Question

How do you neutralize LABSA?

Answer 1

The neutralization of Linear Alkyl Benzene Sulphonic Acid (LABSA) with Caustic Soda (50% concentration i.e. 150kg water and 150 kg NaOH) in the process of slurry making for the detergent industry.

• Starting by charging water (900 kg) into the reactor and then adding caustic soda (300 kg) thereby diluting it to 10%.
• Then LABSA (1050 kg) is added for neutralization reaction.
• The reaction is as follows:  

CH₃ (CH₂)₁₁C₆H₄SO₃H + 3NaOH =====> CH₃ (CH₂)11C₆H₄SO3Na + 3H₂O

• The resulting paste from the above reaction contains no acid which means that all of the LABSA should be consumed (making it the limiting reactant). However, Stoichiometric ally NaOH is the limiting reactant according to the provided masses.

Note: Water is added to make up the quantity of NaOH, so that it is enough to react with the supplied LABSA. But adding water does not convert it into NaOH which means that the quantity of NaOH remains the same (i.e. 150 kg).