In the field of food hygiene. There are strict standards and requirements for the transportation and use of sodium hypochlorite solutions.
First of all, food hygiene grade finished sodium hypochlorite solution must be transport by tank truck. This mode of transport is not only to ensure the safe arrival of the solution to the destination. But also to ensure food hygiene and safety. The tank car must be dedicate and must not be mix with other chemicals, which can effectively avoid cross contamination and ensure the purity of sodium hypochlorite solution. Moreover, regular spot checks are also require on the tank trucks to ensure that they always meet food hygiene requirements.
From the price point of view. The price including tax and freight of general food hygiene grade finished sodium hypochlorite solution (more than 10%) is 1000-1500 RMB/ton. But the transportation cost will be affect by the transportation distance and the volume of each transportation.
However, there is a problem that cannot be ignore in the finish solution, that is, the decomposition loss is faster. Especially when the temperature is higher, the decomposition rate will be further accelerated. When the effective chlorine concentration of the solution reaches about 10%. The effective chlorine concentration can be reduce by nearly 20% after 20 days of storage. Which will undoubtedly increase the cost of the finish solution by nearly 20%.
In contrast, the low concentration (0.8%) sodium hypochlorite solution produced by electrolysis of food salt prepared on site has obvious advantages. On-site preparation can save freight, and its main cost is only the cost of food salt and electricity consumption. With the continuous innovation of electrolysis technology, we currently achieve lower operating costs. Generally, 3.4Kg/ kg.cl of edible salt is consum per Kg of effective chlorine, and 4.0KW/ kg.cl of electricity is consum per Kg of effective chlorine. The price of edible salt is generally 600-700 RMB/ton, and the price of electricity is 0.65 RMB/KW.H.
The salt cost is 2.38 RMB/Kg.CL
The electricity cost is 2.6 RMB/Kg.CL
The total cost per kilogram of available chlorine is only 4.98 RMB,
The cost of effective chlorine equivalent to 10% of the finished solution is 498 RMB/ton.
Taking a 300,000-ton water plant as an example, the total amount of chlorine injection is 4mg/L (the total amount of chlorine added before and after filtration), and 900 kg of effective chlorine needs to be added every day, that is, 9 tons of 10% finished sodium hypochlorite solution is required. Through calculation, it can be find that compare with the use of finished solution. The daily cost can be save 502 RMB, and the annual cost can be save up to 183230 RMB.
In summary, in the application of sodium hypochlorite solution in the field of food hygiene, the on-site preparation method has significant advantages in terms of cost and stability, and is worthy of widespread promotion and application.