1.448×10^-9·T²A determination is made.

The standard electrode potential is a known term, the actual ORP value of the sulfuric acid slurry is measured by the redox electrode, the temperature T is measured by the thermometer, [ H ]⁺]Measured by a pH meter, [ O ]₂]Measured by a dissolved oxygen meter, [ Ca ]²⁺]Measured by a calcium ion meter detector.

Example one

The specific process of this embodiment is as follows:

taking a proper amount of desulfurization slurry to be detected, placing the desulfurization slurry in a beaker, and filtering the desulfurization slurry by using quick filter paper to obtain clear filtrate;

according to the volume ratio of the clear filtrate to the deionized water of 1: 5, adding quantitative deionized water, and fully shaking up;

inserting electrodes of required instruments (a thermometer, a PH meter, an oxygen dissolving instrument and a calcium ion detector) into the slurry until the readings of the instruments are stable;

obtaining the temperature T of the slurry according to a thermometer; calculating the concentration of H + according to the pH value; reading Ca by calcium ion meter²⁺Concentration; obtaining O from dissolved oxygen meter₂Concentration; at a temperature T, H is obtained₂SO₃、HSO₃ ^-And SO₃ ^2-，HSO₄ ^-And SO₄ ^2-The concentration relationship of (a); and calculating the solubility product of the calcium sulfate at the temperature T;

the calculation according to the invention yields the sulfur (IV) containing species (H) in the liquid phase of the slurry₂SO₃、HSO₃ ^-And SO₃ ^2-) The content of (a).

Example two

The specific process of this embodiment is as follows:

taking a proper amount of desulfurization slurry to be measured, placing the desulfurization slurry in a beaker, adding magnetons, and uniformly dispersing the slurry under stirring of a magnetic stirrer;

inserting electrodes of required instruments (a thermometer, a PH meter, an oxygen dissolving instrument and a calcium ion detector) into the slurry until the readings of the instruments are stable;

obtaining the temperature T of the slurry according to a thermometer; calculating the concentration of H + according to the pH value; reading Ca by calcium ion meter²⁺Concentration; obtaining O from dissolved oxygen meter₂Concentration; at a temperature T, H is obtained₂SO₃、HSO₃ ^-And SO₃ ^2-，HSO₄ ^-And SO₄ ^2-The concentration relationship of (a); and calculating the solubility product of the calcium sulfate at the temperature T;

the calculation according to the invention yields the sulfur (IV) containing species (H) in the liquid phase of the slurry₂SO₃、HSO₃ ^-And SO₃ ^2-) The content of (a).

The applicant states that the invention provides a method for calculating the content of sulfur (IV) containing material in the liquid phase of a wet desulfurization slurry based on ORP value by the above examples, but the invention is not limited to the above examples, i.e., it is not meant that the invention must rely on the above examples to be practiced. It will be apparent to those skilled in the art that any modifications of the present invention are within the scope and disclosure of the present invention.