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.
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.
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.
