Dilution of concentrated sulfuric acid
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When diluting 98% sulfuric acid to around 50%, at a rate of 2 tons per hour, should an enamel-lined reactor or a graphite diluter be used? ? Their respective advantages, disadvantages, and precautions. Please let me know
The dilution of sulfuric acid is exothermic; diluting it to 50% concentration releases approximately 45 KJ/mol of heat. Regarding sulfuric acid: 1. Corrosion resistance – if no cooling is used, the maximum temperature during dilution and mixing is 100 degrees, so either material should work fine. 2. Cooling area – the reaction vessel only has a jacket; is an additional heat exchanger needed, perhaps one made of graphite? 3. Price comparison
Cooling is necessary. Is the 98% acid produced internally or purchased externally? If it’s purchased, a low-concentration version can be chosen; using enamel-lined tanks will result in lower costs, and a 5-cubic-meter enamel-lined tank will suffice for dilution
The things to note are the order of addition, as well as diluting a portion first to lower the temperature before use. Diluted with dilute acid and 98 acid; it should be 983
Enameled tanks or steel tanks lined with acid-resistant tiles can be used, but a heat exchanger and a cooling water system are required.
If 2 tons are diluted per hour, ice-based dilution can be used, utilizing the phase change heat of ice to absorb the heat required for diluting sulfuric acid. Using an enamel container would be better; it’s inexpensive and corrosion-resistant.
This post was last edited by heart_qcssu on 2024-9-14 at 11:34. It is recommended to use silicon carbide coolers; concentrated sulfuric acid and water are mixed and fed into these coolers, with circulating water serving as the cooling medium. This setup allows for continuous operation and high processing capacity, whereas reaction vessels can only operate intermittently, with poor dilution capabilities
It is best not to use jackets on reaction vessels, mainly due to the risk of magnetic explosion; jackets can be considered only when the temperature difference is small. Using an external graphite heat exchanger is the best option, as it also ensures continuous operation. In this way, the concentration can be kept stable.