Каталітична переробка хлорорганічних відходів у цінні мономери
The paper is devoted to experimental development of method for 1,1,2-trichlorethane (TCE) dehydrochlorination (DHC). The economic and environmental issues of organic chlorinated compounds processing are described. The basic principle and possible products of TCE processing are presented. The DHC of...
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| Дата: | 2021 |
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V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine
2021
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Catalysis and petrochemistry| _version_ | 1872009044463452160 |
|---|---|
| author | Stepasiuk, B. Haievska, T. Spaska, O. Bilokopytov, Yu. Boichenko, S. Yakovlieva, A. |
| author_facet | Stepasiuk, B. Haievska, T. Spaska, O. Bilokopytov, Yu. Boichenko, S. Yakovlieva, A. |
| author_institution_txt_mv | [
{
"author": "B. Stepasiuk",
"institution": "National Aviation University"
},
{
"author": "T. Haievska",
"institution": "National Aviation University"
},
{
"author": "O. Spaska",
"institution": "National Aviation University"
},
{
"author": "Yu. Bilokopytov",
"institution": "National Aviation University"
},
{
"author": "S. Boichenko",
"institution": "Ukrainian Research & Educational Center of Chemmotology and Certification of Fuels, Lubricants and Technical Liquids, 1 Liubomyra Huzara ave., Kyiv 03058, Ukraine"
},
{
"author": "A. Yakovlieva",
"institution": "National Aviation University"
}
] |
| author_sort | Stepasiuk, B. |
| baseUrl_str | https://kataliz.org.ua/index.php/journal/oai |
| collection | OJS |
| datestamp_date | 2021-12-10T12:35:04Z |
| description | The paper is devoted to experimental development of method for 1,1,2-trichlorethane (TCE) dehydrochlorination (DHC). The economic and environmental issues of organic chlorinated compounds processing are described. The basic principle and possible products of TCE processing are presented. The DHC of TCE, which is one of the chlorinated organic wastes produced in the ethylene dichloride process, to vinylidene chloride (VDC) was carried out over CaO, MgO supported on SiO2 and modified with CsCl catalysts. This process was carried out in a continuous flow fixed-bed reactor. The prepared catalysts were characterized by surface area and base properties before/after reaction. The methodology for determining properties of catalyst is described. Laboratory activity test apparatus was developed, and the schematic diagram is presented in the paper. The method of determination of TCE concentration of was calculated from its partial saturation vapor pressure at a given temperature is presented. Encouraging results were obtained on the catalyst containing 10 % CsCl/CaO·SiO2. The direction of the DHC reaction changed radically under described conditions: VDC was not formed at all and the major products were cis- and trans-1,2-dichloroethene. Interesting results were obtained with the catalytic system comprising 10 % (MgO-CsCl) (1:1) supported on SiO2. DHC of 2 % TCE/Ar at 302 °C proceeds quantitatively over 20 h with selectivity for VDC of more than 80%. These systems are suitable to study the factors providing the binding and removal of HCl from the reaction zone. A possible way to increase the selectivity for VDC is the creation of the conditions favoring the DHC of TCE into VDC by the radical mechanism, which was observed in experiments with 10% CsCl/CaSiO3. The directions for future researches are formulated and described. |
| doi_str_mv | 10.15407/kataliz2021.31.041 |
| first_indexed | 2026-03-12T15:50:15Z |
| format | Article |
| fulltext |
Каталіз та нафтохімія,2021, № 31 41
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
Catalytic processing of organochlorine wastes into valuable monomers
B. Stepasiuk1, T. Haievska1, O. Spaska1, Yu. Bilokopytov1, S. Boichenko2,1, A. Yakovlieva2,1
1National Aviation University, 2Ukrainian Research & Educational Center of Chemmotology and Certification of Fuels,
Lubricants and Technical Liquids,1, Liubomyra Huzara ave., Kyiv 03058, Ukraine1
spaskaolena@ukr.net, bilokoputov@ukr.net, a.v.iakovlieva@ukr.net
The paper is devoted to experimental development of method for 1,1,2-trichlorethane (TCE)
dehydrochlorination (DHC). The economic and environmental issues of organic chlorinated compounds processing
are described. The basic principle and possible products of TCE processing are presented. The DHC of TCE, which is
one of the chlorinated organic wastes produced in the ethylene dichloride process, to vinylidene chloride (VDC) was
carried out over over CaO, MgO supported on SiO2 and modified with CsCl catalysts. This process was carried out in
a continuous flow fixed-bed reactor. The prepared catalysts were characterized by surface area and base properties
before/after reaction. The methodology for determining properties of catalyst is described. Laboratory activity test
apparatus was developed, and the schematic diagram is presented in the paper. The method of determination of TCE
concentration of was calculated from its partial saturation vapor pressure at a given temperature is presented.
Encouraging results were obtained on the catalyst containing 10 % CsCl/CaO·SiO2. The direction of the DHC
reaction changed radically under described conditions: VDC was not formed at all and the major products were cis-
and trans-1,2-dichloroethene. Interesting results were obtained with the catalytic system comprising 10 % (MgO-
CsCl) (1:1) supported on SiO2. DHC of 2 % TCE/Ar at 302 °C proceeds quantitatively over 20 h with selectivity for
VDC of more than 80 %. These systems are suitable to study the factors providing the binding and removal of HCl
from the reaction zone. A possible way to increase the selectivity for VDC is the creation of the conditions favoring the
DHC of TCE into VDC by the radical mechanism, which was observed in experiments with 10 % CsCl/CaSiO3. The
directions for future researches are formulated and described.
Keywords: dehydrochlorination, 1,1,2-trichloroethane, vinylidene chloride, supported catalyst
__________________________________________________________________________________________________
Introduction
Many types of chlorinated organics are important
chemical raw materials. However, due to unreasonable
wastewater discharge, these chlorinated compounds
pose a serious threat to safety of the ecosystem and
groundwater [1]. Therefore, how to use chlorinated
hydrocarbons is an important topic. Gas-phase catalytic
conversion of chlorinated organic wastes into useful
hydrocarbons via dehydrochlorination is known as one
of more promising methods. It has the advantages of
economic efficiency and low environmental pollution
and has attracted more attention from the academic and
industrial circles. In addition to environmental
advantages, this process has obvious economic merits
because the resulting hydrocarbons can be recycled [2].
1,1,2-trichloroethane (TCE) is a typical
chlorinated hydrocarbon that formed as a by-product in
the production of 1,2-dichloroethane, which is the main
intermediate in the synthesis of vinyl chloride (VC). It is
contained in sufficient quantity in the distillation residues
of the rectification of 1,2-dichloroethane. As a result of
the distillation process of so-called "heavy fraction", it is
possible to obtain about 10 kg of industrial grade 1,1,2-
TCE / t VC [3]. In currently working factories of VC, it is
utilized as a raw material in the chlorinolysis process or
for combustion.
Therefore, it has been a long-term goal to develop
the gas phase synthesis of 1,1-dichloroethene (1,1-DCE)
from TCE in the presence of supported catalysts. Only
catalytic processes for DHC of TCE can comply with the
ecological requirements and provide the utilization of the
major by-product - hydrogen chloride [2].
Dehydrochlorination of TCE results in four
products (as shown in Fig. 1). Сhlorineatoms within the
molecules are shown with green color; carbon atoms –
with dark grey and hydrogen atoms – with light grey:
Fig. 1. Various products for dehydrochlorination of 1,1,2- trichloroethane.
UDС 66.092.097:66.097.3:66.094.48
https://doi.org/10.15407/kataliz2021.31.041
mailto:spaskaolena@ukr.net
mailto:yurii.bilokopytov@npp.nau.edu.ua
mailto:chemmotology@ukr.net
mailto:a.v.iakovlieva@ukr.net
42 Каталіз та нафтохімія, 2021, № 31
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
Cis-DCE has been widely used as solvents for
paint, resin, wax, rubber and acetate fibers. Vinylidene
chloride (VDC) is the monomer of
polyvinylidenechloride, that has been widely applied in
food package due to its good performance in retarding
food spoilage [3]. And VC is the monomer of
polyvinylchloride that is one of the most widely used
polymers.
In this study, the catalytic dehydrochlorination of
1,1,2-trichloroethane was carried out in a continuous
flow fixed-bed reactor. The prepared catalyst was
characterized by surface area and base properties
before/after reaction.
Experimental part
Catalyst preparation
Calcium oxide was obtained by precipitation from a
solution of CaCl2 with KOH followed by washing out Cl-
ions and calcination at 650 C for 2 h.
MgO/SiO2 (20 wt.% MgO) was prepared by
impregnation of SiO2 with a solution of Mg(OH)2 and
calcination at 400 C for 2 h to decompose Mg(OH)2 to
MgO.
CaO/SiO2 was prepared by impregnation of SiO2
with suitable amount of CaCl2, treatment with aqueous
KOH, washing, drying and calcination at 650C for 2 h
to decompose Ca(OH)2 to CaO.
Calcium silicate, CaSiO3 was prepared by heating
SiO2 of Grade KSS (SBET= 520 m2/g, pore diameter 70.8
Å) with 1 M solution of calcium chloride in ammonia
buffer at 100 °C for 24 h. The product was dried at 120
°C for 3 h and calcined at 500 °C for 3 h. The sample
obtained was analyzed to determine the content of
calcium and silicon. Calcium was leached out with acid
and determined by complexometric titration. Silicon was
determined by the gravimetric method. Chemical
composition is 1.08SiO2
.0.48CaO.0.47H2O.
MgO·CaO·CsCl. The 1:1 mixture of saturated
solutions of MgCl2 and CaCl2 was treated with an
aqueous solution of cesium oxide preliminarily prepared
by calcination of Cs2CO3 at 650 C. The suspension was
evaporated and calcined at 600 C for 3 h. This
temperature is enough for magnesium and calcium
hydroxides to be converted into the oxides [4].
Determination of catalystsurface area.
The sample is placed in the adsorber and flushed
with the gas mixture for 0.5 h at 250 °C to remove
moisture. The adsorber is heated with the electric
furnace. After cooling the sample to room temperature
under a flow of gas mixture(Ar-He),the katharometer
current (100 mA) is conveyed. Once the baseline of the
has been stabilized, the adsorber is immersed in liquid
nitrogen.
During the adsorption of argon on a sample, we
have a “reversed” peak. After a while the ADC fixes the
normalization of the baseline which indicates that the
adsorption is complete. The adsorptionduration depends
on the surface area of a sample. After completion of the
process, the adsorber is taken out of the Dewar vessel
and defrosted. As aadsorber is warmed up to room
temperature, argon is desorbed from the surface of the
sample. It arrives, through the four-way cock, at the
katharometer and the corresponding signal is recorded by
ADC.
The surface area of the catalysts (S, m2) was
calculated from the volume of desorbed argon [5]:
4.73Ar ArS F V V= = ,
whereVAr is the volume of desorbed argon (ml) and
F=4.73 m2/ml is the surface covered under normal
conditions with 1 ml of argon adsorbed in a monolayer
fashion. The area occupied by an argon atom on the
surface was taken to be 17.6 A2.
The VArwas determined by comparing peak areas
of the desorbed argon (Q) and the sample of the gas with
known volume Vst (Qst) introduced through the dosing
cock:
( ) /Ar St St StV Q V Q= ,
Specific surface area (Ssp, m2/g) was estimated as the
ratio of the total surface area (S, m2) to the weight (m,g)
of the solid sample, i.e.[6],
/spS S m= ,
Estimation of catalyst base properties
The base properties are quantified after the
measurement of specific surface area of sample. The
surface basicity is determined from the data on
adsorption of carbon dioxide.
The volume of adsorbed carbon dioxide (Vads) is
calculated as difference in volumes of the fed (Vst) and
coming-out (V) gas.
Total number of B sites can be estimated as
23 19 2
2( 6.023 10 ) / ( 22400) 2.7 10 / ( / )ads adsB V S V S CO molecules m= = ,
` where S is the total surface sample area.
Каталіз та нафтохімія, 2021, № 31 43
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
Catalytic test
The catalytic cracking of TCE was carried out in
the flow-type apparatus (Fig.2).
Fig. 2. Schematic diagram of laboratory activity test
apparatus.
The reaction mixture was prepared by saturation
of nitrogen (1) flow with TCE vapor in the saturator (2,3)
at a given temperatureand fed, through the four-way cock
(5), to the reactor (6) filled with a catalyst. The
concentration of TCE in the feed gas can be controlled
by changing temperature of the saturator (4). The
reaction products were admitted to the six-way sampling
cock (5). The outlets of the cock (9) are connected with
the metal tube (10), the capacity of which determines the
size of the sample.
With the cock (9) in the position indicated by solid
lines, the products, having passed the way, fill the tube
(10) and enter, through the cock (5), the receiver (7). At
the same time, the carrier gas, helium, via the six-way
cock (9) is admitted to the chromatographic column (11)
and then it passes to the katharometer (12) and modified
flame ionization detector (FID) (14) built in the
chromatograph LKhW-72.
The capacity of the tube and its connectors is
0.906 ml at 150 °C. All the cocks and fittings are
maintained at the indicated temperature to avoid
condensation of the products.
Thus, with the cock (5) in the position indicated by
solid lines, the effluents from the reactor are conducted
to the analysis. In the alternative position (broken lines),
the starting reaction mixture is analyzed. It is evident that
the samples of the starting mixture and the reaction
products to be analyzed are of the identical size and the
relative error of the measurements is the same in all
experiments.
The gas phase dehydrochlorination process of
TCE was performed in a tubular fixed-bed stainless steel
reactor (20 cm long and 4 mmi.d) at atmospheric
pressure mounted in the thermostat. The temperature of
the heated units was controlled accurate to within ± 0.3
°C.
In a typical procedure, the catalyst bed was
charged with 0.5 g of catalyst, and then pretreated with
Ar atmosphere at a flow rate of 30 cm3/min at 200°C.The
reactant flow (30 cm3/min) was generated by flowing N2
through a bubbler containing the liquid TCE. Once
stabilized, the reactant flow was introduced to the
catalyst bed consisting of catalysts. The compositions of
the reaction effluent were analyzed by gas
chromatograph with an FID detector and 3 m long, 3 mm
diameter column filled with 3% OV-225 on Inerton-
Super.
The 1,1,2-trichloroethane (Acros Organics) was of
99.9% purity. The identification of the reaction products
and the calibration of the FID were performed with
model mixtures of pure compounds (VC, VDC, trans-
and cis-l,2-DCE).
The concentration of TCE was calculated from its
partial saturation vapor pressure (Pi) at a given
temperature (t) of saturator and pressure (P) in the
condenser, i.e.,
100 / ( .%) 2240 ( / )v i vC P P vol or C C mol l= = =
whereCv and C is TCE concentration in terms of
vol.% and mol/l, respectively [6],
lg 6.84164 1262.6 / ( 205)iP t= − +
The conversion of TCE, X (%), was estimated by
the formula:
0 0100 ( ) /TCE TCE TCEX C C C= − ,
where C°TCE and CTCE are the concentrations of
TCE before and after the reaction.
The selectivity for a particular product Si (%) was
calculated as
0100 / ( )i i TCE TCES C C C= − ,
where Ci is product concentration (mol/l).
In the cases where the material balance on carbon
was obeyed accurate to within 20%, the selectivity for
products was determined by the formula
100 /i i prodS C C= ,
where ∑Cprod is sum of product concentrations.
The balance on carbon δ (%) in TCE and the
products was calculated by the formula
0 0100 ( ) 100 /TCE TCE prod TCEС C C C = − − −
Result and discussion
In our previous study [7] we investigated catalytic
activity of II A group metal oxides (MgO, CaO, BaO
etc.). In this work we investigated the activity of mixed
oxides composed of SiO2 and Group IIA metal oxides,
i.e. MgO·SiO2 and CaO·SiO2 modified by CsCl.
The DHC of TCE over mixed oxide CaO.SiO2
modified with CsCl is characterized in Table 1.
44 Каталіз та нафтохімія, 2021, № 31
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
Table 1. Dehydrochlorination of TCE over catalysts CsCl/CaO·SiO2 (Space velocity = 144h-1)
Catalyst , h T°,C
TCE,
vol.%
Conversion,
%
Selectivity,% ,%
VC VDC
trans-
DCE
cis-
DCE
1%CsCl/CaO·SiO2
1 250 1.8 73.5 1.7 98.3 0.0 0.0 71.4
2 250 1.8 41.0 8.6 85.2 6.1 0.0 75.9
5.5 300 1.8 62.6 33.2 61.0 5.7 0.0 78.6
6.5 300 1.8 62.4 11.3 60.2 5.0 23.5 69.9
8.5 300 1.8 59.4 17.0 58.6 4.7 19.7 75.0
10%CsCl/ CaO·SiO2
1 250 1.8 99.9 0.8 94.2 3.2 1.8 79.8
2 250 1.8 99.9 0.9 92.0 5.0 2.1 95.5
3 250 1.8 99.8 0.6 93.3 3.5 2.6 90.7
5 365 1.8 99.9 13.9 67.3 9.9 8.9 75.8
6 365 1.8 99.5 13.7 61.7 9.9 14.7 92.8
20%CsCl/CaO·SiO2
1 320 14.8 99.8 0.3 70.0 7.8 8.4 90.0
1.5 320 14.8 59.7 1.2 62.9 12.3 23.6 88.6
2 320 14.8 60.1 1.7 59.8 13.0 25.5 87.6
6 320 14.8 62.5 3.5 51.2 12.4 32.9 86.8
20%CsCl/CaSiO3
1 330 9.5 59.5 17.4 32.6 10.0 40.1 84.2
2 330 9.5 42.9 17.7 13.5 10.8 58.0 94.8
2.5 330 9.5 38.0 17.1 10.2 10.6 62.0 100.0
3 330 9.5 41.5 16.6 8.0 10.4 65.1 95.7
3.5 372 9.5 95.0 18.9 6.2 14.2 58.9 79.1
10%CsCl/CaSiO3
in the air
0.5 346 14.8 72.1 7.4 0 29.6 62.8 66.0
1.5 346 14.8 89.3 0 0 30.5 69.4 70.0
2.0 318 14.8 57.0 0 0 27.7 72.2 57.6
2.5 318 14.8 77.5 0 0 27.3 72.6 68.5
δ (%) -balance on carbon, VC – vinyl chloride;
- duration of the test, hour VDC – vinylidenechloride
TCE – trichloroethene DCE – dichloroethene
When 2 % TCE/N2 was passed through 1%
CsCl/CaO·SiO2 at 300-350 C, the catalyst provided 95-
99% conversion and higher than 60% selectivity for
VDC over 10 h. Only with fivefold increase in
concentration of TCE in the feed gas the selectivity
began to decrease. With 10 % TCE/N2, the quantitative
conversion of TCE over 10 % CsCl/CaO·SiO2 was
achieved at 365 C, but VDC selectivity under these
conditions decreased to 60%. The low decrease in the
selectivity of the process conducted at higher
temperature (365 C) for 6 h should be considered as a
positive result.
At 14.8 % concentration of TCE in N2 the
conversion was ~ 80 % at 346 C and VDC selectivity
was 48%.
Thedehydrochlorination over 10 %
CsCl/CaO·SiO2 conducted in the presence of air gave the
unexpected result. The reaction direction waschanged
radically under these conditions: VDC was not formed at
all and the major products were cis- and trans-1,2-DCE.
As oxygen is known to inhibit many homolytic reactions,
we can suggest that VDC is formed over this catalyst by
the radical mechanism [5]. Therefore, the use of radical
initiators may increase the selectivity of this catalyst for
VDC.
Interesting results were obtained with the catalytic
system comprising 10 % (MgO-CsCl in a mass ratio of
1: 1) supported on SiO2 (Table 2).
DHC of 2 % TCE/N2 at 302 C
proceedsquantitatively over 20 h with selectivity for
VDC of more than 80%. As TCE concentration is raised
to 8.5%, the conversion and VDC selectivity gradually
decrease and over first 5-10 h they remain almost
constant, that is, ~ 30% and 57-60%, respectively.
Каталіз та нафтохімія, 2021, № 31 45
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
Table 2. Cracking of TCE over catalytic system 10%(MgO-CsCl)/SiO2
, h T, °C
Space velocity,
h-1
TCE,
vol.%
Conversion, %
Selectivity,% , %
VC VDC trans-DCE cis-DCE
1 200 120 2 30.2 0.0 96.3 0.9 2.8 96
5 200 120 2 13.6 3.2 86.5 5.1 5.1 94
7 254 120 2 63.1 1.2 89.5 3.9 5.4 86
8 302 120 2 100.0 3.4 84.9 5.5 6.3 100
1.6 200 133 3.4 16.7 0.1 87.2 6.6 6.2 92
2.2 246 133 3.5 57.0 0.0 95.2 2.4 2.4 64
3.4 246 133 3.5 38.1 1.4 81.8 8.4 8.4 80
4.0 300 133 3.5 97.6 3.5 75.0 9.3 12.2 47
5.5 300 114 3.3 97.4 0.0 75.1 10.6 14.3 48
6.2 300 114 3.2 90.7 0.0 74.3 10.7 14.9 52
8.3 300 114 3.3 80.3 0.0 73.1 11.5 15.5 58
0.4 300 121 7.9 99.8 0.3 74.5 10.4 14.9 52
1.5 300 121 7.5 86.8 2.2 71.2 10.9 15.7 62
2.4 300 121 7.6 79.6 3.2 69.1 11.0 16.7 60
3.0 300 121 7.7 71.8 3.3 65.9 12.0 18.8 64
4.1 300 121 7.5 56.4 4.1 64.7 11.6 19.6 71
7.8 300 132 8.0 30.6 3.4 57.5 14.5 24.6 85
8.5 300 132 7.8 29.7 3.4 56.8 14.3 25.6 87
10.0 300 132 7.9 31.8 1.8 56.5 13.2 28.5 83
δ (%) -balance on carbon,
- duration of the test, hour
TCE – trichloroethene
VC – vinyl chloride;
VDC – vinylidenechloride
DCE – dichloroethene
Table 3. Determination of specific surface area and relative basicity of some metal oxides before and after
dehydrochlorination (Stot, - total surface,m2;Ssp- specific surface area, m2/g)
Sample Before/afterwork
Weight,
g
VAr,
adsorbed,
ml
Stot, m
2
Ssp,
m2/g
VCO2,
ml
BCO2,
mol/m2.1019
20%CsCl/CaO·SiO2
before 2.0084 1.40 6.6 3.3 0.58 0.24
after 1.003 1.82 8.6 8.6 0.48 0.20
1%CsCl/CaO·SiO2
before 0.7798 0.66 3.1 4.0 0.66 0.57
after 0.9980 0.91 4.3 4.3 0.07 0.04
10%CsCl/MgO·SiO2
before 0.9994 9.7 45.9 46.0 0.76 0.04
after 1.0024 5.13 24.28 24.22 0.35 0.04
10%CsCl/CaO·SiO2
before 0.5140 0.31 1.47 2.8 0.52 0.97
after 0.5100 0.54 2.55 5.1 0.07 0.08
10%CsCl/CaSiO3
before 0.4020 4.28 20.23 50.33 0.12 0.02
after 0.4070 3.49 16.51 40.55 0.12 0.02
46 Каталіз та нафтохімія, 2021, № 31
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
As it follows from table 3, the Ssp values for metal
oxides loaded with 10% CsCl increases after the
dehydrochlorination. It can be conjectured that the
increase in Ssp of the strongly basic metal oxide after
dehydrochlorinationis associated with phase
transformations in the bulk of catalysts induced by
chlorination reactions [8]. On the other hand, the low-
basicity oxides are passivated evidently through
chlorination of the extended surface area of MgO, neat or
in systems with other oxides.
A great body of patent data on the use of Group IA
metal chloride and, in particular, CsCl as the catalysts of
dehydrochlorination displayed the problem of the effect
the chlorides make on basicity of the catalytic systems
composed of the metal chlorides and oxides.It can be
supposed that Cl- ions in CsCl/MgO act as additional
proton-acceptor centers while cations Cs+ play the role of
L-acid sites on which the abstraction of Cl- from TCE
occurs [8, 9].
The current results clearly show the very different
behaviors of the catalysts, which implies various reaction
pathways on these catalysts, based on the analysis of
literature data can be assumed thatdehydrochlorinationof
CHCl2()−CH2Cl() the VDC is formed owing to
abstraction of the more reactive -proton for which
purpose even weakly basic sites of surface. It can be
assumed that strongly basic sites react with the less acidic
-protons as well and this may deteriorate a selectivity of
thedehydrochlorination reaction. For this reason, it is
difficult to predict the dependence of selectivity of the
metal oxide catalysts for VDC on their basicity. Moreover,
the basicity of oxides can influence their chemical
interaction with hydrogen chloride evolving on
dehydrochlorinationand, therefore, the contribution of the
catalytic dehydrochlorinationto the overall process [10].
Conclusions
The exploration of the systems based on simple
and double magnesium, calcium and silicon oxides is a
prospective direction in the development of the selective
catalyst for TCE dehydrochlorination. Two promising
catalysts of this type have already been found, namely,
10% (MgO·CsCl)/SiO2 and 10% CsCl/CaO·SiO2.
As in both cases TCE conversion and VDC
selectivity slowly decrease in time, it is necessary to find
the means to stabilize these parameters. These systems
are suitable to study the factors providing the binding
and removal of HCl from the reaction zone. A possible
way to increase the selectivity for VDC is the creation of
the conditions favoring TCEdehydrochlorinationinto
VDC by the radical mechanism, which was observed in
experiments with 10% CsCl/CaSiO3.
References
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Надійшла до редакції 03.06.21 р.
https://www.ipcc.ch/working-group/wg1/
Каталіз та нафтохімія, 2021, № 31 47
ISSN 2707-5796. Kataliztanaftohimia. 2021, 31
Каталітична переробка хлорорганічних відходів у цінні мономери
Б. Степасюк1, T. Гаєвська1, O. Спаська1, Ю. Білокопитов1, С. Бойченко2,1, А. Яковлева,1
1 Національний авіаційний університет, 2Український НДНЦ хімматології і сертифікації ПММ і ТР,
Любомира Гузара 1, Київ 03058, Україна
Дегідрохлорування 1,1,2-трихлоретану, який є одним із хлорвмісних органічних відходів, що
утворюються в процесі перероблення дихлориду етилену, до хлориду вінілідену здійснювали за допомогою
каталізаторів MgO·SiO2 та CaO·SiO2, модифікованих CsCl. Цей процесс проводили в проточному реакторі з
нерухомим шаром каталізатора. Синтезовані каталізатори було охарактеризовано за площею поверхні та
основними властивостями до/після реакції. Перспективні результати були одержані на каталізаторі 10 % MgO-
CsCl, нанесеному на SiO2. Дегідрохлорування 2 % 1,1,2-трихлоретану/N2 при 302 C відбувається кількісно
протягом 20 год із селективністю щодо хлориду вінілідену понад 80 %. Ці системи придатні для вивчення
факторів, що забезпечують зв'язування та виведення HCl із зони реакції.
Ключові слова: дегідрохлорування, 1,1,2-трихлоретан, вініліденхлорид, каталізатор
|
| id | oai:katalizorgua:article-7 |
| institution | Catalysis and petrochemistry |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2026-03-12T15:50:15Z |
| publishDate | 2021 |
| publisher | V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine |
| record_format | ojs |
| resource_txt_mv | katalizorgua/b6/67e1832c6cfe25b8881d162afd73f1b6.pdf |
| spelling | oai:katalizorgua:article-72021-12-10T12:35:04Z Catalytic processing of organochlorine wastes into valuable monomers Каталітична переробка хлорорганічних відходів у цінні мономери Stepasiuk, B. Haievska, T. Spaska, O. Bilokopytov, Yu. Boichenko, S. Yakovlieva, A. dehydrochlorination, 1,1,2-trichloroethane, vinylidene chloride, supported catalyst дегідрохлорування, 1,1,2-трихлоретан, вініліденхлорид, каталізатор The paper is devoted to experimental development of method for 1,1,2-trichlorethane (TCE) dehydrochlorination (DHC). The economic and environmental issues of organic chlorinated compounds processing are described. The basic principle and possible products of TCE processing are presented. The DHC of TCE, which is one of the chlorinated organic wastes produced in the ethylene dichloride process, to vinylidene chloride (VDC) was carried out over CaO, MgO supported on SiO2 and modified with CsCl catalysts. This process was carried out in a continuous flow fixed-bed reactor. The prepared catalysts were characterized by surface area and base properties before/after reaction. The methodology for determining properties of catalyst is described. Laboratory activity test apparatus was developed, and the schematic diagram is presented in the paper. The method of determination of TCE concentration of was calculated from its partial saturation vapor pressure at a given temperature is presented. Encouraging results were obtained on the catalyst containing 10 % CsCl/CaO·SiO2. The direction of the DHC reaction changed radically under described conditions: VDC was not formed at all and the major products were cis- and trans-1,2-dichloroethene. Interesting results were obtained with the catalytic system comprising 10 % (MgO-CsCl) (1:1) supported on SiO2. DHC of 2 % TCE/Ar at 302 °C proceeds quantitatively over 20 h with selectivity for VDC of more than 80%. These systems are suitable to study the factors providing the binding and removal of HCl from the reaction zone. A possible way to increase the selectivity for VDC is the creation of the conditions favoring the DHC of TCE into VDC by the radical mechanism, which was observed in experiments with 10% CsCl/CaSiO3. The directions for future researches are formulated and described. Дегідрохлорування 1,1,2-трихлоретану, який є одним із хлорвмісних органічних відходів, що утворюються в процесі перероблення дихлориду етилену, до хлориду вінілідену здійснювали за допомогою каталізаторів MgO·SiO2 та CaO·SiO2, модифікованих CsCl. Цей процесс проводили в проточному реакторі з нерухомим шаром каталізатора. Синтезовані каталізатори було охарактеризовано за площею поверхні та основними властивостями до/після реакції. Перспективні результати були одержані на каталізаторі 10 % MgO-CsCl, нанесеному на SiO2. Дегідрохлорування 2 % 1,1,2-трихлоретану/N2 при 302 C відбувається кількісно протягом 20 год із селективністю щодо хлориду вінілідену понад 80 %. Ці системи придатні для вивчення факторів, що забезпечують зв'язування та виведення HCl із зони реакції. V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine 2021-11-10 Article Article application/pdf https://kataliz.org.ua/index.php/journal/article/view/7 10.15407/kataliz2021.31.041 Catalysis and petrochemistry; No. 31 (2021): Catalysis and petrochemistry; 41-47 Каталіз та нафтохімія; № 31 (2021): Каталіз та нафтохімія; 41-47 2707-5796 2412-4176 10.15407/kataliz2021.31 en https://kataliz.org.ua/index.php/journal/article/view/7/3 |
| spellingShingle | дегідрохлорування 1,1,2-трихлоретан вініліденхлорид каталізатор Stepasiuk, B. Haievska, T. Spaska, O. Bilokopytov, Yu. Boichenko, S. Yakovlieva, A. Каталітична переробка хлорорганічних відходів у цінні мономери |
| title | Каталітична переробка хлорорганічних відходів у цінні мономери |
| title_alt | Catalytic processing of organochlorine wastes into valuable monomers |
| title_full | Каталітична переробка хлорорганічних відходів у цінні мономери |
| title_fullStr | Каталітична переробка хлорорганічних відходів у цінні мономери |
| title_full_unstemmed | Каталітична переробка хлорорганічних відходів у цінні мономери |
| title_short | Каталітична переробка хлорорганічних відходів у цінні мономери |
| title_sort | каталітична переробка хлорорганічних відходів у цінні мономери |
| topic | дегідрохлорування 1,1,2-трихлоретан вініліденхлорид каталізатор |
| topic_facet | dehydrochlorination 1,1,2-trichloroethane vinylidene chloride supported catalyst дегідрохлорування 1,1,2-трихлоретан вініліденхлорид каталізатор |
| url | https://kataliz.org.ua/index.php/journal/article/view/7 |
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