CC BY
23
© Yalechko VI., Kochubey V.V, Gnatishin Ya.M., Dzyadevich B.N., Zaikov G.E., 2014
УДК 674.8 ББК 37.13
THE INVESTIGATION OF THERMAL POWER CHARACTERISTICS OF WOOD PULP
Yalechko Vladimir Ivanovich
Postgraduate Student, Department of Automation and Computer-Integrated Technologies,
Institute of Engineering Mechanics, Automation and Computer-Integrated Technologies
of Ukrainian National Forestry University
nltu_pk@ukr.net
Generala Chuprinki St., 103, 79057 Lviv, Ukraine
Kochubey Viktoriya Vitalyevna
Candidate of Chemical Sciences, Associate Professor, Department of Physical and Colloid Chemistry, Institute of Chemistry and Chemical Technologies of Lviv Polytechnic National University nltu_pk@ukr.net
Stepana Banderi St., 12, 79013 Lviv, Ukraine
Gnatishin Yaroslav Mikhaylovich
Candidate of Technical Sciences, Associate Professor, Department of Automation and Computer-Integrated Technologies, Institute of Engineering Mechanics,
Automation and Computer-Integrated Technologies of Ukrainian National Forestry University nltu_pk@ukr.net
Generala Chuprinki St., 103, 79057 Lviv, Ukraine
Dzyadevich Boris Nikolaevich
Candidate of Agricultural Sciences, Professor, Department of Forest Inventory and Forest Management, Institute of Forestry and Landscape Gardening of Ukrainian National Forestry University nltu_pk@ukr.net
Generala Chuprinki St., 103, 79057 Lviv, Ukraine
Zaikov Gennadiy Efremovich
Doctor of Chemical Sciences, Professor, Head of Division of Biological and Chemical Physics of Polymers, Institute of Biochemical Physics named after N.M. Emanuel (RAS) chembio@sky. chph. ras.ru
Kosygina St., 4, 119334 Moscow, Russian Federation
Abstract. To study the heating value of wood we used integrated thermal analysis.
We have studied the aspen wood aged 10 years. For sample 3 (bark), which is characterized by the largest coke residue, the heterogeneous oxidation process occurs most rapidly.
The thermal analysis shows that the pattern of the cortex has the highest heating value.
Key words: wood biomass, thermal analysis, mathematical modeling, heating value, utilization.
Introduction
The use of wood pulp as an energy feedstock is rather vital. Effective and ecologically combustion of biomass in fuel devices is determined by the characteristics of combustion mode.
The important role today is given to the issues of using wood biomass, including fast-growing types, as energy resources. In order to determine the combustion characteristics of wood biomass and setting the optimal parameters it is necessary to carry out the complex research.
The investigation methods of burning process are the physical modeling in the laboratory and semiindustrial plants, with further full-scale tests of the developed flowsheets and analytically through the mathematical models. Analytical research requires the information about the kinetic and thermal power characteristics of wood biomass.
It should be noted that the process can be followed by possible significant reduction of substantial funds and resources expended in obtaining the necessary information from the relevant experimental setups [2; 4; 9].
Research methodology
To study the calorific value of wood the authors used integrated thermal analysis, including thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). The objects of research were represented by samples: stem wood of aspen (sample 1), stem wood of aspen,
mixed in equal proportions from the bark of aspen (sample 2), aspen bark (sample 3).
The age of aspen wood was 10 years.
Thermal analysis of samples of aspen wood was performed on derivator Q - 1 500 D system “F. Paulik- J. Paulik- L. Erdey” with the registration of the analytical signal of mass loss and thermal effects using a computer. Samples of wood were analyzed in dynamic mode with the heating rate of 10 °C/min in air. The mass of each sample was 100 mg. The reference substance was aluminum oxide [3; 6].
Results and discussion
The thermograms of samples are presented in figures 1-3, and the results of their treatment -in table. Figures 4 and 5 show the comparison of TG and DTA curves of aspen wood samples.
At the first stage (20-187 °C) the endothermic processes take place due to evaporation of chemically bound water and constitutional water. Intensive mass loss is observed in samples of TG curves at temperatures higher than 200 °C.
At the second stage of thermolysis, which according to the differential thermogravimetric analysis takes place in the temperature range of 186-277 °C, along with the endothermic dehydration and pyrolysis processes (cleavage of volatile degradation products), which are accompanied by sharp decrease of the degree of cellulose polymerization, developing exothermic thermooxidative destructive processes, as DTA curve shows the course aspen samples (fig. 1-3).
Temperature, C
Fig. 1. Thermogram of the sample 1
Unlike other samples of aspen, the sample 3 in the second phase of thermolysis loses much mass (fig. 4). This indicates that the sample of bark undergoes the processes of cleavage of volatile decomposition products [3; 7; 8].
The third stage of thermolysis (277-383 °C) is accompanied by the largest mass loss of the aspen samples (see the table) and the appearance of bright exothermic effect on the curves DTA, there are active thermooxidative destructive processes, accompanied by flame combustion of volatile decomposition products (fig. 5). For sample 3 thermooxidative processes in the air
sfl
0s
phase flow are less intense. This shows a small weight loss of the sample and the appearance of the smallest compared with other samples, exothermic effect at the DTA curve.
At the fourth stage of thermolysis (372624 °C) burning of the carbonated residue of aspen samples occurs. For sample 3, which is characterized by the largest coke residue, heterogeneous oxidation process occurs most rapidly. This is evidenced by the appearance of the most striking in comparison with other samples exothermic effect on the DTA curve, which is shifted into the region of higher temperatures [3; 7].
T, °C
Fig. 2. Thermogram of the sample 2
Temperature,°C
Fig. 3. Thermogram of the sample 3
Т, “с
Fig. 4. TG curves of samples:
1 - sample 1; 2 - sample 2; 3 - sample 3
Fig. 5. DTA curves of samples:
1 - sample 1; 2 - sample 2; 3 - sample 3
Results of comprehensive thermogravimetric and differential thermogravimetric analysis of samples 1-3
Sample Stage Temperature range, 0C Loss of mass, %
sample 1 1 20-187 7,6
2 187-277 19,5
3 277-372 43,3
4 372-569 28,5
sample 2 1 20-187 9,2
2 187-272 17,5
3 272-373 42,9
4 373-564 28,1
sample 3 1 20-186 10,0
2 186-277 20,4
3 277-383 31,2
4 383-624 32,0
Chemical analysis of elemental composition of dry weight mixture of aspen wood: carbon -52.65 %, hydrogen - 4.38 %, oxygen - 37.4 %, nitrogen - 0.42 %, ash - 1.5 %, heating value is 18,4 MJ/kg.
Conclusions
As seen from conducted thermal analysis the sample of bark has the highest heating value. The processes of thermooxidative degradation and burnout of carbonated residue is accompanied by the largest exothermic effect.
The results of mathematical modeling make it possible to use them to develop effective constructions of appropriate fuel devices for efficient utilization of wood waste and wood biomass. During the combustion of biomass in power plants or boilers emitting only CO2 gas that will be absorbed by the plant during its growth.
REFERENCES
1. Bakhracheva Yu.S. Fracture Toughness Prediction by Means of Indentation Test.
International Journal for Computational Civil and Structural Engineering, 2013, Vol. 9, no. 3, pp. 21-24.
2. Khzmalyan D.M. The Theory of Combustion Processes. Moscow, Energoatomizdat Publ., 1990. 221 p.
3. Lipskis A.L., Kvikli A.V., Lipskene A.M., Maciulis A.N. The Calculation Kinetic Parameters of Thermal Degradation of Polymers. Macromolecular compounds, 1976, Vol. XVIII, pp. 426-431.
4. Madoyan A.A. et al. More Efficiently Burn Low Grade Coal in Power Boilers. Moscow, Energoatomizdat Publ., 1991. 143 p.
5. Semenova L.M., Bakhracheva Yu.S., Semenov S.V. Laws of Formation of Diffusion Layers and Solution of the Diffusion Problem in Temperature-Cycle Carbonitriding of Steel. Metal Science and Heat Treatment, 2013, Vol. 55, no. 1-2, pp. 34-37.
6. Shestak Y. The Theory of Thermal Analysis. Moscow, Mir Publ., 1987. 326 p.
7. Tsapko Y.V. The Study of Kinetic Parameters During Pyrolysis of Fire Protected Wood by Impregnating Agents. Fire safety, 2011, no. 19, pp. 163-169.
8. Yegunov V.P. Introduction to Thermal Analysis. Samara, 1992. 154 p.
9. Zeldovich Y.B., Bernblatt G.I., Librovich VB., Makhviladze G.M. The Mathematical Theory of Combustion and Explosion. Moscow, Mir Publ., 1980. 122 p.
ИССЛЕДОВАНИЕ ТЕПЛОВЫХ ХАРАКТЕРИСТИК ДРЕВЕСНОЙ ЦЕЛЛЮЛОЗЫ
Ялечко Владимир Иванович
Аспирант кафедры автоматизации и компьютерно-интегрированных технологий Института инженерной механики, автоматизации и компьютерно-интегрированных технологий Национального лесотехнического университета Украины nltu_pk@ukr.net
ул. Генерала Чупринки, 103, 79057 г. Львов, Украина
Кочубей Виктория Витальевна
Кандидат химических наук, доцент кафедры физической и коллоидной химии института химии и химических технологий Национального университета «Львовская политехника» nltu_pk@ukr.net
ул. Степана Бандери, 12, 79013 г. Львов, Украина
Гнатишин Ярослав Михайлович
Кандидат технических наук, доцент кафедры автоматизации и компьютерно-интегрированных технологий Института инженерной механики, автоматизации и компьютерно-интегрированных технологий Национального лесотехнического университета Украины nltu_pk@ukr.net
ул. Генерала Чупринки, 103, 79057 г. Львов, Украина
Дзядевич Борис Николаевич
Кандидат сельскохозяйственных наук, профессор кафедры лесной таксации и лесоустройства Института лесного и садово-паркового хозяйства Национального лесотехнического университета Украины nltu_pk@ukr.net
ул. Генерала Чупринки, 103, 79057 г. Львов, Украина
Заиков Геннадий Ефремович
Доктор химических наук, профессор, заведующий отделом биологической и химической физики полимеров Института биохимической физики им. Н.М. Эмануэля РАН chembio@sky. ЛрЬ ras.ru
ул. Косыгина, 4, 119334 г. Москва, Российская Федерация
Аннотация. В работе исследовались тепловые свойства древесины с помощью средств комплексного термического анализа. Объектом изучения служила древесина осины в возрасте 10 лет. Было доказано, что в образце 3 (кора), который характеризуется самым большим коксовым остатком, гетерогенный процесс окисления протекает наиболее быстро. Термический анализ показывает, что структура коры имеет наивысшие тепловые свойства.
Ключевые слова: древесная биомасса, термический анализ, математическое моделирование, тепловое значение, утилизация.
