Open up modern chemical industry production
Soda ash, sometimes referred to as alkali, transliterated from English as soda, its chemical composition is sodium carbonate (Na2CO3), which is widely found in nature and distributed in All over the world. Most of them are contained in surface alkali lakes and outcrop mineral deposits, such as the alkali dry valley (Wady Natron) near Cairo, the capital of Egypt, Africa, the trona deposits in southwestern Wyoming, the United States, and the alkali lakes in Hungary, Europe. famous. The Alkali Lake Group in Otok Banner, Inner Mongolia, is also very famous. In places where it doesn't rain two or three times a year, strong winds blow all day and night in autumn. When the cold season comes in winter, the alkali contained in the lake water freezes like ice, and is covered with a layer of snow. of alkali cream. People took it out, performed some rough processing nearby, and made it into pieces. They were carried on livestock and transported to Zhangjiakou and Gubeikou, and then transported to all parts of the country. This is what was once known as "mouth alkali".
Many plants contain potassium carbonate and sodium carbonate, especially those growing in saline-alkali land, coasts and seas. They absorb sodium ions (Na) from the soil or seawater, and when they rot or are burned to ashes Finally, it contains sodium carbonate, the content can be as high as 30. In the "Compendium of Materia Medica" written by Li Shizhen (1518-1593), a medical scientist of the Ming Dynasty in my country more than 400 years ago, it was written: "Collect the genus Artemisia and Polygonum, dry it in the sun, burn the ashes, and pour the juice with raw water." In today's words. In other words, the grass is dried and burned into ashes, then the ashes are soaked in water and the juice is drained out, and there is alkali in the juice. The book also writes about its uses: "Descaling and leavening dough." This is exactly what alkali was used for in our daily lives.
Europeans also know how to extract alkali from the ash juice of seaweed. However, as the industrial revolution began in Britain in the mid-18th century, the demand for alkali in textile, papermaking, soapmaking, glass, printing and dyeing and other industries increased dramatically. The amount of trona alone and extracted from plant ash was obviously insufficient, which required Artificial production.
Based on analysis, chemists realized that ordinary table salt, sodium chloride (NaCl), and soda ash contained exactly the same ingredients, and they began to try to convert table salt into soda ash.
In 1737, French chemist Henri Louis Duhamel du Monceau (1700-1781) first heated table salt with sulfuric acid (H2SO4) to obtain sodium sulfate (Na2SO4). The sodium sulfate and charcoal are then heated to generate sodium sulfide (Na2S) and carbon dioxide gas (CO2). Then use acetic acid (CH3COOH) to convert sodium sulfide into sodium acetate (CH3COONa) and then increase the heat. After sodium acetate releases acetone ((CH3)2CO) vapor, leaving soda ash, the process of artificially preparing soda ash is completed in the laboratory, using chemistry反应方程式表示如下：
2NaCl H2SO4══Na2SO4 2HClNa2SO4 2C══Na2S 2CO2↑Na2S 2CH3COOH══2CH3COONa H2S↑2CH3COONa══Na2CO3 （CH3）2CO↑他还用硝酸（HNO3）与食盐作用, also obtain soda ash:
3NaCl 4HNO3══3NaNO3 NOCl Cl2↑ 2H2O4NaNO3 5C══2Na2CO3 2N2↑ 3CO2↑ where NOCl is nitrosyl chloride, a component of aqua regia.
Next, in 1773, Swedish pharmacist and chemist Carr Wilhelm Scheele (1742-1786) filtered the salt solution through lead oxide (PbO) to form a caustic alkali (sodium hydroxide NaOH) solution. Exposure to the air absorbs carbon dioxide gas to obtain yellow lead oxychloride (PbOCl? PbCl) precipitate and sodium carbonate solution:
2NaCl 2PbO H2O══2NaOH 2PbOCl?PbCl2NaOH CO2══Na2CO3 H2O 1780 British Chemist Foundation James Keir (1735-1820) used this method to build a factory for the production of soda ash and soap in Dudley, opening up the commercial market for soda ash in the UK.
In 1777, French priest Joseph Francois Marie Malherbe (1733-1827) converted table salt into sodium sulfate with sulfuric acid, then mixed sodium sulfate, charcoal and iron filings and heated them to expose the product in the air, and then decanted with water to obtain sodium carbonate. A factory was built in 1779 for production. Later, French pharmacy professor Emil Kopp (1817-1875) improved this method of making alkali, using iron oxide (Fe2O3) instead of iron filings. After his method was spread to the UK, a factory was built for production. The annual output of soda ash has reached thousands of tons. This production process is divided into four steps, and the chemical reaction is expressed by the following formula:
2NaCl H2SO4══Na2SO4 2HCl3Na2SO4 2Fe2O3 16C══Fe4Na6S3 14CO↑ 2CO2↑Fe4Na6S3 O2 2CO2══Fe4Na2S3 2Na2CO3Charles C. Gillispie． The Discovery of the Leblanc Process. Isis, 1957, 48(2): 152-170.
Fe4Na2S3 7O2══2Fe2O3 Na2SO4 2SO2↑ This has emerged as the beginning of modern chemical production, allowing the by-products generated during the production process to be recycled and used, reducing production costs.
At the same period, in 1778, French natural history professor Jean Claude De la Metherie (1743-1817) proposed the same method as Diameldi Monceau. A factory was built in the suburbs of Paris for production. This is the same as the method used by Ma Houbi and others. Production was stopped due to the large amount of sulfuric acid consumed and the impurity of the product.
In 1783, the French Academy of Sciences offered a reward of 1,200 livres (livre, the old name of the French currency unit franc, 1 livre was about $40 at the time) for a method of making soda ash to adapt to the French soap and The needs of textile, bleaching and dyeing industries.
In 1789, Nicols Leblanc (1742-1806), the personal physician of the Duke of Orleans (Duc d'Orlêans) in France, modified the alkali-making method of his predecessors. In 1791, he obtained a patent and obtained the name of the Orleans Province. With the Duke's funding, an alkali plant with a daily output of 250 to 300 kilograms was established in St. Denis, a suburb of Paris.
Loubrand served as an apprentice to a pharmacist in his youth, and later studied at the Paris College of Surgeons. In 1780, he became the personal physician of the Duke of Orleans. At that time, most of the pharmacists and doctors in Europe were chemists or chemists. They conducted chemical experiments while preparing various pharmaceuticals.
The French Academy of Sciences formed a committee to review Lou Blanc's method of making alkali. The raw materials used were salt, sulfuric acid and charcoal, as well as limestone (CaCO3).
The production operation process is mainly divided into three steps: the first step is to react salt with sulfuric acid to generate sodium sulfate; the second step is to put sodium sulfate, charcoal and limestone into a rotary furnace to increase heat: Na2SO4 4C══Na2S 4CO↑, NaS CaCO3══Na2CO3 CaS, produces a black melt that turns into black ash after cooling. It is actually a mixture of sodium carbonate, calcium sulfide and charcoal, containing sodium carbonate 17~20 (Figure 1-1): Chapter 1 In three steps, soak the black ash in clean water and then decant the solution.
On November 6, 1793, the Duke of Orleans was guillotined by the bourgeois revolutionaries who broke out in France at that time. On January 28, 1794, the Saint-Denis factory was confiscated. Lubrand did not receive the bonus. Although the Saint-Denis factory was assigned to him in 1801, he was too poor to survive by that time and had to enter an almshouse. He committed suicide in 1806.
Lubrand died, and the factory he founded was confiscated, but his alkali production method was still used in factories in Marseille, France and several other cities, and later in Germany and Austria. Factories based on his method of making alkali were also built one after another. The UK has more and larger textile industries than France and requires a large amount of soda ash. In 1818, the British chemist Smithson Tennant (1761-1815) introduced Lublanc's alkali production method in Saint-Rorox ( St. Rollox) built the factory. In 1823, the British government announced that salt was tax-free, which promoted the British chemical industry production using salt as raw material. Chemical industry entrepreneur James Muspratt (1793-1886) seized this opportunity to build factories in famous British cities such as Liverpool, Newton, and Flemington. By 1886, the United Kingdom had produced tens of millions of tons of soda ash using the Lublan process. The soda ash content in black ash increased to 41. In 1830, white ash, anhydrous sodium carbonate, began to be produced, which dissolved in water and crystallized into hydrated crystals.
Hydrogen chloride gas, a by-product of the Lubulan soda production process, was initially discharged into the atmosphere. Later, due to serious environmental pollution, the British Parliament passed management regulations, forcing producers to find ways to recycle it. In 1836, soap manufacturer William Gossage (1799-1877) created a scrubber filled with coke, so that the rising hydrogen chloride gas was absorbed by the falling water to obtain hydrochloric acid. In 1866, production workers Henry Deacon (1822-1876) and Ferdiand Hurter (1844-1896) mixed this hydrogen chloride gas with preheated air through copper or manganese oxide (as a catalyst), and converted it into Chlorine: 4HCl O2══2H2O 2Cl2↑, and then absorb the obtained chlorine with lime water to make a bleaching solution, which was patented. In 1822, industrial chemist Alexander Macomb Chance (1844-1917) passed flue gas containing carbon dioxide into waste materials, converting calcium sulfide in the waste materials into hydrogen sulfide (H2S), and then oxidized into sulfur:
CaS CO2 H2O══CaCO3 H2S↑2H2S O2══2S 2H2O not only recycles the by-products produced, but also removes products that pollute the environment, opening up a path for modern chemical industrial production.
In 1814, eight years after his death, a statue of Lou Blanc was erected at the Ecole Polytechnique in Paris as a memorial to people (Figure 1-2).
Although the Lubulan alkali production method has been popular for a while, it still has many shortcomings. The main reasons are that the reaction process is carried out in solids, requires high temperature, equipment production capacity is small, serious corrosion, insufficient utilization of raw materials, and labor shortage. Poor working conditions, poor soda ash quality, etc. So producers are scrambling to research other methods of making alkali. This is an inevitable trend in the development of science and technology.