Kinetics of pyrolysis of ethanol-air mixture
The article presents the results of studying the high-temperature zone (about 1100 K) of ethanol pyrolysis at atmospheric pressure. Physical model is proposed for this zone and its validation is done. ZDPlaskin software package was used for numerical modeling of chemical reactions in this zone. It...
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| Zitieren: | Kinetics of pyrolysis of ethanol-air mixture / O.M. Tsymbaliuk, V.Ya. Chernyak, E.V. Martysh, T.S. Donchenko, A.O. Fayzulin // Вопросы атомной науки и техники. — 2016. — № 6. — С. 283-285. — Бібліогр.: 8 назв. — англ. |
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irk-123456789-1154642017-04-06T03:02:34Z Kinetics of pyrolysis of ethanol-air mixture Tsymbaliuk, O.M. Chernyak, V.Ya. Martysh, E.V. Donchenko, T.S. Fayzulin, A.O. Low temperature plasma and plasma technologies The article presents the results of studying the high-temperature zone (about 1100 K) of ethanol pyrolysis at atmospheric pressure. Physical model is proposed for this zone and its validation is done. ZDPlaskin software package was used for numerical modeling of chemical reactions in this zone. It was shown with obtained results that pyrolysis has several stages and molecular oxygen has strong influence on the process staging. Oxygen influence on the chemical reactions during reforming was studied. The main channels of generating of ethanol reforming aimed components such as H2 and CO, were examined. The most important reforming reactions are determined. Приведены результаты исследования зоны высокотемпературного (около 1100 К) пиролиза этанола при атмосферном давлении. Для этой зоны предложена физическая модель, и дано её обоснование. Проведено численное моделирование течения химических реакций с помощью программного пакета ZDPlaskin. Используя полученные результаты, показано, что пиролиз протекает в несколько стадий. Показано значительное влияние молекулярного кислорода на стадийность процесса. Исследовано его влияние на ход химических реакций в процессе реформирования. Рассмотрены основные каналы генерации целевых компонентов реформирования этанола, а именно H2 и CO. Определены наиболее важные реакции реформирования. Наведено результати дослідження зони високотемпературного (приблизно 1100 К) піролізу етанолу при атмосферному тиску. Для цієї зони запропонована фізична модель та дано її обґрунтування. Проведено числове моделювання перебігу хімічних реакцій за допомогою програмного пакету ZDPlaskin. Використовуючи результати, які отримані, показано, що піроліз протікає в декілька стадій. Показано значний вплив молекулярного кисню на стадійність процесу. Досліджено його вплив на перебіг хімічних реакцій в процесі реформування. Розглянуто основні канали генерації цільових компонентів реформування етанолу, а саме H2 та CO. Визначено найбільш важливі реакції реформування. 2016 Article Kinetics of pyrolysis of ethanol-air mixture / O.M. Tsymbaliuk, V.Ya. Chernyak, E.V. Martysh, T.S. Donchenko, A.O. Fayzulin // Вопросы атомной науки и техники. — 2016. — № 6. — С. 283-285. — Бібліогр.: 8 назв. — англ. 1562-6016 PACS: 80., 82., 82.20.Wt http://dspace.nbuv.gov.ua/handle/123456789/115464 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Low temperature plasma and plasma technologies Low temperature plasma and plasma technologies |
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Low temperature plasma and plasma technologies Low temperature plasma and plasma technologies Tsymbaliuk, O.M. Chernyak, V.Ya. Martysh, E.V. Donchenko, T.S. Fayzulin, A.O. Kinetics of pyrolysis of ethanol-air mixture Вопросы атомной науки и техники |
| description |
The article presents the results of studying the high-temperature zone (about 1100 K) of ethanol pyrolysis at
atmospheric pressure. Physical model is proposed for this zone and its validation is done. ZDPlaskin software
package was used for numerical modeling of chemical reactions in this zone. It was shown with obtained results
that pyrolysis has several stages and molecular oxygen has strong influence on the process staging. Oxygen
influence on the chemical reactions during reforming was studied. The main channels of generating of ethanol
reforming aimed components such as H2 and CO, were examined. The most important reforming reactions are
determined. |
| format |
Article |
| author |
Tsymbaliuk, O.M. Chernyak, V.Ya. Martysh, E.V. Donchenko, T.S. Fayzulin, A.O. |
| author_facet |
Tsymbaliuk, O.M. Chernyak, V.Ya. Martysh, E.V. Donchenko, T.S. Fayzulin, A.O. |
| author_sort |
Tsymbaliuk, O.M. |
| title |
Kinetics of pyrolysis of ethanol-air mixture |
| title_short |
Kinetics of pyrolysis of ethanol-air mixture |
| title_full |
Kinetics of pyrolysis of ethanol-air mixture |
| title_fullStr |
Kinetics of pyrolysis of ethanol-air mixture |
| title_full_unstemmed |
Kinetics of pyrolysis of ethanol-air mixture |
| title_sort |
kinetics of pyrolysis of ethanol-air mixture |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2016 |
| topic_facet |
Low temperature plasma and plasma technologies |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/115464 |
| citation_txt |
Kinetics of pyrolysis of ethanol-air mixture / O.M. Tsymbaliuk, V.Ya. Chernyak, E.V. Martysh, T.S. Donchenko, A.O. Fayzulin // Вопросы атомной науки и техники. — 2016. — № 6. — С. 283-285. — Бібліогр.: 8 назв. — англ. |
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Вопросы атомной науки и техники |
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AT tsymbaliukom kineticsofpyrolysisofethanolairmixture AT chernyakvya kineticsofpyrolysisofethanolairmixture AT martyshev kineticsofpyrolysisofethanolairmixture AT donchenkots kineticsofpyrolysisofethanolairmixture AT fayzulinao kineticsofpyrolysisofethanolairmixture |
| first_indexed |
2025-07-08T08:49:19Z |
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2025-07-08T08:49:19Z |
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| fulltext |
ISSN 1562-6016. ВАНТ. 2016. №6(106)
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2016, № 6. Series: Plasma Physics (22), p. 283-285. 283
KINETICS OF PYROLYSIS OF ETHANOL-AIR MIXTURE
O.M. Tsymbaliuk, V.Ya. Chernyak, E.V. Martysh, T.S. Donchenko, A.O. Fayzulin
1
Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
E-mail: tsimbaluk.alexander@gmail.com, chernyak_v@ukr.net
The article presents the results of studying the high-temperature zone (about 1100 K) of ethanol pyrolysis at
atmospheric pressure. Physical model is proposed for this zone and its validation is done. ZDPlaskin software
package was used for numerical modeling of chemical reactions in this zone. It was shown with obtained results
that pyrolysis has several stages and molecular oxygen has strong influence on the process staging. Oxygen
influence on the chemical reactions during reforming was studied. The main channels of generating of ethanol
reforming aimed components such as H2 and CO, were examined. The most important reforming reactions are
determined.
PACS: 80., 82., 82.20.Wt
INTRODUCTION
There are two main approaches for the conversion of
liquid hydrocarbons in plasma chemistry: plasma and
plasma-catalytic. During the first approach the
conversion takes place because of the plasma chemical
transformations in plasma itself. All required reagents,
such as hydrocarbon and various gases (H2O, O2, CO2,
air) are injected into the plasma. The peculiarity of the
second approach is that main conversion
transformations occur in the high-temperature chemical
reactor. Plasma is used as a catalyst of the chemical
transformations. The distinct reforming products and
their mixtures can be used as plasma gases. At the same
time, the plasma can be used to activate only a part of
the reagents.
Various reforming techniques were examined under
the experimental studies [1, 2]. The reagents
composition at the system inlet and outlet was
controlled and the plasma emission spectra were
measured during the experiments. So, these
measurements do not give a complete pattern what is
going on inside the reactor volume. Due to this, the
numerical modeling of the kinetics is required for the
more complete understanding of the physical and
chemical processes in plasma and plasma-catalytic
systems.
Nowadays, the numerical kinetics of conversion is
more researched for the plasma reforming, while for the
plasma-catalytic approach it was not conducted. This is
despite the knowledge that it is more promising based
on energy efficiency and productivity [3]. This is why
this work considers the available approaches to the
numerical modeling of the conversion of the
hydrocarbon vapors in the plasma-catalytic system with
the vortex injection of the reagents. The model
hydrocarbon was ethanol, which is a promising “green
fuel”.
1. PHYSICAL MODEL
Numerical modeling of the kinetic is performed for
the ethanol reforming in the plasma-catalytic systems.
Fig. 1 presents the scheme of one of the experimental
systems, which are used for studying the liquid
hydrocarbon reforming in the plasma-catalytic scheme
[4].
Fig. 1. Scheme of experimental setup: 1 – quartz
chamber; 2, 3 – flanges; 4,5 – sleeves; 6 – t-shaped
electrode; 7 – water cooling; 8 – oxidant inlet;
9 – directing channel; 10 – gas flow direction;
11 – pyrolytic (reaction) chamber; 12 – heater;
13 – plasma torch; 14 – hydrocarbon inlet;
15 – reforming products outlet; 16 – gas flow direction;
17 – power source
The main goal of the numerical modeling of kinetics
is the study of the processes that take place in the
pyrolytic (reaction) chamber volume. The mixture of the
hydrocarbon vapors and a part of the oxidant was
introduced into the chamber tangentially to its wall via
the inlet 14 (see Fig. 1.) and formed “tornado”-type
reverse vortex flow. Rotating mixture descended to the
bottom of reaction chamber, moved to the axis, where
plasma-activated oxidant is introduced into reaction
chamber, and then the mixture moves upwards and
leaves through the aperture 15. Thus, the volume of
reaction chamber can be separated into several zones:
chemical reforming process or pyrolytic part; plasma
part; main reforming zone.
The first zone has constant high temperature, the
mixture of the initial hydrocarbon and a part of the
oxidant is injected into this zone.
mailto:tsimbaluk.alexander@gmail.com
284 ISSN 1562-6016. ВАНТ. 2016. №6(106)
The second zone is filled with the discharge plasma.
A part of the oxidant is injected and activated in this
zone. The peculiarity of the kinetics calculations in
plasma zone is ability to set reduced electric field
according to the experimentally measured field and a
gas temperature, which can be evaluated from the
plasma emission spectra [5].
The third zone is the main reaction zone of the
reactor, which receives the final products of the first and
second zones. The main processes of the initial
hydrocarbon reforming take place in this zone.
This work contains the numerical modeling of the
kinetics in the first zone. 130 chemical reaction between
30 components are examined [6]. Because there is no
plasma in the studied zone, the investigation can be
limited to the chemical reactions. The mixture
temperature in this zone was 1100 K and considered to
be stable. The modeling time was in the range of
10
-2
… 1 s. This range was selected because it is close to
the time that the mixture spends in the conditions of the
first zone in the hybrid plasma-catalytic reactors with
power less than 50 kW.
ZDPlaskin software package was used for
numerical modeling of chemical reactions in this zone
[7, 8]. This software code allows investigating the
evolution of component concentrations in time for the
non-thermal plasma with the freely set processes
between the components while taking into account the
chemical reactions.
2. RESULTS AND DISCUSSION
Fig. 3 shows the results of the numerical modeling
of the components concentration change with time. The
modeling was performed at T=1100 K, P = 1 atm, and
with 10
-5
s discreet modeling time step. The ratio
between the ethanol and oxygen was 4 to 1. This ratio
was chosen because during the plasma catalytic
reforming part of the oxidant is introduced with ethanol
and other part is activated by plasma and only then it is
mixed with the main mixture. Only part of the oxidant
has to be taken into account because only the first zone
is modeled.
The changes in the dependence of H2 and CO
concentrations on time are shown in Fig. 2. Rather sharp
decrease (approximately during 0.15 s) of O2 can also
be seen. The concentrations of H2, CO and H2O start to
increase with the beginning of the decrease of O2
concentration. After the decrease of oxygen
concentration by an order of magnitude the
concentrations of H2O and CO achieve stable value, and
almost do not change after that.
As we can see from Fig. 2, the decrease of O2
concentration correlates with the increase of H2O
concentration. Aside from that, after the significant
decrease of O2 concentration the increase of H2O
concentration stops and remains stable. This allows us
to assume that H2O is one of the final products that are
generated using O2.
From the conducted analysis of the rate of the
chemical reaction we can conclude that the decrease of
O2 concentration is caused by the reactions:
C2H5OH+O2 → CH3CHO+HO2. (1)
Fig. 2. The results of the numerical modelling of the
dependence of some components concentrations on time
The domination of this reaction explains the
decrease of HO2 concentration after the decrease of O2
concentration. After the generation, HO2 becomes an
important link in the reforming reaction chain.
For the whole time the most important H2 generation
reactions are :
CH2O +M → CO+H2+M. (2)
Also important is Н component. The main channels
of its generation are the reactions like:
CH3O + M → CH2O+H+M, (3)
HCO + M → CO+H+M. (4)
But before 0.15 s the dominant generation reaction is
(5), and after that (6).
СО generation can be also separated into two stages.
Before the stage of sharp O2 concentration decrease the
main reaction for CO generation is:
HCO+O2 → CO + HO2. (5)
After the decrease of O2 concentration, following
reactions become dominant:
HCO + M → CO + H + M, (6)
HCO + CH3 → CH4 + CO. (7)
HCO is also the important component for the
generation of CO during the whole time. The main
channels of its generation are:
CH3CHO → CH3 + HCO, (8)
CH2O + CH3 → CH4 + HCO. (9)
CONCLUSIONS
The numerical modeling of the high-temperature
pyrolysis of the reach ethanol and oxygen mixture (4 to
1 ratio) was performed with usage of ZDPlaskin
software complex. The obtained results were analyzed.
ISSN 1562-6016. ВАНТ. 2016. №6(106) 285
According to modeling results the reforming has several
stages.
The active radicals are produced during the first
stage via the reactions of C2H5OH with oxygen. Their
products turn after several transformations into H2O2. It
fractures onto OH radicals and they create new link of
reaction chain.
The period of rapid decrease of oxygen
concentration can be considered as the second stage. It
can be characterized as a start of oxidizing dry
reforming. The role of H2O2 during this reforming stage
should be noted. This component is the important link
that supports the reforming chain. The period after the
almost complete “burning” of oxygen, during which the
sufficient amount of water is produced (which can point
out at the beginning of steam reforming) can be
considered as the third stage.
The disappearance of oxygen decreases the
production rate of the desired reforming components.
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on plasma Chemistry. 2005, p. 1-4.
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V.V. Iukhymenko, Iu.P. Veremii, K.V. Iukhymenko,
E.V. Martysh, V.P. Demchina, I.I. Fedirchyk,
D.S. Levko, O.M. Tsymbalyuk, A.I. Liptuga,
S.V. Dragnev. Hybrid plasma-catalytic reforming of
ethanol aerosol // Problems of Atomic Science and
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3. V.Ya. Chernyak, O.A. Nedybaliuk, E.V. Martysh, et
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4. O.A. Nedybaliuk, V.Ya. Chernyak, V.V. Kolgan,
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5. O.A. Nedybaliuk, O.V. Solomenko, E.V. Martysh,
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Article received 20.10.2016
КИНЕТИКА ПИРОЛИЗА СМЕСИ ЭТАНОЛ-ВОЗДУХ
А.Н. Цымбалюк, В.Я. Черняк, Е.В. Мартыш, Т.С. Донченко, А.А. Файзулин
Приведены результаты исследования зоны высокотемпературного (около 1100 К) пиролиза этанола при
атмосферном давлении. Для этой зоны предложена физическая модель, и дано её обоснование. Проведено
численное моделирование течения химических реакций с помощью программного пакета ZDPlaskin.
Используя полученные результаты, показано, что пиролиз протекает в несколько стадий. Показано
значительное влияние молекулярного кислорода на стадийность процесса. Исследовано его влияние на ход
химических реакций в процессе реформирования. Рассмотрены основные каналы генерации целевых
компонентов реформирования этанола, а именно H2 и CO. Определены наиболее важные реакции
реформирования.
КІНЕТИКА ПІРОЛІЗУ СУМІШІ ЕТАНОЛ-ПОВІТРЯ
О.М. Цимбалюк, В.Я. Черняк, Є.В. Мартиш, Т.С. Донченко, А.О. Файзулін
Наведено результати дослідження зони високотемпературного (приблизно 1100 К) піролізу етанолу при
атмосферному тиску. Для цієї зони запропонована фізична модель та дано її обґрунтування. Проведено
числове моделювання перебігу хімічних реакцій за допомогою програмного пакету ZDPlaskin.
Використовуючи результати, які отримані, показано, що піроліз протікає в декілька стадій. Показано значний
вплив молекулярного кисню на стадійність процесу. Досліджено його вплив на перебіг хімічних реакцій в
процесі реформування. Розглянуто основні канали генерації цільових компонентів реформування етанолу, а
саме H2 та CO. Визначено найбільш важливі реакції реформування.
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