The purpose of acrylamide

Acrylamide is a white transistor chemical, a raw material for the production of polyacrylamide. Polyacrylamide is mainly used for water purification treatment, processing of pulp, and internal coating of pipelines. Starch foods are prone to acrylamide under high temperature (> 120 ° C). Studies have shown that the human body can contact acrylamide through a variety of ways such as digestive tract, respiratory tract, skin and mucous membranes, and drinking water is one of the important contacts. In April 2002, researchers from the State Food Administration of Sweden and Stockholm University first reported that acrylamide was detected in some fried and barbecue starch foods, such as fries, fried potato chips, etc. Limited more than 500 times. Later, Norway, Britain, Switzerland, and the United States have reported similar results.
If according to the research of the Hong Kong Consumer Council, foods containing carbohydrates will produce acrylamide after frying. Studies are known that acrylamide can cause cancer. However, the World Health Organization stated that it is difficult to count which concentration of acrylamide to be carcinogenic.
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acrylamide () has two forms as a product: aquatic solution and crystal, where the crystals are colorless and transparent. Ethanol, ether, acetone, chloroform, insoluble in benzene and heptane. It is very stable at room temperature, but when the temperature, oxidation conditions above the melting point, and the influence of ultraviolet rays, are prone to polymerization reactions. When heating makes it dissolved, a strong corrosive gas and nitrogen oxide are released.
Thuelamide is a kind of unsaturated amine, which is used in large quantities to manufacture water-soluble polymers-polyacrylamide cluster; a small amount of hydrophilic centers that make the parenting polymer form water permeable to increase the adhesive force Increase softening points and anti -solventability; there are also a small part of the cross -linked agent for ethylene polymer.
Themide production method

production technology In 1954, USAlamin company first developed legal production technology of sulfate to achieve industrial production. Since then, the production process of acrylamide has undergone two changes: in the mid -1970s, the copper catalytic water was legal, and the production process of microbial method was developed in the mid -1980s. The legal process of sulfuric acid water is complicated, and copper catalytic water legal contains a small number of by -products due to an additional reaction; the single -produced monomer produced by microbial method is particularly suitable for the production of polyacrylamide with high molecular weight. Respect. Compared to microbial methods, the legal sulfuric acid water and copper catalytic water are legal.
2.1 The traditional method of sulfuric acid is legally, first hydrolysis of acrylics below 100 ° C into acrylamide sulfate, and then neutralization of acrylamide (AM). Initially, non -ionic polyacrylamide was made through acrylamide, and the product was relatively single. Soon after developing an ionic type polyacrylamide with alkaline partial hydrolysis (post -hydrolysis method).
The copper catalytic water is legally used to prepare acrylamide in the existence of copper -based catalysts to prepare acrylamide. The compound or its salt, and then the solution containing acrylamide is in contact with weak alkaline or moderate alkaline anion. In the above -mentioned hydrophilic reactions, the production of impurities is suppressed, but the catalyst activity is not affected by any. The acrylamide obtained can be used to make flocculants with high molecular weight and good water -soluble.
The copper catalytic water can also be processed by at least two purified steps. First, the acrylic is connected to the resin with strong acid cedies, and then contacted with resin or activated charcoal with benamin or amino amino groups. Finally, the propylene cylinder obtained by the copper -based catalyst reacts through the hydrolysis. Even if the general quality acrylin is used, this method can produce high -quality acrylamide and further produce a well -soluble polyacrylamide.
The disadvantage of copper catalytic water is to recover acryline and separate copper, waste resources and energy; at the same time, there are more side reactions, not easy to control, and the purity of the product is not high.
2.2 Microbial method Microbiology method is mixed with acrylic, water, and fixed biochemical catalysts into hydraulic solutions. After the catalytic reactions are separated, waste catalysts can be obtained by obtaining acrylamide products. Compared with the traditional copper catalytic water, its characteristics are: reaction at normal temperature, simple equipment, and safe operation; extremely high one -way conversion rate, no need to separate the recycling of uncompressed acrylic; the specific performance of the enzymes makes the selectivity extremely high in selectivity , No side reaction. When using J-1 bacteria, the reaction temperature is 5-15 ° C, the pH value is 7-8, and the acrylic concentration in the reaction area is 1%-2%. The transformation rate of acryline is 99.99%, the acrylamide is 99.98%, and the concentration of the acrylamide export of the reactor is close to 50%; The treatment makes the separation and refining operations simplifying; the product concentration is high, no need to reinforce, the entire process is simple, the equipment investment is small, the economic benefits are high, and it is conducive to small -scale production.
The microorganisms have the following specific technologies:
(1) Microbial method of application film technology. The process contains the process of microbial bacteria, the preparation of the bacterial weight suspension, and the acrylamide hydraulic solution obtained by the acrylic hydrophilic response and the separation reaction. It is characterized by a microfiltrate film to wash the bacteria in the purification fermentation solution to prepare the bacteria weight suspension, and use the ultrafiltration membrane to separate the acrylamide hydraulic solution and biological impurities. The use of this process to produce acrylamide can significantly improve production efficiency and bacterial utilization rate. At the same time, the biological impurities in hydrochloric products are reduced, and the obtained acrylamide quality is good and high.
(2) Microbial continuous catalytic method. This method produces pylori or cell cells containing hydrophobly enzymes, and then catalyzed acrylamide with free cell method or fixed cell method, and then processed to obtain high -purity acrylamide.
(3) Use microbial catalysts washed by acrylic solution. This method was washed with acrylic solution to wash microbial catalysts, and then the washed microbial catalyst was used to transform the reaction to prepare acrylamide.