Treatment of dilute sulfuric acid

What is the sulfuric acid content in dilute sulfuric acid? Chlorine in strongly acidic solutions exists entirely in the form of free chlorine. Gas membrane dechlorination can be considered for this purpose; it achieves thorough dechlorination without any odor. I posted a thread exactly in the middle of the night yesterday about using gas-phase membranes to remove residual chlorine from liquid materials (aqueous solutions). Recently, we conducted an on-site pilot test using polytetrafluoroethylene hollow fiber microporous hydrophobic membranes to carry out gas-phase membrane dechlorination on saline solutions containing 6% sodium chloride, 0.2% cyanuric acid, 0.10–0.55% available chlorine, and a pH of 0.6–1.8. The results show that the gas-phase membrane process can easily reduce residual chlorine from its initial value to around 10 mg/L; if further dechlorination is required, adding some sodium sulfite will suffice. The so-called gas-phase membrane dechlorination process involves the use of a microporous hydrophobic membrane: one side of the membrane is in contact with an aqueous solution containing free chlorine, while the other side has a reactive absorbent such as sodium hydroxide (or sodium sulfite). This arrangement ensures that the concentration of free chlorine in the absorbent solution remains strictly zero at all times and in all locations, thereby providing the greatest driving force for mass transfer and enabling the maximum removal and recovery of free chlorine. Theoretically, as long as the pH value of the solution is low enough, the concentration of free chlorine in it can be reduced to very low levels, for example below 1 mg/L. Theoretically, the relationship between the free chlorine concentration in the fluid entering and leaving a membrane module, the membrane area S, the mass transfer coefficient K, and the flow rate of the fluid is given by: ln(C0/C1) = KS/Q, where C0 is the free chlorine concentration of the fluid when it enters the membrane module, and C1 is the free chlorine concentration of the fluid when it exits the membrane module. Therefore, the membrane area required to remove free chlorine from the feed solution from 100 mg/L to 10 mg/L is the same as that required to remove it from 1000 mg/L to 100 mg/L. Since the equipment is made of perfluoroplastics, there is no issue with corrosion. It’s no problem even if the liquid is sulfuric acid with a concentration of 1-98%. This process requires very little electricity; it is estimated that less than 1 kilowatt-hour of power is needed to treat one cubic meter of dilute sulfuric acid.

Agree with the person above; a dechlorination unit can be installed

What is the concentration of dilute sulfuric acid? If it’s convenient, I can carry out on-site pilot testing for you. For existing membrane modules, a sulfuric acid concentration of less than 50% is preferable.

Upstairs, the concentration of dilute sulfuric acid is 70%~80%, and I’m very interested in that.

The adhesive parts of existing membrane modules cannot withstand 95-98% concentrated sulfuric acid. As for the 70-80% “dilute” sulfuric acid, should we first conduct experiments using the existing membrane modules to see how it performs? It doesn’t matter if the existing membrane modules don’t work; anyway, for another project, we are developing membrane modules that can withstand 95-98% concentrated sulfuric acid.

Your takeaway must be much cheaper than concentrated sulfuric acid, right? Is the cost after processing reasonable?

We are all in the delivery business; it seems that our downstream clients are involved in the production of magnesium sulfate. . .

Who has the technology for evaporating and concentrating dilute sulfuric acid? Our company is interested in pursuing this project; if anyone has such knowledge, please leave a message:

Available in Berth, Switzerland, www.bertrams.cn

This issue is not easy to handle. In the chlorine production process, there is a section where chlorine gas is dried using concentrated sulfuric acid; it would be advisable to consider recycling this acid after appropriate design!