CN1293938C

CN1293938C - Methanal disintegrant and preparation thereof

Info

Publication number: CN1293938C
Application number: CNB2005100202803A
Authority: CN
Inventors: 潘晓明; 姜和
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-01-27
Filing date: 2005-01-27
Publication date: 2007-01-10
Anticipated expiration: 2025-01-27
Also published as: CN1680018A

Abstract

The present invention relates to methanal disintegrant which is composed of activated carbon and Ag (NH3)2 +OH<->, wherein the activated carbon is used as carriers; Ag(NH3)2 <+>OH<-> is coated on the carriers. The preparing method comprises the following procedures: the activated carbon is baked and cooled in 200 to 230 DEG C, is put into Ag (NH3)2 <+>OH<-> solution for immersing, and then is filtered and aired in 80 to 100 DEG C. The present invention takes modification on the activated carbon, decomposes and absorbs chemical pollutant which is difficult to adsorb by common activated carbon, and overcomes the defects of low ultraviolet energy, and unsafe and inconvenient use of liquid chemical reagents, etc. The present invention needs no photocatalysis oxidation for decomposing the formaldehyde, and needs no liquid chemical reagent reaction for decomposing the formaldehyde. The present invention has the advantages of good effects, safe and convenient use, etc.

Description

Application of modified activated carbon as formaldehyde decomposer

Technical Field

The invention relates to an application of a formaldehyde decomposer for purifying air, in particular to an application of modified activated carbon as a formaldehyde decomposer.

Background

With the continuous improvement of living standard of people, houses are decorated and furniture is replaced more and more frequently. Because many adhesives, coatings, paints and the like volatilize pollutants mainly containing formaldehyde to different degrees, the formaldehyde-free environment-friendly coating causes different degrees of harm to human bodies. Therefore, the demand for treating formaldehyde pollution is more urgent. At present, the materials or methods for treating formaldehyde pollution have some technical defects, such as: the static adsorption method of the activated carbon or the molecular sieve has low existing speed and small adsorption quantity, can not generate chemical reaction with formaldehyde, namely can not fundamentally remove the formaldehyde, and has no obvious effect on removing the formaldehyde in a newly decorated room; the device adopting the photocatalyst or the cold catalyst has the problems of high price and low formaldehyde decomposition efficiency, and is not easy to be accepted by people; the formaldehyde remover and the like which exist in a liquid form are inconvenient and unsafe to use, can bring secondary pollution and are inconvenient to popularize; moreover, the formaldehyde in the paint such as adhesive, coating, furniture and the like has a long release period, and some formaldehyde can last for decades, so that the pollution of harmful gases cannot be thoroughly eliminated by adopting a ventilation method.

The technology of purifying indoor air was developed in the 90 s of the 20 th century. At present, the existing formaldehyde decomposers are used for researching photocatalytic oxidation decomposition of formaldehyde at home and abroad. The photocatalytic oxidation decomposition of formaldehyde utilizes ultraviolet light to convert solar energy absorbed by a reaction system into chemical energy through photocatalytic reaction, so that indoor formaldehyde, peculiar smell gas and the like are thoroughly decomposed into odorless and harmless products, and bacteria and germs in indoor air can be killed. In addition, a formaldehyde remover such as Chinese patent (publication number) 1413750 is a chemical reagent method for generating new substances by reacting with chemical reagents, and the formaldehyde remover is a concentrated solution prepared by 0.9-1.1 parts of triethanolamine, 0.22-0.28 parts of sodium metabisulfite, 0.22-0.28 parts of ethylene diamine tetraacetic acid disodium, 0.2-0.6 parts of 2, 3, 4, 5, 6-pentahydroxyhexanal and 125 parts of distilled water (all by weight), and is diluted to 1000 parts by weight with distilled water before use. In particular to a production site of adhesive and synthetic board containing aldehyde (urea formaldehyde, phenolic aldehyde and the like) and a production site of the synthetic board, and formaldehyde which is liberated from the adhesive and the synthetic board can be removed by using the formaldehyde remover when the formaldehyde remover is used for indoor decoration.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the application of the modified activated carbon which integrates adsorption, decomposition and removal, has no secondary pollution, good removal effect, convenient and safe use and low price and can be regenerated and used for a long time as the formaldehyde decomposer.

The purpose of the invention is realized as follows: use of a modified activated carbon consisting of activated carbon and the toleren agent Ag (NH) as a formaldehyde decomposer₃)₂ ⁺OH^-Composition is carried out; in which activated carbon as a carrier, Ag (NH)₃)₂ ⁺OH^-Applied on a carrier to decompose and absorb formaldehyde.

The preparation method of the formaldehyde decomposer comprises the following steps:

1) drying and cooling the activated carbon at the temperature of 200-230 ℃;

2) is placed in Ag (NH)₃)₂ ⁺OH^-Soaking in the solution for 8-12h, filtering, and air drying;

3) drying at 80-100 deg.C.

The invention uses the modified active carbon as the formaldehyde decomposer, decomposes and absorbs chemical pollutants which are difficult to be absorbed by common active carbon, overcomes the defects of low ultraviolet energy, unsafe and inconvenient use of liquid chemical reagents and the like, does not need to decompose formaldehyde by photocatalytic oxidation, does not use the reaction of the liquid chemical reagents to decompose the formaldehyde, and has the advantages of good effect, convenient and safe use and the like.

Drawings

FIG. 1 is a waveform diagram showing the adsorption amounts of formaldehyde by three materials.

Detailed Description

Use of a modified activated carbon consisting of activated carbon and toleren's reagent (Ag (NH) as formaldehyde decomposer₃)₂ ⁺OH^-) Composition is carried out; in which activated carbon, Ag (NH), is used as carrier₃)₂ ⁺OH^-It is applied on a carrier for adsorbing and decomposing formaldehyde. Activated carbon, Ag (NH)₃)₂ ⁺OH^-The source is rich.

1) drying and cooling the activated carbon at 200, 210, 220 or 230 ℃;

2) is placed in Ag (NH)₃)₂ ⁺OH^-Soaking in the solution for 8h, 10h or 12h, filtering and air drying;

3) drying at 80-100 deg.C.

Ag(NH₃)₂ ⁺OH^-Is a conventional saturated solution. Ag (NH)₃)₂ ⁺OH^-And activated carbon can be formulated or purchased directly.

The basic principle of the invention is as follows: activated carbon is a porous substance with a sponge-like structure. Activated carbon can be classifiedaccording to its material source: coal, wood, fruit shell, coconut shell carbon. Wherein the MAC-B coconut shell carbon with advanced manufacturing process and pure texture is the top grade of the active carbon because of the abundant micropore knotsThe spreading area of 1 gram can reach 600-²) The pore size of the micropores can be as small as a few nanometers. Hundreds of billions of abundant micropores can contain more than 60 percent of various toxic and harmful gases and peculiar smell by weight per se and firmly absorb and lock the toxic and harmful gases and the peculiar smell in the micropores, so that the microporous plate is called as 'black gold'. After different proper amounts of catalyst and additive are added, the absorption variety of the activated carbon can be enlarged and the absorption efficiency of the activated carbon can be improved. The active carbon is porous and has a large specific surface area, so that the active carbon can absorb surrounding chemically toxic gases and peculiar smell like sponge water, and when the active carbon absorbs 60% of the weight of the active carbon, the active carbon loses energy efficiency. Therefore, the quality and quantity of the carbon of the activated carbon determine the service life of the activated carbon. Some air cleaners have filter material coated over only a small portion of the surface of the filter screen and must have a limited useful life.

The active carbon is the only high-quality filter material which can safely, economically and effectively remove various toxic and harmful gases and peculiar smell at present. The more the amount of the active carbon is, the more toxic gas and peculiar smell can be absorbed, and the longer the service life is.

After adding special substance and additive into active carbon, it can greatly increase the adsorption capacity of active carbon, for example, a certain proportion of natural zeolite and special catalyst-potassium iodide are added into active carbon to form a special active carbon filter core, and said filter core can absorb more than 400 kinds of chemical toxic gas and abnormal smell in different degrees.

The aldehydes can be reacted with toleren agents, such as:

based on the principle, formaldehyde is removed by the combined action of physical adsorption and chemical reaction by adding a certain amount of compounds containing tolan reagents on the surface of the activated carbon.

And (3) comparison test:

1. drying the activated carbon at the temperature of 200 ℃,

2. cooling, and respectively placing in 30% H₂O₂And Ag (NH)₃)₂ ⁺OH^-Soaking in the solution for 8 hr, and filteringDrying;

3. oven drying at 100 deg.C, and using another part of activated carbon as blank control to obtain 3 samples numbered FQY-H₂O₂FQY-OH, FQY-blank, and then determining the amount of formaldehyde adsorbed by each material. The results are shown in FIG. 1.

As can be seen from FIG. 1, the saturation adsorption amount of FQY-OH was the highest after modification, FQY-H₂O₂Next, FQY-blank is lowest. At the same time, FQY-OH and FQY-H₂O₂Not only the adsorption capacity is greatly improved compared with that before the modification, but also the time for reaching saturation is greatly advanced. This indicates that a larger amount of formaldehyde can be adsorbed in a shorter time. In N₂(200 ml/min. times.120 min) FQY-OH and FQY-H under blowing₂O₂Formaldehyde was not released, while FQY-blank released 76% formaldehyde, indicatingFQY-OH and FQY-H₂O₂With formaldehyde, a compound is produced which reacts to form a new substance.

The test shows that the maximum saturated adsorption amount of FQY-OH after modification is as follows: 0.52 mg/g.

At a 30M³In a closed room, releasing formaldehyde more than ten times of the national standard (GB/T18883-2003), putting the formaldehyde into a purifying material for absorption, and then measuring the value of the formaldehyde. Their purification efficiency over 24 hours was compared. The sampling time is 20min, the flow rate is 0.5L/min, the pressure is one atmosphere, and the temperature is 293K. The results are as follows: (unit is mg/m)³)

From the above table, it can be seen that: compared with the commercial nano photocatalyst material, the purification efficiency of the modified activated carbon is improved by 32.59 percent, and compared with the common activated carbon, the purification efficiency of the modified activated carbon is improved by 40.36 percent. Since the formaldehyde remover is a chemical agent existing in a liquid form, it is unsafe and inconvenient to use, and many chemical agents may cause secondary pollution, it is not compared with the formaldehyde remover.

Claims

1. The use of modified active carbon as formaldehyde decomposer is characterized in that the modified active carbon is used as formaldehyde decomposerThe active carbon is prepared from active carbon and Ag (NH)₃)₂ ⁺OH^-Composition is carried out; in which activated carbon as a carrier, Ag (NH)₃)₂ ⁺OH^-Is applied on the carrier.