This article covers the main processes to reclaim oil concentrates in cannabis manufacturing, which can lead to many kilograms of saved material a year.
by Jeff Wu - August 10, 2022
Banner

Reclaiming Oil Concentrates from Cannabis Waste

Properly implementing recapture of “waste” concentrates like resin/distillate on glassware, tools, wipes, and equipment can lead to many kgs of saved material a year. This guide to recovering and recapturing cannabis waste covers the main processes to reclaim oil concentrates in cannabis manufacturing — keep in mind, that there are additional methods, and solvents available other than the proposed solvents — some processes require a C1D1 environment to function, and some solvents are restricted by state laws.

Cannabis Waste Falls Primarily Into Two Categories:

direty-waste-reclamation-cannabis-waste

“Dirty” material that has hydrocarbon solvents like ethanol or isopropanol, or even a caustic cleaning agent like industrial purple.

clean-waste-cannabis-waste

“Clean” material that can readily be re-used — examples include; fresh jar scraping, tool coating, and machine purge material.

clean-but-oxidized-waste-cannabis-waste

“Clean but oxidized material” is old material that can readily be re-used, but has developed off-putting flavors — examples include; filter paper from rosin press, activated/denatured live resin from overheating, oil exposed to activated media, and machine purge material left for months in open containers.

 

Dirty Waste Reclamation

How to collect:Spray & wash down dirty waste materials with food-grade ethanol in a pan and collect the mixture in 5-gallon carboys.

Separation & pH correction:Mixture typically washed with heptane and water in a vigorously stirred 40C reactor.  pH correction was initially performed and retested after water and saline washes.

What to avoid:Avoid soaking recycled paper towels — recycled towels tend to be made from cardboard that contains heavy metals and will leach into your solution. If material is from only washed glassware, then the “waste” material can be directly sent to distillation to repurify, otherwise, it will need to be processed through chromatography to remove heavy metals.

Catalysts to watch for:Caustic agents like industrial purple are basic which will cause D9 to isomerize to D8 and D10 during distillation. If recollecting agents from sonicators neutralizes the basic material with an acid, then wash to remove ions.

End product:Purified distillate that can be reinfused with terpenes or used in products.

Clean Waste Reclamation

How to collect:Spray & wash down clean waste materials with propylene glycol and collect mixture in 5-gallon carboys.

Separation:PG (propylene glycol) immediately crashes out of the mixture to form a milky aqueous material when water is added. Vigorous stirring in a 40C reactor is required to remove small pockets of PG after multiple water washes.

What to avoid:Avoid regular solvents like ethanol and propanol — these are difficult to purge out without removing live resin terpenes.

Catalysts to watch for:Oxygen and time — it is essential that fresh material is collected and processed in about six weeks — oxidation impacts taste and color.

End product: A mixture blend of live resin or rosin from all batches can also be partly re-flavored with additional terpenes.

Clean Oxidized Waste Reclamation

How to collect:pray & wash down clean waste materials with propylene glycol and collect mixture in 5-gallon carboys.

Profile Picture

Jeff Wu

Technical Director
Investor & entrepreneur, bringing a unique blend of scientific knowledge and hands-on experience in pharma, laboratory, manufacturing, and cannabis. Deep understanding of chemistry, electronics manufacturing, automation, and cannabis processing.