How can hydrochloric acid contained in dilute sulfuric acid be recovered and reused?
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I’m facing a difficult problem right now and I’m seeking help from all the experts out there! During production, dilute sulfuric acid is produced as a by-product, but it contains hydrochloric acid; even through heating and distillation, it is not possible to remove all of the hydrochloric acid, with at least 10% of it remaining. What are good methods for recycling such dilute sulfuric acid? If it’s sold directly, surely no one will want it – it contains hydrochloric acid. If it is used to produce other products (such as sulfates, ammonium sulfate, etc.), the chlorides contained in it are certainly difficult to handle. My current idea is to use this dilute sulfuric acid to absorb the sulfur trioxide exhaust gases, thereby producing concentrated sulfuric acid. In that case, wouldn’t the hydrogen chloride be driven out? And wouldn’t the resulting concentrated sulfuric acid no longer contain hydrochloric acid? Is this method feasible? Thank you all!
Is this a bit too difficult? No one has a good solution
2# The little tiger that loves honey: It’s practically impossible to separate it in a valuable way, but it can be sold to manufacturers that produce agricultural fertilizers. If it’s in Shandong, I can help with that. Email: bz0500@163.com
Won’t using a mixture of dilute sulfuric acid and hydrochloric acid as a fertilizer affect the quality of the product?
Could we try to carry out the separation at the gas stage? If it has already been absorbed into a liquid state, it’s indeed difficult to separate it. If separation can be achieved at the gas phase, it should be possible to do something with the water-absorbing mist of HCl
This post was last edited by px1018 on 2013-8-3 08:20. The presence of hydrochloric acid in dilute sulfuric acid is a very common issue. The best solution at present is continuous evaporation distillation: the bottom liquid of the reactor can yield 60% dilute sulfuric acid (containing 1% hydrochloric acid), while the condensate from the top of the tower can produce 31% high-purity hydrochloric acid. Generally, such dilute sulfuric acid contains organic matter, and this is the most troublesome issue. The solution involves taking the dilute sulfuric acid that has been concentrated to 60%, adding some concentrated nitric acid as an oxidizing agent, and then evaporating it at high temperatures to obtain 92% concentrated sulfuric acid.
Can a mixed acid of hydrochloric acid and nitric acid be evaporated and recovered?
After concentration, see if nitrogen displacement will work