When thinking of distillation columns, it is often overlooked what goes into the column itself. Distillation systems are filled with packing. Which can come in two different common varieties: structured and dump packed columns.
Structured columns, are exactly what they sound like; columns packed with a premade packing. It could be made of metal, plastic, or ceramic. Dumped packing is comprised of the same material, but like the name says, the packing is simply dumped into the column. Dumped packing generally is in individualized pieces, unlike structured packing, that comes in-preformed segments.
One column packing strategy is not better than the other. As a general guideline when it comes to packing your distillation column, if the system is four inches in diameter or smaller, dump packing is a must. There is no structured packing available that is small enough to fit.
On the contrary to that, structured packing is not always the best option in larger columns. Operating conditions, vapor flow, and liquid flow must be evaluated before deciding what packing is to be implemented in your distillation system.