What does the reflux ratio do?

The higher the reflux ratio, the more vapor/liquid contact can occur in the distillation column. So higher reflux ratios usually mean higher purity of the distillate. It also means that the collection rate for the distillate will be slower.

What is reflux in distillation column?

Reflux in industrial distillation

In that context, reflux refers to the portion of the overhead liquid product from a distillation column or fractionator that is returned to the upper part of the column as shown in the schematic diagram of a typical industrial distillation column.

How is reflux ratio control in distillation column?

When the reflux ratio is large and reflux is used to control the reflux-drum level, a frequently used scheme controls the reflux ratio by measuring the reflux flow rate and rationing the distillate flow rate to the reflux flow rate.

Why is reflux used in distillation?

The purpose of reflux is to provide down-flowing liquid throughout the rectification section to contact with the up-flowing vapor in order to achieve stage-by-stage equilibrium heat and mass transfer and, hence, purification of the top product.

How is reflux ratio calculated?

The reflux ratio is defined as the ratio of the liquid returned to the column divided by the liquid removed as product, i.e., R = Lc/D.

What is maximum reflux ratio?

Typically the optimum reflux ratio is approximately 1.2 to 1.5 times Rmin.

How is reflux different from distillation?

Refluxing and distillation are chemical techniques used in many laboratories. The main difference between reflux and distillation is that reflux method is used to complete a certain chemical reaction whereas distillation is used to separate components in a mixture.

What is reflux process?

Reflux involves heating the chemical reaction for a specific amount of time, while continually cooling the vapour produced back into liquid form, using a condenser. The vapours produced above the reaction continually undergo condensation, returning to the flask as a condensate.

What happens in a distillation column if the reflux ratio is zero?

No liquid is recycled back to the column. Step by step the only vapour phase will be present in the rectification section and no mass transfer is possible anymore.

Which distillation uses reflux?

Reflux in industrial distillation

The use of reflux is widely practiced in industries that utilize large-scale distillation columns such as petroleum refineries, petrochemical and chemical plants, and natural gas processing plants.