Agricultural giant since 1983

Chapter 206 Process Route
"Potassium sorbate? Oh, that's right. You have a food factory and you really need potassium sorbate, especially ham sausage. You can't do without it!" Although Tang Liqiang is not a food additive, potassium sorbate is such a famous compound , of course I have heard of it.

Potassium sorbate, potassium 2-hexadienoate, is the potassium salt of sorbic acid. Its molecular formula is C4H6O7K. It is internationally recognized as the least toxic preservative. Now, the most used preservative in China is sodium benzoate, which is more harmful than potassium sorbate. more sexual.

There are two main standards to measure the safety and toxicity of food additives, ADI and LD50. The former is the minimum daily intake, which refers to the daily intake of food additives without any known adverse effects on health. The unit is generally mg/kg body weight; at this dose, life-long intake of the chemical will not cause any measurable harm to health, and the higher the ADI value, the lower the toxicity of the chemical.

LD50 is the median lethal dose, which means the minimum number of bacteria or toxins required to kill half of a certain animal of a certain weight or age through a specified infection route within a specified period of time. The smaller the LD50 value, the stronger the toxicity of the exogenous chemical ; Conversely, the larger the LD50 value, the lower the toxicity

The minimum daily intake of potassium sorbate is 0-25mg/kg, and the median lethal dose is 4.2-6.17g/kg. Assuming that a person's body weight is 50 kg, then there is no risk for his daily intake of potassium sorbate below 750 mg. Any effect would be fatal if ingested at 210 grams.

According to the "Use of Food Additives in National Food Safety Standards", the dosage of potassium sorbate in ham sausage should be less than 1.5g/kg, and a ham sausage is about [-] grams. Calculated according to this standard, a [-]-kg consumption Otherwise, eating ten sticks of potassium sorbate a day will exceed the minimum safe intake. If it is replaced by [-] grams of small ham sausage, then you have to eat twenty sticks.

If you want to eat yourself to death by eating potassium sorbate in ham sausage, you have to eat at least 140 kilograms. I'm afraid even an elephant can't eat so much, right?How else can it be said that talking about toxicity regardless of dosage is hooliganism?

Theoretically speaking, water is also toxic, and drinking water will poison people to death. The LD50 of water is 90 grams per kilogram of body weight. A person weighing [-] kilograms may be poisoned if he drinks [-] kilograms of water. So if you go to three And being a great god, drinking two liters of water per bottle is about the same as drinking two bottles a day, and it is dangerous if you drink three bottles.

The food additive with the longest and widest range of human use must be table salt, and the LD50 value of table salt is 3.3-4.2 g/kg. According to this data, it can be seen that the safety of potassium sorbate is similar to that of table salt, and it is more suitable than the current one. Sodium benzoate with a wider range is safer and has fewer side effects.

Compared with other food additives, potassium sorbate also has many advantages. First, sorbic acid is equivalent to natural products. Sorbic acid was first discovered in a strawberry called Sorbus aucuparial, so it is named; also known as prickly acid, which occurs naturally In the pepper tree seeds.

Although the sorbic acid used today is all artificially synthesized, its chemical structure, properties and biochemical effects in the human body are exactly the same as those of natural products, and this artificial product is called equivalent to natural products.

So when someone sees the potassium sorbate written on the ham sausage and makes a fuss, and then starts complaining about technology and hard work, you can look at him with caring eyes and ask him if he eats pepper?There is not much difference between what is inside and what is inside the peppercorns.

In addition, sorbic acid can participate in metabolism in the human body and be oxidized into water and carbon dioxide without affecting the color and fragrance of the food, so it is widely used in Europe and the United States.

Because sorbic acid is difficult to dissolve in water, it is very inconvenient to use, so experts have improved it and made it into a water-soluble potassium salt, so there is potassium sorbate.

In 1990, the global production of potassium sorbate was about 2 tons. The United States used about 1992 tons of potassium sorbate in 7200, and then the consumption of potassium sorbate increased year by year. Ton.

By the time Li Lei crossed, China produced about 90 tons of potassium sorbate per year, accounting for about 91% of the world's total production; the global production capacity of another important preservative, benzoic acid, was about 50 tons, and the production capacity in mainland China was about 50 tons. tons, reaching more than [-]% of global production capacity.

It is because of these preservatives that more people can enjoy more delicious food more conveniently and cheaply. What people should resist is the abuse of food additives, instead of shouting at the additives. No, then I can only go to the grassland to chase after cattle and sheep. Oh, no, cattle and sheep also sweat when exercising, and sweat contains salt, which is also a food additive.

"Not only ham sausage, apricot jam, and hawthorn rolls are used in many foods. Since it is safer than sodium benzoate, then use this! It's just that the production technology of other domestic factories is not up to standard, and the quality often fluctuates. I'll just give birth myself, so I don't have to worry about it." Li Lei is also worried.

"The construction of this factory really requires talents in chemical industry, and it can also produce other food additives. In the future, our country's demand for food additives will only increase. There is still a lot to do in this industry! Then he should be in a better mood, don't worry The things I learned are useless!" Tang Liqiang was also very happy, he and Shu Yuanchun had the same idea, and hoped that these children would live up to the four years of study.

"I'll call him over, let's have a chat first?" As he spoke, he was about to make a phone call.

"I also made an appointment with Professor Ma from the Department of Mechanical Engineering. There is also a student coming from him. I will go to Professor Ma's place first, and then we will have dinner and talk together at night!" Talented people can buy imported equipment now, but they will definitely develop their own research and development in the future, so talents in this area must be reserved first.

Tang Liqiang was asked to help call the students to the office. Li Lei went to Professor Ma's place first. The situation on his side was much better. As long as it is a factory, machinery and equipment are inseparable, so the students are still acceptable to go to his place. He was even a little excited, because Li Lei's salary was much higher than other units. His family's conditions were not very good, and he owed a lot of money. He also hoped to find a job with a better salary so that he could pay back the money sooner.

After Professor Ma's students came over, they went to meet Tang Liqiang together, then boarded the car and went to the restaurant outside the school to eat, and naturally chatted about the production process at the dinner table.

"Currently, there are several industrial processes for potassium sorbate. Which one do you plan to choose?" Tang Liqiang asked. After Li Lei left, he looked through some materials.

"Since Debree, Germany, first synthesized sorbic acid in 1900, researchers from all over the world have developed a variety of processes for industrial production, and these are the most popular ones today!" Li Lei Looking at Lin Youlin, a student from the Chemistry Department of Chung Yuan University, he asked, "How many do you know?"

He did this not only to see the student's level, but also to help Professor Ma and Yunfan, a student of the Department of Mechanical Engineering, to popularize science. They don't understand this aspect of things.

"The first one is to condense crotonaldehyde and malonic acid under the action of pyridine base catalyst to obtain sorbic acid. This route is simple in process and does not require high quality of raw material malonic acid, and the product quality is also very good. Some domestic units use it This kind of craft is used for production." Lin Youlin recalled for a moment and replied.

"However, malonic acid is easy to decarboxylate into acetic acid, and crotonaldehyde is easy to self-polymerize. These side reactions seriously affect the yield, so the yield of sorbic acid is generally only 30.00%, even if the raw material is purified, it can only be increased to 60.00%, and other Compared with the production process, the cost is too high; and malonic acid is synthesized by the reaction of chloroacetic acid and highly toxic sodium cyanide. The waste gas, waste water, and waste residue in the production process are seriously polluted and cause great damage to the environment, so I do not recommend using this kind of production craft."

Yield, also known as reaction yield, is generally used in chemical and industrial production. It refers to the ratio of the actual product output obtained by inputting a unit amount of raw materials to the theoretically calculated product output in a chemical reaction or related chemical industrial production. The same chemical reaction will have different yields under different pressures and temperatures.

It can be seen from the last sentence that Lin Youlin is quite bookish. The boss only asks you which routes you have, and you should be clear about it. How can you decide for the boss?If you meet someone who doesn't care about pollution, won't it be annoying to hear people's ears?

Fortunately, Li Lei is not this kind of person, and he doesn't like heavily polluting production methods, so he praised him with a smile, "As expected of Professor Tang's outstanding student, the foundation is solid."

The big guys clinked a glass with a smile, and Professor Ma continued to ask, "If there is the first type, there must be a second type and a third type. These problems must be avoided, right?"

"The second method is to use crotonaldehyde and acetone to condense into croton selenide acetone in an environment of [-] degrees Celsius in the presence of a barium hydroxide catalyst, and then oxidize it to sodium sorbate with sodium hypochlorite, then acidify to obtain sorbic acid, and Chloroform and butyral are produced as by-products."

"This method is simple to operate, does not require high temperature, and the product quality is good, but because the chemical reaction process is relatively cumbersome, the yield is not high; the Soviet Union has done a lot of research in this area, and some factories in our country also adopt this kind of production process for production.”

This time, without waiting for Professor Ma to ask, Lin Youlin continued to introduce other production processes, "The third production process also uses crotonaldehyde, but replaces malonic acid with acetaldehyde, and uses oxygen under the catalysis of silver oxide. Oxidized to sorbic acid, I saw in a foreign journal that an American company started to use this method to produce it in the 70s."

"Although this method is difficult, it has fewer steps, broken routes, and simple raw materials. It is very attractive. It is that the article did not write more details. We may have to do some research if we want to replicate it! But as long as we can research it , definitely better than the first two crafts!"

"That's right!" Li Lei applauded first, "It's really not easy for you to learn so much information without entering the food additive production industry!"

Li Lei feels that he has found a treasure. His foundation feels much more solid than the four juniors of the Agricultural College. However, this is directly related to the higher ranking of Zhongyuan University than the Agricultural College. If the ranking is higher, the funds will be sufficient and can provide for the students. Provide better learning conditions.

At the same time, the scores of recruited students are also higher than those of the Agricultural College. Adding the two together, in terms of average level, it is naturally better for Zhongyuan University.

"I haven't studied this information before, so I don't know much about it, but based on the information I have seen, I still think the third is better." Lin Youlin is still making suggestions.

"This route is indeed better than the first two, but it is not without problems. Firstly, the yield is still not high enough, and secondly, there are patent barriers. The union-carbide company in the United States has applied for a patent for the key silver oxide catalytic process. Even if we We can research the technology they use, but we still can’t use it in actual production, otherwise the union-carbide company will definitely sue us!" Li Lei vetoed his suggestion.

When he assisted his mentor in writing the "History of Agriculture in New China", he also collected information on this aspect, and he was very clear about the problems with these technological routes, and which one was the final winner; this advantage alone was enough to make him ahead of the others. Competitors, because other competitors still need to try and make mistakes one by one, and he knows the correct answer as soon as he comes up, and then reverses the process based on the answer.

"He applied for a patent in the United States, what does it have to do with us? Could they still come to China to sue us?" Lin Youlin didn't understand.

Although the "Patent Law" was passed in China four years ago, just like the "Labor Law", its implementation is hard to describe. At least for now, almost no one takes it seriously.

"First, although it is unlikely that this American company will come to China to sue us in the short term, many of our products containing potassium sorbate are exported to European and American countries. They can sue us in Europe and the United States. If so, we will not only If you lose money, you may lose the opportunity to continue exporting!"

"Second, we will go to the international market sooner or later. If we get used to this kind of practice, I am afraid it will be difficult to compete with foreign companies! Therefore, from a technical point of view, we can find out the production process of union-carbide company, but in specific production In the process, it is best not to use it."

The reason why Li Lei said such righteous words is that he has a way to bypass union-carbide's patent barriers. If he doesn't have one, he won't be able to control so much. Let's use it first.

This is the case for almost all late-developing industrial countries, imitating first and then surpassing; Germany copying Britain, the United States copying Europe, Japan copying Europe and the United States, everyone came here like this.

"The key to this process line is the use of the oxidant. If we can find a better oxidant, we can break the patent monopoly of the union-carbide company! So your first task after work is to find this oxidant." Li Lei After arranging the mission, he already knew what the most suitable oxidizing agent was, but he didn't intend to tell Lin Youlin directly.

(End of this chapter)