Peffer Holt (1958), male, Danish, researcher.
The role of global science and technology chemicals in the modern washing process (to be continued) Hans Sergey Olsen (Dan), Peffer Holt (Dan), Hua Zhangxi translation (1. Novo Nordisk Corporation Denmark 2. Novo Nordisk Corporation American Biochemical Corporation USA) Each of the white enzymes, lipases, amylases and cellulases provides specialized laundry and automatic dishwasher applications. benefit. Historically, proteases were the first enzymes widely used in laundry detergents. In addition to improving the level of washing, the enzyme is also environmentally friendly because it can reduce the washing time, lower the washing temperature, and reduce the amount of water used to save energy. Today, the use of proteases in combination with lipases and amylases can improve the cleaning performance, especially in household laundry at low temperatures and industrial cleaning operations at lower pH conditions. Cellulase contributes to the overall protection of the fabric by enabling the washed garment to be restored or to maintain its original new appearance. All types of enzymes are produced by fermentation techniques using renewable resources.
Storage stability Washing performance The field of enzymology is an important branch of biotechnology. The development of deep fermentation processes and genetic engineering has led to tremendous advances in the manufacture of industrial enzymes.
Enzymes act as a functional component in detergents and aid in the cleaning of clothing and dishes in an efficient, environmentally friendly and energy efficient manner. This largest of all industrial enzyme applications began slowly in the early 1980s due to Roehm's 1913 patent on the use of pancreatic enzymes in prepreg washes.
Pancreatic enzymes include proteases (trypsin and chymotrypsin), carboxypeptidase, alpha amylase , Lactase , sucrase , maltase and lipase . Therefore, in addition to cellulase, the application of enzymes in commodities has laid the foundation as early as 1913, and its importance continues to this day.
The most widely used industrial enzymes today are hydrolases. This enzyme removes dirt based on proteins, lipids and polysaccharides. Cellulolytic enzymes are another class of hydrolases. The latter acts to protect the fabric by a selective reaction that has not previously occurred on the fabric. At present, research is being conducted on the possibility of bleaching a dye component using an oxidoreductase (oxidase or peroxidase).
The world's Detergent enzymes supply the annual sales of laundry and dishwashing detergents in the global market of 18 million to 19 million tons. In 1995, the total sales of Detergent Enzymes worldwide was about 500 million US dollars. The main producers of enzymes are Novo Nordisk (headquartered in Denmark and Genencor (headquartered in Rocheser, NY, USA).
The two companies provide 90% of the total Detergent Enzyme products worldwide.
1 The role of enzymes in detergents For many years, enzymes have become an important factor in the development and improvement of detergent products. Enzymes in washing clothes, dishwashing, and cleaning in industrial and public places, because the washing temperature can be lowered, the discharged washing water is more compatible with the environment, the pH of the washing liquid can be lowered, and the fabric can be protected. Helps reduce washing time, energy and water consumption. Enzymes are derived from renewable resources and are therefore inherently environmentally friendly. They have a high potency and are particularly advantageous for the formulation of concentrated detergents. The development of genetic engineering and protein engineering contributes to the long-term improvement of the stability, economy, specificity and overall potential development of industrial enzyme products.
1.1 Enzyme-Based Detergent Mechanism From the enzyme point of view, the main components of various detergents on the international market operate almost under the same decontamination mechanism. Dirt and stains are removed mechanically with the aid of surfactants, auxiliaries and enzymes. Alkaline proteases, amylases, and lipases hydrolyze the substrate soil attached to fabric or hard surfaces such as dishes to become soluble. The cellulase is cleaned by removing the particulate dirt adhering to the cotton micro-short fibers by hydrolyzing the glucosidic bonds on the cellulose. The key role of cellulase is to soften the surface of the worn textile and improve the color of the textile. Surfactants reduce the surface tension at the interface and enhance the repulsive forces between the original soil and the enzymatically degraded soil and the fabric. The role of the auxiliaries is to sequester, precipitate or ion exchange the calcium and magnesium salts, provide alkalinity, prevent redeposition of the soil, provide buffering capacity and inhibit corrosion.
1.2 For 35 years, the role of enzymes in detergents has changed from a small amount of additive to a key ingredient. The largest increase in the field of application of enzymes is domestic laundry.
Prior to the introduction of modern detergent formulations, soap and sodium carbonate were the main detergent components, and the effectiveness of the cleaning relied primarily on mechanical action. Table 1 shows a comparison of chemical, water and energy consumption over the past 50 years. The chemical consumption of the washing machine is significantly lower than that of hand washing.
During the period from 1967 to 1970, the energy consumption 40 decreased due to the successful introduction of enzymatic detergent. In 1969, at least 50 of the European detergents claimed to be biologically aggressive (ie, enzymes with protein degradation), and the washing temperature was reduced from 95 ° C to 60 ° C and the washing temperature of 40 ° C became more common. Moreover, pre-wash and overnight pre-dip can also be omitted. More efficient washing machine (nozzle jet, cascade), better washing machine electronic management system and concentrated detergent due to the combination of more varieties of enzyme components (cellulase, amylase and lipase) The use has reached a further reduction in energy consumption. In Japan, protease was introduced by Lions in 1979. In the United States, the use of enzymes in detergents was first introduced in 1971 and later stopped due to worker health problems at the factory, and resumed in the 1980s.
Throughout the various stages in Table 1, the optimization of the new combination of ingredients (various auxiliaries and bleaching systems) and the washing machine is combined with the improvement in the cleaning performance provided by the enzyme system. At the same time, the development of new enzyme systems is also affected by the new composition of detergents. Comparing the distribution of washing costs calculated from 1943 to 1997 reflects the dramatic changes in society and the benefits of new developments. Table 2 shows the annual laundry costs in two years on a family basis.
Interestingly, there is no change in the proportion of costs attributed to detergents. The energy consumption in the washing costs has dropped significantly, but the cost of water has increased considerably due to the rising trend of clean water shortages and the increase in environmental resource tax rates.
The development of laundry technology. The new detergent composition and enzymes reduce the washing temperature, making it possible to reduce energy consumption. Therefore, it is easy to understand that the current trend in the design of washing machines is toward the development of reducing water consumption.
1.3 Dishwashing The use of automatic dishwashers is almost as long as washing machines, but not as extensive as washing machines. Today, automatic dishwashers are used in 50-60 homes in the United States, western Germany, Norway, Sweden, and Denmark.
It is about 30 in France and Italy, and less than 20 in other European countries such as the Netherlands and Spain. In Japan, less than 5 use automatic dishwashers in the home.
When washing dishes by hand, the removal of food residue depends mainly on the surface of the global technology Hans Sergey Olsen (Dan) Pefo Holt (Dan): the role of enzymes in the modern washing process a typical Annual laundry costs for Danish households (DKK Danish Krone) and cost distribution consumption / kg fabric 1944 (hand wash) (machine wash) 1995 (machine wash) chemicals (g) ordinary powder concentrate powder heating energy (kWh) (heated water ) Motor and Pump Energy Cost Composition Cost (DKK) Cost Distribution Cost (DKK) Cost Distribution Electric Fuel Water Detergent Daily Chemical Science Global Technology Active and Mechanical Energy. When mechanically dishwashing, the cleaning performance depends on the entire detergent, temperature and mechanical energy. Mechanical energy is input by a pump that circulates the water flow. Therefore, the chemical contribution provided by the detergent must be large. The most serious cleaning problem is caused by a film formed in a dish (ceramics, cups, cutlery, and glasses). These food films may be dry and attached, or may be baked and attached, or even grilled, resulting in complex compounds formed by carbohydrates, proteins and lipids. Tea stains formed by plant pigments or calcium citrate compounds in soaked tea are also issues to be aware of. In addition, the dirt formed by the combination of polyphenols and carbohydrates from coffee is also quite difficult to remove. Therefore, if the stains of tea and coffee can be completely removed, the cleaning of the dishes can be said to be successful. Complex compounds based on proteins, polysaccharides and lipids require hydrolysis to swell and degrade the soil, which can then be separated from the surface of the dish. In order to remove stains from fruits, coffee, tea, wine and vegetables, it is also necessary to add a bleaching system capable of oxidizing polycyclic aromatic hydrocarbons.
To take into account the short washing time, high temperature, and to avoid the invasion of the dishes, you have to look for chemicals with special properties. Highly alkaline oxidizing chemicals are required to ensure that the food chemicals are hydrolyzed and oxidatively hydrolyzed and dispersed in the wash liquor without foam formation. There is also a need for chemicals that can effectively bind to ions that cause moderate hardness to prevent precipitation of calcium, as well as agents that protect glass and enamel decorations.
Prior to the introduction of the enzyme product into the European automatic dishwasher detergent (ADD) in 1990, the formulation of ADD was based on a strong alkaline, strong complexing agent [sodium tripolyphosphate (20-30), sodium metasilicate ( 40 to 70) and sodium carbonate (0 to 10), an oxidizing compound (usually dichloro or trichloroisocyanurate (1 to 30)) and a nonionic surfactant (0 to 2). pH (1 solution) = 12.0 ~ 12.5. Typical dosage is 80 g per batch.
At pH values of 12 to 13, the chemicals must be removed very efficiently by rinsing. This is why the automatic dishwasher used a lot of water. Although the glass is resistant to chemical attack within a reasonable range, under high alkaline conditions, the silicate structure is destroyed by the hydrolysis cracking of the Si O Si bond, resulting in blurring of the glass surface. Tests have shown that the disilicate can effectively prevent the weight loss caused by the invasion of the glass.
In the past 20 years, the water consumption per dishwashing cycle has dropped from 60 L to 15 L. The consumption of detergent has dropped from 80 g to 15 g. The energy consumption has been reduced from 2.8 kWh to 1.5 kWh. Hypochlorite or chlorine release. Bleaching compounds such as chloroisocyanurate are important for removing certain stains, such as stains on the cup.
In the ADD market in the United States, although some enzyme-containing products have been on the market for many years, most of them are still based on traditional chlorine-containing products.
To date, efforts to introduce ADD with enzymes and low bases in the United States have not been effective. Unlike dishwashers in the United States, dishwashers in the United States lack both ion-exchanged water softeners and water heaters that are installed inside. This allows the main cleaning task to be relied upon only by detergents, which is not conducive to the use of mild detergent formulations.
Like the formulation of laundry detergents, the introduction of new enzymes (amylases and proteases) ADD has made it possible to replace strong chemicals such as bleaches and strong bases. Since low concentrations of hypochlorite can destroy enzymes, peroxy/activator bleaching systems based on sodium perborate or sodium percarbonate plus activators (TAED, etc.) are often used to make fruits, coffee, tea, wine and vegetables Oxidation of polycyclic aromatic hydrocarbons. In the use of reduced values of chlorine-free ADD, the hydrolysis swell required to separate the food residue from the surface of the vessel is supported by the action of the corresponding starch degrading enzymes and protein degrading enzymes. These systems are widely used in concentrated powdered and flaky ADDs in Europe.
1.4 The use of enzymes in the laundry and public space laundry in the industrial and public spaces, washing in public places, and cleaning in the food industry has been significant.
Textiles treated under industrial and public conditions include hospital bed sheets, outerwear and uniforms, workers' suits, white coats in slaughterhouses, and tablecloths and napkins in hotels and restaurants.
The machine used may be a washing and dewatering machine capable of adding 120 kg of clothes per batch, or a tunnel washing machine with a capacity of 550 kg/h divided into several compartments.
In the washing and dewatering machine, pre-washing at low temperature (for example, 35 ° C) and pH 11 for 8 min to 10 min allows the use of the enzyme. The main wash is usually carried out at 85 ° C and pH 11.5 for 15 min. In order to enable the enzyme to work, the temperature can be lowered to 60 ° C. Typically, the final bleaching step is carried out with chlorine in cold water.
In the tunnel washer, the residence time of each compartment is 4 min to 5 min. The enzyme can be added in the pre-rinsing and the first washing stage followed by bleaching with chlorine or hydrogen peroxide.
1.5 Dishwashing in public places During the washing of dishes in a conventional public place, the dishes are placed vertically in a dish and then washed with a washing solution of 60 °C. The washing liquid comprises a detergent of 0.5 g/L to 5 g/L and contains sodium hydroxide, potassium hydroxide, phosphonate, polycarboxylate and sodium edetate. In the absence of enzyme, the normal pH is 13 to 14. The normal washing process is to use the detergent cleaning time of 60 s to 90 s, followed by rinsing at a temperature of 75 ° C to 85 ° C for 20 s. Then the bowl The dish is placed in the machine to dry or placed outside and naturally dry.
In a large public dish dishwasher, the dishes are placed on a belt conveyor that pulls the dishes through the compartments of the above processing steps.
In the process of dishwashing in public places, the use of enzymes provides the same cleaning effect as in home applications. A suitable temperature range is from 45 ° C to 65 ° C when a low alkali detergent system is used and no bleach is used. A two-part liquid detergent system is often used. The first part consists of a liquid detergent containing sodium hydroxide, a calcium ion binder (such as a phosphonate), an amphoteric or nonionic surfactant, and a polycarboxylate. A typical dose is about 2 g / L ~ 4 g / L of washing solution, the pH of the washing solution is 8.5 ~ 9. The second part of the composition is an enzyme that degrades starch and protein. These enzymes are added directly to the washing chamber from a separate container.
1.6 Cleaning in the food industry For many years, proteases have been used as a small amount of functional components in the formulation of detergent systems for cleaning reverse osmosis membranes. The enzyme requirements and dosages are similar to those used for laundry detergents and ADD. Enzymes have also been used for the cleaning of milk plants and for the cleaning of microfiltration and ultrafiltration membranes in the beer industry. Enzymatic washing has also been used to clean the filter membrane used in juice production. Both organic and inorganic soils are removed by in-line cleaning (CIP). In the CIP plant, the normal cleaning medium is a 0.5 to 1 NaOH solution (± surfactant and ethylenediaminetetraacetate). The cleaning temperature is 75 °C to 85 °C. Next, it is rinsed with (±surfactant) or acidic sulfate.
In the milk factory, the most difficult of the dirt removed from the hard surface is the dirt formed on the heating surface (for example, the heat exchanger or the tube of the evaporator) due to the sintering of the milk. This substrate is a complex colloid formed by the Maillard reaction between protein, lactose and fat.
Milkstone, a complex of calcium phosphate and protein, may also be included. Enzymatic CIP systems based on proteases and lipases have proven to be effective in such applications, especially in the cleaning of spiral wound ultrafiltration modules, because such devices are sensitive to harsh chemicals, while conventional Washing supplies are often difficult to work with.
In the pure enzymatic cleaning process of a highly pasteurized plate heat exchanger for sweet milk surfactant (soap), the combination of protease and lipase causes emulsifier and foaming from protein and fat in situ. The reaction of the agent. This reaction is illustrated in Figure 1.
1.7 Regulatory management and quality assurance of detergent enzymes In most countries, regulation, classification and labeling are regulated by existing chemicals. Many types of enzymes are listed in the chemical list. For example: EINECS in the EU and TSCA in the US. In some cases enzymes are considered natural and not included in the chemical. It is also managed by legislation based on specialized biotechnology products.
The Fermentation Enzyme Product Manufacturers Association has established rules for the operation of excellent manufacturing companies for microbial Food Enzymes. This operating rule can also be used for detergent enzymes. The most important principle is to ensure the pure culture of the production organism.
Commercial enzymes are usually formulated as aqueous solutions or processed into dry, dust-free particles.
1.8 Safety Just like other foreign proteins other than the human body, enzymes may cause allergies due to inhalation. Even inhalation of low concentrations of foreign proteins in the dust or aerosol state can stimulate the body's immune system and produce antibodies. For some individuals, an increase in the concentration of the antibody (enzyme protein complex) can trigger an increase in histamine concentration. The latter can cause symptoms like hay fever, such as tears, stuffy nose and sore throat. These effects stop when exposed exposure stops.
In order to prevent sensitization, the enzyme is not inhaled. Sensitization can trigger an allergic reaction. Therefore, all workplaces that use enzymes are subject to extensive monitoring to confirm that the enzyme content in the atmosphere does not exceed the threshold (TLV). In many countries the TLV of the enzyme is determined based on the protease-degrading subtilisin. It is specified that the content of pure crystalline subtilisin per cubic meter of air is 0.00006 mg.
Procter & Gamble has a report on successful exposure to enzyme exposure and protection of workers' health. As early as 1971, the National Institute of Research reported that consumers who use enzyme-containing laundry detergent products do not cause respiratory allergies. Subsequent studies have also confirmed that enzyme-containing laundry detergents and dishwashing detergents are safe for consumer use.
(To be continued) Global Technology Hans Serge Gil Olsen (Dan) Pefo Holt (Dan): The role of enzymes in the modern washing process (English) correction statement 515 ads yellow printed in black, hereby corrected, And apologize to customers and readers.
Shanxi Xinhua Printing Factory
