CN107626303A - Preparation method of high-efficient purification formaldehyde materials and products thereof and application - Google Patents

Abstract

The invention discloses a preparation method of a high-efficiency formaldehyde purification material and its product and application. The preparation method can prepare two kinds of formaldehyde purification materials, powdered MnOx and modified activated alumina. The method is obtained by simple stirring, suction filtration and post-treatment of potassium permanganate solution and formic acid solution with a molar ratio of 2:3. The powdered MnOx is obtained by directly placing the filter cake of the reaction of potassium permanganate and formic acid solution in a blast drying oven at 40-60 ^o C, and the modified activated alumina is obtained by impregnating the obtained filtrate with equal volume of activated alumina. The molar concentration of potassium permanganate solution is controlled at 0.10~0.20 mol/L, and the concentration of formic acid solution is controlled at 0.30~0.60 mol/L. The obtained purification material can realize efficient and stable purification of formaldehyde under low concentration, high space velocity and flow conditions. The method disclosed by the invention not only has zero waste liquid discharge, but also rationally utilizes the waste liquid to turn waste into treasure.

Description

Preparation method, product and application of high-efficiency purification formaldehyde material

technical field

The invention belongs to the field of material preparation, and in particular relates to a preparation method of a high-efficiency formaldehyde purification material and its product and application.

Background technique

The popularity of decoration makes indoor pollutants an important factor affecting people's health. Formaldehyde is one of the most toxic and relatively high content of indoor pollutants. Excessive formaldehyde has three major hazards: sensitization, stimulation, and mutagenesis. For example, direct skin contact with formaldehyde can cause allergic dermatitis, stains, and necrosis, and inhalation of high concentrations of formaldehyde can induce bronchial asthma. Stimulating effect on skin and mucous membranes, can be combined with protein, severe respiratory tract irritation and edema, eye irritation, headache when inhaled at high concentrations. Under certain conditions, the concentration of formaldehyde in the air of the indoor environment can accumulate above the standard allowable level, and the release period is relatively long, generally 3-15 years.

At present, the purification methods of formaldehyde at room temperature mainly include adsorption method and photocatalytic degradation. In the adsorption method, the adsorbent is easy to reach saturation, and needs to be regenerated and the material needs to be replaced at a fixed time; in the photocatalytic degradation technology, a light source needs to be introduced, and it is easy to generate O ₃ during use, which will cause further damage to the human body. Materials that can completely purify formaldehyde at room temperature and maintain high stability are the most demanded in the market, and are also preferred in purifiers. At present, materials for catalytic degradation of formaldehyde at room temperature mainly include noble metals such as Pt, Au, and Ag-based materials in the literature, and the resources are few and expensive. Transition metal oxides are the most promising materials because of their multivalent states, fast electron transfer, and anti-S and anti-Cl performances in the removal of hydrocarbons.

It is worth noting that although there are many purification materials for formaldehyde on the market, there are actually few efficient purification materials that can completely purify formaldehyde, especially for the thorough treatment of indoor low-concentration formaldehyde. Usually, even if a more efficient formaldehyde purification material is prepared, its preparation process is often more complicated, and at the same time, it is easy to generate more waste liquid during large-scale production, and these waste liquids are difficult to treat and require high costs. . Therefore, the present invention intends to address the above two problems and provide a simple preparation method that can simultaneously prepare high-efficiency formaldehyde purification materials and rationally utilize waste liquid.

Contents of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a preparation method for highly efficient formaldehyde purification material.

Another object of the present invention is to provide the product prepared by the above method.

Another object of the present invention is to provide the application of the above product.

A preparation method for efficient purification of formaldehyde materials, characterized in that the specific operations are as follows: stirring potassium permanganate solution and formic acid solution at room temperature for 2 to 2.5 hours, then suction filtration to obtain filter cake and filtrate, the filter cake is placed in 40-60 ^o Dry in a blower drying oven at C for 10-14 h to obtain MnOx; impregnate spherical activated alumina with an equal volume of the filtrate to obtain modified activated alumina.

The purification material obtained by the method of the present invention can realize high-efficiency and stable purification of formaldehyde under low concentration, high space velocity, and flow conditions, and two kinds of purification formaldehyde materials can be obtained by using the method, one is the target product directly produced by the method, and the other is waste liquid The formaldehyde purification material obtained after reasonable utilization. Different from the inventive method reported in the literature, the method provided by the present invention not only produces no waste liquid, but also makes rational use of the waste liquid, turning waste into treasure.

The high-efficiency purifying formaldehyde material is one or a combination of MnOx and modified activated alumina.

The molar concentration of the potassium permanganate solution is 0.10-0.20 mol/L; the molar concentration of the formic acid solution is 0.30-0.60 mol/L. Wherein, the molar ratio of potassium permanganate and formic acid is 2:3.

The present invention provides a kind of high-efficiency purifying formaldehyde material, it is characterized in that it is prepared according to any one of the above-mentioned methods.

The invention provides an application of a formaldehyde purifying material with high efficiency.

The specific operation process is as follows: Potassium permanganate solution (molar concentration is 0.10~0.20 mol/L) and formic acid (molar concentration is 0.30~0.60 mol/L) solution is stirred at room temperature for 2~2.5 hours, and the filter cake is obtained after suction filtration and filtrate. Wherein, the molar ratio of potassium permanganate and formic acid is 2:3. The filter cake layer was dried in a blast drying oven at 40-60 ^o C for 10-14 h to obtain MnOx; the filtrate was impregnated with spherical activated alumina in equal volume to obtain modified activated alumina. The obtained MnOx and modified activated alumina can be used in the purification process of indoor low-concentration formaldehyde gas. MnOx can be loaded onto activated alumina through solid-loading technology and used in the purification module of air purifiers. Modified activated alumina can be directly Applied in the purification module of the air purifier.

The method provided by the invention divides the product into two parts, the filter cake part is MnOx and the filtrate part. The time limit for the reaction of potassium permanganate and formic acid is 2-2.5h. By comparing the actual amount of product produced with the theoretical value, the two did not completely react within the limited time. Combined with the XRD results, it shows that the product is a variety of Manganese oxide composed of valence manganese, that is, the incomplete reaction product MnOx. The pH of the corresponding fresh filtrate is between 8 and 9, which is slightly alkaline. Performance tests found that under low concentration, high space velocity, and flow conditions, MnOx can completely purify formaldehyde, the removal rate of formaldehyde can reach 100%, and it has very good stability, and can still maintain 100% conversion after 6.5 hours; Active alumina balls have a purification rate of 70-80% for formaldehyde and have very good stability.

The inventive method mainly has the following characteristics:

(1) Taking zero waste liquid as the starting point, while preparing high-efficiency formaldehyde purification materials, the waste liquid is rationally utilized, that is, turning waste into treasure and realizing zero waste liquid production.

(2) The method is simple, and no waste liquid is produced, which is extremely important for large-scale production, and the harm to the environment in the production process is avoided.

(3) The purification rate of formaldehyde is high. It can completely convert formaldehyde and has very good stability. To achieve complete purification of indoor formaldehyde.

Description of drawings

Fig. 1 is the purifying curve of MnO in embodiment 1 to formaldehyde;

Fig. 2 is the purification curve of modified activated alumina to formaldehyde in Example 2.

detailed description

Example 1

Weigh 3.16 g of potassium permanganate (KMnO ₄ ) and dissolve it in 100 mL of water, stir at room temperature until dissolved; measure 1.33 mL of 85% (mass fraction) formic acid solution and dissolve it in 50 mL of deionized water. After mixing evenly, add the formic acid solution dropwise to the potassium permanganate solution under stirring, and continue stirring at room temperature for 2 h. The filter cake and the filtrate part were obtained by vacuum filtration. The filter cake was directly dried in a blast oven at 50 ^o C for 12 h to obtain MnOx-1. The filtrate is impregnated with activated alumina in equal volume to obtain modified activated alumina, which is denoted as modified activated alumina-1.

Fig. 1 is the purification curve of MnOx to formaldehyde in the present embodiment.

Example 2

Change the quality 3.16 g of potassium permanganate in Example 1 to 1.58 g, and the volume 1.33 mL of 85% formic acid becomes 0.67 mL, and other preparation conditions are the same as in Example 1 to obtain MnOx-2 and modified activated alumina -2.

Fig. 2 is the purification curve of modified activated alumina to formaldehyde in this example.

Example 3

Change the quality 3.16 g of potassium permanganate in Example 1 to 2.37 g, and the volume 1.33 mL of 85% formic acid becomes 1.0 mL, and other preparation conditions are the same as in Example 1 to obtain MnOx-3 and modified activated alumina -3.

Example 4

Change the quality 3.16 g of potassium permanganate in Example 1 to 2.84 g, and the volume 1.33 mL of 85% formic acid becomes 1.9 mL, and other preparation conditions are the same as in Example 1 to obtain MnOx-4 and modified activated alumina -4.

application example

The sample MnOx-1 and modified activated alumina-1 obtained in Example 1 were applied to indoor low-concentration formaldehyde purification reaction, and their performance was first tested in a continuous flow fixed bed device. The total gas flow rate is 500 mL/min, the reaction pressure is normal pressure~1atm, the initial concentration of formaldehyde is 4.8~5.4 mg/m ³ , and the sample dosage is 0.2 g. The results showed that the concentration of formaldehyde could be completely purified, that is, the initial purification rate was 100%, and the initial efficiency did not change after continuous reaction for 6.5 h. The initial purification rate of formaldehyde by modified activated alumina is 70%, and the conversion rate can be maintained for 2.5 h.

Further, the material was coated on alumina pellets using the method in the inventor's previously authorized patent ZL201510403899.6, and its purification performance for formaldehyde in a 30 m ³ purification chamber was tested after filling. The initial concentration of formaldehyde in the purification chamber is 1 mg/m ³ , and the results show that the complete purification of formaldehyde can be achieved.

Claims (5)

1. A preparation method for efficiently purifying formaldehyde material is characterized in that concrete operations are as follows: potassium permanganate solution and formic acid solution are stirred at room temperature for 2 to 2.5 h and then suction filtered to obtain filter cake and filtrate, and the filter cake is placed in 40 Dry in a blast oven at -60 ^o C for 10-14 h to obtain MnOx; impregnate spherical activated alumina with an equal volume of the filtrate to obtain modified activated alumina. 2. The preparation method of the high-efficiency purification formaldehyde material according to claim 1, characterized in that, the high-efficiency purification formaldehyde material is one or a combination of MnOx and modified activated alumina. 3. the preparation method of the described efficient purification formaldehyde material of claim 1, is characterized in that, the molar concentration of potassium permanganate solution is 0.10～0.20 mol/L; The molar concentration of described formic acid solution is 0.30～0.60 mol/L. Wherein, the molar ratio of potassium permanganate and formic acid is 2:3. 4. A high-efficiency purifying formaldehyde material, characterized in that it is prepared according to any one of claims 1-3. 5. according to the application of the efficient purifying formaldehyde material described in claim 4.