The different carbon footprints of the three types of crystallized salts – solar salt, rock salt, vacuum salt – will play an increasingly important role in the future, with CO2 tax adding to the cost of the product.
The calculation of the carbon footprint of a given salt type is rather complex. The production process of solar salt generates the lowest amount of carbon dioxide of about 2-4 g CO2 per ton of salt. Rock salt production generates about 9 -12 g CO2 per ton of salt, and for vacuum salt production at the example of Switzerland, CO2 generation varies over a larger range of 18 to 50 g of CO2 per ton of salt depending on the source of electricity.
The CO2 footprint of a product must also include the CO2 that is generated during transportation. Water carriage generates less CO2 than transportation via rail or truck. Depending on the distance from production site, the mode of transportation and the distance, each of the three salt types may be favorable.
(Lit. Oekobilanz Auftausalze, 2019, Carbotech)