The Maleta cyclic distillation LLC at the conference Distillation and Absorption 2014 showed Pilot Distillation Column in Cyclic Operation

From 14-th to 17-th of September 2014, Friedrichshafen, Germany held the 10th International Conference on Distillation & Absorption 2014. Maleta cyclic distillation LLC (Tallin/EST) participated as sponsor, exhibitor and poster presentation. At the conference Maleta cyclic distillation LLC presented scientific achievements in processes intensification of mass transfer in distillation column through cyclic distillation. The key benefit of cyclic distillation technology is lower investment cost of your project: less column height; smaller column diameter; smaller square of the heat exchanger; less steel construction; consumes less space; improvement of product quality.

More over at exhibition was introduced pilot cyclic distillation column (cold stand) that has 5 distillation trays: two maleta distillation trays and three combined trays (maleta distillation tray + structured packing; maleta distillation tray+ pall ring; maleta tray + catalytic).

We demonstrated advantages of cyclic distillation technology in three cases:

1. First demonstration of cyclic pilot column was for show flexibility of the liquid flow from 5.9 to 29.4 m3/m2hr when factor Fs was constant about 1.9. We can modify the liquid flow in five times. The liquid flow resistance of the column does not depend on the liquid load, because amount of liquid on the tray remains unchanged. In cyclic pilot column we completely control of the fluid amount on the tray and its residence time.

2. Second demonstration of cyclic pilot column was for show flexibility of the vapor flow factor Fs from 1.6 to 3.6 when the liquid flow was constant 9 m3/m2hr. We can modify the vapor load in two times. The upper limit of vapor speed is limited by carryover.

3. Third demonstration was devoted to additional technological capabilities of cyclic distillation technology. It is possible to raise the efficiency of mass transfer due to the location of any type of packing between the trays and, as a result, we get the effect of bubble layer partitioning by height. The most efficient use of structured packing is achieved in a flooded condition and in emulsification mode. In this case, mass transfer area and volumetric mass transfer coefficient are increase up to 1.5…3 times. For cyclic distillation there is no fluid motion from tray to tray during vapor period. The increase in performance of the distillation column by minimizing the flow resistance in the cross-flow of liquid from the tray on a tray (single-phase fluid flow. Also we can place catalytic between maleta distillation trays. It has next technological advantages comparing to classical reactive distillation column: placement catalyst on trays in a boiling layer; ability to control the reaction time; high mass transfer efficiency.

During the exhibition Maleta cyclic distillation LLC informed about company service: pilot plant testing of separation process; basic and detail design; industrial automation and control solution; supplier of mass transfer equipment; reconstruction of the existing column; installation and commissioning work; staff training; project management.

In a poster presentation Maleta cyclic distillation LLC informed about industry implementation of tray dividing-wall columns (DN 1500/1700mm) in cyclic mode.

Increase Efficiency of Distillation Columns through Maleta Distillation Trays

The distillation columns are widely used in chemical, petrochemical, oil refining, gas processing, organic synthesis, pharmaceutical, and other industries for separation of inhomogeneous liquid mixtures. The dominant of the separation processes are the distillation processes, covering about 90%. Energy consumption for distillation can reach up 50% of total energy expenditure total production.

Distillation column sets a cylindrical shell with special internals. The purpose of column internals is to create maximum contact surface phase (mass transfer) and maintain the set of hydrodynamic conditions of their interaction. Implementation of these conditions is possible due to the constructive design of the column internals. All distillation columns we can divide for two types: tray columns design and packed columns design. Examples of tray columns design: sieve distillation tray; tunnel cap tray; bubble cap tray; floating valve tray with rectangular-shaped valves and others; Examples of packed columns design: structured packings; common random packings; pall ring; berl saddle; raschig ring; raschig super-ring and others.

The efficiency of distillation column depends from type internals, diffusion potential factor, viscosity, surface tension of the liquid, and other physical values. High efficiency of mass transfer can provide reducing of capital costs for construction of new and reconstruction of existing facilities; energy saving; improving the quality and increasing the yield of final products.

One of the ways of increase mass transfer efficiency of interaction phase is the use of non-stationary modes. This method is called - cyclic distillation technology and implemented as follows: lack of outflow of liquids to the trays vapor admission; lack of mixing of liquids in adjacent trays upon outflow of liquid. This result is related to the organizational structure of the flow in the distillation column that provides real conditions - the perfect displacement in liquid and vapor. Today, cyclic distillation technology works in stripping column, rectification column and tray dividing wall columns with a diameter ranging from 400 to 1700 mm.

High mass transfer efficiency: a decrease of the column height by half... two thirds and reducing energy consumption by one third through increasing of mass transfer efficiency;

Additional possibilities of columns: tray dividing-wall columns, any geometric shape whatsoever of the trays, combination trays: packing between trays, tray reactive distillation columns;

Self-similar process: the mass transfer efficiency doesn’t depend on the column diameter and simplification of the transfer of the results of physical modeling for industrial columns;

Flexibility of the liquid flow: we can modify the liquid load by one third... two thirds. The liquid flow resistance of the column does not depend on the liquid load. Full control of the amount of fluid on the tray and its residence time in the column;

Flexibility of the vapor flow: we can modify the vapor load by one third ... half. The upper limit of vapor speed is limited by carryover;

Economic benefits: lowering of investment; reduction of operating costs; improvement in product quality; increase in product yield; reduction in the burden on the environment.