Vitamin C, also known as ascorbic acid, has a molecular formula of C6H8O6 and can be used as medicines, health products, feed additives and food additives. According to estimates from the US BUSINESSWIRE company, the total global sales of vitamin C in 2020 will be 220,000 to 230,000 tons, with a market size of approximately
$1.1 billion.
Another data is that China's domestic vitamin C production in 2020 was 213,000 tons, and exports exceeded 160,000 tons.
In human terms, by the 2020s, China had basically monopolized the global production of vitamin C.
However, in the early 1980s, China's vitamin C production was still in a very weak state. In 1982, the country's total vitamin C production was about 3,500 tons, less than 5% of the global total.
The raw materials required to produce vitamin C are very simple, mainly glucose. The earliest synthesis method of vitamin C was invented by the Swiss chemist Reichstein, which is called the Reich method. The process is to first reduce glucose to sorbitol at high temperature, and then ferment it.
It becomes sorbose, and then acetone is added to make diacetone sorbose, which is oxidized with chlorine and sodium hydroxide to become diacetone gulonic acid (DAKS), and then undergoes catalytic recombination to produce vitamin C.
In the 1970s, Chinese scientist Yin Guanglin invented a two-stage fermentation method, commonly known as the "two-step method", which added a fermentation process to the Wright's half method, using acetone, chlorine and sodium hydroxide to generate DAKS.
The process is replaced by another fermentation, which directly generates 2-ketogulonic acid (KGA) from sorbose, and then generates vitamin C.
One of the major advantages of the two-stage fermentation method is that it reduces the use of chemical raw materials, simplifies the production process, reduces equipment investment, and also reduces the pressure on industrial waste treatment.
At this time point in the early 1980s, the two-stage fermentation method was still a newly proposed method. The technological process was far less mature than the nearly 50-year-old Lehman method. There were many problems in the production process, so that some domestic
The newly constructed vitamin C plant is still using the Lehman method.
Other companies do not master the technical essentials of the two-stage fermentation method, which does not mean that Gao Fan does not also master it. He is well aware of the advantages of this process and knows what improvements have been made in this process in the next few decades.
Previously, he did not directly put the production of vitamin C on the agenda because the production equipment of vitamin C is indeed relatively expensive. He couldn't even apply for a loan of 2 million yuan, so how could he dare to think of a loan of 100 million yuan?
However, now there is a solution to the funding problem, and that is to find the wealthy Hatch Group.
Doesn't the Hatch Group have a stake in the vitamin factory? Then this matter is its own business. Providing a loan of 30 to 50 million US dollars is just a matter of pulling out the hairs on the elephant's legs. Looking back
10% of the money earned belongs to the Hatch Group. What reason does it have for not agreeing?
"Two-step method? I heard it from the engineers of the Northern Pharmaceutical Factory." Hai Qingwen was indeed knowledgeable. He recalled, "It seems that this method still has many problems, and the product quality is not stable enough. By the way, they said the most important thing is
The key point is that the concentration of the fermentation substrate is low. For a device with the same output, the number of fermentation tanks must be increased several times, which not only takes up a large area, but also consumes higher energy.”
"Master Hai!" Gao Fan sincerely praised Hai Qingwen. This guy is not in this field. He could remember it so clearly after just listening to someone talk about it. There was no mistake in the expression. In fact,
It's amazing.
"What I draw here is an improved fermentation tank. The mixing machinery in the original fermentation tank is eliminated, and compressed air is directly used to achieve stirring. This can increase the volume of the fermentation tank and reduce the number of fermentation tanks. Moreover, it has
Very obvious energy-saving effect." Gao Fan pointed at the drawings he brought and introduced it to Hai Qingwen and Zhou Xiaoyun.
Hai Qingwen nodded. Using compressed air to stir liquids is not a new technology. It is a very mature chemical process. He also pointed at the drawings with his fingers and commented: "The idea of using compressed air to achieve stirring is completely feasible.
.But how to design the tank, the ventilation volume, airflow density, and airflow speed must be calculated very accurately, otherwise..."
Speaking of this, he suddenly paused. When he raised his eyes to look at Gao Fan, he found that Gao Fan was looking at him with a smile. He understood immediately:
"You're not asking me to help you calculate these formulas, are you?"
Gao Fan denied it repeatedly: "No, no, just let your graduate students do the math. I fully believe in the level of my senior brothers and sisters."
"At best, they can help with it." Hai Qingwen said, "This fluid model is very complicated. I dare not say that I can calculate it, let alone them."
"You can definitely calculate it." Gao Fan said firmly, actually denying himself what he said before about asking graduate students to calculate.
"Where are the rest of these?" Hai Qingwen asked, pointing to the remaining drawings.
"Similar to this one, they are all process optimization plans that I have thought up." Gao Fan said, and he explained to the two of them one by one: "This is a scraper-type bottom discharge centrifuge used to separate sodium sulfate and crude VC crystals.
, used to replace the traditional three-legged centrifuge, which can greatly improve efficiency; this is a piston centrifuge, used to separate fine VC crystals; this is a continuous crystallizer, used to replace the currently used crystallizer, production efficiency
It can be improved by more than three times..."
"You don't want me, an old man, to help you complete all these designs, do you?" Hai Qingwen's eyes stood up.
Gao Fan's drawings only put forward the design ideas of the equipment, but a lot of work needs to be done to transform it into the final design. For example, a centrifuge for liquid-solid separation needs to consider the density and viscosity of the liquid, and the solid particles during the design.
Density and particle size, as well as Stokes zone, Charchef force, cough, cross it out... Anyway, there are a lot of things that need to be calculated, which is extremely troublesome.
Of course Hai Qingwen could do these calculations, but after some calculations, he felt that if he completed these designs alone, he would not have to do anything else while staying in Cangtang, and just work exclusively for Gao Fan.
But he clearly came to study whether coal liquefaction is good or not!
"It's definitely not possible for Professor Hai to do it alone." Zhou Xiaoyun quickly smoothed things over. She looked through the drawings and asked Gao Fan: "Xiaofan, how long do you hope it will take to complete these designs?"
"A month, right?" Gao Fan asked.
"At least 20 engineers with solid skills are needed. Professor Hai is responsible for arranging tasks, and I can also provide some support." Zhou Xiaoyun said.
"What does a solid foundation of skills mean? Can an engineer from the technical department be qualified?" Gao Fan asked.
Zhou Xiaoyun shook her head: "Our technical department can have up to three to four people to meet the requirements. You must find foreign aid."