Recently we started water washing our crude but when we’re done and it’s time to recover back out heptane we’re experiencing a tremendous amount of loss.
What are the proper specs to recover heptane? If anyone has any pointers on how to recover as much heptane back as possible it would be much appreciated.
Right now we are using a cooling tower to use our cooling column; water is only circulating through the column around 80f, I’m assuming that’s to warm.
You need to pull less vacuum to make up for the warm water.
How is your vacuum pump routed and what type of vacuum pump is it? You are pulling heptane vapors through your vacuum pump and pumping it out of the outlet possibly into your room if the outlet isn’t plumbed elsewhere.
A good rule of thumb is having a Delta (difference) of 50c between your vapor and condenser. This is inclusive of vacuum, so if you’re dropping yout BP from vacuum your condenser needs to go colder too
I’d agree with you to a point, much of it depends on the surface area and efficiency of the condenser itself, and the relative vapor pressure at hand.
Many people use rotovaps, and the glass is just terribly inefficient, so in the cannabis space with glass In mind, I’ve found a “delta 20” to be inadequate for solvent recovery in general.
I suppose we should ask for more info from OP on how he’s recovering to see what makes the most sense.
Provided we’ve got efficient surface area to condense with you’re definitely right, but across a bunch of real world applications I find I’ve needed to get minimum 30c delta, if not higher.
I tend to also set things at a 40+ degree delta, and by the time it’s actually running it’s tighter too once the chiller is under load.
Of Course! I was just pointing out that it’s generally known as the Delta 20 rule, not 50.
A bunch of cannabis applications throw this rule right out the door (IE condenser at an extremely low temp; dry ice condensers, -80 Cold traps, etc), which tends to work quite well. You’re definitely right that the delta 20 rule can sometimes be inadequate for solvent recovery — keep in mind the definition of “rule of thumb”…
We are using a 500L ball reactor , pulling .025MPa on the Vaccum. We have a cooling tower hooked up the jacket that has 108000 kcal:hr of cooling power but our water never really gets below 80.
Was thinking of hooking up our -30/80 touch science recirculating chiller. Would that work and if so what temp would you recommend setting the chiller temp.
I mean, could probably just mostly ditch the vacuum and add more heat if you’re not too concerned with keeping temps low.
If you’re going to put a chiller in line, but use water, I’d recommend not having it go below 0c, cuz water tends to stop flowing around there. Add some glycol to your reservoir to lower the BP if you need to condense colder than that.
but I’d say you’re ok with either less vacuum more heat on the evap end if you wanna run 80f water for cooling.
assuming you’re not actually regulating that vac, and are just sucking as hard as you can; with a vac level of 0.025MPa (0.25bar), one might guesstimate that your solvent was only getting down to 330k (57C) as it is leaving your condenser.
you’re suggesting putting the chiller after the cooling tower, but before the condenser right? Which seems like the correct way to play that game.
I don’t think that chiller alone would be up for the task, and I’m not certain OP got that you were suggesting supplementing the cooling tower rather than replacing it.
I suspect ditching the vac entirely, even without adding more heat is the easiest/cheapest way to recover more solvent. if more heat is available, that will speed things up, if it’s not, who cares, they’re no longer loosing most of their solvent to atmosphere.
It we got rid of the vaccum completely would we not just build up pressure inside the reactor?
Also not sure how much heptane was diluted into
The water, we just went ahead and replaced with fresh water. We lost about 25 gallons of heptane so I’d imagine most of that went into the water.
Not if you are condensing the vapor appropriately. ie balancing condensation with evaporation.
Think about a CLS being run passively…
So how are you heating this contraption?
(Temp, power, implementation)
Is it adjustable?
So that is a “yes” to “just sucking as hard as possible”?
If it’s on your boiler, that suggests you’re boiling at 57C, rather than condensing at 57C, which might mean you’ll need to add a few more ergs to run at atmospheric