Many people do not know that soda ash is a very important basic chemical raw material. But interestingly, soda ash is actually a salt, and its composition is sodium carbonate.
It's like a pencil doesn't contain lead, its main ingredient is graphite; mercury is not silver, it's actually metallic mercury; dry ice is not ice, it's actually carbon dioxide.
soda ash
Then, since it is called soda ash, it has two meanings.
On the one hand, it means that sodium carbonate is alkaline after hydrolysis in aqueous solution;
On the other hand, it means that the purity obtained by the initial alkali making technology is not high, and then the improved technology greatly improves the purity of the alkali.
Therefore, sodium carbonate has been given such a common name - soda ash.
The role of soda ash can be described as very extensive, it can be used to make glass, such as flat glass, bottle glass, optical glass and high-grade utensils; but also the use of fatty acids and soda ash reaction to make soap; as well as the softening of hard water, the refining of petroleum and oil, the removal of sulfur and phosphorus in the metallurgical industry, mineral processing, and the preparation of copper, lead, nickel, tin, uranium, aluminum and other metals, the preparation of sodium salts, metal carbonates, bleaches, fillers, detergents, catalysts and dyes in the ceramic industry, and the preparation of refractory materials and glazes in the ceramic industry. All inseparable from soda ash.
It can be said that without soda ash, a modern industrial industry would not have evolved.
At present, China's soda ash production capacity, output and consumption are the world's first. But more than a hundred years ago, the production and sale of soda ash in the world was monopolized by a British company. At its most expensive, you need an ounce of gold for a pound of soda ash.
At this time, a Chinese scientist "turned out to be born", he was not afraid of the powerful British chemical giant, broke the technical barriers to the manufacture of soda ash, and opened the alkali technology to the world for free, making great contributions to the establishment and development of China's chemical industry.
Hou Debang
He is the Chinese scientist Mr. Hou Debang.
<h1 class= "pgc-h-arrow-right" > the history of alkali production in China is a history of anti-monopoly</h1>
Before entering the Industrial Revolution, people's demand for soda ash was really not high.
At that time, soda ash was often used as a food additive. We know that if soda ash is not added in the process of making noodles, the noodles will have a sour taste, which will affect the taste.
However, some of the food in that era was good, and the taste was secondary. Therefore, soda ash is not a must. People's consumption of soda ash is also very small. This has led to a long period of time, even if the inefficient plant extraction method is used to produce soda ash, the yield can fully guarantee the demand.
plant ash
The so-called plant extraction method means that the plant body generally contains a certain amount of potassium carbonate and sodium carbonate. The plants are dried and then burned to ash. After that, the grass and wood ash is put into a cloth bag and washed with water to get the lye.
This seemingly calm demand and satisfaction changed dramatically since the beginning of the Industrial Revolution.
The first is that the increase in food production has led to a large increase in the population, resulting in an increase in the demand for soda ash in food processing.
In addition, the industrial revolution has also led to the rapid development of a series of chemical industries, from the textile industry to glass processing to the paper industry, each industry needs a large amount of soda ash. At this time, the production of natural soda ash is not enough, in this case, chemical synthesis of soda ash technology has become hot.
Swedish chemist Scheler
The earliest chemical synthesis of soda ash technology appeared in 1737 (the second year of the Qianlong Qing Dynasty), followed by the Swedish chemist Scheler (1773) and the French chemist LeBlanc (1791) successively developed two alkali production technologies and achieved industrial production.
The Scheler method uses table salt water (sodium chloride) to produce sodium hydroxide by oxidizing lead, and then injects carbon dioxide into sodium hydroxide to generate soda ash.
LeBlanc method is the use of sodium chloride and concentrated sulfuric acid reaction to generate sodium sulfate, sodium sulfate and iron oxide and charcoal co-heating product contains a certain amount of soda ash, and then wash this product with water to obtain soda ash solution.
These two alkali production technologies are not only very cumbersome in process, but also seriously polluted. But there was no way to do it, because the chemical industry at that time was very backward, and many of today's common chemical raw materials had not yet appeared.
It is also worth noting that both alkali production technologies chose sodium chloride as the starting material, which is related to the development of chemistry at that time.
Lavoisier
In the mid-eighteenth century, Lavoisier, known as the "father of modern chemistry," made a major contribution by using metrological analysis of compounds.
Under the guidance of this method, chemists at that time already knew that table salt and soda ash contained a "common component", so the synthesis of soda ash must use table salt as a raw material. This determines that all subsequent alkali making processes are inseparable from this.
French doctor Lubran
Since then, the soda ash technology has undergone a series of improvements, and the more famous one is Lubranfa.
The first step in this method is to use sodium chloride to form sodium sulfate by interacting with sulfuric acid.
The key improvement occurred in the second step: sodium sulfate and limestone and charcoal were placed in a rotary kiln for heating, and after a series of reactions, soda ash and calcium sulfide could be generated. This is a black substance called black ash.
Finally, the black ash is soaked in water, and since the calcium sulfide and the unreacted charcoal are insoluble in water, the soda ash solution can be obtained.
The period between 1825 and 1880 was the heyday of Lubranfa. It drives the production of a range of chemical products such as sulfuric acid, hydrochloric acid, bleach powder, glauber's salt and sulfur.
However, this method is mainly carried out in the solid phase, so it is difficult to produce continuously. And also use sulfuric acid as a raw material for production, which will lead to serious corrosion of the equipment over time.
In general, the Lubran method is not pure in quality, the raw materials are not fully utilized, and the price is more expensive, so it was eliminated by solvay alkali production method, that is, ammonia alkali method after 50 years of production.
Belgian industrialist Solvay
In 1861, when the Belgian industrialist Solvay was working on the concentration of dilute ammonia in a coal gas plant, he accidentally found that sodium bicarbonate was obtained in a test of absorbing ammonia and carbon dioxide with brine. In the same year, he was granted a patent for an industrial production method for the production of sodium carbonate from table salt, ammonia and carbon dioxide. This production method is called solvay, also known as the ammonia-alkali method.
Flow chart of soda ash production by ammonia alkali method
Ammonia alkali method is still widely used today, its main raw materials are raw salt and limestone, through the ammonia brine to absorb carbon dioxide to obtain sodium bicarbonate (baking soda), and then calcinate sodium bicarbonate to obtain light alkali, after conversion to obtain heavy alkali.
The advantages of the ammonia alkali method are that the raw materials are easy to obtain, the cost is low, the product is pure, and it is mainly based on the liquid and gas phase operation process, which is suitable for large-scale continuous production, thus reducing the price of soda ash per ton at that time from 13 pounds to 4 pounds.
However, the ammonia alkali method still has many shortcomings, such as low salt utilization rate (up to 75% in sodium terms); each production of 1t soda ash, to discharge 9 to 10 m³ of waste residue and waste liquid, in the long run will silt up the harbor and even pollute a wide range of environment.
The original Bunemen Yang alkali company building
In 1867, the patent for Solvay's alkali process was obtained by the British Bonnemen Company. Relying on this patent, Bonnemon became the world's largest producer of soda ash at that time.
Bunemen has built factories in Britain, France, Germany and the United States. Later, these countries jointly established the Solvay Guild, which made custom alkali technology only available to Member States and strictly prevented the outflow of technology.
Interestingly, they did not apply for an international patent, because once the limitation period of the patent right expired, the patented technology would become a socially available technology and could be used directly by anyone.
In addition to the technology blockade, they also adopted the method of zoning monopoly production, for example, the Chinese market was monopolized by the British company Bunemon.
For a long time, no one could ask for the details of the production of the amino alkali method without the charter of the Solvay Guild. Many manufacturers who want to use ammonia alkali to make alkali have ended in failure.
In 1914, the outbreak of the First World War, when the main participating countries happened to be soda ash producers, for the needs of the war, their own consumption of soda ash greatly increased, and did not have time to take care of foreign markets, which led to a serious shortage of soda ash supply in China, directly led to a large number of soda ash as the production of raw materials of soap mills and textile factories have closed down.
Patriotic industrialist Mr. Fan Xudong
When our country was in the depths of the water, Hou Debang, who was studying for a doctorate in the United States, received an invitation from the patriotic industrialist Mr. Fan Xudong to jointly establish China's alkali industry.
Originally, Hou Debang was the first tannery doctor in China, but he had the great dream of "industrial salvation", so he changed to alkali production.
"In the future, China's survival and demise will all be based on the word of persuasion as the pivot of rotation."
Tianjin Yongli Alkali Plant
In 1924, it marked the starting point of China's chemical industry - Tianjin Yongli Alkali Plant was officially put into operation. However, the soda ash produced for the first time turned out to be red. At that time, almost everyone thought that production had failed.
However, Hou Debang believes that the red color appears because the purity of raw materials in our country is too high, not as bad as that used by the British. So he added some impurities to the raw materials.
A miracle happened - the snow white soda ash was actually produced.
Two years later, Hou Debang and his colleagues solved all the alkali process problems and thoroughly mastered all the technical secrets of the ammonia alkali method. In August of the same year, Asia's first alkali plant mass-produced soda ash, which was named the "Red Triangle" brand.
Subsequently, the "Red Triangle" brand of high-quality soda ash won the gold medal at the "World Exposition" in Philadelphia, USA. It is also known as "a symbol of China's industrial progress". A few years later, at the Swiss International Merchandise Fair, the "Red Triangle" brand of soda ash won a gold medal again.
China issues stamps for Hou Debang
Hou Debang is therefore known as the "King of China's Alkali Production".
"We're not going to do a second Solvay, a second Bunemon."
In 1933, in order to make future generations no longer under the control of others, Hou Debang decided to disclose the alkali-making technology. He wrote the book "Made of Soda Ash" in English and published it in New York. Since then, the book has been translated into many languages and published, and has become a technical reference for the alkali industry in many countries. It has made a significant contribution to the vigorous development of the alkali industry all over the world.
<h1 class="pgc-h-arrow-right" > base method</h1>
Five years later, due to the japanese invasion, Hou Debang transferred the Tianjin alkali factory and established the Yongli Chuanxi Chemical Plant in Minjiang, Sichuan. Since there is no suitable salt raw material, it can only rely on the salt brine in the deep wells of Sichuan. However, the salt halogen concentration, which is extremely difficult to collect, is very low and needs to be concentrated to become a raw material, which leads to the high cost of alkali production.
Hou Debang decided not to use solvay alkali production.
Because the German Schreib improved the ammonia alkali method - the ammonium chloride is directly made into crystals as a by-product, which can avoid a large amount of waste liquid and improve the utilization of salt. Therefore, Hou Debang first went to Berlin, Germany, to buy a new alkali production method, but what he did not expect was that the Germans believed that Japan was their ally, so they asked for a price and put forward a series of demands that undermined China's sovereignty, such as not being able to sell it in Manchuria.
Hou Debang immediately angrily rebuked the other party and whisked away.
After returning to China, Hou Debang made up his mind to develop a new alkali-making technology on his own. In the extremely difficult environment during the War of Resistance Against Japanese Aggression, after more than 500 experiments and analysis of more than 2,000 samples, he finally developed a new alkali production process, and made the utilization rate of salt reach more than 95%, which not only saved one-third of the equipment and auxiliary raw materials, but also solved the problem of waste liquid destroying the land and polluting the environment.
This method is the "joint alkali production method", which unites the two major industries of alkali production and ammonium production, thereby pushing the level of alkali production technology to a new height.
In 1943, after research, the Chinese Society of Chemical Engineers unanimously agreed to name this technology "Hou's Combined Alkali Production Method".
Base method
In fact, the alkali making technology created by Hou Debang is based on the improvement and development of the ammonia alkali process, and its raw materials are raw salts and synthetic ammonia. This method is produced by a combined cycle of "salt-to-salt, two ammonia inhalation, and one carbonization" with the ammonia plant. Both soda ash and ammonium chloride are produced using ammonia and carbon dioxide.
Ammonium chloride is a fast-available nitrogen chemical fertilizer, which is suitable for crops such as wheat, rice, corn and rapeseed, especially for cotton and linen crops to enhance fiber toughness and pull and improve quality.
Looking at the reaction of synthetic soda ash alone, the two methods are the same.
The improvement of Hou Debang is that the final ammonium chloride can be used as a fertilizer, which is a fairly valuable economic product.
The production of Hou's alkali method is combined with the process of salt + carbon dioxide producing soda ash under ammonia and the process of synthesizing ammonia from nitrogen into ammonia and then into ammonium salts.
That is to say, As an expert in alkali making technology, Hou Debang has also made significant contributions to the development of "nitrogen fertilizer industrial technology".
< h1 class="pgc-h-arrow-right" > concluding remarks</h1>
Hou Debang's contribution to China's chemical industry is not only a alkali production method, he also set up the entire "three acids and two alkalis" chemical industry foundation in China.
"In the unlikely event that the Chinese people will never dare to talk about chemical engineering again, we will become sinners in China." Today, we can only move forward, to the soup and the fire, and we will take care of everything. ”
From the oath made by Mr. Hou Debang, we can see that he is not afraid of hardships and has the heart of a pure son who is dedicated to the country. Such a scientist is our example of progress, and we must always remember him.