What is RMIN in distillation?

Rmin = 1/xF * 1/(a-1) xF is the mass fraction in the feed and is 0.8, a is the relative volatility, which has been taken average from top and bottom of the column and is 77. This will give a minimal reflux of 0.016. Usually the optimal reflux is somewhere between 1.1 and 1.5, say 1.3, which in this case would be 0.021.

How do you calculate minimum reflux ratio?

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 distillation xF?

Binary distillation. Using a tray column, a binary mixture with components A and B has to be separated by distillation. The feed F with xF,A is a two phases stream with 50% vapor. It is separated into three parts: – a distillate stream D with yD,A (vapor) – a bottom stream B with xB,A – a side stream S with yS,A.

Why the reflux ratio R is important in distillation process?

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 tray efficiency?

Tray efficiency measures the performance of a distillation tray or trays against the maximum theoretical performance. Similarly, a concept called Height Equivalent to Theoretical Plate (HETP) is used to measure the performance in a packed column.

How do you calculate Boilup ratio?

The slope of this line is equal to (Vbmin+1)/Vbmin where Vb is the boilup ratio. The boilup ratio is the fractional amount of liquid that is boiled back into the column to the amount of liquid leaving.

What is bubble cap tray?

Bubble cap tray is a flat perforated plate with risers (like pipes) around the perforations, and caps in the form of inverted cups over the risers. The caps are usually equipped with slots or holes through which vapor comes out.

What affects tray efficiency?

The state of liquid mixing can greatly affects the tray’s efficiency. For example, with liquid traversing the tray in nearly plug flow it is quite possible to realize an overall tray efficiency well in excess of 100%. This is not possible if the liquid is completely mixed or shows recirculation as in Figure 1(a).