CONCURRENT FLOW REACTORS FOR GAS-LIQUID PROCESSES
Prepared by: Prof. William
Zadorsky, Ukrainian State University of Chemical Engineering, Pridneprovie
Cleaner Production Center
E-mail: ecofond@ecofond.dp.ua
Stanislav Induchny,
Technology Transfer Consultant
E-mail: Induchny@btinternet.com
The new
design of concurrent reactors for gas-liquid processes offers an increased
efficiency and stable operation within a wide range of liquid and gas loadings.
The new
column design incorporates the mass-transfer trays with valve contact devices
that provide the effect of phase inversion. Immediately above the tray, the
gas-liquid layer is comprised of a continuous liquid phase with a dispersed gas
phase. Between the gas-liquid layer and the higher tray, there is a separation
zone, which is comprised of a continuous gas phase with a dispersed liquid
phase. The inversion of phases in every section of the column occurs due to a
specific design of trays.
Furthermore,
the new design of mass-transfer trays provides for the capacity of trays to
self-regulate their flow section depending on the velocity of gas flow. This
new design feature made it possible to eliminate reverse mixing of liquid phase
between lower and higher sections.
Another
advantage of the concurrent flow gas-liquid reactors with multiple inversion of
phases is in a regular redistribution of gas and liquid flows throughout the
reactor height under near ideal mixing conditions, which eliminates temperature
and concentration irregularities in the reaction mass and provides a more
uniform velocity profile for material flows.
Trial parameters of concurrent flow
gas-liquid reactor sectioned with valve-contact trays.
Gas flow velocity, m/s 0.3 - 2.5
Liquid flow
velocity, m/s (0.1-30.0).10-3
Volume
ratio of gas and liquid flows 50-5000
Operating
temperature, oC 20-200
Operating
pressure, MPa 0.1
Reactor
diameter, m 0.1-1.5
Number of
sections 3-5
Number of
trays in each section 3-5
Number of
heat-exchange sections 0-2
Distance
between trays, m 0.15-0.3
The
new design of columns provides an extremely high flexibility of the system on
liquid and gas loadings and can be used as a universal basis for the
development of various specific applications.
Reactors of
this design and their modifications have been used in various chemical
productions: synthesis of dimethylformamide from dimethylamine and formic acid
or methylformate; oxidation of 0-xylol to 0-toluic acid; production of dioxan
through dehydration of diethylene glycol; production of b -alanine and tetrabutoxytitanium and others.
Laboratory
and industrial studies of reactor hydrodynamics, flow structures, mixing
conditions and mass transfer conditions resulted in the development of a
mathematical model of the concurrent flow gas-liquid reactor sectioned with
valve-contact trays.
For further enquiries please contact Mr
Stanislav Induchny by phone + 44 1235 810237 or via e-mail Induchny@btinternet.com