A distillation tower design is normally made in two steps; a process design, followed by a mechanical design. The purpose of the process design is to calculate the required stream flows and number of required theoretical stages. Required steam flows could include reflux rate, side draws, and the heat duties (number of pump arounds and the condenser and reboiler). The purpose of the mechanical design is to select the tower internals, column diameter and height.The process and mechanical designs can be completed very quickly utilizing 'cook book' procedures that many Engineering Procurement and Construction (EPC) firms have established. Often the 'cook book' designs can be optimized for improved profitability, operations and maintenance.The best way to review profitability is the life cycle cost, which is the initial capital cost of the plant along with the first 10 years operating and maintenance cost. The life cycle cost includes a reliability factor, which is very important in designing any process plant equipment. Improved reliability has a very large impact on return on investment (ROI).Several factors should be considered when designing distillation equipment;1. Correct distillation equipment for process conditions 2. Correct equipment selection for expected run length 3. Correct process control strategy to achieve stable operations 4. Fouling/corrosion/polymerization potential 5. Thermal stability, chemical stability and safety 6. Maintenance reliability, accessibility and simplicity of repair 7. Evaluation of the most cost effective solution for minimum life cycle cost This review will include general distillation design guidelines applicable to any process along with specifics for the natural gas processing, refining, petrochemicals, and the oleo chemical's industries. 

Steadily increasing requirements on fractionation demands in the oleochemical industry require advanced separation technology. Today, often a distillation column has not only to process several different feeds, but also be able to produce two different products simultaneously. Divided wall columns have been proposed and used in the chemical industry, but there are, presently, few applications of divided wall columns in the oleochemical sector. The main reason prohibiting their use might be in the limited familiarity, higher requirements on operation, potential corrosion problems and last but not least, limited flexibility.Fractionation columns with added side stripper are a well-proven way to satisfy increased demand of separation duties. The availability of second-generation structured packing increases the efficiency and reduces pressure drops while making it possible to increase capacity and/or product purities. A lower pressure drop has a positive impact on the separation itself. Combining these effects with an increase in capacity will result in a synergy effect on the separation performance.The newly developed BXPlus structured packing is a powerful tool for advanced Glycerin separation, combining good wettability resulting in high efficiency with low-pressure drop. New columns can be designed much more compactly. Revamps will improve both capacity and/or purity. 