Carbonation of a Soft Drink

It is common practice in tite soft drink industry to carbonate drinks by dissolving a fixed volume of carbon dioxide in the liquid, rather than by applying a prescribed pressure to the contents. That volume is set at 3 to 5 times the volume of the liquid contents. 

Consider a standard 1.5-1 soft drink bottle with a headspace of 5%. The task is to calculate tire pressure in the bottle after carbonation and the consumption of carbon dioxide in a plant bottling 10,000 containers per day. We assume a CO2 charge equal to 5 1. 

Taking account of the 5% headspace, and assuming a bottling temperature of 298 K together with a molar volume of STP of 22.4 1, this leads to a carbon dioxide volume of 

We apply this value to Henry s law (Equation 6.2) and use a Henry s constant of 2.90 taken from Table 6.1 to obtain 

To this value has to be added the initial air pressure of 100 kPa, which brings the total pressure in the container to slightly above 6.5 atm. 

---