Approaches to new product development in sulfuric acid manufacturing enterprises

It can be combined with high-, medium-, and low-temperature heat recovery using sulfuric acid in processes that involve significant steam consumption, such as the production of caustic soda and chlorosulfonic acid; ideally, an industrial chain should be established to reduce pollution.

Sulfuric acid can be used to produce sulfates; phosphoric acid can be produced to obtain phosphates. Hydrofluoric acid can be manufactured for use in the fluorine chemical industry. Titanium dioxide, silica, dimethyl sulfate can all be produced, as well as dye intermediates such as H-acid, J-acid, and 23-acid. Using SO2, liquid SO2, sodium sulfite, sodium pyrosulfite, and safety powder can be produced. With SO3, liquid SO3, high-concentration fuming sulfuric acid (65-acid), sulfamic acid, and chlorosulfonic acid can be manufactured. The steam and electricity generated from waste heat can be utilized to produce products that require significant amounts of energy and steam, such as those in the chlor-alkali industry, for the production of ion-exchange membrane caustic soda, KOH, sodium chlorate, and more. Last edited by That makes sense on 2008-2-5 18:30]

Sulfuric acid is essentially the mother of industry; it should be paired with downstream products!

Overall, sulfuric acid manufacturers are not doing a good job in developing new products, as the decisions made by those in leadership positions are based on nonsense. In the 1980s, Wuxi began producing sulfamic acid and chlorosulfonic acid. At that time, my classmate was working on the development of new products, and I suggested that he develop saccharin (using sulfamic acid) and saccharin (using chlorosulfonic acid). The pilot and scale-up tests were both successful, but unfortunately the leaders at that time gave up on the idea. Nanjing produced sulfamic acid in the 1990s on a scale of 10 KT/year; unfortunately, it did not develop saccharin. Now it is controlled by Hong Kong-based companies that produce saccharin and has become one of their subsidiaries.

As far as I know, Sushu changed its name to Suzhou Fine Chemicals after acquiring a sodium saccharin production plant; however, after the name change it did not focus on the development of fine chemicals but continued to engage in the production of sulfuric acid and alkalis. It was Zhejiang’s Xiaoshan and Shangyu regions that saw better development in the field of fine chemicals. Currently, President Xu is still striving to develop the sulfuric acid industry. He once claimed that he would drive all the sulfuric acid manufacturers in southern Jiangsu out of business, but it seems that all of them have managed to develop well.

Sodium saccharin is a great product – it sells for 120,000 yuan per ton. Capitalists in Suzhou were already producing it before the city’s liberation; back then it was manufactured using toluene chlorosulfonic acid, and later the phthalic anhydride method was adopted. After Xu took over the sodium saccharin production plants, the production capacity was increased from 3,000 tons per year to 10,000 tons, with 8,000 tons being exported. The phthalic anhydride method causes severe pollution, so it couldn’t be used in Zhangjiagang; as a result, production ceased there. It’s a pity. I’m very fond of the toluene chlorosulfonic acid method – Americans use this method to produce sodium saccharin.

:L, seeing all those experts’ comments upstairs! I truly admire it! It seems there’s never enough for me to learn in my entire life! Heaven and earth! I’m really ignorant! ! :'(

Think about it: before the liberation, the main raw material for producing sodium saccharin in Suzhou, namely chlorosulfonic acid, was imported from the United States. Later, when the U.S. imposed an embargo on China, the process was changed to the phthalic anhydride method. The toluene-chlorosulfonic acid method is simple, produces less pollution, and allows for continuous production, just like the process used for producing sulfuric acid. Later, China began to produce chlorosulfonic acid on its own, but sodium saccharin was still manufactured using the highly polluting phthalic anhydride method.

　　One afternoon in 1879, in the laboratory of Baltimore University in the United States, Russian chemist Faridberg was happily moving around among various bottles and flasks. He is in an especially good mood today; firstly, the synthesis experiment on aromatic sulfonic acid compounds that he is working on is progressing smoothly, and results will be available soon ； Secondly, it’s his birthday today; his wife Natasha has prepared dinner, waiting for him to come home to celebrate together. 　　Dusk fell over the land, and the laboratory gradually grew dark. Faridberg stared intently at the flask under the gas lamp and called out. The churning solution had long since made her forget all about the birthday dinner that night. Finally, the experiment was progressing well; he happily picked up the pencil on the table and recorded the results in the experiment notebook. At that moment, the wall clock began to chime, \"Ding dong,\" \"Oh, it’s already 6 o’clock.\" ”Only then did he remember it was time for dinner; he hurriedly put the pencil in his pocket, put on his coat, and ran home. 　　The wife got busy along with her husband. The husband set out the glasses and tableware, while the wife brought in plates of dishes. Dinner began in a cheerful atmosphere. 　　Fareed Belger picked up a piece of steak and shoved it into his mouth. Suddenly, he stopped chewing and asked, a bit surprised, \"Natasha, did you put sugar in the steak today?\" ”“No, I’ve never heard of adding sugar to steak. Well,” the wife said strangely as well, “the dishes today aren’t quite right; try it – this salad even has a sweet taste to it. ” 　　After dinner, Farid Bergh was still thinking about that strange sweet steak and sweet salad. Out of scientists’ *habit, he wanted to find the cause. After checking the kitchen utensils, he turned his skeptical gaze toward the tableware. He licked the edge of a plate thoughtfully, then licked his own hand. Immediately afterward, he took out the pencil from his pocket and licked it as well. 　　“The problem is with the pencil, it’s the pencil! ”Faridberg started shouting frantically, \"Natalia, look! All the utensils that I’ve touched with my hands have a sweet taste, and this sweetness comes from the pencils I used to write with.\" It is certain that the sweet taste on the pencil was acquired in the laboratory. It seems there must be some strange, extremely sweet substance in the laboratory; I’m going to find out what it is. ” 　　Farid Bergh rushed to the laboratory, lit the gas lamp, and carefully inspected each piece of equipment that had been used in the experiments. Finally, he discovered that the sweetness came from a chemical called sodium o-sulfonylbenzoylimide. 　　This accidental discovery opened a path to new inventions for Faridberg. From then on, he devoted all his energy to studying the substance extracted from coal tar. He extracted toluene from the dark, sticky, and smelly coal tar; after treatment with sulfuric acid, phosphorus pentachloride, and ammonia, followed by oxidation with potassium permanganate, it was finally obtained as a particularly sweet white crystal through crystallization and dehydration. He called it “saccharin” and found that it was 500 times sweeter than sucrose. 　　Farid Belger immediately announced his invention and obtained a patent in the United States. In 1886, this chemist moved to Germany, where he established the world’s first factory for extracting saccharin from coal tar. Saccharin thus began to make its way into people’s lives.

I remember someone saying before that saccharin is harmful to the human body, and it is not recommended to use it as a sweetener in food. Artificial sweeteners are hardly to be found in the market these days. Is it still meaningful to produce it?

It has now been replaced by saccharin.

What is the future of electronic-grade concentrated sulfuric acid?

Ultra-pure grades have a high gold content, but are used in small quantities.

Now many users use imported ones

The sweeteners used in fine chemical food additives include saccharin, acesulfame, aspartame, and acesulfame K; all of them are obtained through sulfonation reactions and are derivatives of sulfuric acid. Saccharin is a first-generation sweetener, produced using toluene chlorosulfonic acid or phthalic anhydride methods. There are 6 manufacturers worldwide, and the current global consumption is 30 kt; it is used in toothpaste, cosmetics, food, and other products. Aspartame is a second-generation sweetener produced from cyclohexylamine and ammonium sulfonate; the manufacturers are mainly those with Hong Kong or Taiwanese investment. The global consumption volume is currently 30kt, and it is used in the food industry, but it is banned in the United States. Aspartame is a third-generation sweetener; its main manufacturer is the American company Monsanto. The global consumption volume is currently 20kt, and it is used in the food industry. Acesulfame is a fourth-generation sweetener produced from divinyl sulfone and liquid SO3; its global consumption is currently 20 kt, and it is used in the food industry.

Working in the fine chemical industry is quite troublesome, mainly due to pollution issues.

Hehe, I’m a student majoring in sulfuric acid; I study hard.

The toluene method was the first approach used by Fakllerg, the inventor of saccharin; it has since been improved numerous times to become a simpler method for producing sodium saccharin. It was also one of the earlier methods used in China for manufacturing sodium saccharin. Its main raw materials include anhydrous toluene, chlorosulfonic acid, ammonia water, activated carbon, liquid sodium hydroxide, hydrochloric acid, potassium permanganate, sodium sulfite, and sodium bicarbonate, involving chemical reactions such as chlorosulfonation, amination, oxidation, acid extraction, and neutralization. Anhydrous toluene is gradually added to a chlorosulfonation reactor containing chlorosulfonic acid, and the reaction is carried out at low temperature. After addition, the reaction proceeds for 3 hours; once it is complete, the mixture is cooled to allow complete decomposition of the chlorosulfonic acid, with the resulting acid being released. The resulting sulfonyl chloride in oily form is then washed with water, and frozen at -15 to -20°C for 12 hours. The para-isomer crystals are filtered out, leaving the liquid as o-toluenesulfonyl chloride. Ammonia water is pre-added to the ammoniation pot, o-toluenesulfonyl chloride is introduced, and the mixture is reacted at 60°C for 2 hours. After cooling, filtration is carried out; the filter cake is decolorized using activated carbon. It is then refined in a purification pot using hydrochloric acid and sodium hydroxide solutions, yielding o-toluenesulfamide. O-toluenesulfonamide, water, and liquid sodium hydroxide are added to the oxidation reactor. Potassium permanganate is added in portions at a temperature of 25–35°C. After addition, the mixture is kept at this temperature for 7 hours. The temperature is then reduced to 25°C, and sodium sulfite solution is slowly added until the oxidation solution becomes colorless. The mixture is filtered, and the filter cake containing manganese dioxide is washed with water until no sweet taste remains. The filtrates are combined, and dilute hydrochloric acid is added to adjust the pH to 3, causing the unoxidized substances to precipitate. This precipitate is filtered again, and the filter cake is washed with slightly acidic water. Finally, insoluble saccharin is obtained. In a neutralization pot containing water, insoluble saccharin and sodium bicarbonate are added alternately; the mixture is heated to facilitate the dissolution reaction. When the reaction temperature reaches 70°C, the solution is adjusted to a neutral pH. Filtration is carried out while the mixture is still hot, and the filtrate is then crystallized and dried to yield the final product, sodium saccharin.

Based on chemical principles, some co-production devices can be developed.