Regarding the issue of acid purification
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The hydrobromic acid produced by my company currently contains certain organic impurities (such as p-tolylformaldehyde), which affects the sales of the product. I tried using tributyl phosphate for extraction; the color of the solution changed from a slight red to a transparent colorless state. However, after separation, the liquid tended to stick to the container walls and appeared thicker than water. I’m not sure what the reason for this is. I’m asking experienced seniors for help – how can I get rid of these organic impurities, and what should be used? ? ? Thank you, looking forward to it urgently :'(
A few words: First of all, what is the concentration of hydrobromic acid? What is the approximate concentration of impurities such as p-tolyl formaldehyde? Secondly, tributyl phosphate is not a good extractant here; it will definitely hydrolyze under highly acidic conditions (it’s just a matter of time). Furthermore, the acid to be treated by extraction should be in the raffinate phase, which certainly contains tiny droplets of the emulsified extractant, with a concentration greater than 300 ppm. This could significantly affect the usability of hydrobromic acid. It is said online that the melting point of p-tolyl formaldehyde is 155–161°C, and its boiling point must be even higher; so perhaps vacuum distillation or multi-effect evaporation could be tried. It is estimated that cooling the concentrated solution can yield p-methanesulfonylbenzaldehyde crystals. If the HBr concentration is not very high, nanofiltration can also be tried; the molecular weight of mesitylbenzaldehyde is 184, which is high enough to be retained by the membrane, while water molecules and acid can pass through freely. Koch can provide acid-resistant nanofiltration membranes. The above is for reference only.
Where are you? What is the daily amount of waste acid? I have the expertise to handle large volumes of waste acid; please contact me at fmch6605@chemnet.com
The HBrde produced by our company has a concentration of 48%; the concentration of p-tolylformaldehyde is unknown, but it is certainly not high, below 2%. Distillation in this case would be somewhat counterproductive, as there are too few impurities, and the production volume is quite large – 3-4 tons per day!
Someone suggested that I use activated carbon. What do you all think?
At the azeotrope, nanofiltration definitely won’t work. At the boiling point, evaporation is used. With two-to-four effect evaporation, only 1–2 tons of steam are used per day, which amounts to 200–300 yuan per day. How about giving our membrane-based multi-stage multi-effect evaporation system a try after some time? Its cost is 70,000 to 80,000 yuan (this type of system has not been used before); with atmospheric pressure steam, the daily steam consumption is less than 1 ton.
Use resin to absorb it; I’ve done it before and the results were good
Thank you for your help! Could you provide me with some information on your multi-stage multi-effect evaporation technology? Let’s take some time to study this. My email address is baiyizuzhang@163.com. This post was last edited by White Ant Chief on 2009-2-11 at 15:38.]
I don’t know much about resin absorption; could you please explain it in detail? What resin? How exactly did you do it? Thank you:handshake
Are there any experts with better suggestions? :(