阅读说明：本技术 一种兼具换热器高耐腐蚀性能的电解合成丁二酸复极式电极 (Electrolytic synthesis succinic acid multipole electrode with high corrosion resistance of heat exchanger ) 是由 甘永平 张允岚 黄辉 张文魁 梁初 夏阳 张俊 贺馨平 于 2020-12-21 设计创作，主要内容包括：本发明属于电极材料领域,具体涉及一种工业化电解生产丁二酸的兼具换热器作用的高耐腐蚀性复极式电极。所述复极式电极结构为密闭空腔长方体,长方体阳极面为铅合金或铱钛氧化物涂层/钛,阴极面为铅合金或钛网/钛板；电极空腔内可通冷却水与电解液换热调控电解液温度,并降低阳极表面和阴极表面温度,显著提高电极的耐腐蚀性能。在10％硫酸电解液中以20000A/m～2的电流密度强化电解,通冷却水的复极式电极可延长电极寿命1.6倍,并解决电解过程中放热问题,可以大幅度降低目前工业中铅合金阳极和铱钛涂层阳极的电极消耗,可应用于大规模电解合成丁二酸工业。(The invention belongs to the field of electrode materials, and particularly relates to a high-corrosion-resistance bipolar electrode with the function of a heat exchanger for industrially producing succinic acid through electrolysis. The bipolar electrode structure is a closed cavity cuboid, the anode surface of the cuboid is lead alloy or iridium titanium oxide coating/titanium, and the cathode surface of the cuboid is lead alloy or titanium mesh/titanium plate; cooling water can be introduced into the electrode cavity to exchange heat with the electrolyte to regulate the temperature of the electrolyte, and the temperature of the surface of the anode and the surface of the cathode can be reduced, thereby showingThe corrosion resistance of the electrode is improved. In 10% sulfuric acid electrolyte at 20000A/m 2 The current density is enhanced to electrolyze, the service life of the electrode can be prolonged by 1.6 times by the multi-pole electrode which is filled with cooling water, the heat release problem in the electrolytic process is solved, the electrode consumption of the lead alloy anode and the iridium-titanium coating anode in the current industry can be greatly reduced, and the method can be applied to the industry of large-scale electrolytic synthesis of succinic acid.)

1. The utility model provides a have electrolysis synthesis succinic acid multipole formula electrode of heat exchanger high corrosion resistance concurrently, a serial communication port, multipole formula electrode is the cuboid that is equipped with airtight cavity, the front of cuboid is the anode surface, the back is the negative pole face, the top surface of cuboid is provided with and feeds through the cooling water in the cavity and advance pipe and cooling water exit tube, outside cooling water advances in the pipe input cavity and discharges from the cooling water exit tube through the cooling water, carry out the heat transfer to the electrolyte with multipole formula electrode contact through the cooling water in the input cavity, regulate and control the temperature of electrolyte, with the temperature that anode surface and negative pole face on the multipole formula electrode can be reduced to the cooling water in the time space intracavity, the corrosion resistance of multipole formula electrode is improved.

2. The electrolytic synthesis succinic acid bipolar electrode with high corrosion resistance of the heat exchanger as claimed in claim 1, wherein the bipolar electrode is made of metal lead alloy.

3. The electrolytic synthesis succinic acid bipolar electrode with high corrosion resistance of the heat exchanger as claimed in claim 1, wherein the bipolar electrode is made of titanium, and the anode surface is provided with IrO₂-Ta₂O₅The cathode surface of the coated titanium plate is a titanium plate.

4. The electrolytic synthesis succinic acid bipolar electrode with high corrosion resistance of the heat exchanger as claimed in claim 1, wherein the bipolar electrode is made of titanium, and the titanium plate of the anode surface is welded with IrO₂-Ta₂O₅The cathode surface of the coated titanium net is a titanium plate.

5. The electrolytic synthesis succinic acid bipolar electrode with high corrosion resistance of the heat exchanger as claimed in claim 1, wherein the bipolar electrode is made of titanium, and the titanium plate of the anode surface is welded with IrO₂-Ta₂O₅Coated titanium mesh, outside of cathode plane titanium plateAnd welding a titanium mesh.

6. The bipolar electrode for electrolytically synthesized succinic acid with high corrosion resistance of a heat exchanger as claimed in claim 1, wherein the cooling water inlet pipe passes through one end of the top surface of the rectangular parallelepiped and extends into the bottom of the cavity, the cooling water outlet pipe is disposed at the other end of the top surface of the rectangular parallelepiped, and the cooling water inlet pipe and the cooling water outlet pipe are connected to a cooling water system outside the electrolytic cell.

7. The electrolytic synthetic succinic acid bipolar electrode with high corrosion resistance of the heat exchanger as claimed in claim 1, wherein the two sides of the rectangular parallelepiped are welded with clamping edges, the bipolar electrode is wedged into the frame of the electrolytic cell through the clamping edges, the bottom surface of the bipolar electrode is tightly attached to the bottom surface of the frame of the electrolytic cell, and the electrolytic cell is divided into 2-100 unit electrolytic cells by the multiple bipolar electrodes.

8. The electrolytic synthesis succinic acid bipolar electrode with the high corrosion resistance of the heat exchanger as claimed in claim 1, wherein the surface temperature of the bipolar electrode and the temperature of the electrolyte are controlled by controlling the temperature and the flow rate of cooling water introduced into the bipolar electrode.

9. The application of the bipolar electrode for electrolytically synthesizing succinic acid with high corrosion resistance of the heat exchanger in any one of claims 1 to 8 is characterized by being applied to large-scale industrial production of the succinic acid by electrolytic synthesis, and the applicable current density of the bipolar electrode is 100-1000A/m²。

Technical Field

The invention belongs to the field of electrode materials, relates to an electrode material for large-scale industrial production of succinic acid, and particularly relates to an electrolytic synthesis succinic acid bipolar electrode with high corrosion resistance of a heat exchanger.

Background

Succinic acid is commonly called succinic acid, is an important synthetic intermediate for synthesizing medicines and fine chemicals, and is widely applied to synthesis of plastics, rubber, medicines, protective coatings and other industries. Succinic acid has most of the typical reactions of diacids such as halogenation, dehydration, esterification, polycondensation, iodination, acylation, oxidation, reduction, and the like. A series of monoesters and diesters can be prepared by using succinic acid as a substrate. Such as succinic acid esterification with starch, cellulose and polyols; the succinic acid and the 1, 4-butanediol can be subjected to polycondensation reaction to synthesize polybutylene succinate (PBS), which is a biodegradable plastic and has a very wide market popularization prospect. In recent years, with the promotion of national plastic prohibition, the domestic market of the succinic acid is expected to break through the scale of more than 20 ten thousand annual products. Therefore, the scale-up of the production is an inevitable requirement for the rapid development of the succinic acid market at present.

The main industrial preparation methods of succinic acid include maleic acid (ester) catalytic hydrogenation reduction method, biochemical method and electrolytic reduction method. The catalytic hydrogenation method uses butene diacid ester as raw material, the product is complex, and the conversion rate is low; the biochemical method is widely researched, but the biochemical method has large amount of wastewater, and products have various monoacids and cannot be used for the polymerization reaction of PBS; the electrolytic method is widely adopted by manufacturers at home and abroad, and is the main method for producing succinic acid at home and abroad at present.

The succinic acid is electrolytically synthesized by taking maleic anhydride as a raw material and adopting diaphragm-free electrolysis. The anode material of the electrolysis device is an iridium-titanium noble metal coating electrode, such as Shandong Feiyang chemical Co., Ltd, Shanxi Jinhui Mfg Co., Ltd; or lead alloy electrodes, such as Anqing and Xing chemical Co., Ltd, Anhui Sanxin chemical Co., Ltd, etc. Lead alloy anode materials have serious electrode corrosion in the electrolytic process, short service life (3-6 months), high maintenance cost of an electrolytic cell and poor product quality; the iridium titanium coating electrode is an electrocatalytic oxygen evolution electrode, has very good oxygen evolution activity and larger working current, but is expensive, the total price of the coating per square meter and the titanium mesh substrate exceeds 1 ten thousand yuan, the service life of the electrode is sharply reduced when the temperature of the electrolyte is increased to 80 ℃, and the service life of the electrode is generally not more than 3 years. Therefore, the corrosion resistance of the anode material for industrially synthesizing succinic acid through electrolysis becomes a key technology for the scale production of succinic acid.

Exothermic exists in the electrolytic process of synthesizing the succinic acid by electrolysis, the temperature of the electrolyte gradually rises along with the electrolysis, even can rise to 100 ℃, and the corrosion resistance of the lead alloy anode and the iridium-titanium coating electrode is rapidly reduced in hot solution. At present, the temperature of electrolyte is controlled by an external or internal heat exchanger, but the problems of difficult material selection, inconvenient use, low heat exchange efficiency and the like of the heat exchanger exist. The invention designs the multi-pole electrode which is filled with cooling water, and the cooling electrode has the function of a heat exchanger while improving the corrosion resistance of the electrode by heat exchange between the electrode and electrolyte, so that the temperature of the electrolyte is regulated and controlled.

Disclosure of Invention

Lead alloy electrodes or iridium titanium oxide coating electrodes are generally adopted as anode materials for industrially synthesizing succinic acid by electrolysis, and the anode materials have the defects of poor corrosion resistance and short service life; particularly, when the temperature of the electrolyte exceeds 60 ℃, the corrosion rate is obviously increased, thereby influencing the cost and the production stability of the industrial electrolytic synthesis of the succinic acid. The invention mainly aims to solve the problems that the existing succinic acid insoluble anode lead alloy material and iridium titanium oxide coating electrode prepared by industrial electrolysis are easy to corrode, short in service life and high in cost, and the practical problems that the material selection of a heat exchanger is difficult and the like, and provides a self-cooling bipolar electrode for industrial electrolysis production of succinic acid.

In order to achieve the above object, the present invention provides the following technical solutions:

the utility model provides a have the electrolytic synthesis succinic acid multipole formula electrode of heat exchanger high corrosion resistance concurrently, multipole formula electrode is the cuboid that is equipped with airtight cavity, the front of cuboid is the anode surface, the back is the negative pole face, the top surface of cuboid is provided with and feeds through the cooling water in the cavity and advance pipe and cooling water exit tube, outside cooling water advances in the pipe input cavity and discharges from the cooling water exit tube through the cooling water, carry out the heat transfer to the electrolyte with multipole formula electrode contact through the cooling water in the input cavity, regulate and control the temperature of electrolyte, the cooling water in the same time space-time intracavity can reduce the temperature of anode surface and negative pole face on the multipole formula electrode, is showing the corrosion resistance who improves the electrode.

Preferably, the material of the bipolar electrode is a metal lead alloy.

Preferably, the material of the bipolar electrode is metallic titanium, and the anode surface is provided with IrO₂-Ta₂O₅The cathode surface of the coated titanium plate is a titanium plate; more preferably, the material of the bipolar electrode is metallic titanium, and the external welding belt IrO of the anode surface titanium plate₂-Ta₂O₅The cathode surface of the coated titanium net is a titanium plate; more preferably, the material of the bipolar electrode is metallic titanium, and the external welding belt IrO of the anode surface titanium plate₂-Ta₂O₅The titanium mesh of the coating is welded outside the cathode surface titanium plate.

Preferably, the cooling water inlet pipe penetrates through one end of the top surface of the cuboid and extends into the bottom in the cavity, the cooling water outlet pipe is arranged at the other end of the top surface of the cuboid, and the cooling water inlet pipe and the cooling water outlet pipe are communicated to a cooling water system outside the electrolytic cell.

Preferably, clamping edges are welded on two side faces of the cuboid and made of titanium or lead alloy, more preferably, the clamping edges are strip-shaped bulges, and the bipolar electrodes are wedged into a frame body of the plastic electrolytic tank through the clamping edges; the bottom surface of the bipolar electrode is tightly attached to the bottom surface of the frame body of the electrolytic tank (PP material), and the electrolytic tank is divided into different unit electrolytic tanks, wherein the number of the unit electrolytic tanks is 2-100.

Preferably, the surface temperature of the bipolar electrode and the temperature of the electrolyte are regulated and controlled by controlling the temperature and the flow rate of cooling water introduced into the bipolar electrode.

Preferably, any one of the above bipolar electrodes with high corrosion resistance of the heat exchanger is suitable for large-scale industrial production of the succinic acid by electrolytic synthesis, and the applicable current density of the bipolar electrode is 100-²。

Compared with the prior art, the bipolar electrode of the invention has the main beneficial effects that: (1) in 10 wt% + (1-15) wt% sulfuric acid succinic acid electrolyte, 500A/m²Under the current density of the anode, the anode material adopts a lead alloy electrode, and the service life is prolonged to 1 year from the original 6 months; (2) in 10 wt% +1-15 wt% succinic acid-sulfuric acid electrolyte at 500A/m²Under the current density of the anode, the anode material adopts an iridium titanium coating electrode, and the service life is prolonged to 48 months from the original 30 months; (3) the problem of difficulty in material selection of the industrial electrolytic synthesis succinic acid heat exchanger is solved, corrosion of the titanium heat exchanger is reduced, the surface temperature of the electrode can be controlled to be lower than 50 ℃, the temperature of the electrolyte is increased to 85 ℃, the temperature range of the electrolyte is increased, and the method is suitable for large-scale industrial electrolytic synthesis succinic acid production.

Drawings

FIG. 1 is a schematic diagram of an electrolytic synthesis succinic acid bipolar electrode with high corrosion resistance of a heat exchanger;

in figure 1, 1-multipole type electrode, 2-anode surface, 3-cathode surface, 4-clamping edge, 5-cooling water inlet pipe, 6-cooling water outlet pipe, 7-titanium net and 8-IrO₂-Ta₂O₅Coating/titanium mesh.

FIG. 2 is a schematic diagram of an electrolysis experiment;

in FIG. 2, the 9-side electrode plate is connected with the positive electrode of the power supply, the 10-side electrode plate is connected with the negative electrode of the power supply, the 11-external cooling water inlet pipe and the 12-external cooling water outlet pipe are connected.

FIG. 3 is a graph of voltage change in an enhanced lifetime test for different multi-polar electrodes of example 1;

FIG. 4 is a graph showing experimental voltage changes of the bipolar electrode without cooling water in example 2.

Detailed Description

The technical solution of the present invention is further specifically described below by way of specific examples in conjunction with the accompanying drawings.

Example 1

Referring to a schematic diagram of fig. 1, a small experimental bipolar electrode 1 is processed, the bipolar electrode 1 is a cuboid with a closed cavity, the front surface of the cuboid is an anode surface 2, the back surface of the cuboid is a cathode surface 3, the top surface of the cuboid is provided with a cooling water inlet pipe 5 and a cooling water outlet pipe 6, the cooling water inlet pipe 5 penetrates through one end of the top surface of the cuboid and extends into the bottom in the cavity, the cooling water outlet pipe 6 is arranged at the other end of the top surface of the cuboid, the cooling water inlet pipe 5 and the cooling water outlet pipe 6 are communicated to a cooling water system outside the electrolytic bath, external cooling water is input into the cavity through the cooling water inlet pipe and is discharged from the cooling water outlet pipe, the cooling water input into the cavity exchanges heat with the electrolyte contacting with the bipolar electrode to regulate the temperature of the electrolyte, the cooling water in the cavity can cool the anode surface and the cathode surface of the bipolar electrode at the same time, so that the corrosion resistance of the bipolar electrode is obviously improved; two sides of the bipolar electrode 1, namely two sides of the cuboid, are welded with clamping edges 4; the material of the bipolar electrode 1 is metal lead alloy or metal titanium, when the material of the bipolar electrode 1 is metal titanium, the anode surface of the bipolar electrode 1 is provided with IrO₂-Ta₂O₅Coated titanium plates, or plates with IrO welded thereto₂-Ta₂O₅Titanium plate of coating/titanium mesh 8, said IrO₂-Ta₂O₅The coating/titanium mesh 8 is provided with IrO₂-Ta₂O₅Of coatingsA titanium mesh; the cathode surface of the bipolar electrode 1 is a titanium plate or a titanium plate welded with a titanium mesh 7; the titanium plate is a corresponding electrode surface formed when the material of the bipolar electrode 1 is metal titanium; the length (L) of the rectangular solid of the multi-pole electrode, the height (H) of the rectangular solid of the multi-pole electrode, the thickness (W) of the rectangular solid of the multi-pole electrode, the specification of the clamping edge, the specification of the cooling water inlet pipe and the specification of the titanium mesh are 40mm, 20mm and 1mm respectively. The electrode specifications for the strengthening experiment were as follows:

TABLE 1 multipole type electrode for experiments

And (3) carrying out a strengthening life test on the electrode to evaluate the corrosion resistance of the electrode. Electrolyte 10 wt% H₂SO₄+5 wt% succinic acid solution, the electrolytic tank is divided into 5 electrodes and 4 chambers by adopting a multi-electrode type electrode A-D, as shown in figure 2, wherein 9 is an edge plate connected with a power supply anode, 10 is an edge plate connected with a power supply cathode, 11 is an external cooling water inlet pipe, 12 is an external cooling water outlet pipe, the distance between the multi-electrode type electrodes is 1cm, and the actual test area of the electrodes is 6cm²Constant current density 12A (Current Density 20000A/m)²) And (3) electrolyzing, starting a cooling water system, regulating and controlling the flow rate of cooling water to control the temperature of the electrolyte to be 55 +/-1 ℃, recording the change of the bath voltage along with the time, and recording the electrolysis time when the bath voltage is suddenly increased to be regarded as anode failure. After the electrode fails, cleaning, drying at 120 ℃, weighing the mass of the middle 3 pieces of the multi-pole electrode, and recording the weight loss average value of the electrode before and after electrolytic strengthening. A. B, C, D the four electrodes are electrolyzed to 120h, wherein the electrode A needs to remove deposited lead mud, and the cumulative weight loss is 36.02g, 0.564g, 0.64g and 0.54g respectively. The results of the change in the electrolytic voltage are shown in FIG. 3.

The result of FIG. 3 shows that the service life of the D electrode strengthening experiment is as long as 130h, the service life of the plate-shaped coating electrode of the titanium-based bipolar electrode is shorter than that of a mesh electrode, and the mesh electrode adopted by the cathode is beneficial to reducing the current density and improving the service life of the electrode; B. c, D the weight loss of the three titanium-based electrodes is not obvious, which is probably related to the mass of the titanium dioxide electrode which is generated when the coating on the surface of the titanium-based electrode is peeled off. The lead alloy A electrode test result shows that the cell voltage is slowly increased, and the weight loss reaches 39.04 percent after the electrode is seriously corroded for 120 hours.

Example 2

According to the method of the embodiment 1, A, B, C, D four multipole electrodes are used as research objects, cooling water is not introduced, electrolysis is naturally carried out, temperature is raised, electrolyte lost due to evaporation is supplemented timely, the temperature is raised to 90-95 ℃ after 2 hours of electrolysis, the voltage-time relation of electrolysis is tested, the reinforced service life of the electrodes is tested, and the corrosion resistance of electrolysis is evaluated, and the result is shown in figure 4.

The results of FIG. 4 show that the temperature of the electrolyte naturally rises under the condition of no cooling water, the temperature of the electrolyte reaches 90-95 ℃, the service life of the electrode is obviously reduced, the average cell voltage of the D electrode after 70 hours exceeds 4.5V, and then the electrode coating is rapidly damaged, and the cell voltage rises rapidly. Lead alloy is seriously corroded, and the weight loss of the electrode after 70 hours of electrolysis is 52.3 percent.

Examples 3 to 7

The method of example 1 was followed, using a D multi-polar electrode as the study subject, controlling the temperature and flow rate of the cooling water, controlling the temperature of the electrolyte at 40 deg.C, 50 deg.C, 60 deg.C, 70 deg.C and 80 deg.C respectively to perform life-strengthening tests, adding the electrolyte lost by evaporation at appropriate times, and when the cell voltage increased to 25.0V, the electrode was considered to be failed, and the test results were recorded as the cumulative electrolysis time shown in Table 2.

TABLE 2 electrode strengthening life by regulating and controlling different electrolyte temperatures

Examples	Example 3	Example 4	Example 5	Example 6	Example 7
						Temperature/. degree.C	40	50	60	70	80
Time/h	162.8	151.4	146.0	145.5	144.8

Example 8

The succinic acid is electrolytically synthesized by adopting the device in the figure 1, the electrode adopts a multi-electrode type electrode D, the electrolyte consists of 8 percent of sulfuric acid and 10 percent of maleic acid (the initial concentration of the fed materials), the flow rate and the temperature of cooling water are controlled, the temperature of the electrolyte is regulated and controlled to be 70 +/-2 ℃, and the current densities of a cathode and an anode are both 600A/m²(the current value is 3.6A), the electrolysis is finished after the constant current is combined with the variable current to control the electrolysis for a specific time. And crystallizing, centrifugally filtering, recrystallizing, drying and the like the electrolyte to obtain the succinic acid product. 5-batch electrolysis, and counting the electrolysis results of 4 batches, wherein the current efficiency is 92.2 percent and the conversion rate is 99.6 percent.

The above-described embodiments are merely preferred embodiments of the present invention, which is not intended to be limiting in any way, and other variations and modifications are possible without departing from the scope of the invention as set forth in the appended claims.