Saline / Salt color scrub SOP

Hey folks,

Looking to see if anyone has a simple to follow SOP for doing a saline scrub. A bit of backstory. We’re able to produce pretty good quality distillate and have incorporated a AC (Activated Carbon) scrub into the work flow. We normally do the AC scrub after the first SPD pass. However we noticed the material (oil and etho) turning reddit after the AC scrub. Doing some digging showed that doing a saline wash/scrub would help with the redness. But unfortunately I can’t see to find any instructions on how to actually achieve this.

Thanks in advance

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4:1 if its crude and 3:1 if its first pass.
If u have 1L of crude, use 4L of heptane.
Now get 20L ready of each:
Ph 4 water @30C with 15% salt.
Ph 7 water @30C with 15% salt.
Ph 9 water @30C with 15% salt.
Ph 7 water with 5% salt.
Ph 7 water.
Use Citric acid for ph up and and baking soda for ph down.
U want to mix ur heptane mix 1:1 with each mixture in the order i listed. (Order of first 3 doesnt matter, atleast i cant tell) You will do 4 washes of each ph before moving onto the next mixture and make sure you finish it off with 4 rinses of plain ph 7 water.
Shake/agitate the shit out of it for 2 minutes, then let it settle for 15 minutes before emptying out the water portion. I like to collect all the end portions (the part that is part water and part heptane) in a separate sep funnel, and I usually catch a couple grams that would have been dumped with the water

I really like to filter through a packed silica/T5/ Activated alumina column or even butchner after these steps.
If u can do it all under nitrogen and slight pressure, it helps a ton with the color

At the very least flush the solvent through some molecular beads like 3a but 10a works better. To capture all the mini particles of water that are suspended in the heptane mixture


I agree - it helps with emulsions a lot too!

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Hey thank you so much for the step by step. Much appreciated.

Quick quandry.
I’m pretty sure the pulls wouldn’t saturate.
Do you discard after each use? (I realize it’s cheap to make) or do you re-use your rinses?

No I wouldnt reuse ur rinse water.

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Noticed you said baking soda drops ph. It does not. Baking soda raises ph and vinegar lowers ph in water citric acid aswell lowers ph. just pointing out the switch up there


Thanks for the catch, I accidently switched up and down. Citric acid is Down. Baking Soda is UP. Sorry about the confusion earlier, thanks @rushfarm

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i thought that is what happened. has anybody used vinegar to lower there ph? i used vinegar today for the saline scrub at 4ph. and it REALLY CRASHED out the soliubles fast as hell


No, but I’m kinda intruiged

I think the acetic acid can only get down to 4 but it seems to be crashing faster than the citric acid as the ph down buffer.

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Only true if the pH is below the pka of the titratable proton on baking soda!!! Baking soda has both acid and base capabilities!!! Will for sure donate proton in strongly alkaline solutions, dropping pH