Sodium Bicarbonate (Food) - India

Brief Overview

Sodium bicarbonate, also known as baking soda, is a white, crystalline or powdered material that readily dissolves in water or mineral springs. Its chemical formula is NaHCO3. Minerals like thermokalite and nahcolite naturally contain it. Sodium bicarbonate functions as an amphoteric molecule that interacts with both basic and acidic chemicals. It creates carbonates when it reacts with base chemicals like sodium hydroxide, and sodium acetate when it reacts with acetic acid. Sodium bicarbonate decomposes at temperatures higher than 149°C, releasing carbon dioxide and water as byproducts while also creating sodium carbonate.

Manufacturing Process

The manufacturing of sodium bicarbonate can be performed by the Solvay method, which was initially established by Ernest Solvay in the 1860s. Sodium chloride reacts with carbon dioxide and ammonia in water using this approach. The sodium bicarbonate produced through this method has the potential to be converted into additional chemicals like soda ash (Na₂CO₃) or washing soda (Na₂CO₃.10H₂O). The following describes the production process:

1. Production of Sodium Bicarbonate
Ammonia, carbon dioxide, and sodium chloride react in water throughout the production process. Calcium carbonate acts as the supply of carbon dioxide in this process, with the resultant calcium oxide working to separate ammonia from ammonium chloride. Another way to get carbon dioxide is using dry ice. The reaction is as follows:
NaCl(aq) + NH₃(aq) + CO₂(s) + H₂O → NH₄Cl(aq) + NaHCO₃(s)

2. Retrieving Sodium Bicarbonate
Step 1's reaction produces sodium bicarbonate and ammonium chloride as its products. At room temperature, both compounds are soluble; however, ammonium chloride is more soluble than sodium bicarbonate below that temperature, which makes it easier to separate the crystals from the solution. An other technique is to react calcium hydroxide with ammonium chloride in order to extract sodium bicarbonate from it. The products of this process are liquid-phase calcium chloride, water vapor, and ammonia gas.

Food Industry

Sodium bicarbonate is frequently used as a leavening agent in the culinary industry. It combines with very little acid, like vinegar or buttermilk, to create bubbles that provide the dough a fluffy, soft feel. When making dough, the mixture of acid and sodium bicarbonate can take the place of yeast. Moreover, sodium bicarbonate is used to make effervescent drinks and salts.