Gutter oil and its classification The transformation of gutter oil into edible gutter oil is actually a general concept, which is a general term for all kinds of inferior oils in people's lives. Waste oil can be divided into three categories: first, waste oil in a narrow sense, that is, oily floating objects in sewers or leftovers from hotels and restaurants (commonly known as swill) are simply processed and refined; The second is the oil produced by the processing and refining of inferior pork, pig offal and pig skin; Third, the oil used for fried food should be reused after being used more than the specified number of times, or after adding some new oil to the oil. When law enforcement officers check, they use the test paper for rapid detection of edible oil rancidity to compare whether the peroxide value and acid value of the detected oil exceed the standard, and once it exceeds the standard, it can be determined that it is a problem oil. The four major flow directions of "gutter oil" are 1. Chemical plant (producing chemical products). Restaurant → collector → restaurant, restaurant (buy at a low price) → customer table 3. Farms (livestock feed) 4. Waste oil from factories and school canteens can produce biodiesel. It is a headache for gutter oil to return to the table. The best solution is to recycle and turn waste into treasure. How to "turn waste into treasure"? Fujian Zhuoyue New Energy Development Co., Ltd. has found a new way. They successfully extracted biodiesel from waste animal and vegetable oils by using self-developed technology and equipment, and took the lead in realizing industrialization in China. In 2000, Ye, a private entrepreneur from Zhangzhou, Fujian, visited Austria. The practice of extracting biodiesel from animal and vegetable oils, which is being promoted in Europe, has opened his eyes. After returning to China, they founded Fujian Zhuoyue New Energy Development Co., Ltd., an R&D manufacturer, in 200 1, and organized technology research and development and equipment development. Now, the enterprise has formed an annual production capacity of 40,000 tons of biodiesel. The appraisal organized by relevant authoritative organizations shows that the biodiesel produced by Fujian Zhuo Yue Company "meets the performance requirements of No.0 diesel internal combustion engine fuel, and it is a clean liquid fuel product, which fills the domestic blank. Experts from Shanghai Institute of Internal Combustion Engine pointed out that the sulfur content of this biodiesel is much lower than that of No.0 fossil diesel, and the alkane value of 16 is higher than that of fossil diesel, and it does not contain aromatic hydrocarbons and heavy metals. The oxygen value of 1 1% can ensure full combustion and almost no pollution. " "Waste cooking oil" is animal and vegetable oil with poor quality. According to the estimation of relevant departments, China's catering industry produces more than 26 million tons of "gutter oil" every year. In addition, there are almost 80 million to 90 million tons of cottonseed oil, rapeseed oil, lard and other oils that cannot be sold in China every year. The total amount of waste or idle animal and vegetable oil in China is about 654.38 billion tons every year. Based on the current extraction of 800 kilograms of biodiesel from 654.38+0 tons of animal and vegetable oil, more than 80 million tons of biodiesel can be produced. "Waste cooking oil" becomes biodiesel, which has a broad market prospect after industrialization. Buying a ton of "gutter oil" costs 2300 yuan, the direct cost of refining and processing into biodiesel is 3600 yuan per ton, and the market price of the product is 4400 yuan per ton, which is cheaper than fossil diesel 1000 yuan. [1] According to experts, after cooking oil is added to the reaction tank, alcoholysis and esterification can be carried out simultaneously through the technology of slightly acidic catalyst, and the reaction speed is obviously accelerated. In addition, the key problem of high residual acid value in diesel oil production from waste animal and vegetable oil is solved by using metal salt treatment agent. These two key technologies can reduce the production cost of biodiesel and make biodiesel enter the production workshop from the laboratory. The biggest feature of this fuel is its good environmental protection. The tail gas emitted by diesel vehicles does not contain sulfur dioxide, and hydrocarbons and carbon monoxide are greatly reduced. Under the current international background of high oil prices, the world biodiesel industry has developed rapidly. In just three or four years from 2002 to 2005, the output of biodiesel in China increased rapidly to 60,000 tons. Technically, China has the advantages of systematic innovation in the production of biodiesel from waste oil from high condensation point, mainly from grease trap, and from wild tree seeds, but the collection of biodiesel raw materials, especially the treatment of waste oil, still hinders the development of the industry. Waste edible oil is a complex mixture of various oils and food residues (including rice, noodles, various vegetable leaves, peppers, peppers, etc.). ) and wooden chopsticks that flow into the sewer with water in the process of washing dishes in families, restaurants and hotels. After biological fermentation, these substances form a brown, sticky and foul-smelling porridge. According to experts, grease trap garbage is also a kind of resource if it is specially treated, but there is no good treatment method for this complex system in the world at present. On the contrary, at present, some unscrupulous traders simply process the garbage in the grease trap into edible oil and then circulate it to the market, which directly threatens people's health. In the process of studying the project of producing biodiesel from waste oil, technicians found that how to extract waste oil from the garbage in the grease trap is a difficult point that hinders the development of the project. The garbage in the grease trap is a continuous phase, which is mainly composed of pasta and unknown flocs. In this continuous stage, different foods absorb oil differently: the adsorption law of pasta can be summarized as "oil absorption but no water absorption, water absorption and no oil absorption". Fried foods such as fried dough sticks and pork no longer absorb water after entering the water body; Cooked pasta, such as noodles, is scalded with boiling water and no longer absorbs oil, but the oil only sticks to the surface of pasta; Cooked food, such as steamed bread, cakes, rice grains, etc. Or cooked and dehydrated pasta cooked in the sun, enters a mixed system formed by water and oil in a grease trap, and animal oil combines pasta absorbed with water and vegetable oil with other substances. Pepper, vegetable leaves, wood products, pepper, melon seeds and other substances are not easy to absorb water if they are fried in oil; If you don't fry it, it's easy to absorb water, which is faster than vegetable oil. These substances, which form saturated adsorption on oil and water or water and vegetable oil respectively, are suspended in the mixed system composed of pasta and oil and are bound together by oil. Colloids with unknown properties form saturated adsorption on water and oil. When the colloid is destroyed, about 50% of the solids can sink into the water, and there is basically no oil. It is difficult to separate the continuous phase composed of water, colloid and solid (mainly pasta) with oil as binder. After studying the characteristics of waste oil, technicians developed a green waste treatment device with zero energy consumption and zero pollution under the guidance of fuzzy mathematics and biochemistry. Under the conditions of no pretreatment, no separation, no artificial energy input and no colloid damage, the solid-liquid separation is realized by using new separation materials, and no odor and pollutant discharge are produced in the process. Dr. Ji pointed out that traditional separation technology needs to destroy colloid and gradually separate various substances in liquid-solid system. Because the garbage in the grease trap includes solid, liquid and colloid systems, and each system includes water, oil and hydrophilic and lipophilic substances, it is difficult to completely destroy it in the separation process, and conventional means such as centrifugation and filtration are difficult to work. The new method directly separates the system from the system and different phases. In the separation process, colloid acts as a filter medium; After separation, the colloid has been naturally destroyed. Firstly, the gel breaker is added to the waste oil to quickly destroy the colloid and reduce the viscosity of the waste in the grease trap, so that the waste oil floats to the surface. The gutter oil is divided into three layers, the upper layer is oil, and the middle layer is mixed particles composed of fine starch, protein and oil. Pasta granules and some vegetable residues sink to the bottom of the water, and pasta granules and vegetable residues are oil-free. This is due to the competitive adsorption of gel breaker with water and waste oil in pasta. Gel breaker has a strong adsorption effect on pasta, and its adsorption performance is obviously better than that of water and oil. In order to test the adsorption effect of gel breaker on oil, water and pasta, the separated pasta was first dried in vacuum, and then oil and water were added. It was found that the existence of gel breaker weakened the adsorption of water, while pasta did not adsorb oil. This shows that the gel breaker changed the saturated adsorption ratio and mode of oil and water in pasta, and reduced the interaction between water, oil and pasta. At the same time, the denatured protein contained in the gel breaker can adsorb the protein in the grease trap garbage, so that the protein can quickly coagulate, thus achieving the purpose of separating the grease trap garbage. The water produced in the separation process can be used to water vegetables after laboratory tests; After further fermentation, the solid residue can be used as fertilizer or pyrolyzed into fuel oil. Oil products can be used as raw materials for biodiesel. The gel breaker can be recycled. The machinery developed in the laboratory for separating the garbage from the grease trap includes the recovery system of rubber breaker, the extraction system of oily garbage from the grease trap, the separation system of rubber breaker, water and waste oil, the separation system of rubber breaker, the wastewater discharge system and the residue compression packaging system. At present, the daily processing capacity of the unit reaches 7 tons of oil, which is equivalent to 20 tons of grease trap garbage, and the oil separation rate reaches 98%, which has reached the practical stage. [2] A large amount of waste oil returned to the dining table as "swill oil". In most cities, people often see such a scene: a farmer-like person rides a small truck full of swill, slowly moving along the street, dripping swill all the way, constantly emitting swill smell, which makes pedestrians on the road hide their noses. And these disgusting garbage may have been piled up 1 hour ago to prevent the gutter oil from flowing into a restaurant where catering services are piled up. Farmers come here by bike after dinner every day, and then collect swill and carry it away. In the kitchens of these restaurants, open the manhole cover of waste water, and you will see some sticky brown things floating inside, which are a mixture of grease, detergent and rice residue after washing dishes. People call these gutter oil "gutter oil". The purpose of farmers coming here is to collect these waste oil. He took out the gutter oil bit by bit with a big spoon, and then mixed it into a black iron bucket full of swill and carried it away. According to a person in charge of Beijing Environmental Protection Bureau, there are about 50,000 hotels, restaurants and canteens in Beijing alone, and 50% of the 1.6 million tons of swill and 1.2 tons of gutter oil generated every day will be fished by private individuals. By dinner time, this kind of slop truck will stop at the gate of most restaurants. These slops will be transported to a residential area in the suburbs. Swill and gutter oil are mixed in a big pot with a burning flame at the bottom. The farmer scraped off the grease floating on it with a big spoon and poured it into another container next to it. The oil they extract will be specially purchased, processed and then resold. According to insiders, there are thousands of "oil refining" farmers in Beijing alone. The processing of "black oil" is near the old palace in Daxing District, Beijing. Beijing has a private "black oil" distribution center. There are hundreds of huge oil drums in the 600-square-meter yard, which contain gutter oil and swill oil purchased from various places. According to the boss, his family has been doing this business since grandpa's generation, and it has been more than 30 years now. He can emit forty or fifty tons of waste oil a day. His family has the largest number of people doing this business in Beijing. In those dirty and broken oil drums, there is a clear and transparent liquid, which looks like edible salad oil. It is a "refined oil" that they "carefully processed" and ready to sell to the grain and oil market for human consumption. This "refined oil" can't smell any peculiar smell. It is hard to imagine that this clear and odorless liquid should come from those dirty sewers. On the residential road behind the hot pot in Cuizhu Mountain City, Dalian Development Zone, I entered the yard and saw weeds and chaos around me. Some German shepherds in the yard kept barking when they saw the stranger coming. This is the processing workshop. There, the reporter witnessed the whole process of processing and refining "refined oil" The first step is decolorization. They poured a lot of swill oil and gutter oil into the filter, and then added a kind of "white clay" to produce a chemical reaction, and the original reddish brown liquid became clear and transparent in a blink of an eye. At this point, according to them, the acid value of oil (acid value is an indicator to measure the quality of oil, the lower the acid value, the better the oil) will be greatly reduced. After such "treatment", oil can easily escape the inspection of the health department; The second step is to rinse with water. They poured the decolored oil into a large pool, and then kept stirring to remove impurities and further decolor. The last step is vacuumizing, that is, heating the oil in a vacuum tank to remove the odor. According to the boss, in his workshop, there are always two sets of such processing equipment, which he spent several years developing, which is convenient and easy to use. They keep processing like this every day, and people come here to pull oil every night. It has been selling well for more than ten years. Waste cooking oil is processed into "chains". According to insiders, the treatment of "gutter oil" has now formed a "one-stop" chain. From acquisition to processing to sales, many people enjoy it. This industry of extracting oil from food residue is a profiteering industry. According to a swill collector, they can produce 1 barrel (about 180 kg) of swill fat or waste oil every three days, and the average price per barrel is 580 to 600 yuan. Then according to this calculation, they can earn 6000 yuan a month. With such huge profits, how can those unscrupulous traders not "rush"? For the kind of oil merchants who combine production and sales, the profits are extremely rich. According to the boss of Daxing District mentioned earlier, the waste oil they bought is 3,400 yuan per ton, and the processed "refined oil" can be sold for 5,000 yuan per ton. After removing various costs, the net profit per ton is about 1000 yuan. It is also known that those who look for oil dealers to collect oil will mix about 1/3 salad oil and 1/3 palm oil into the oil after returning it. These mixtures will be packed in small bottles and flow to people's tables together with the "authentic oil" mixed into the grain and oil market. [3] China eats 3 million tons of gutter oil every year, 10 meal, 1 meal will lead to gutter oil. I don't know when it started, and urban sewers became a place where some people made a fortune. They fished out a lot of dim, turbid and reddish paste from there every day. These foul-smelling garbage can be turned into clear "edible oil" after only one night of filtration, heating, precipitation and separation, and finally returned to people's dining tables through low-price sales. This three-no product, called "waste oil", is still composed of triglycerides, but there are many more toxic substances that cause disease and cancer than real edible oil. "You must have eaten gutter oil. "He Dongping, a professor at the School of Food Science and Engineering of Wuhan Institute of Technology, told the reporter. His other identity is the head of the Oil Working Group of the National Grain and Oil Standardization Committee. According to his estimation, at present, there are 2-3 million tons of waste oil returning to the table every year in China. In China, the total consumption of animal and vegetable oils in 1 year is about 22.5 million tons-that is to say, if you eat 10 meal, there may be 1 meal, which is gutter oil. So far, scientists have not found an ideal means to detect and identify gutter oil. The oil dug out can earn tens of thousands of yuan every month, which forms an industrial chain. During the investigation, He Dongping and his students learned that the cost of extracting 1 ton waste oil from restaurant kitchen waste is only about RMB in 300 yuan. Interest-driven is one of the main reasons for the long-term existence of waste oil. The people who dig gutter oil seem inconspicuous. In fact, they can earn an average of 70 to 80 yuan by digging a barrel of oil. A person can usually dig up four barrels a day. After recycling and refining, even if it is only sold at half the market price of edible oil, it can earn more than 1 10,000 yuan per month, which is equivalent to the income of senior white-collar workers. Students are told that even if they do odd jobs in this business, they can earn 2,500 yuan a month. In a restaurant near Fruit Lake in Wuchang, the boss said that there are at least 50 tables of guests every day, and there are about two barrels of kitchen waste, which are then transported away by sanitation workers every day for treatment. The relevant person in charge of the urban management department in Wuhan said that sanitation workers have never delivered the kitchen waste of this restaurant. It seems that there are not a few restaurants that are unwilling to take the initiative to "hand in" kitchen waste. As an insider, Ceng Wei, the person in charge of Wuhan Airui Biodiesel Co., Ltd., which extracts biodiesel from kitchen waste oil, once said: "Many restaurants have contracted the right to purchase kitchen waste oil to special personnel, and the purchaser has established a relatively stable purchase and sale relationship with catering enterprises, and outsiders are not allowed to intervene. "It is reported that a large hotel can earn 2 million yuan only by selling kitchen waste a year. According to He Dongping's calculation, every 654.38+00000 people can produce 654.38+0 tons of kitchen waste every day, and after refining, it can produce 654.38+030 kilograms of gutter oil, the price is only half of that of ordinary edible oil. The comprehensive statistical results show that the total annual profit of gutter oil in China reaches 65.438+500-200 million yuan. For the kitchen waste processor, the cost per ton of kitchen waste oil is about 1000 yuan, and 0.8 tons of edible oil can be extracted per ton of kitchen waste oil. The processing cost is only in 300 yuan, but now the price of edible oil on the market exceeds 6,000 yuan per ton, which is sold at a discount at the market price. The profit per ton is close to 2000 yuan, and the profit rate is close to 200%. Driven by huge profits, it is not difficult to understand that the illegal cooking oil trade is hot. [4] The use of waste oil is the responsibility of the government. " People who engage in oil "all know a sentence:" Oil mixed with oil makes the gods worry. "In the eyes of researchers, the difficulty in the treatment of waste oil is that it is difficult to distinguish it from ordinary oil only in appearance and sense after washing, distillation, decoloration and deodorization. Illegal traders usually mix cooking oil with gutter oil, and if the content is small, it will be more difficult to detect. Professor He Dongping has been engaged in the research of waste oil for 7 years. He and his research team are still undertaking the task of the National Standardization Administration Committee-"Research and formulation of the reuse standard of waste oil in urban kitchen waste". At present, the important task is to find an effective means to detect and identify waste oil. As a researcher engaged in oil research, He Dongping always believes that the treatment of waste oil is not determined by testing methods or standards, but the key lies in government management. He once calculated that 10000 people can produce 1 ton of kitchen waste every day, and these kitchen wastes can produce 130 kg of gutter oil after washing, distillation, decoloration and deodorization. When it returned to the market for sale, the price was half that of ordinary edible oil. Then the comprehensive statistical results show that the total profit of domestic gutter oil can reach 65.438+0.5 billion yuan to 2 billion yuan a year. However, in the treatment of kitchen waste, China has been in an "anarchy" for a long time, which provides a large-scale "gray industry" space for some unscrupulous traders. Therefore, He Dongping's vision is that "kitchen waste must be centrally purchased and treated by the government, and gutter oil must be eliminated from the source". According to the scientist who has been engaged in cooking oil all his life, it may take about 10 years for China to completely ban cooking oil. [5] The harm of waste oil to human body Anorectal experts explained that "waste oil" is indeed the enemy of people's health, especially for people's gastrointestinal health, which has immeasurable destructive power. 1, "gutter oil" can cause indigestion: in the process of refining "gutter oil", a series of chemical changes such as rancidity, oxidation and decomposition occur after pollution, resulting in substances that are highly toxic to human body; Arsenic is one of them. Once people use "waste oil" containing a lot of arsenic, it will cause symptoms such as indigestion, headache, dizziness, insomnia, fatigue and discomfort in the liver area. Interest+black heart = waste oil 2. " Gutter oil will have diarrhea: the production process of gutter oil is doomed to be unsanitary. Once a large number of harmful microorganisms such as bacteria and fungi reach people's intestines, it will cause diarrhea, and in severe cases, it will cause a series of gastrointestinal diseases such as nausea and vomiting. 3, "gutter oil" can cause strong abdominal pain: "gutter oil" is mixed with a lot of sewage, garbage, detergent, and can not remove bacteria and harmful chemical components after being refined outdoors in underground workshops. It is an indisputable fact that all "gutter oil" will have a serious lead content exceeding the standard. Eating food made from "gutter oil" with excessive lead content will cause serious abdominal cramps, anemia, toxic liver disease and other symptoms. 4, "gutter oil" can lead to gastric cancer and intestinal cancer: the disgusting refining process is the cause of the breeding of gutter oil toxins. "Waste oil" is the refined oil from swill (swill, leftovers, etc.). ) and waste edible oil collected from hotels and restaurants to remove odor and flow to the edible oil market. Gutter oil contains aflatoxin and benzopyrene, both of which are carcinogens, which can cause gastric cancer, intestinal cancer, renal cancer and cancers of breast, ovary and small intestine. Anorectal experts remind consumers that once they have symptoms such as abdominal pain, nausea and vomiting after eating in restaurants, food stalls or vendors, they must go to the hospital as soon as possible to avoid causing more harm to your health. Identification of waste oil: Once "waste oil" enters the market, consumers should learn sensory identification. According to experience, edible vegetable oil can be identified by looking, smelling, tasting, listening and asking. Take a look. Look at the transparency, pure vegetable oil is transparent, and the transparency will be reduced due to the mixing of alkaline grease, wax and impurities in the production process; Look at the color, pure oil is colorless, oil will have color because the pigment in oil is dissolved in oil during production; Look at the sediment, its main component is impurities. Color contrast of two smells. Each oil has its own unique smell. You can put a drop or two of oil on your palm, rub your hands together and smell it carefully while it is hot. Odd oil indicates that there is a problem with the quality, and it is likely to be smelly waste oil; You can't buy it if it smells of mineral oil. Three flavors. Take a drop of oil with chopsticks and taste it carefully. Oil with sour taste is unqualified, oil with bitter taste has been rancid, and oil with peculiar smell may be "gutter oil". Listen 4: Take one or two drops of oil from the bottom of the reservoir, spread it on flammable paper, ignite it and listen to its sound. Products with normal combustion and no noise are qualified products; If the combustion is abnormal, it will make a "squeaky" sound, indicating that the water content exceeds the standard and it is an unqualified product; When burning, there is a "crackling" explosion, indicating that the water content of the oil is seriously exceeding the standard, which may be an adulterated product and must not be purchased. Five questions: ask the merchants about the purchase channels, ask for the purchase invoices or check the sampling inspection report of the local food hygiene supervision department if necessary. Waste oil can also be detected quickly and accurately by the following methods: using the relationship between metal ion concentration and conductivity, the content of metal ions in oil can be judged by detecting the conductivity of oil. Many experiments show that the conductivity of waste cooking oil is 5 to 7 times that of first-class edible oil, so it can accurately identify waste cooking oil. Emergency Notice of the US Food and Drug Administration On March 10, the Office of the US Food and Drug Administration issued the Emergency Notice on Preventing the Waste Oil from Flowing into Catering Services (No.2010 of the Food and Drug Administration). The "Emergency Notice" pointed out: Recently, some media reported that criminals were processing "gutter oil". In order to prevent "gutter oil" from flowing into catering services and effectively protect consumers' food safety, please quickly organize supervision and inspection on the procurement and use of edible oil in catering service units, and strictly check the inspection records of catering service units and the implementation of the system of claiming certificates and tickets. At the same time, we must attach great importance to complaints and reports from the masses and verify clues in time. If it is found that the source of edible oil purchased by catering service units is unknown, or "gutter oil" is purchased and used, it is necessary to supervise the catering service units to immediately stop using and destroy it, and at the same time severely investigate and deal with it according to law. If the circumstances are serious, the license shall be revoked. The urgent notice also requires the health departments (bureaus) of all provinces, autonomous regions and municipalities directly under the Central Government and the Food and Drug Administration to report the supervision and inspection to the Food Safety Supervision Department of the US Food and Drug Administration before the end of April. [6]