what sodium bicarbonate used for

What is Sodium Bicarbonate?

Sodium bicarbonate is also known as Baking Soda. It is a white powder or fine crystal, odourless and tasteless, soluble in water. The chemical formula is NaHCO3. Sodium bicarbonate is an acid salt formed by the neutralization of a strong base with a weak acid, and it is weakly alkaline when dissolved in water.

The solid begins to decompose at a temperature above 50 ° C to form sodium carbonate, carbon dioxide and water and completely decomposes at 270 ° C.


Applications and Uses of Sodium Bicarbonate:

Because Sodium Bicarbonate is safe and non-toxic, it is often widely used as an important food additive in life. The use of Sodium bicarbonate is weakly alkaline, which can neutralize sourness. The carbon dioxide produced during decomposition can play a fluffy role in food. Sodium bicarbonate is often used in bread, biscuits, and beverage soda.


Sodium Bicarbonate Production:

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

  1. Ammonia base method:

Main raw materials: liquid ammonia, water, carbon dioxide.

Chemical formula CO2+NH3+H2O=NH4HCO3

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.

  1. Combined alkali method:

Total reaction equation:

NaCl + CO2+NH3+H2O=NaHCO3↓+NH4Cl (nitrogen fertilizer)

2NaHCO3=Na2CO3+H2O+CO2↑ (CO2 recycling) (heating as reaction conditions)

(NaHCO3 precipitates in the reaction, so there is a precipitation symbol here, which is the convenience of this method)
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.

  1. 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. The process flow is shown in the figure below.

sodium bicarbonate process flow

Sodium Bicarbonate process flow chart


  1. Trona Method

The trona production method is also called the trona carbonization method. China has rich natural tron resources. Carbonization (strictly speaking, carbonation) is a major trona processing technology in China. The trona carbonization method produces Sodium Bicarbonate. It plays a pivotal role in the country.


Main producers and exporters of Sodium Bicarbonate:

Today, China and the United States account for the majority of the world’s Sodium Bicarbonate exports. China is considered as the exporter with the largest increase.

The main producing areas of Chinese Sodium Bicarbonate are distributed in Hunan, Inner Mongolia, Shandong and Henan. The techniques used vary slightly depending on the natural innate conditions of each location. For example, Inner Mongolia uses the trona to produce the soda ash of the trona method. Shandong uses the coastal advantage to produce the combined alkali method and the synthetic method of Sodium Bicarbonate.

China’s export of Sodium Bicarbonate is mainly supplied to Japan, South Korea, Southeast Asia and the Middle East. The US exports of Sodium Bicarbonate to the Americas and Europe.


Factors affect production:

Based on the above information, it is important to mention that the price of Sodium Bicarbonate is mainly affected by factors such as raw materials (liquid ammonia, soda ash), supply and demand ratio, and environmentally friendly production.