Recovery Assembly

Quick Answer: A recovery assembly is a glass distillation set-up used to remove a solvent from an extract or solution and collect it for reuse. In a solvent recovery assembly the solvent boils off, condenses and runs into a receiver, while the dissolved extract is left concentrated in the flask.

Getting Solvent Back After an Extraction

Extractions often end with a large volume of solvent holding a small amount of product, such as fat from a Soxhlet run or a plant extract in ethanol. Evaporating that solvent in the open wastes it and fills the room with vapour. A recovery assembly distils it off instead, so the solvent is condensed and collected and the product stays in the flask as a concentrate or residue.

The listing does not state its exact parts. Solvent recovery set-ups are generally a boiling flask, a still head or bend, a condenser and a receiver, sometimes arranged to take the flask from a Soxhlet apparatus directly so the extract does not have to be transferred. Heating is by water bath or mantle, kept steady and stopped before the residue overheats. Some set-ups can also run under reduced pressure for heat-sensitive extracts, which needs round-bottomed flasks and a trap.

Recovered solvent is not always pure enough for every use; it may carry traces of water or co-extracted material, so label it clearly and test it before using it in sensitive work. The recovery assembly pairs naturally with the Soxhlet extraction apparatus, and for purifying high-boiling liquids see the vacuum distillation assembly.

Applications

• Recovering petroleum ether or hexane after Soxhlet fat determination, leaving the fat in a weighed flask
• Concentrating ethanolic plant extracts in pharmacognosy and natural product practicals
• Cutting solvent purchases and waste in teaching laboratories that run many extractions
• Removing solvent from a reaction mixture where a rotary evaporator is not available

Specifications

Care & Handling

• Never distil the flask to dryness; stop while a little solvent remains and finish drying as the method directs.
• Test ethers and similar solvents for peroxides before recovering them, as peroxides concentrate in the residue.
• Keep the receiver cool and away from the heat source, and run the assembly in a fume cupboard or well-ventilated area.
• Store reclaimed solvent in a bottle labelled as recovered, separate from fresh stock.

Why Choose LabEquip

Food testing laboratories, pharmacy colleges and research groups that run repeated extractions use a solvent recovery assembly to cut solvent use and fumes. Browse it with the rest of LabEquip’s chemistry lab equipment, and share the flask size and parts required on the contact page.

Frequently Asked Questions

How is a recovery assembly different from an ordinary distillation?

The aim is different. In recovery the valuable product is the non-volatile residue left in the flask, and the distilled solvent is reclaimed for reuse, whereas an ordinary distillation usually aims to collect a purified liquid.

Can recovered solvent be reused?

Often, for the same extraction or for cleaning, provided it is dry and free of residue. Check its boiling range or run a blank before using it in quantitative work, because traces of water or extracted material can remain.

Why stop before the flask is dry?

The last few millilitres contain the concentrated extract, which can overheat, char or spatter when no solvent is left. With ethers, dangerous peroxides can also concentrate in the residue.

What heat source should be used?

A thermostatic water bath or heating mantle. Most extraction solvents, such as petroleum ether, hexane and ethanol, are flammable, so open flames and hot plates with exposed elements should be avoided.

Can the assembly work under reduced pressure?

Some recovery set-ups can be connected to a vacuum source to lower the boiling point for heat-sensitive extracts. Only use round-bottomed, undamaged glass under vacuum, fit a cold trap, and make sure the parts supplied are suited to it.

How is the Soxhlet flask used in recovery?

After the extraction, the extractor is removed and the flask containing solvent and extract is connected to the recovery assembly. The solvent is distilled off, leaving the extract in the same weighed flask, which saves a transfer step.

Last Updated: September 2026