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  Distillation - Fractional & Simple

CBG Technologies offers both Fractional and Simple distillation recyclers.

Distillation

This is a process which is used to separate volatile solvents from non-volatile materials, such as a mixture of alcohol, paint thinner and paint resins.  The process consists of heating the mixture to boil off the alcohol and paint thinner, leaving just the paint resins behind in the boiling tank.  The alcohol and paint thinner vapors are then condensed back to a liquid mixture of alcohol and paint thinner.

Fractional distillation

"Fractional Distillation" utilizes a specially packed column (a reflux column) is placed between the boiling tank and the condenser.  As solvent vapors travel upward from the boiling tank through the reflux column to the condenser, they are purified and separated.

Solvent recoveries approach 100% as CBG systems are "closed systems", and solvent purities often approach 100%, depending upon what the other solvents were in the original mixture.

Simple distillation

Unlike fractional distillation, simple distillation does not use a reflux column. Solvent vapors travel directly from the boiling tank to the condenser. The process described above for "Distillation" also describes "Simple Distillation".  However, there are two very important additional observations that need to be made. 

First, simple distillation cannot separate the different volatile components like alcohol and paint from each other.  Both of these volatile components are collected together. 

Second, during the boiling process, many small micro-droplets of the dirty paint mixture are carried upward along with the volatile vapors into the condenser.  The result is that the collected liquid alcohol and paint thinner mixture is usually contaminated with as much as 4-5% of the dirty paint mixture. 

In some applications, these disadvantages are not a problem, and fractional distillation is not needed. For example, simple distillation can be used to recycle solvents used to clean paint lines, remove fiberglass resins from equipment, and clean auto parts in service stations.

However, whenever recycled solvents need to be either clean and/or separated from one another, then fractional distillation must be used.