1.3. Factors affecting efficiencies:[4] Factors which affect efficiencies can be divided into three groups: the structural factors, the functional factors, and the system factors and physical properties.
Structural factors that affect efficiencies are for example flow patterns, tray types, outlet weirs, down comers, and tray spacing. Functional factors are for example flow, pressure drop, liquid entrainment, liquid channeling, flooding, capacity and eddy. System factors and physical properties are for example surface tension, liquid and vapor density, diffusion coefficients, concentration, viscosity, relative volatility, pressure, and temperature. Common ways distillation columns can waste energy:-

1. Operating the column at the wrong pressure: …show more content…
Putting the feed in the wrong location: Extent of separation is typically determined by the reboiler, condenser, and feed system. Most engineers generally concentrate on the two ends that is condenser and the reboiler it is the right thing but forget about the feed system itself. In cases where multiple feed entrances are possible always look at the proper tray to introduce the feed. The feed location depends heavily on the composition and final product specifications introducing a feed at the wrong location means the trays or plates around the feed entrance will operate inefficiently and thus require more work, use more energy, to perform the required separation. If feed composition changes or if it has changed since the tower was designed, run tower simulations to see if you can introduce feed on a different tray to reduce energy …show more content…
Over purifying of the products: In a distillation column, mainly primary control protects the most valuable product. Consider if you have a specification of less than 5% unwanted material in the overhead liquid, you typically will set a target to achieve that. However, it’s very common for a plant to produce 2% to 3% unwanted material in product even when allowed 5%. This generally happens because operators are taught to respond immediately to results close to the limit but are less likely to make changes when the results are far below the target. Although you never want to produce material in a distillation column far below target takes a lot more energy than running a column to produce very near the target. With the advanced control technologies and equipment available today, can help in producing products close to desired target by consuming low energy.

2. Prediction methods to improve efficiencies:
There are many factors that affect efficiencies and the phenomena that take place inside a distillation column are complicated. A small change in some value may have a considerable effect on other parameter values and column functioning. Due to this the prediction of efficiencies is very difficult.
2.1 Smart Use of Energy:[6]
As per the study only chemical industry consumed 19 % of the energy in Europe in 2010, distillation is clearly a significant driver of overall energy consumption and it can reduce energy consumption through following ways;
• Improvement of the overall