Method of Manufacturing Baking Soda
Baking Soda, also known as sodium bicarbonate, is an important inorganic chemical raw material, widely used in food, medicine, chemical and other fields. The following are the manufacturing methods of baking soda.
I. Ammonia-alkali method
Ammonia-alkali method is one of the most commonly used methods in the production of baking soda. This method takes table salt, ammonia and carbon dioxide as raw materials and obtains baking soda through chemical reaction. The specific steps are as follows:
1. Dissolve table salt in water and pass ammonia gas into it to make saturated ammonia brine.
2. Pass carbon dioxide into the saturated ammonia brine to precipitate sodium bicarbonate.
3. Filter to get sodium bicarbonate crystals, and then go through drying, crushing and other processes to get baking soda products.
Ammonia-base method has the advantages of easy availability of raw materials, simple operation and low production cost, but the waste liquid produced contains a large amount of calcium chloride, which needs to be treated.
II. United Alkali Method
The United Alkali Method, also known as Hou's Alkali Method, is a method for the joint production of soda ash and baking soda. The method takes table salt, ammonia and carbon dioxide as raw materials, and after a series of chemical reactions, both soda ash and baking soda are obtained. The specific steps are as follows:
1. Dissolve table salt in water and pass ammonia gas to make saturated ammonia brine.
2. Carbon dioxide is passed into the saturated ammonia brine to produce a mixed solution of sodium bicarbonate and ammonium chloride.
3. The mixed solution is heated so that sodium bicarbonate precipitates out while ammonium chloride decomposes into ammonia and hydrogen chloride gas.
4. The precipitated sodium bicarbonate is filtered, dried and pulverized to obtain a baking soda product. At the same time, the hydrogen chloride gas is passed into the lime emulsion to produce calcium chloride and water to recover calcium chloride.
Union alkali method has the advantages of high raw material utilization, high product purity and low waste liquid emission, but the equipment investment is larger and the production cost is higher.
Third, natural alkali processing method
Natural alkali processing method is to use natural alkali as raw material, after calcination, dissolution, carbonization and other processes, to make baking soda. The specific steps are as follows:
1. Calcine the natural alkali ore into sodium carbonate.
2. Dissolve sodium carbonate in water to make saturated sodium carbonate solution.
3. Pass carbon dioxide gas to convert sodium carbonate into sodium bicarbonate and precipitate.
4. Filter, dry and pulverize to obtain baking soda product.
The natural alkali processing method has the advantages of unique raw materials, good product quality and low cost, but it is limited by the reserves of natural alkali resources.
In short, there are various manufacturing methods of baking soda, and different methods have different advantages and disadvantages and scope of application. In actual production, suitable manufacturing methods should be selected according to specific conditions to improve product quality and reduce production costs.
