Alkali washing section separation process in hydrogen peroxide production

Abstract

The invention provides an alkali washing section separation process in hydrogen peroxide production, and relates to the field of hydrogen peroxide production, the process specifically comprises the following steps: (1) pumping a working solution in an alkali washing tower and phosphoric acid in a phosphoric acid tank into a phosphoric acid mixer to obtain a mixed solution; (2) feeding the mixed solution obtained in the step (1) into a water washing tower for washing; and (3) respectively pumping the mixed solution obtained in the step (2) into a buffer tank A and a buffer tank B, sampling at regular time to detect the acidity, circularly pumping the mixed solution in the buffer tank A and the buffer tank B into a water washing tower and an alkaline washing tower for water washing and alkaline washing if the acidity is unqualified, and transferring into a vacuum dehydrator if the acidity is qualified to finish alkaline washing. According to the principle of the invention, the alkali tower is isolated from the system, so that the working solution is mixed with phosphoric acid to be qualified after being subjected to alkali washing by the alkali tower, and is supplemented into the vacuum dehydrator after reaching the water washing tower, thereby ensuring safe production, reducing system degradation and reducing consumption of aluminum oxide and the like.

Description

Technical Field

[0001] The invention relates to the field of hydrogen peroxide production, and in particular to a separation process for an alkali washing section in hydrogen peroxide production. Background Art

[0002] Hydrogen peroxide is a green chemical product with almost no pollution in its production and use process, so it is called a "clean" chemical product. As an oxidant, bleaching agent, disinfectant, deoxidizer, polymer initiator and cross-linking agent, it is widely used in chemical, papermaking, environmental protection, electronics, food, medicine, textile, mining, agricultural waste processing and other industries.

[0003] At present, the production of hydrogen peroxide mainly adopts the anthraquinone method synthesis process. Compared with the electrolysis method, the anthraquinone method has the advantages of less energy consumption, low cost and easy large-scale production. The anthraquinone method acid-base alternating fixed bed production process generally includes hydrogenation process, oxidation process, extraction and purification process, post-treatment process and other auxiliary processes. Due to the particularity of the cyclic work of the working liquid system in the anthraquinone method, the post-treatment requirements are very high. In addition to removing the water of the working liquid, adjusting the pH value, and decomposing the residual hydrogen peroxide, it also has the functions of washing the working liquid, removing impurities, and regenerating degradation products. It is a key process in the production of hydrogen peroxide. However, the current device still uses an acid-base mixed system. This system poses a great hidden danger to the safe production of hydrogen peroxide. The main reason is that improper alkali control causes hydrogen peroxide decomposition and explosion. Due to the unstable operation of the alkali washing tower, the working liquid carries alkali, and the alkaline substances enter the hydrogen peroxide-containing system (such as the oxidation tower, the oxidation liquid receiving tank, the extraction tower, the purification tower, etc.), catalyzing the uncontrolled decomposition of hydrogen peroxide and overpressure explosion.

[0004] Chinese patent CN108483405A discloses a hydrogen peroxide post-treatment alkali washing method, in which a portion of the working liquid from the coalescing separator is treated in an alkali washing step and then mixed with the working liquid treated in a vacuum dehydration step for post-treatment of the clay bed. The advantages of this invention are: 1. Potassium carbonate is a weak base, and the reaction is gentle and easy to control during the neutralization process; 2. The alkali tower relies on the potential difference to flow by itself, with basically no energy consumption, which well ensures the uniformity of the working liquid components and the stability of the system; 3. It well neutralizes the organic acids produced in the production, extending the service life of the activated alumina and palladium catalyst; 4. It is convenient to adjust the acidity of the system, further reduce the water and hydrogen peroxide content in the working liquid, and at the same time regenerate a portion of the degradation products in the working liquid, extending the service life of the clay bed; 5. After the acidity of the working liquid is reduced and purified, the side reactions of the hydrogenation tower will be reduced, reducing the production cost.

[0005] However, improper alkali control in the existing working liquid alkali washing process will cause hydrogen peroxide decomposition and explosion. Therefore, in view of the problems existing in the prior art, it is very necessary to find a separation process for the alkali washing section in hydrogen peroxide production. Summary of the invention

[0006] The invention aims at solving the problems in the prior art and provides a highly safe separation process for the alkali washing section in hydrogen peroxide production.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A separation process for an alkali washing section in hydrogen peroxide production comprises the following steps:

[0009] (1) The working liquid in the alkali washing tower is pumped into a buffer tank and then pumped into a phosphoric acid mixer by a buffer pump; the phosphoric acid in the phosphoric acid tank is pumped into the phosphoric acid mixer by a phosphoric acid metering pump; the phosphoric acid and the working liquid are mixed in the phosphoric acid mixer to obtain a mixed liquid;

[0010] (2) the mixed solution obtained in step (1) enters a water washing tower through the high-position tank level difference in the phosphoric acid mixer, and the mixed solution is washed with water in the water washing tower to obtain a mixed solution from which impurities are removed;

[0011] (3) The mixed solution obtained in step (2) is pumped into buffer tank A and buffer tank B respectively, and the mixed solution in buffer tank A and buffer tank B is sampled and the acidity is detected regularly. If the acidity is unqualified, the mixed solution in buffer tank A and buffer tank B is circulated and pumped into a water washing tower and an alkali washing tower for water washing and alkali washing. If the acidity is qualified, it is transferred to a vacuum dehydrator to complete the alkali washing.

[0012] The working solution in step (1) is prepared using 2-ethylanthraquinone as a working carrier and a mixture of heavy aromatics (AR), trioctyl phosphate (TOP) and acetate (2-MCA) as a solvent.

[0013] The volume ratio of heavy aromatics (AR), trioctyl phosphate (TOP) and acetate (2-MCA) is 70%-80%:10%-15%:10%-15%; preferably 75%:15%:10%.

[0014] The mass volume ratio of the 2-ethylanthraquinone to the solvent is 110-150 g:1 L, preferably 125-135 g:1 L.

[0015] As a preferred embodiment, the working solution is prepared with 130 g of 2-ethylanthraquinone as the working carrier and 1 L of a mixture of 75% by volume of heavy aromatics (AR), 15% of trioctyl phosphate (TOP) and 10% of acetate (2-MCA) as the solvent.

[0016] The concentration of phosphoric acid in step (1) is 200-300 g / L, preferably 250 g / L.

[0017] The working liquid in the alkali washing tower in the above step (1) is pumped into the buffer tank at a rate of 15-25 cubic meters per hour; the flow rate of the phosphoric acid metering pump is 4-6L / h;

[0018] Preferably, the working liquid in the alkali washing tower in the above step (1) is pumped into the buffer tank at a rate of 20 cubic meters per hour; and the flow rate of the phosphoric acid metering pump is 5 L / h.

[0019] The flow rate of the circulation pump described in the above step (1) is 10-30 cubic meters per hour.

[0020] The flow rate of the mixed liquid in the above step (2) entering the water washing tower is 10-30 cubic meters per hour, preferably 15-25 cubic meters per hour.

[0021] The water washing method described in the above step (2) is to use pure water to wash in reverse flow to remove impurities in the mixed solution.

[0022] The mixed liquid in step (3) is pumped into buffer tank A and buffer tank B at a flow rate of 10-30 cubic meters per hour, preferably 15-25 cubic meters per hour.

[0023] The flow rate of the mixed liquid in the buffer tank A and the buffer tank B in the above step (3) pumped into the water washing tower and the alkali washing tower is 2-6 mg / L, preferably 3-5 mg / L.

[0024] The buffer tank A and buffer tank B are fed in turn. When the water washing tower feeds into the buffer tank A, the buffer tank B is analyzed to be qualified, and then the vacuum dehydrator is supplemented. The mixed liquid in the buffer tank A and the buffer tank B can both enter the water washing tower and the alkali washing tower. The acidity of the mixed liquid needs to be tested before entering the water washing tower and the alkali washing tower. When the acidity is high, the mixed liquid enters the alkali washing tower for circulation, and when the acidity is low, the mixed liquid enters the water washing tower for circulation.

[0025] The acidity of the mixed liquid transferred to the vacuum dehydrator after alkali washing according to the above method is 2-6 mg / L.

[0026] The technical effects achieved by the present invention are:

[0027] The present invention aims at the problem that the working liquid carries alkali due to the unstable operation of the alkali washing tower, separates the alkali washing section alkali tower, adds buffer equipment and facilities, optimizes the safety of the post-processing section, and at the same time improves the utilization rate of the working liquid to the catalyst, reducing system degradation. Improper alkali control during the alkali washing process of the working liquid will cause hydrogen peroxide decomposition and explosion. Due to the unstable operation of the alkali washing tower, the working liquid carries alkali, and the alkaline substance enters the hydrogen peroxide-containing system (oxidation tower, oxidation liquid receiving tank, extraction tower, purification tower, etc.), catalyzing the uncontrolled decomposition of hydrogen peroxide and overpressure explosion. The principle of the present invention is mainly to isolate the alkali tower from the system, so that the working liquid is mixed with phosphoric acid after alkali washing in the alkali tower until it is qualified, and then it is added to the vacuum dehydrator after the water washing tower, thereby ensuring safe production, reducing system degradation, and reducing the consumption of alumina, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a separation process flow chart of the alkali washing section in the hydrogen peroxide production of the present invention. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0030] Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention.

[0031] When the embodiment gives a numerical range, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs.

[0032] It is worth noting that the raw materials used in the present invention are all common commercially available products, so their sources are not specifically limited.

[0033] Example 1 A separation process for the alkali washing section in hydrogen peroxide production

[0034] The steps include:

[0035] (1) The working liquid in the alkali washing tower is pumped into the buffer tank at a rate of 15 cubic meters per hour, and then pumped into the phosphoric acid mixer by the buffer pump at a flow rate of 20 cubic meters per hour; phosphoric acid (200 g / L) in the phosphoric acid tank is pumped into the phosphoric acid mixer by a phosphoric acid metering pump at a flow rate of 4 L / h; phosphoric acid and the working liquid are mixed in the phosphoric acid mixer to obtain a mixed liquid;

[0036] (2) the mixed solution obtained in step (1) enters a water washing tower at a flow rate of 20 L / h through a high-level tank in a phosphoric acid mixer, and the mixed solution is washed with water in the water washing tower to obtain a mixed solution from which impurities are removed;

[0037] (3) The mixed solution obtained in step (2) is pumped into buffer tank A and buffer tank B at a flow rate of 20 L / h, and the mixed solution in buffer tank A and buffer tank B is sampled and the acidity is detected regularly. If the acidity is unqualified, the mixed solution in buffer tank A and buffer tank B is circulated and pumped into a water washing tower and an alkali washing tower at a flow rate of 4 L / h for water washing and alkali washing. If the acidity is qualified (the acidity is 2 mg / L), it is transferred to a vacuum dehydrator to complete the alkali washing.

[0038] The working solution has a concentration of 130 g / L and is prepared using 130 g of 2-ethylanthraquinone as a working carrier and a 1 L mixture of 75% by volume heavy aromatics (AR), 15% by volume trioctyl phosphate (TOP) and 10% by volume acetate (2-MCA) as a solvent.

[0039] Example 2 A separation process for the alkali washing section in hydrogen peroxide production

[0040] The steps include:

[0041] (1) The working liquid in the alkali washing tower is pumped into the buffer tank at a rate of 25 cubic meters per hour, and then pumped into the phosphoric acid mixer by the buffer pump at a flow rate of 10 cubic meters per hour; phosphoric acid (200 g / L) in the phosphoric acid tank is pumped into the phosphoric acid mixer by a phosphoric acid metering pump at a flow rate of 6 L / h; the phosphoric acid and the working liquid are mixed in the phosphoric acid mixer to obtain a mixed liquid;

[0042] (2) the mixed solution obtained in step (1) enters a water washing tower at a flow rate of 10 L / h through a high-level tank in a phosphoric acid mixer, and the mixed solution is washed with water in the water washing tower to obtain a mixed solution from which impurities are removed;

[0043] (3) The mixed solution obtained in step (2) is pumped into buffer tank A and buffer tank B at a flow rate of 10 L / h, and the mixed solution in buffer tank A and buffer tank B is sampled and the acidity is detected regularly. If the acidity is unqualified, the mixed solution in buffer tank A and buffer tank B is circulated and pumped into a water washing tower and an alkali washing tower at a flow rate of 3 L / h for water washing and alkali washing. If the acidity is qualified (the acidity is 6 mg / L), it is transferred to a vacuum dehydrator to complete the alkali washing.

[0044] The working solution has a concentration of 130 g / L and is prepared using 130 g of 2-ethylanthraquinone as a working carrier and a 1 L mixture of 70% by volume heavy aromatics (AR), 15% trioctyl phosphate (TOP) and 15% acetate (2-MCA) as a solvent.

[0045] Example 3 A separation process for the alkali washing section in hydrogen peroxide production

[0046] The steps include:

[0047] (1) The working liquid in the alkali washing tower is pumped into the buffer tank at a rate of 20 cubic meters per hour and then pumped into the phosphoric acid mixer by the buffer pump at a flow rate of 30 cubic meters per hour; phosphoric acid (250 g / L) in the phosphoric acid tank is pumped into the phosphoric acid mixer by a phosphoric acid metering pump at a flow rate of 5 L / h; the phosphoric acid and the working liquid are mixed in the phosphoric acid mixer to obtain a mixed liquid;

[0048] (2) the mixed solution obtained in step (1) enters a water washing tower at a flow rate of 30 L / h through a high-level tank in a phosphoric acid mixer, and the mixed solution is washed with water in the water washing tower to obtain a mixed solution from which impurities are removed;

[0049] (3) The mixed solution obtained in step (2) is pumped into buffer tank A and buffer tank B at a flow rate of 30 L / h, and the mixed solution in buffer tank A and buffer tank B is sampled and the acidity is detected regularly. If the acidity is unqualified, the mixed solution in buffer tank A and buffer tank B is circulated and pumped into a water washing tower and an alkali washing tower at a flow rate of 6 L / h for water washing and alkali washing. If the acidity is qualified (acidity is 4 mg / L), it is transferred to a vacuum dehydrator to complete alkali washing.

[0050] The working solution has a concentration of 130 g / L and is prepared using 130 g of 2-ethylanthraquinone as a working carrier and a 1 L mixture of 80% by volume heavy aromatics (AR), 10% trioctyl phosphate (TOP) and 10% acetate (2-MCA) as a solvent.

[0051] Comparative Example 1

[0052] The difference from Example 3 is that the working solution is prepared by using 130 g of 2-ethylanthraquinone as the working carrier and a mixture of 0.5 L of heavy aromatics (AR) and 0.5 L of trioctyl phosphate (TOP) as the solvent. The rest is the same as Example 3.

[0053] Comparative Example 2

[0054] The difference from Example 3 is:

[0055] The working liquid in the alkali washing tower is pumped into the buffer tank at a rate of 20 cubic meters per hour, and then enters the water washing tower by the buffer pump at a flow rate of 30 cubic meters per hour. The mixed liquid is washed in the water washing tower to obtain a mixed liquid with impurities removed; the subsequent steps are consistent with Example 3.

[0056] The acidity of the mixed solution in the last buffer tank A and buffer tank B in the above-mentioned Examples 1-3 and Comparative Examples 1-2 was tested by sampling, and the test results are shown in Table 1 below.

[0057] Table 1

[0058] acidity Example 1 2mg / L Example 2 6mg / L Example 3 4mg / L Comparative Example 1 4.1mg / L Comparative Example 2 6.8mg / L

[0059] According to the data in Table 1 above, it can be seen that after the alkali system separation and transformation described in the present invention is adopted, the components and properties of the mixed liquid are optimized, and the acidity is suitable for production requirements.

[0060] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A separation process for the alkali washing section in hydrogen peroxide production, characterized in that: The steps include: (1) The working liquid in the alkali washing tower is pumped into a buffer tank by a working liquid pump and then pumped into a phosphoric acid mixer by a buffer pump; the phosphoric acid in the phosphoric acid tank is pumped into the phosphoric acid mixer by a phosphoric acid metering pump; the phosphoric acid and the working liquid are mixed in the phosphoric acid mixer to obtain a mixed liquid; (2) the mixed solution obtained in step (1) enters a water washing tower through the high-position tank level difference in the phosphoric acid mixer, and the mixed solution is washed with water in the water washing tower to obtain a mixed solution from which impurities are removed; (3) The mixed solution obtained in step (2) is pumped into buffer tank A and buffer tank B respectively, and the mixed solution in buffer tank A and buffer tank B is sampled and the acidity is detected regularly. If the acidity is unqualified, the mixed solution in buffer tank A and buffer tank B is circulated and pumped into a water washing tower and an alkali washing tower for water washing and alkali washing. If the acidity is qualified, it is transferred to a vacuum dehydrator to complete the alkali washing.

2. The alkali washing section separation process in hydrogen peroxide production according to claim 1, characterized in that: The working solution in step (1) is prepared using 2-ethylanthraquinone as a working carrier and a mixture of heavy aromatic hydrocarbons, trioctyl phosphate and acetate as a solvent.

3. The alkali washing section separation process in hydrogen peroxide production according to claim 2, characterized in that: The volume ratio of the heavy aromatics, trioctyl phosphate and acetate is 70%-80%:10%-15%:10%-15%; preferably 75%:15%:10%.

4. The alkali washing section separation process in hydrogen peroxide production according to claim 2, characterized in that: The mass volume ratio of the 2-ethylanthraquinone to the solvent is 110-150 g:1 L, preferably 125-135 g:1 L.

5. The alkali washing section separation process in hydrogen peroxide production according to claim 2, characterized in that: The working solution is prepared by using 130 g of 2-ethylanthraquinone as a working carrier and 1 L of a mixture of 75% by volume of heavy aromatics, 15% of trioctyl phosphate and 10% of acetate as a solvent.

6. The alkali washing section separation process in hydrogen peroxide production according to claim 1, characterized in that: The working liquid in the alkali washing tower described in step (1) is pumped into the buffer tank at a speed of 15-25 cubic meters per hour; the flow rate of the phosphoric acid metering pump is 4-6L / h.

7. The alkali washing section separation process in hydrogen peroxide production according to claim 6, characterized in that: The working liquid in the alkali washing tower described in step (1) is pumped into the buffer tank at a rate of 20 cubic meters per hour; The phosphoric acid metering pump has a flow rate of 5 L / h.

8. The alkali washing section separation process in hydrogen peroxide production according to claim 1, characterized in that: The flow rate of the mixed liquid in step (2) entering the water washing tower is 10-30 cubic meters per hour, preferably 15-25 cubic meters per hour.

9. The alkali washing section separation process in hydrogen peroxide production according to claim 1, characterized in that: The mixed liquid in step (3) is pumped into buffer tank A and buffer tank B at a flow rate of 10-30 cubic meters per hour, preferably 15-25 cubic meters per hour.

10. The alkali washing section separation process in hydrogen peroxide production according to claim 1, characterized in that: The flow rate of the mixed liquid in the buffer tank A and the buffer tank B pumped into the water washing tower and the alkali washing tower in step (3) is 2-6 mg / L, preferably 3-5 mg / L.

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