1070-4272/02/7502-0241 $27.00 C 2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 2, 2002, pp. 241!244. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 2, 2002,
Original Russian Text Copyright + 2002 by Vorotyntsev, Drozdov, Kirillov.
PROCESSES AND EQUIPMENT
OF CHEMICAL INDUSTRY
Thorough Cleaning of Argon and Germanium Tetrahydride
To Remove Admixture of Water by Membrane Gas Separation
V. M. Vorotyntsev, P. N. Drozdov, and Yu. P. Kirillov
Nizhni Novgorod State Technical University, Nizhni Novgorod, Russia
OOO Firma Horst, Moscow, Russia
Received March 19, 2001
Abstract-Thorough cleaning of argon and germanium tetrahydride to remove admixture of water with gas-
separating membranes of the Lestosil type was studied. Schemes of the installation and the membrane unit
necessary for performing thorough cleaning are presented. The selectivity of radial counterflow membrane
units was studied and a mathematical model is presented making it possible to calculate their separating power
and evaluate the effect of longitudinal agitation on the cleaning process.
The method of membrane gas separation is beginn-
ing to be used for gas cleaning to remove admixture
of water. For example, raw natural gas can be cleaned
to remove water to a level of (1.431.5) 0 10
using cellulose acetate membranes . Cleaning of
nitrogen to remove water was studied in , and that
of argon and helium, in [3, 4]. Of interest is to study
the process of thorough cleaning of gases to remove
admixture of water with highly permeable commercial
membranes based on polydimethylsiloxane (of the
The aim of this work was to study theoretically and
experimentally the process of thorough cleaning of
gases to remove admixture of water with a membrane
of the Lestosil type for the example of germanium
tetrahydride and argon.
The cleaning installation is shown schematically in
Fig. 1. It comprises a unit for preparing a model mix-
ture and sections for cleaning and analysis. The model
mixture is prepared by bubbling a gas under study,
contained in cylinder 1, through water in vessel 2.
The gas pressure in vessel 2, determining the concen-
tration of water impurity at the temperature of ex-
periment (293 K) is set with reducer 3 and monitored
with pressure gage 4. Reducer 5 is used to set the gas
pressure in the high-pressure zone of the membrane
unit 6, monitored with pressure gage 7. A membrane
having higher permeability to water, than to gas being
cleaned is employed. In the unit, part of a gas mix-
ture with increased content of water impurity passes
through the membrane into the low-pressure zone and
may condense in cylinder 8 or be evacuated through
cock 9. Vacuum gages 10 and 11 serve for determin-
ing the pressure in the low-pressure zone. The flow
rate of a cleaned gas mixture at the exit from the high-
pressure zone is monitored with rotameter 12 and con-
trolled with fine adjustment valve 13. The rotam-
eter 12 shows the total flow rate of the gas mixture
at the unit inlet. At closed valve 13, it shows the rate
of the gas flow through the membrane into the low-
pressure zone of unit 6.
As membrane unit was used a counterflow radial
element in which the gas mixture moves radially,
from periphery to center, in the high-pressure zone
and from center to periphery in the low-pressure zone.
A schematic of the membrane unit is given in Fig. 2.
Fig. 1. Membrane installation: (1, 8, 17) cylinders, (2) bub-
bler, (3, 5) reducers, (4, 7, 18) pressure gages, (6) mem-
brane unit, (9, 13!15, 19) valves, (10, 11) vacuum gages,
(12) rotameter, and (16) dew point sensor.