Deep catalytic treatment of waste gas from sulfur dioxide, nitrogen oxides and carbon monoxide at processing products of detoxication of toxic substances

Article abstract of DOI:10.1134/S1070427209090365

The Russian Federation in January 1993 signed the Parisian "Convention about the prohibition of development, production, accumulation and application of chemical weaponry and about its destruction." In 1996 Federal target program "The destruction of the reserves of chemical weaponry in the Russian Federation" that has status of presidential was approuved for purposes of the realization of the Convention. The convention came into force on April 29, 1997.

Full text of DOI:10.1134/S1070427209090365

ISSN 1070-4272, Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 9, pp. 1721−1728.  Pleiades Publishing, Ltd., 2009.
Original Russian Text  F.A. Baibikov, G.A. Vlasov, A.L. Kozen, G.I. Buravtseva, M.E. Balduev, 2009, published in Khimicheskaya Promyshlennost’, 2009,
Vol. 86, No. 4, pp. 189−200.
TECHNOLOGY OF ORGANIC
AND INORGANIC CHEMISTRY
Deep Catalytic Treatment of Waste Gas from Sulfur Dioxide,
Nitrogen Oxides and Carbon Monoxide at Processing Products
of Detoxication of Toxic Substances
F. A. Baibikov, G. A. Vlasov, A. L. Kozen, G. I. Buravtseva, and M. E. Balduev
Russian Scientific Center “Applied Chemistry,” St. Petersburg, Russia
Received April 18, 2009
Abstract—The Russian Federation in January 1993 signed the Parisian “Convention about the prohibition of
development, production, accumulation and application of chemical weaponry and about its destruction.” In
1
996 Federal target program “The destruction of the reserves of chemical weaponry in the Russian Federation”
that has status of presidential was approuved for purposes of the realization of the Convention. The convention
came into force on April 29, 1997.
DOI: 10.1134/S1070427209090365
The Perm branch of Russian Sci. Center “Applied
Chemistry” was practically immediately involved into the
works on chemical disarmament. In particular, a work on
the destruction of the chemical weaponry of 2nd class,
phosgene, was carried out on the mobile plant developed
according to technology that was suggested by Perm
branch, in 20012002. Phosgene was recalibrated from
present as the admixtures. The content of francolite in
the slime reaches 80%. During processing RM-Vx the
slime contains mainly calcium sulfite and calcium sulfate,
calcium nitrate and calcium oxide.
The neutralization of the waste gas is attained firstly
by a wet alkaline cleaning in a nozzle scrubber then by the
final treatment of gases in two bulk filters [2, 3]. The first
filter (on the motion of gas) is equipped with chemisorbent
MDS, and the second filter is filled with activated carbon
of grade SKT-6 impregnated with urea.
3
844 artillery ammunition into the 40-liter balloons and
utilized in the experimental production of the Permian
branch of Russian Sci. Center “Applied Chemistry.”
In the context of State Contract since 2003 in
the Permian branch were carried out studies on the
developmentofthealternativetechnologyoftheprocessing
the products of the detoxication of the organophosphorus
toxic substances (POS]), reaction masses (RM), by a
technique of low-temperature oxidation by calcium
nitrate. The technology that consisted in the oxidation of
RM at 300450°C by calcium nitrate in a reactor with the
aerated bed was suggested [1, 2].
The nozzle scrubber is sprinkled by 6–9% NaOH
solution and intended for the recovery of a basic amount
of SO from the gas.An efficiency of the treatment is 95%.
2
The deep treatment of the gas from SO is conducted with
2
the aid of the bulk filter equipped with the chemisorbent
MDC, and from NOX, with the aid of a filter with the
activated carbon SCT-6.
Drawbacks in this scheme of purification are:
–
the necessity of the presence of a unit for recovery
A solid slime and a waste gas containing SO2,
of the spent scrubber liquid produced in the course of
regeneration of a hard realized dump of calcium sulfite.
NO, NO , CO are the main products of processing
2
RM. The solid slime from the processing RM-sarin or
RM-soman according to the data of X-ray diffraction
analysis is the analog of natural mineral francolite
– the necessity of conducting the operations of the
regeneration of worked out chemisorbents MDS and
coal SKT-6 directly in the filters themselves that requires
additional apparatuses in the plant of the gas purification.
(carbonatehydroxyfluoroapatit]) of the general formula
Са (РО ) СО (ОН)F, fluoride, nitrate and calcium oxide
5
4 3
3
1
721

1722
BAIBIKOV et al.
Furthermore, the regeneration is accompanied by the
periodic formation of drains and additional gas emissions
is a sealed heated Erlenmeyer flask (4) with a dropping
funnel intended for dosing liquid reagents. The generation
of the toxic admixtures indicated is produced due to the
realization in the flask of chemical reactions according
to the procedures described in [4, 5].
(from the stage of drying);
–
the high material, power and operational expenditures
at the stage of gas purification and at the stages of the
regeneration of the worked out chemisorbents;
Gasair mixture (GAM) from flask (4) enters tee
tube (6) where it is divided into two flows: small
–
a removal of carbon monoxide from gases by the
(
35% of total flow) and large fed to column (10)
used chemisorbents is not possible. Therefore a highly
effective technology of the treatment of the waste gas
should be developed from nitrogen oxides, carbon
monoxide and sulfur dioxide. We solved this problem
with the help of catalysts of selective action.
with the external electric radiator filled with the
catalyst (Vnozzles = 525 cm ) being investigated. The
3
adjustment of the small flow is produced with the aid of
the needle-shaped teflon gate (1'). A destination of the
flow is measurement of the initial concentration of the
toxic admixture in GAM with the aid of the universal gas
analyzer “Kaskad”, and also constant gas probing for the
chemical analysis to determine an average concentration
of the admixture in the gas before the column. Necessary
condition is a constant (during the experiment) feed rate
GAM into the Drechsel vessel (7) filled with absorbing
solution. For maintaining room temperature in the
absorbing solution the Drechsel vessel is placed into the
water thermostat (beaker with water). The volume of air
which passed in experiment through Drechsel vessel, is
recorded with gas counter (9).
EXPERIMENTAL
Varioscatalystswereconsideredforthegastreatment.We
selected alumovanadium [AOK] 78-55, cupromangamese
catalyst AOK 63-22, alumocuprochromium IKT 12-8
and carried out studies of the chemical activity of these
catalysts in the course of removal of the toxic admixtures
from air. The scheme of laboratory setup is presented in
the figure.
The compressed air from the main gas pipe is fed
with the given speed through reducer (2) and rotameter
(
3) into the generator of vapors of NO , CO and SO that
The introduction of ammonia and water vapors in
2
2
9
Scheme of the laboratory setup for the study of chemical catalyst activity. Designations: (1, 18, 20, 21, 22, G) shutoff valves (G, 18,


2
0, 21, 22 are teflon stop cocks); (2) air reducer; (3) air rotameter (to 1000 dm h ); (4) generator of vapors NO , CO. SO ; (5) the
x 2
sand bath, the magnetic mixer with the electric heating; (6, s') teflon (quartz) tees; (7) Drechsel’s vessel with the absorbing solution
determination of the initial concentration of the admixture); (8, 13) cooling vessels; (9, 14, 15) gas drum counters; (10) column with
(
the external electric heating filled with the catalyst; (11) thermocouple (control of the temperature in the catalyst bed); (12) the system
of the probing the treated gas for the chemical analysis (determination of residual impurity content); (16) balloon with ammonia; (17)
U-shaped manometer; (19) generator of ammonia and water vapors; (V) the needle-shaped gate; (K) capillary; (GA) universal gas
analyzer “Kaskad.”
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DEEP CATALYTIC TREATMENT OF WASTE GAS
1723
GAM (for the purpose of the determination of their
influence on the efficiency of purification) is performed
150–250°С
2
Ce(NO3)3 ————→ 6NO ↑ + CeО + 1.5О
2 3 2
as follows:
Production of GAM with CО

–
NH flow (mg h ) regulated by gate V is given from
3
balloon (16) through the capillary (K) and maintained
on the adjusted level with the aid of calibrated U-shaped
manometer (17);
In order to get CO vapors 100 ml of concentrated
sulfuric acid (d = 1.84) is added into three neck flask (4).
The flask is connected to a system of air feedoutlet. The
dropping funnel that contains 25–50 ml of 85% formic
acid is hermetically fixed in the upper (vertical) neck.
Then the flask is placed in the sand bath and heated up to
–
a supply of NH and H O in GAM occurs due
3 2
to the tension of aqueous ammonia vapors of known
composition placed into the same flask. Concentration of
NH and H O in GAM is calculated on the losses of the
3
2
100°С. The air movement in the system of the gas treating
weight of the aqueous ammonia in the flask and by data
on the vapor tension of the components of the aqueous
ammonia at the various temperatures;
is then tuned. Then into the vapor generator (4) from the
dropping funnel formic acid is added at a rate of 1 drop
in 35 minutes. The concentration of CO in GAM varies
by the rate of adding formic acid. The formation of CO
can be described by a reaction
–
the supply of the water vapors in GAM is executed
by the evaporation of pure water. The concentration of
the water vapors is determined also by the losses of the
weight of the liquid phase in the flask. Reagents are heated
in flask (19) by electroheating of magnetic stirer (5). The
gas probing after column (10) is produced analogously
with one for determining the initial concentration of
the admixture in the gas. For this GAM after column is
directed to tee (6’) and we get two flows, one of which is
probed for the chemical analysis (12), and another flow
is supplied to the gas analyzer (GA).
НСООН + H SO → СО↑ + H SO · H О
2
4
2
4
2
Production of GAM with SО2
In order to get SO vapors the saturated solution of
2
sodium sulfite (or solid sodium pyrosulfite Na S O ) is
2
2
5
added into three-neck flask (4). The flask is connected
to a system of air feedoutlet. The dropping funnel that
contains 20–30 ml of concentrated sulfuric acid (d =
The universal gas analyzer “Kaskad” which made it
possible to practically instantly measure the concentrations
NO, NO , CO, and SO at the points of the probing was
1
.84) is hermetically fixed in the upper (vertical) neck.
The air movement in the system of the gas treating is
tuned. Then into the flask (4) from the dropping funnel
sulfuric acid is added at a rate of 1 drop in 35 minutes.
2
2
the basic means of the monitoring of the content of the
toxic admixtures in GAM in the course of the studies on
the laboratory setup.
The concentration of SO in GAM varies by the rate
2
of adding sulfuric acid. The formation of SO can be
2
described by a reaction
Production of GAM with NО2
Na SO + H SO → SO ↑ + Na SO + H О
In order to get NO vapors cerium nitrate (trihydrate
2
3
2
4
2
2
4
2
2
or anhydrous) or lead nitrate is added into three neck
flask (4). The flask with nitrate is immersed in the heated
sand bath and connected to a system of air feedoutlet.
The temperature of the sand bath must be in the range of
RESULTS AND DISCUSSIONS
Studies were carried out at different regimes of the gas
treating to determine an influence of the most important
technological parameters on the efficiency of the catalytic
processes: the temperature of catalysis, time of the contact
of the phases gassolid, additives in GAM before the
catalytic treating vapors of ammonia and water, the initial
concentration of the toxic admixture in the gas.
1
50250°C at the use of cerium nitrate, and in the range
of 500550°C in the case of lead nitrate. The required
air flow is maintained with the aid of reducer (2) and
rotameter (3), then 35% gas bleeding into the Drechsel
vessel (7) and a supply of a basic amount of the gas to
the catalytic treatment into column (10) are established.
Concentration NO in GAM varies by the temperature
The results of studies of the chemical activity of the
selective catalysts at the air treatment from nitrogen
oxides, carbon monoxide, and sulfur dioxide on the
2
of sand bath (5). The formation of NO can be described
2
by a reaction
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1724
BAIBIKOV et al.
laboratory setup are presented in the table. The analysis of
experimental data has revealed the features of proceeding
of the catalytic processes at different regimes of the gas
treating which is described below for each catalyst.
250°C the degree of NO and NO removal substantially
2
decreases varying in the ranges of 86.778%, 5737.5%
and 29.13.6% (runs 26–28). It was revealed that with the
3
high concentrations of NO (> 840 mg m ) the catalytic
2
treating of GAM at 250°C occurred not at all or was very
insignificant.
GAM treatment from sulfur dioxide with catalyst
AOK-63-22 demonstrates:

Moistening GAM that contains the relatively
–
For insuring the high efficiency of sulfur dioxide
moderate concentrations of the nitrogen oxides
<840 mg m ) lead to the reduction in the degree of
removal of NO, NO at temperature in the reactor 50°
and 150°C (runs 26, 27, and 29, 30).
removal at elevated temperatures (250°C) a preliminary
treatment of gases consisting in the addition of the
ammonia gas before the reactor in a quantity no less than

3
(
2
3
0
.60.8 g m GAM should be carried out. As the source
of NH vapors it is possible to use ammonia, aqueous
ammonia or crystalline carbonate of ammonium heated
to the temperature of 3040°C.
– For ensuring the high degree of removal of nitrogen
oxides in the range of temperatures of 50°, 150°, 250°C
ammonia gas in the amount >0.175 g m should be
added in GAM before the reactor (runs 21–23). As in
3
3
–
The presence in GAM of water vapors increases
the case of the neutralization of the SO containing gas
the efficiency of catalytic removal of SO from gases,
2
2
ammonia, aqueous ammonia or crystalline ammonium
carbonate of ammonium can be used as the generator of
in the absence of NH vapors the process of purification
3
proceeds unstably, and the degree of SO removal varies
2
NH vapors.
in the range of 0 of 70%.
3
–
Moistening GAM containing ammonia practically
–
A decrease in the temperature of the catalytic
does not lead to reduction in the efficiency in catalytic
removal of nitrogen oxides in the range of temperatures
of 50°, 150°, 250°C (runs 25, 3335).
treatment of gases (1050°C) ensures the high efficiency
of removal GAM of SO without the preliminary
processing the treated gases by vapors of ammonia and
in this case the degree of purification practically does not
depend on the moisture content of the treated gases.
2
– The contact time of the phases gas–solid equal to
1 s ensures deep neutralization of GAM which contains
the nitrogen oxides at the investigated temperature range
in the case of preliminary processing GAM before the
reactor by means of ammonia vapors.
–
It is noted that the high degree of SO removal
2
for the short time after a stop of the ammonium vapor
supply to GAM (run 10). This is probably due to the
accumulation in the catalyst bed of ammonium sulfite
GAM treatment from carbon monoxide with
catalyst IKT-12-8 demonstrates:
forming because of the excessive NH supply to the gas.
3
Obviously at a temperature 250°C ammonium sulfite
–
The temperature in the catalyst bed is the determining
dissociates according to the scheme (NH ) SO →
4
2
3
parameter which ensures the high degree of removal
of carbon monoxide. In the range of 50250°C the
temperature 250°C is optimum at which are reached 99%
degree of gas treating (runs 26–28).
+
NH ↑ + NH HSO creating an alkaline medium of gases
3
4
3
both in the reactor itself, and after it. The isolation of NH3
ceases upon complete transition of sulfite to bisulfite.
The removal of SO drastically deteriorates, and the gas
2
–
Moistening GAM or feeding it with ammonia vapors
medium after the reactor becomes neutral or slightly acid
before the reactor practically does not exert a substantial
influence on the efficiency of the neutralization of the
CO containing gas (runs 38–41). At a temperature in the
reactor 50°C the process of the catalytic treating of wet
GAM from CO obeys the law of chemical kinetics. It
was shown that an increase in the degree of gas cleaning
proceeds with an increase in the initial concentration of
the carbon oxide in GAM from 210 to 1990 mg m at
a temperature 50°C (run 42) from 14 to 28%, and at the
temperature in the catalyst bed 150°C (runs 4244), from
53 to 65%.
(run 11). The contact time of the phases gassolid equal
to 1 s ensures the deep neutralization of SO -containing
2
gas in the case of its preliminary processing by means of
ammonia vapors.
GAM treatment from nitrogen dioxides with
catalyst AOK-78-55 demonstrates:
3

The neutralization of gas occurs insufficiently
effectively without the preliminary processing GAM or
the catalyst by ammonia gas, in this case with an increase
in the temperature in the catalyst bed up to 50°, 150°, and
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 82 No. 9 2009

DEEP CATALYTIC TREATMENT OF WASTE GAS
1725
Results of the investigation of the chemical catalyst activity at treatment of GAM from nitrogen oxides, carbon oxide, and sulfur
dioxide
toxic
admixture
(TA)
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1726
BAIBIKOV et al.
Table (Contd.)
t
toxic
admix-
ture
r
%
(TA)
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 82 No. 9 2009

DEEP CATALYTIC TREATMENT OF WASTE GAS
1727
Table (Contd.)
t
toxic
admix-
ture
r
%
(TA)
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1728
BAIBIKOV et al.
Table (Contd.)
–
The influence of the concentration (i.e. changes in
all toxic gases must be maintained about 250°C, and the
contact time must be not less than 1 s.
the initial concentration of CO in the gas) on the rate of the
CO removal at T = 150°C practically is not manifested.
REGERENCES
–
The contact time of the phases gassolid equal to 1 s
ensures the deep neutralization of the CO containing gas
at a temperature in the catalyst bed 250°C. Preliminary
treating GAM by means of ammonia vapors before the
reactor does not required.
1. RF Patent N2286822, 2006.
2
. Iskhodnye dannye dlya proektirovaniya modul’nogo
proizvodstva po pererabotke RM na osnove FOB
moshchnost’yu, 5 000 tonn v god (Start data for Designing
of Modular Plant on RM Treatment on the Basis of POB
power, 5000 tons per year), Perm, 2006.
CONCLUSIONS
On the basis of the studies taking into account the
nature of the selective catalysts the treatment of the gases
which simultaneously contain the sulfur dioxide, nitrogen
oxides, and carbon monoxide should be performed in
three connected in series filled filters: the first filter is
3
. Vlasov, G.A., Baibikov, F.A., Lekontssva, G.I. et
al., Abstracts of Papers, III nauchno-prakticheskaya
konferentsiya “Nauchno-tekhnicheskie aspekty bezopasnosti
pri unichtozhenii khranenii i transportirovke khimicheskogo
oruzhiya” (3rd Sci. Pract. Conf. on Scientific Technique
Aspects of Safety at Neutralization, Storing, Transportation
of Chemical Weapory), Moscow: Okt., 2006, pp. 15–18.
equipped with the catalyst of SO removal, the second
2
one, with the catalyst of removal of nitrogen oxides, the
third, with the catalyst of CO removal.
4
. Khimicheskie sredstva dlya resheniya ekologicheskikh
problem. Otchet NIR (Chemical Techniques for Solving
Environmental Problems. Reports of Sci. Investigations),
Russ. Sci. Center “Applied Chemistry,” Perm, 1994.
The optimum conditions which ensure the 99100%
degree of removal of the toxic admixtures from GAM
for each catalyst are determined. So removal of SO and
2
NO requires additional processing GAM by means of
ammonia gas. The temperature of catalytic removal of
5. Karyakin, Yu.V. and Angelov, I.I., Chistye khimicheskie
veshchestva (Pure Chemicals), Moscow: Khimiya, 1974.
x
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 82 No. 9 2009