Sodium Bicarbonate

According to the difference in density:sodium bicarbonate is mainly divided into light sodium bicarbonate (hereinafter referred to as light alkali) and heavy sodium bicarbonate (hereinafter referred to as heavy alkali). Their ingredients are all sodium carbonate, but their physical shapes are different: light alkali has a density of 500-600kg/m3 and is a white crystalline powder; heavy alkali has a density of 1000-1200kg/m3 and is in the form of white fine particles. Different from light alkali, heavy alkali has the characteristics of firmness, large particles, high density, low hygroscopicity, not easy to agglomerate, not easy to fly, and good fluidity. In addition, there are ultra-light sodium bicarbonate and super-heavy sodium bicarbonate with a density of around 370kg/m3 and 1550-2553kg/m3.

According to different uses:Sodium bicarbonate can be divided into industrial sodium bicarbonate and edible sodium bicarbonate. Industrial sodium bicarbonate complies with the National Standard of the People's Republic of China GB/T210-2004 (hereinafter referred to as the national standard), including GB/T210.1-2004 Industrial Sodium Carbonate Test Method Part 1 and GB/T210.2-2004 Industrial Sodium Carbonate Test Methods Part 2. Edible sodium bicarbonate is the GB1886-1992 food additive sodium carbonate standard. On the basis of meeting the industrial sodium bicarbonate low-salt-alkali standard, arsenic and heavy metal content limits have been added.

The chemical formula NaHCO3 of Sodium Bicarbonate is a typical inorganic compound. In industrial production, there are four main methods of preparation

Ammonia base method
CO2+NH3+H2O=NH4HCO3,NaCl+NH4HCO3=NaHCO3+NH4Cl
This method requires attention: Since NaHCO3 is soluble, it is necessary to precipitate NaHCO3 in order to make the concentration of NaCl and NH4HCO3 large. Moreover, since the solubility of CO2 in water is small, and the solubility of NH3 in water is large, in order to generate more NH4HCO3, must first pass NH3 and then enter CO2.

Combined alkali method
TNaCl+CO2+NH3+H2O=NaHCO3↓+NH4Cl(nitrogen fertilizer)
2NaHCO3=Na2CO3+H2O+CO2↑ (CO2 recycling) (heating as reaction conditions)

The advantages of the ammonia-based method are retained, and its disadvantages are eliminated, and the utilization rate of salt is increased to 96%. NH4Cl can be used as nitrogen fertilizer (nitrogen fertilizer cannot be mixed with alkaline substances, but its purity can be checked by plant ash). It can be combined with a synthetic ammonia plant to convert raw ammonia gas CO into CO2 and remove CaCO3 to CO2 in order to reduce possible environmental pollution.

Synthesis method
The synthesis method is also called the soda ash method. The production is often together with soda ash factory production. Therefore, the synthetic Sodium Bicarbonate production unit is basically constructed with the soda ash plant to directly utilize the high-temperature soda ash from the calculation system of the process to accelerate the mother liquefaction process. Provide qualified lye for subsequent operations.

In order to ensure that the excess NaHCO3 in the mother liquor is fully decomposed, the phenomenon of NaHCO3 crystallization blockage during the transportation of the lye is reduced, and the high material temperature is maintained throughout the operation. Therefore, the synthesis method is often referred to as a high-temperature alkali process.

Trona method
The trona production method is also called the trona carbonization method. Carbonization (strictly speaking, carbonation) is the main trona processing technology in my country. Sodium bicarbonate is produced by trona carbonization method. It plays a decisive role in the country.