Trichloroisocyanuric acid, chemical formula: C3O3N3Cl3, molecular weight: 232.41, is an organic compound, white crystalline powder or granular solid, with strong chlorine irritating taste.
Trichloroisocyanuric acid is an extremely strong oxidant and chlorinator. It is mixed with ammonium salt, ammonia and urea to produce explosive nitrogen trichloride. When it is wet and heated, it will also release nitrogen trichloride. When it is flammable in organic matter. Trichloroisocyanuric acid has almost no corrosion effect on stainless steel, and the corrosion of brass is stronger than that of carbon steel.
The product is widely used, including the following aspects:
1. Disinfection and sterilization:
Trichloroisocyanuric acid is a highly effective disinfectant and bleaching agent with stable storage, convenient and safe use. It is widely used in food processing, drinking water disinfection, sericulture and rice seed disinfection. It has a killing effect on almost all fungi, bacteria and virus spores, has a special effect on killing hepatitis A and hepatitis B viruses, and has a good disinfection effect on sexual viruses and HIV. It is safe and convenient to use. It has been used as disinfectant in industrial water, swimming pool water, cleaning agent, hospital, tableware, etc.; it is also used as sterilization agent in silkworm breeding and other breeding. In addition to being widely used as disinfectant and bactericide, trichloroisocyanuric acid is also widely used in industrial production.
2. Application in printing and dyeing industry:
Trichloroisocyanuric acid contains up to 90% active chlorine and is used as a bleaching agent in the printing and dyeing industry. It is suitable for bleaching cotton, linen, wool, synthetic fiber and blended fiber. It not only does not damage the fiber, but also has better performance than sodium hypochlorite and bleach, and can be used instead of imported sodium hypochlorite.
3. Application in food industry:
Instead of chloramine T for food disinfection, its effective chlorine content is three times that of chloramine t. And can be used as decolorizing and deodorizing agent of dextrin.
4. Application in wool textile industry: it is used as wool anti shrinking agent in wool textile industry instead of potassium bromate.
5. Application in rubber industry: used as chlorination agent in rubber industry production.
6. Used as industrial oxidant: the oxidation-reduction electrode potential of trichloroisocyanuric acid is equivalent to hypochlorite, which can be used as a high-quality oxidant instead of hypochlorite.
7. Other aspects: it is used as raw material in the organic synthesis industry, and can synthesize a variety of organic substances such as Tri (2-hydroxyethyl) isocyanurate. Cyanuric acid, the product of decomposition of trichloroisocyanuric acid, is not only non-toxic, but also has many uses, such as producing a series of resins, coatings, adhesives and plastics.
The main synthesis methods of trichloroisocyanuric acid include chlorine gas method, liquid chlorination agent method, solvent method and sodium dichloroisocyanuric acid (SDC) deep chlorination method.
(1) Chlorine method:
Step 1: cyanuric acid (CA) synthesis cyanuric acid is mainly produced by urea thermal cracking ammonia release method. The reaction formula is as follows:
Step 2: alkali dissolution
Step 3: chlorination
The process is simple. However, in the process of preparing TCCA by chlorination of Ca, there are many by-products such as biuret, biuret, cyanuric amide and unreacted raw material urea in Ca, which react with chlorine to form NCl3 and ca. It is easy to generate NCl3 in alkaline solution. TCCA products will also decompose to generate NCl3 under heating or alkaline conditions. The chlorine passing reaction is carried out in closed containers. As is known to all, NCl3 is easy to explode when it accumulates.
(2) Liquid chlorination method:
Cyanuric acid is prepared into a slurry and chlorinated at a certain pH with a prefabricated chlorinating agent (such as CL20, HOCl, na0cl, etc.). The reaction formula is:
Similarly, in order to avoid the generation of NCl3, on the one hand, the CA intermediate is refined to reduce the impurity content to below 3%, and on the other hand, the process conditions are strictly controlled to control the pH between 3 and 4 and the chlorination temperature between 20 and 25 ℃. This method is a liquid-liquid phase reaction. When a certain amount of air is introduced into the inlet, the chlorination reactor is equipped with an exhaust system to discharge the generated trace NCl3 in time. The reaction of this method is rapid and does not pollute the environment. The disadvantage is that hypochlorous acid is unstable, resulting in a reduction in product yield.
In addition, dry products without NCl3 can be prepared after Ca reacts with pre prepared CL20 under 200 ℃, without separation and drying.
(3) Solvent method
Inert solvent such as methane chloride, which is not miscible with water, has no reaction activity and can dissolve TCCA, is used. This method has the advantages of continuity, automation, large scale and small pollution. It is also used in large-scale production in developed countries.
Deep chlorination of sodium dichloroisocyanurate (SDC)
Sodium dichloroisocyanurate is one of the series of chlorinated isocyanurate products. In the joint production of SDC and taac, cyanuric acid and sodium hypochlorite solution are reacted at 20-25 ℃ to form SDC, and then it is deeply chlorinated to form TCCA. The reaction formula is as follows:
Trichloroisocyanuric acid (TCCA) is one of the important varieties of chlorinated isocyanuric acid products. It is a new generation of high-efficiency bleaching agent, chlorinating agent and disinfectant. It has the characteristics of high sterilization and bleaching power, stable storage and transportation, making tablets safe and releasing effective chlorine in water for a long time.
Domestic market:
Disinfection and sterilization of sericulture and aquaculture are the main consumption areas of trichloroisocyanuric acid in China, accounting for 50% ~ 60% of the total consumption. With the improvement of people's living standards, the increase of silk and aquatic products will certainly drive the increase of trichloroisocyanuric acid demand. The serious pollution of drinking water in China has caused people's high concern. In order to ensure the quality of water, the product tablets used for drinking water disinfection will receive much attention. In addition, it can not only improve the utilization rate of circulating water, purify water quality and save water consumption, but also ensure the normal, stable and safe operation of the circulating water system and greatly reduce the comprehensive energy consumption.
According to statistics, in 2002, the actual consumption of trichloroisocyanuric acid in China was about 30000 tons. The amount of disinfection in silkworm breeding and aquaculture accounted for 50% of the total consumption, the amount of disinfection in medical and catering industries was 15%, the amount of daily disinfection was 10%, and the consumption of domestic water and circulating water treatment accounted for 8%. The consumption of agriculture, fishery, textile, papermaking and swimming pool will increase in the future.
Due to the relatively high cost of producing trichloroisocyanuric acid in foreign countries and the certain restrictions on the production of chlorinated products in foreign countries, some small and medium-sized enterprises in foreign countries have stopped producing trichloroisocyanuric acid and instead imported it from developing countries, and then produced its compounded preparation to form the final product. Therefore, China's export volume of this product has increased in recent years.