The role of fine chemical industry in modern construction

In recent years, the domestic fine chemical industry has been paying attention to a problem: the development trend of fine chemical industry in 2 1 century. Since the late 1990s, China has decided to increase its investment in high-tech fields such as energy, information, biology and materials. As a traditional industry, chemical industry has not been included in the priority development category of the country, but has been attributed to sunset industry by some people. But this is not the case, especially our fine chemical industry, because of its special position in the national economy and its close connection with energy, information, biochemistry, materials and other disciplines, will play an increasingly important role in China's modernization and become an irreplaceable and indispensable key link. I am confident to tell you here that fine chemical industry is still a sunrise industry in China and even the world, with bright prospects.

1. the position of fine chemicals in the national economy

We all know that fine chemical industry is a chemical industry that produces fine chemicals, mainly including traditional chemical departments such as medicine, dyes, pesticides, coatings, surfactants, catalysts, additives and chemical reagents, as well as new fields that have been gradually developed in recent 20 years, such as food additives, feed additives, oilfield chemicals, chemicals for electronic industry, leather chemicals, functional polymer materials and materials for life sciences. China is a populous country, and the survival and quality of life of more than one billion people are closely related to fine chemical industry. To improve grain yield, we need a variety of high-efficiency and low-toxicity pesticides, plant growth regulators, herbicides and compound fertilizers. A variety of drugs and antibiotics are needed to fight this disease; The petrochemical industry needs catalysts, surfactants, petroleum additives and rubber additives. Clothing and silk industries need high-quality dyes, textile auxiliaries and pigments; To beautify the environment and improve living conditions, different paints and adhesives are needed; It is reported that a TV set is related to more than 2,000 kinds of chemicals, most of which are fine chemicals.

It is precisely because of the great contribution of fine chemicals to the national economy and people's lives that China has listed fine chemicals as the strategic focus of national economic development in the Sixth Five-Year Plan, the Seventh Five-Year Plan, the Eighth Five-Year Plan and the Ninth Five-Year Plan as one of the seven key projects. After more than 20 years' efforts, China fine chemical industry has made great progress. At present, the total number of fine chemical enterprises in China has reached more than 1 1000, and there are more than 7,000 fine chemical enterprises in traditional fields, including dye and pigment enterprises 1525, pesticide and its preparation processing enterprises 65,438 and paint production enterprises 4,544. 3,900 fine chemical enterprises in new fields. The total output value of fine chemicals reached 654.38+02 billion yuan, of which the output value of fine chemicals in new fields was 60-70 billion yuan. The output of dyes, pesticides and other fine chemical products ranks among the top in the world. Some fine chemical products can meet domestic demand.

The development of fine chemical industry has promoted the level of clothing, food, transportation and use in agriculture, medicine, textile printing and dyeing, leather and paper making. At the same time, it has brought economic benefits to these industries.

The development of fine chemical industry provides a guarantee for the development of high and new technologies such as biotechnology, information technology, new materials, new energy technology and environmental protection.

The development of fine chemical industry directly provides catalysts, additives, special gases, special materials (corrosion resistance, high temperature resistance and solvent resistance), flame retardants, membrane materials, various additives, industrial surfactants, environmental chemicals and so on. It is used in the production and processing of three major synthetic materials (plastics, rubber and fibers) in the petrochemical industry, thus ensuring and promoting the development of the petrochemical industry.

The development of fine chemical industry has improved the processing depth of chemical industry and the economic benefits of large oil companies and chemical companies.

The development of fine chemical industry has improved the overall economic benefits of the national chemical industry and enhanced the country's economic strength.

Nowadays, fine chemical industry has become one of the strategic focuses of the development of the chemical industry in the world, and it is also one of the focuses of fierce competition in the chemical industry. Therefore, the State Economic and Trade Commission pointed out in the outline of the tenth five-year plan for industrial restructuring that the development of chemical industry should focus on "fertilizers, pesticides and fine chemicals". Fertilizers and pesticides are directly related to food production, so fine chemicals are as important as food production, and they can only be based at home and cannot rely on foreign countries. They are indispensable economic sectors related to the national economy and people's livelihood.

Two. Development status of fine chemical industry at home and abroad

According to statistics, there are 17 chemical enterprises in the global top 500, among which the first few are DuPont, BASF, Hearst and Bayer, Dow in the United States and Ciba-Cargill in Switzerland. They all have a history of 100 years. Before the 1970s, petrochemical industry was vigorously developed, and then it gradually turned to fine chemical industry. Germany is the earliest country to develop fine chemicals. They started from coal chemical industry, which accounted for about 80% of raw materials before the 1950s. However, due to the poor process route and benefit of coal chemical industry, the proportion of chemical products with petroleum as raw materials soared from 65438 to 0970, reaching more than 80%.

Dupont is the largest chemical company in the world, established in 1802. From 1980 to fine chemical industry, it started later than Germany and Japan, but it developed rapidly. The company aims to improve quality, reduce costs and improve the market competitiveness of general products in the past. Since 1980s, it has expanded the production of special chemicals, mainly fine chemical products, such as pesticides, drugs, special polymers and composite materials. The company's long-term goal is to develop life science products, such as health care products, anticancer, anti-aging drugs and bionic medical products. From 65438 to 0995, the company earned $3.3 billion.

Dow Chemical Company was established in 1897. At the end of 1970s, through product structure adjustment, we strengthened the production of medicine and various engineering polymers, especially automotive coatings and adhesives. In 1973, the company's output value of fine chemicals was only $540 million, and the rate of fine chemicals was 18%, which soared to 50% in 1996. In the early 1990s, the total output value was $20 billion, and the output value of fine chemicals accounted for110 billion.

BASF, Hearst and Bayer are the three pillars of German chemical enterprises. Most of them increase investment by means of merger, transfer and sale, implement core business with the strength of technical force, and try their best to increase the proportion of core business and the market share of leading products. Focus on the development of high-tech fields such as health care and medical supplies, agricultural chemicals, electronic chemicals, medical diagnostic supplies, information and video supplies, aerospace chemicals and new materials, and greatly improve the scientific and technological content and economic benefits of fine chemical products. For example, the sales of BASF's special products, such as coatings and photosensitive resins, increased from 65438+ 1 1% in 1980 to 30% in 1995. The company's turnover in 1994 was 46.2 billion Deutsche Mark, that in Hearst 1996 was 52/kloc-0.0 million Deutsche Mark, and that in Bayer 1994 was 26.7 billion dollars. They all attach great importance to the development of high technology. By the end of 1995, Bayer had obtained 155000 patents and 24000 products. Its leading pharmaceutical product has a history of 100 years.

Ciba-Jiaji Company of Switzerland is a world-famous manufacturer of pesticides, medicines, dyes, additives, cosmetics, detergents and aviation adhesives. And it is the only large enterprise in the world that outsources all raw materials to develop fine chemicals. 1994 turnover 16 1 100 million USD, and the rate of fine chemicals ranks first in the world, reaching over 80%.

Developed countries constantly adjust the product structure of chemical industry according to the needs of economic benefits and development, as well as the guidance of market, environment and resources. The focus of their transformation is fine chemical industry, and the development of fine chemical industry has become a worldwide trend. 199 1 year global sales of fine chemicals are more than 40 billion dollars, mainly in western Europe, the United States and Japan. In the early 1990s, the rate of fine chemicals in developed countries was about 55%, and it rose to 60% in the late 1990s. The development speed of fine chemicals has been higher than other industries. Take the United States as an example In the late 1980s, the growth rate of industry was 2.9%, while that of fine chemicals was as high as 5%. The main goal of their development is to expand the production of special products such as medical and health products, electronic chemicals, special polymers and composite materials, and vigorously develop life science products, such as anticancer drugs, bionic medical products, pollution-free and efficient herbicides and fungicides.

Since China took fine chemical industry as its key development goal in 1980s, the policy has been tilted and developed rapidly. During the Eighth Five-Year Plan period, there were 10 fine chemical technology development centers, with an annual production capacity of more than 8 million tons and about 1 10,000 kinds of products, with an annual output value of 90 billion yuan, which laid a certain foundation. By the end of the 20th century, the rate of fine chemicals reached 35%. Compared with foreign developed countries, there is a big gap. They need16,000 kinds of fine chemicals, and the electronics industry alone needs more than 7,000 kinds of color TVs. The matching rate of domestic products is less than 20%, and the rest are all imported. Others are in short supply in terms of fabric finishing agents and leather finishing agents. In addition, the quality, variety, technical level, equipment and experience of fine chemical products in China can not meet the needs of many industries.

Three. Opportunities of fine chemical industry

Fine chemical industry is closely related to people's daily life, and its importance is no less than that of grain production, which is related to national security. Therefore, fine chemical industry is one of the pillar industries in China. At the beginning of the new century, fine chemical industry has been listed as one of the development priorities by the State Economic and Trade Commission. This is one of the good opportunities for fine chemical industry.

Most of the fine chemicals produced are chemicals with new technology, fast variety renewal, strong technical specificity, strong monopoly, fine technology, accurate separation and purification, high technical concentration, small relative production, high added value, functionality and specificity. Many experts and scholars at home and abroad define fine chemical industry in 2 1 century as high and new technology. There are many fine chemical enterprises in foreign high-tech parks, such as Les Ulis high-tech park in the southwest suburb of Paris, France. The same is true at home. There are a large number of fine chemical enterprises in high-tech development zones in Shanghai, Suzhou and Hangzhou. As long as they are high-tech enterprises, they can enjoy preferential conditions in policy, financing, foreign trade, land acquisition and employment. This is one of the good opportunities for fine chemical industry.

At present, industrial restructuring is taking place all over the world. With the continuous improvement of environmental protection requirements, industrialized countries such as Europe, America and Japan have successively transferred many chemical enterprises to developing countries. Although they tried to transfer pollution, they did transfer a certain amount of high-tech fine chemicals production abroad, and this trend is expanding. Judging from the world economic map, it is mainly Asia, South America and Africa that can accept this transfer. As Africa's economy and technology are backward, it can't afford this transfer. Although the South American Economic Cooperation Zone headed by Brazil has a certain foundation in economy, technology and resources, its political instability and economic dangers make foreign investors daunting. Asia's economy has developed rapidly, especially in East Asia and South Asia, where natural and human resources are unique and the economic and technological level has reached a considerable level. Among them, ten ASEAN countries have cheap labor, and China and India are the most competitive. Because of China's stable political situation, preferential policies, large market capacity, and its commitment to economic construction, it has laid a solid foundation for 20 years of reform and opening up, so China is better than India. According to the statistics of 1995, there are nearly 20,000 foreign-funded chemical enterprises in China, including 2,206 fine chemical enterprises. Especially in recent years, international multinational companies have entered China on a large scale, such as the hydrazine hydrate production enterprise built by Bayer Company in Shanghai, the lysine of Ajisen Company in Sichuan Chemical Plant, the synthetic pyridine of Lililly Company in Nantong, Jiangsu Province, the nicotinic acid and nicotinamide of Lonza Company in Guangzhou, and the joint venture between DuPont Company and Shanghai. This will promote the improvement of the production level and development of fine chemicals in China. This is one of the good opportunities for fine chemical industry.

With the development of high and new technologies in the world and China, nanotechnology, information technology, modern biotechnology, modern separation technology, green chemistry and many other high and new technologies will be combined with fine chemical industry to serve high and new technologies. High and new technologies will further transform fine chemical industry, further broaden the application fields of fine chemical products, further upgrade, refine, compound and functionalize products, and develop in the direction of high and new fine chemical industry. Therefore, the benign interaction of various high technologies is the fourth good opportunity for fine chemical industry.

Faced with these four good opportunities, it is no wonder that domestic experts, scholars and people of insight agree that fine chemical industry is definitely a sunrise industry in China with a bright future.

The progress of the industry and the development of enterprises need the support of outstanding professionals. This provides a place for our students to display their talents. In fact, the annual employment rate of our fine chemical graduates is as high as 95%. Many fine chemical enterprises inside and outside the province came to our school to ask for the introduction or recruitment of fine chemical graduates. Because there are many fine chemical enterprises in society, the economic benefits of fine chemical enterprises are generally good, the export and domestic market potential of fine chemical products are huge, and the development prospects of fine chemical products are broad, so the social capacity of fine chemical graduates is very large. In the foreseeable future, there will be basically no employment problem.

Four. Development direction of fine chemical industry

According to the regulations of the Organization for Economic Development and Cooperation (OECD), automobile, machinery, nonferrous metallurgy and chemical industry belong to medium-tech industries in terms of technology intensity. High-tech and its industries are specific fields determined by their high R&D content, such as aerospace, information industry and pharmacy. As a branch of chemical industry, fine chemical industry generally belongs to the category of medium technology, but as fine chemical industry, high-performance chemical new materials, medicine, biochemistry and so on have been identified as high-tech categories. 2 1 century is the era of knowledge economy, and a new technological revolution of three frontier sciences with bioengineering, information science and new material science as the main body is bound to have a great impact on the chemical industry. The development trend of traditional industries such as fine chemicals is bound to increase the intensity of technical knowledge and complement each other with high and new technologies.

1. the combination of nanotechnology and fine chemical industry

The so-called nanotechnology refers to the science and technology that studies the motion law and interaction of the system composed of substances with the size between 0. 1 ~ 100nm, as well as the possible technical problems in practical application. Nanotechnology is one of the important contents of the revolution of science and technology industry in 2 1 century. It is a comprehensive discipline that highly intersects with physics, chemistry, biology, materials science and electronics, including basic science with observation, analysis and research as the main line and technical science with nano-engineering and processing as the main line. Undeniably, nanotechnology is a complete system integrating scientific frontier and high technology. Nanotechnology mainly includes nano-electronics, nano-machinery and nano-materials. Just like microelectronics and computer technology in the 20th century, nanotechnology will be one of the brand-new technologies in the 20th century. Its research and application will surely bring a new technological revolution.

Nano-materials have many characteristics, such as quantum size effect, small size effect, surface effect and macroscopic quantum tunneling effect, which make nano-particles obviously superior to ordinary particles in thermomagnetism, light, sensitivity, surface stability, diffusion and sintering properties, mechanical properties, etc. Therefore, nano-materials are widely used in fine chemicals. Specific performance in the following aspects:

(1) Nano-polymers are used to make foams with high strength/weight ratio, transparent insulating materials, laser-doped transparent foams, high-strength fibers, high-surface adsorbents, ion exchange resins, filters, gels and porous electrodes.

(2) Nano-daily chemical nano-daily chemical and cosmetics, nano-pigments, nano-photographic films and nano-fine chemical materials will bring us to a colorful world. Recently, the research department of Kodak Company in the United States has successfully developed a new nano-powder with both pigment and molecular dye functions, which is expected to bring revolutionary changes to color images.

(3) Adhesive and sealant nano-SiO2 _ 2 has been added to adhesive and sealant as an additive abroad, which greatly improves the bonding effect of adhesive and the sealing performance of sealant. Its mechanism is that the surface of nano-silica is coated with a layer of organic material, which makes it hydrophilic. When it is added into sealant, the structure of silicon dioxide is rapidly formed, that is, nano-SiO _ 2 forms a network structure, which limits the flow of colloid, accelerates the curing speed, improves the bonding effect, and improves the sealing performance of adhesive due to its small particle size. Mu chong's academic blog, M oe {%|*LW.

(4) Coatings Adding nano-SiO2 _ 2 into various coatings can improve its aging resistance, smoothness and strength, and the quality and grade of coatings will naturally upgrade. Nano-SiO2 _ 2 is a kind of anti-ultraviolet radiation (that is, anti-aging) material, and its tiny particles have a large specific surface area, which can quickly form a network structure when the coating is dried, and at the same time increase the strength and smoothness of the coating. Woodworm academic blog1n&; Y/Pi[V.A

(5) High-efficient combustion improver Adding nano-nickel powder to rocket solid fuel propellant can greatly improve the combustion heat and efficiency of fuel and improve the combustion stability. Nano-explosives will increase the power of explosives by a thousand times;

(6) Hydrogen storage materials FeTi and Mg2Ni are important candidate alloys for hydrogen storage materials, which absorb hydrogen slowly and must be activated, that is, the hydrogen absorption-dehydrogenation process is carried out for many times. Zaluski et al. directly formed Mg2Ni by ball milling Mg and Ni powders, with an average grain size of 20 ~ 30 nm, and its hydrogen absorption performance is far superior to that of ordinary polycrystalline materials. Hydrogen absorption of common polycrystalline Mg2Ni can only be carried out at high temperature (when the pH is less than 20 Pa, T is greater than T ≥ 250 C), but the hydrogen absorption time at low temperature is long and the hydrogen pressure is high. Nanocrystalline Mg2Ni can absorb hydrogen below 200℃ without activation treatment. After the first hydrogenation cycle at 300°C, the hydrogen content can reach about 3.4%. In the subsequent cycle, the hydrogen absorption rate is 4 times faster than that of ordinary polycrystalline materials. The hydrogen absorption and activation properties of nanocrystalline FeTi are obviously better than those of ordinary polycrystalline materials. The activation process of common polycrystalline FeTi is: heating to 400 ~ 450℃ in vacuum, then annealing in 7Pa H2, cooling to room temperature, and exposing to higher pressure (35 ~ 65 Pa) of hydrogen. The activation process needs to be repeated several times. However, the nanocrystalline FeTi formed by ball milling only needs to be annealed at 400℃ for 0.5 h in vacuum, which is enough to complete all hydrogen absorption cycles. Nanocrystalline FeTi alloy consists of nanocrystalline grains and highly disordered grain boundary regions (about 20% ~ 30% of the material).

(7) In the catalyst material, the active site of the reaction can be a cluster atom on the surface or another substance adsorbed on the surface. These positions are closely related to surface structure, lattice defects and crystal angle. Nanocrystalline materials are suitable as catalytic materials because they can provide a large number of catalytically active sites. In fact, many nano-structured catalytic materials have appeared decades before the term "nano-materials" appeared. Typical catalysts, such as metal nanoparticles supported on inert substances, such as RH/Al2O3 and Pt/C, have been used in petrochemical, fine chemical and automobile exhaust. In the chemical industry, the use of nanoparticles as catalysts is another aspect of nanomaterials. For example, ultrafine boron powder and ammonium chromate powder can be used as effective catalysts for explosives; Ultrafine platinum powder and tungsten carbide powder are efficient hydrogenation catalysts; Ultrafine silver powder can be used as a catalyst for ethylene oxidation; Copper and its alloy nano-powders have high efficiency and strong selectivity as catalysts, and can be used as catalysts in the process of methanol synthesis from carbon dioxide and hydrogen. Nano-nickel powder has a strong catalytic effect and can be used for hydrogenation of organic compounds and treatment of automobile exhaust.

Ping Jin et al. prepared Pd colloidal ultrafine particles (average particle size 65438±0.8nm) supported by polyvinylpyrrolidone by colloidal method, which were used to catalyze the following reactions:

It was found that its activity was 2 ~ 3 times higher than that of ordinary palladium catalyst, and its selectivity was close to 100%.

More than two kinds of osmium ultrafine particles or alloys can also be used as catalysts to obtain higher catalytic activity and selectivity. For example, amorphous Ni-B nano-catalyst prepared by chemical reduction method and Co-Mn/SiO _ 2 nano-alloy catalyst for ethylene hydrogenation have good catalytic performance. Metal nanoparticles such as nickel, cobalt, iron and TiO _ 2-γ-Al _ 2O _ 3 are mixed, molded and roasted to purify automobile exhaust. The activity is similar to that of ternary Pt catalyst, and the activity does not decrease after working at 600℃ 100 hours.

2. The combination of modern biochemistry and fine chemistry.

Biochemical engineering is considered as an interdisciplinary subject of biology and chemical engineering. Although the biochemical industry in China developed slowly from brewing, sauce making and vinegar making thousands of years ago, the traditional biochemical industry is limited to food industries such as brewing, pharmaceutical industries such as vitamins (vitamin B and vitamin C), antibiotics (penicillin, streptomycin), biological pesticides such as Jinggangmycin (rice blast prevention) and Qingfengmycin (rice blast prevention), but since the 1980s, with the development of microbiology and microbiology, On the basis of traditional biotechnology, modern bioengineering technologies with strong vitality, such as gene recombination technology, cell fusion technology, mass cell culture technology and biological reaction technology, have been gradually applied in the fields of medicine, food, chemical industry, metallurgy, energy, medicine, agriculture, forestry, animal husbandry and by-products. In recent years, the status of biochemistry in biotechnology has been rising, and biotechnology is shifting from traditional medicine and agriculture to biochemistry.

Compared with the traditional chemical industry, biochemistry has the following characteristics:

A. mainly use renewable resources as the main raw materials.

B. The reaction conditions are mild, and most of them are carried out at normal temperature and pressure, with low energy consumption, good selectivity and high efficiency.

C. less environmental pollution.

D. simple equipment and low investment.

E. be able to produce compounds with excellent performance that cannot be produced at present or are unknown, and develop and produce new varieties.

F it is an ideal green chemical technology with high atom utilization rate.

Traditional biochemistry focuses on the processing of biological resources and produces many useful products through fermentation. Such as monosodium glutamate, alcohol, amino acids, etc. Now biochemical technology has been widely used in medicine, food, basic organic chemical raw materials, biological pesticides and other fields. With the development of modern biotechnology, fine chemicals such as vitamins, hormones, vaccines, biopesticides, biosurfactants, acrylamide and organic acids, which are based on genetic engineering and centered on microbial engineering, have reached a new level, and biological functions have been quantitatively transformed and utilized at molecular and cellular levels.

(1) vitamins

Vitamins are trace organic substances necessary for normal growth and metabolism of organisms. Humans and higher animals cannot synthesize vitamins themselves and need to obtain them from the outside world. Once you can't take it, it will cause vitamin deficiency and get sick. Vitamins not only have therapeutic effect, but also have health care function. Their applications in food, feed and cosmetics are increasing day by day, and they have good development prospects. The main vitamins developed are VC, VA, VE, VB 1, VB6, nicotinic acid and calcium pantothenate.

For example, vitamin E is also called α tocopherol, the molecular formula is C29H50O2, the molecular weight is 430.72, and the structural formula is

There are seven isomers of vitamin E, among which α activity is the highest, β activity is the second, and δ activity is the smallest. Vitamin E affects the metabolism of sugar, lipid and protein. It is clinically used to treat abortion and muscular dystrophy. Now research has found that vitamin E has a certain therapeutic effect on arteriosclerosis, anemia, encephalomalacia, liver disease and cancer.

Natural vitamin E has different isomers in different kinds of raw plants. For example, American wheat oil is mainly α isomer, and soybean oil is mainly δ isomer. The preparation method of vitamin E is to take wheat germ oil or soybean oil as raw materials, collect the fraction below 240℃ by molecular distillation, dissolve it in acetone, cool to remove sterols, saponify it with potassium hydroxide and ethanol, then extract it with ether to obtain unsaponifiable matter, and then concentrate it by molecular distillation to obtain vitamin E concentrate.

Vitamin e is synthesized by chemical method, that is, 2,3,5-trimethylhydroquinone and vegetable alcohol react with condensation agent in solvent;

Condensing agent [acetylation]

α -vitamin E β -vitamin E

solvent

(2) Biological pesticides

Chemical pesticides are the most commonly used in agricultural production, and their benefits are self-evident in killing insects and sterilizing to ensure a bumper harvest in agriculture. But at the same time, it will inevitably harm beneficial organisms, remain in agricultural products, pollute the environment and cause ecological damage. In order to overcome these shortcomings of chemical pesticides, the research and development of biological pesticides have developed rapidly.

Biological pesticides, that is, microbial pesticides, have many advantages: specificity, only acting on target pests, germs or weeds, harmless to humans, livestock and other organisms; Easy degradation, no cumulative toxicity and environmental safety; The substrate will not produce drug resistance. Its disadvantages are not as good as chemical pesticides, high production cost and strict use requirements. These unfavorable factors in the development of biopesticides lead to a low share of biopesticides in the pesticide market. In the past 20 years, biological pesticide technology has made new progress, which not only improved their performance, expanded their application scope, but also added new varieties. Especially after 1983 introduced foreign genes into plants for the first time, genetically engineered crops endowed with insect resistance, disease resistance and herbicide resistance through genetic engineering were successively studied successfully, thus expanding the field of biological pesticides and promoting the new development of biological pesticides.

Biological pesticides can be divided into traditional biological pesticides, genetically engineered biological pesticides and genetically engineered crops.

Traditional biological pesticides refer to preparations that use microorganisms themselves or their metabolites to control crop diseases, insects and weeds. It includes microbial pesticides, herbicides and agricultural antibiotics. Microbial pesticides include bacterial pesticides such as Bacillus thuringiensis and Lactobacillus, fungal pesticides such as Beauveria bassiana and viral pesticides. Agricultural antibiotics include antifungal agents, antibacterial agents, acaricides and herbicides. In Japan, mirex has been used since 1958, and now there are 1 1 species of biological pesticides used in agriculture, such as kasugamycin for controlling rice blast, effective mycin for controlling rice blast, acaricide for controlling mites in fruit trees, etc. The traditional biological pesticides in China are Jinggangmycin, Jiuer O and so on.

Genetic engineering biopesticides refer to biopesticides obtained by transforming microorganisms by genetic engineering methods such as gene cloning and DNA recombination. The most studied is the genetic engineering insecticide developed by using Bt gene, the insecticidal toxin gene of Bacillus thuringiensis. For example, two kinds of microencapsulated genetic engineering pesticides MVP and M-one Plus, which are listed by Mycogen Company 1993 in the United States, overcome the shortcomings of common Bacillus thuringiensis, such as easy degradation and short residual effect, and their efficacy is 2 ~ 5 times longer than that of common Bacillus thuringiensis. Scientists introduce the insecticidal Bacillus thuringiensis gene into Pseudomonas fluorescens to produce insecticidal toxin, and then kill the bacteria through a process of stabilizing the cell wall, that is, form a biological capsule outside the insecticidal toxin protein to avoid its degradation in the environment. This pesticide is also a dead bacterium, which will not reproduce and is safe to the environment. MVP is mainly used to control Plutella xylostella and other caterpillars of cabbage and cauliflower. M-One Plus is mainly used for potatoes, tomatoes and eggplant.

Genetic engineering crops introduce various characteristic genes into plant cells or tissues through plant biotechnology, such as genes for insect resistance, herbicide resistance and nutrition improvement, and then cultivate crops with various excellent characteristics. The development and commercialization of genetically engineered crops will greatly reduce the use of chemical pesticides. For example, insect-resistant crops give crops insecticidal properties. Herbicide-resistant crops have the ability to resist herbicides, so when using this non-selective herbicide, they can not be harmed, while other plants such as weeds are killed.

China's biological pesticides have also developed rapidly. There are several varieties of Bacillus thuringiensis: Bacillus thuringiensis, Cordyceps sinensis, moth killer and Dendrolimus punctatus, all of which are broad-spectrum insecticidal bacteria. The virus insecticide successfully developed in 1970s has better effect and stronger insecticidal selectivity. Bombyx mori nuclear polyhedrosis virus and Helicoverpa armigera nuclear polyhedrosis virus have been used in production. The main agricultural antibiotics in China are kasugamycin, bactericide, Qingfengmycin (to prevent rice blast), Jinggangmycin (to prevent rice blast), streptomycin (to prevent bacterial diseases of fruit trees and vegetables) and oxytetracycline (to prevent wheat rust).

Great progress has also been made in the research of transgenic plants with disease resistance and insect resistance in China. The synthetic crystal protein gene of Bacillus thuringiensis was successfully transformed into cotton, and the transgenic cotton strain 13 was obtained, with insect resistance above 80%. Wheat resistant to powdery mildew, gibberellin and yellow dwarf disease was cultivated by cell engineering and transgenic technology, and the gene was introduced into common wheat. Researcher Wang Danian of China Rice Research Institute introduced herbicide-resistant gene Bar into direct-seeded rice varieties with gene gun, and selected excellent herbicide-resistant Basta direct-seeded rice lines. Combined with spraying herbicide Basta on paddy field, the main weeds and miscellaneous rice in paddy field were killed, while transgenic rice was harmless, saving time and effort.

(3) biosurfactant

Biosurfactants are indispensable components of normal physiological activities of cells and biofilms, which are widely distributed in animals and plants. Compared with chemically synthesized surfactants, biosurfactants have low toxicity, natural biodegradability, high surface activity and environmental safety. It also has the structural characteristics of hydrophilic groups and lipophilic groups. Its hydrophilic groups are sugar, polyol, polysaccharide and peptide, while lipophilic groups are fatty acids and hydrocarbons. According to the structure of hydrophilic groups, biosurfactants can be divided into six categories: (1) glycolipid system, (2) acyl peptide system, (3) phospholipid system, (4) fatty acid system, (5) macromolecular biosurfactant combined with polysaccharide, protein and lipid, and (6) cell surface itself.

Biosurfactants can be prepared in two ways:

A. extracting from organisms

Gleditsia sinensis was used in ancient China and soap extracted from Gleditsia sinensis was used in ancient Egypt to wash clothes. This is an example of using natural biosurfactants. At present, human beings have been able to extract phospholipids and lecithin biosurfactants from egg yolk, soybean oil and its residues, and they are widely used in food, cosmetics and medicine industries. For biosurfactants that are relatively easy to separate, rich in content and high in yield, they can be directly extracted from organisms.

B. prepared by microorganisms

Biosurfactants can be prepared by fermentation with renewable substrates. Many microorganisms such as bacteria, yeast and fungi can form biosurfactants. The types of surfactants produced in the culture medium are not only related to the types of microorganisms, but also related to the fermentation substrates used. Adding hydrocarbons to the culture medium can affect the yield of biosurfactants. Various metals