PHYSICO-CHEMICAL PARAMETERS OF SIBERIAN LARCH (LARIX SIBIRICA) BARK EXTRACTED WITH WATER-AMINO-ALCOHOLIC EXTRACTANTS

This paper presents the results of a thermal analysis, that involved thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC), of natural bark of Siberian larch (Larix sibirica Ldb.) vs. the bark extracted with 5% water-monoethanolamine (MEA) and (vs.) 5% water-triethanolamine (TEA). Thermogravimetric data obtained in an oxidative (air) atmosphere allowed us to identify temperature ranges of thermal decomposition stages for the larch bark samples, as well as to determine the corresponding mass loss and mass loss rate at programmed heating. The Ozawa-Flynn-Wall (OFW) method was used to calculate the dependence of activation energy of the thermal decomposition of experimental samples on the conversion degree (Еа = f(a)); the symbate run of Еа = f(a) curves was established. The DSC data obtained agreed with those of TG/DTG. The integral heat of the bark thermal decomposition (9.60 kJ/g and 14.12 kJ/g for MEA and TEA, respectively) indicated the bark to be competitive with other biofuels, such as briquetted lignin, wood pellets, sunflower husk, rapeseeds, and straw.

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Аналіз термодеструкції компонентів стовбура сосни звичайної в умовах Північного Степу України

Вісник Полтавської державної аграрної академії ◽

10.31210/visnyk2018.03.06 ◽

2018 ◽

pp. 39-44

Author(s):

В. М. Ловинська ◽

І. В. Рула

Keyword(s):

Activation Energy ◽

Thermal Decomposition ◽

Mass Loss ◽

Scots Pine ◽

Mass Loss Rate ◽

Oxidative Degradation ◽

Main Process ◽

Exothermic Effect ◽

Scanning Calorimetry ◽

Pine Wood

Проведено дослідження процесу термодеструкції деревини і кори сосни звичайної в умовах північного байрачного Степу України. Методами термогравіметричного (TG), диференційно-термогравіметрич-ного (DTG) та диференційно-термічний (DTA) аналізів в окислювальному середовищі зі швидкістю нагріву 10 °С/хв здійснено якісний і кількісний аналіз та встановлено стадії термічного розкладання досліджуваних структурних компонентів стовбура. Отримано класичні криві, що описують процес термічного розкладання основних компонентів біомаси. Визначено основні температурні інтервали (етапів) процесів термоокислювальної деструкції. Розраховано енергію активації як в усьому досліджуваному діапазоні температур, так і для кожного із визначених етапів. Thermal decomposition of wood and bark from such coniferous species as Scots pine (Pinus sylvestris L.) within Northern Steppe of Ukraine has been studied using thermogravimetry (TG) and differential scanning calorimetry (DSC). Thermal qualitative and quantitative analysis of wood and bark samples was carried out in an oxidizing (air) atmosphere under conditions of a programmable heating up to 620 °C at heating rate 10 °C/min. The stages of thermal decomposition, the temperature intervals, the mass loss, the mass loss rate, the temperature peaks were determined for investigated species. The kinetic thermal degradation parameters of wood and bark were obtained by the Broido method. Scots pine wood and bark was characterized from the data of activation energy analysis at various stages of thermal decomposition. It is shown that the thermal decomposition process of pine wood and bark biomass is characterized by the behavior of the three main components of lignocellulosic biomass: hemo-cellulose, cellulose, and lignin. Four temperature ranges is identified, which characterize the basic stages of thermal decomposition of samples. The main process of thermo-oxidative degradation of cellulose in the bark began at a temperature ~ 220 °С, while for the wood – at ~ 240 °С. Less exothermic effect is observed for the bark at lower temperatures. There are two peaks on differential thermogravimetric curves of Scots pine wood and bark. The first was at a maximum at 320 °C for wood and 300 °C for bark, the second is at 440 °C for bark and 490 °C for wood, which correlates with the burning of coal. It was established that the activation energy values, that corresponding to the destruction process of the Scots pine trunk phytomass components in the studied temperature range were almost unchanged for wood and bark. But each of the destruction stages is characterized by different activation energy, which is well demonstrated by the peaks of differential thermogravimetric curves.

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Flammability and Thermal Kinetic Analysis of UiO-66-Based PMMA Polymer Composites

Polymers ◽

10.3390/polym13234113 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4113

Author(s):

Ruiqing Shen ◽

Tian-Hao Yan ◽

Rong Ma ◽

Elizabeth Joseph ◽

Yufeng Quan ◽

...

Keyword(s):

Thermal Decomposition ◽

Mass Loss ◽

Polymer Composites ◽

Flame Retardants ◽

Loss Rate ◽

Mass Loss Rate ◽

Protective Layer ◽

Average Mass ◽

Microscale Combustion Calorimeter ◽

Combustion Calorimeter

Metal–organic frameworks (MOFs) are emerging as novel flame retardants for polymers, which, typically, can improve their thermal stability and flame retardancy. However, there is a lack of specific studies on the thermal decomposition kinetics of MOF-based polymer composites, although it is known that they are important for the modeling of flaming ignition, burning, and flame spread over them. The thermal decomposition mechanisms of poly (methyl methacrylate) (PMMA) have been well investigated, which makes PMMA an ideal polymer to evaluate how fillers affect its decomposition process and kinetics. Thus, in this study, UiO-66, a common type of MOF, was embedded into PMMA to form a composite. Based on the results from the microscale combustion calorimeter, the values of the apparent activation energy of PMMA/UiO-66 composites were calculated and compared against those of neat PMMA. Furthermore, under cone calorimeter tests, UiO-66, at only 1.5 wt%, can reduce the maximum burning intensity and average mass loss rate of PMMA by 14.3% and 12.4%, respectively. By combining UiO-66 and SiO2 to form a composite, it can contribute to forming a more compact protective layer, which shows a synergistic effect on reducing the maximum burning intensity and average mass loss rate of PMMA by 22.0% and 14.7%, respectively.

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Thermal decomposition kinetics of raw and treated olive waste

Thermal Science ◽

10.2298/tsci171012078w ◽

2019 ◽

Vol 23 (6 Part A) ◽

pp. 3501-3512

Author(s):

Zhihong Wang ◽

Chengzhang Wang ◽

Mijun Peng

Keyword(s):

Activation Energy ◽

Thermal Decomposition ◽

Thermodynamic Characteristics ◽

Nitrogen Atmosphere ◽

Enzyme Hydrolysis ◽

Conversion Degree ◽

Thermal Decomposition Mechanism ◽

Scanning Calorimetry ◽

Two Samples ◽

Olive Waste

The pyrolysis characteristic of raw and ultrasound assisted enzyme hydrolysis treated (UAEH) olive waste was investigated using the thermogravimetric analysis at 5, 10, 15, and 20?C per minute in the nitrogen atmosphere. The thermal decomposition was divided into three stages in the thermograph curve, and the thermogravimetric curve showed the same decomposition trend for two samples. The temperature interval and peak temperature were different for two different samples, and moved to higher temperature with the increase in heating rate. Differential thermogravimetric and differential scanning calorimetry curves depicted that the structure and composition of samples were changed by UAEH. Meanwhile, the kinetic parameters were calculated by the Kissinger, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa, and Coats-Redfern methods. For untreated and treated olive waste, the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa methods revealed the similar kinetic characteristics for the conversion degree from 0.1 to 0.9, and the average values of activation energy were 201.42 kJ/mol and 162.97 kJ/mol, respectively. The change in activation energy was clearly dependent on the extent of conversion. The Coats-Redfern method suggested the second-order model (F2, f(?) = (1 ? ?)2) could be used to better describe the thermal decomposition mechanism of untreated and treated olive waste. Besides, thermodynamic characteristics of olive waste treated were consistent with that of the untreated sample.

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Analysis of explosion characteristics of combustible wood dust in confined system using the thermal decomposition rate and mass loss rate

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2016.08.010 ◽

2016 ◽

Vol 109 ◽

pp. 432-439 ◽

Cited By ~ 8

Author(s):

Min Chul Lee ◽

Yun Seok Kim ◽

Dong Ho Rie

Keyword(s):

Thermal Decomposition ◽

Mass Loss ◽

Decomposition Rate ◽

Loss Rate ◽

Mass Loss Rate ◽

Wood Dust ◽

Confined System

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Preparation and thermal behavior of mixture of basic carbonate and 4-dimethylaminocinnamylidenepyruvate with lanthanides (III) and yttrium (III) in the solid state

Eclética Química ◽

10.1590/s0100-46701999000100003 ◽

1999 ◽

Vol 24 (0) ◽

pp. 29-44 ◽

Cited By ~ 2

Author(s):

Maria Ines Gonçalves LELES ◽

Cristo Bladimiros MELIOS ◽

Lázaro Moscardini D’ASSUNÇÃO ◽

Massao IONASHIRO

Keyword(s):

Thermal Stability ◽

Differential Scanning Calorimetry ◽

Thermal Decomposition ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Alumina Crucible ◽

X Ray ◽

Air Atmosphere ◽

Basic Carbonate ◽

Derivative Thermogravimetry

Solid Ln-OHCO3-DMCP compounds, where Ln represents lanthanides (III) and yttrium (III) ions and DMCP is the anion 4-dimethylaminocinnamylidenepyruvate, have been prepared. Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scanning calorimetry (DSC), x-Ray diffraction powder patterns and elemental analysis have been used to characterize the compounds. The thermal stability as well as the thermal decomposition of these compounds were studied using an alumina crucible in an air atmosphere.

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THE STUDY OF THERMAL IMPACT ON THE TRANSFORMATION OF ASPEN WOOD AND BARK

chemistry of plant raw material ◽

10.14258/jcprm.2017042018 ◽

2017 ◽

pp. 53-64 ◽

Cited By ~ 4

Author(s):

Надежда (Nadezhda) Михайловна (Mikhailovna)) Микова(Mikova) ◽

Ольга (Ol'ga) Юрьевна (Yur'evna) Фетисова (Fetisova) ◽

Иван (Ivan) Петрович (Petrovich) Иванов (Ivanov) ◽

Нина (Nina) Ивановна (Ivanovna) Павленко (Pavlenko) ◽

Николай (Nikolaj) Васильевич (Vasil'evich) Чесноков (Chesnokov)

Keyword(s):

Thermal Decomposition ◽

Thermal Destruction ◽

Scanning Calorimetry ◽

Temperature Range ◽

Air Atmosphere ◽

Adsorption Of Nitrogen ◽

Ft Ir ◽

Loss Of Mass ◽

Two Temperature ◽

Ft Ir Spectroscopy

Thermal gravimetry analysis (TGA) and differential scanning calorimetry (DSC), scanning electron microscopy (SEM), FT-IR spectroscopy, and thermal adsorption of nitrogen (BET) methods were used to study the thermal destruction of woody biomass of aspen (bark and wood) in argon and air in the temperature range from 25 to 800 °C. The composition and properties of the products obtained as a result of thermal decomposition of the initial wood biopolymers are characterized. It is established that the main range of thermal decomposition of wood in an inert medium included an interval from 227 to 500 °C, and aspen bark covered a temperature range from 180 to 600 °C. In the air atmosphere, the temperature zone of thermal decomposition narrows, the loss of mass of matter is observed in two temperature intervals of preferential decomposition of the substance with a shift toward a decrease in the maximum rate of decomposition for the bark (~40 °C), and for wood – 34,6 °C.

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A Study on the TG/DTA Behavior of Decabromodiphenyl Ether

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.850-851.177 ◽

2013 ◽

Vol 850-851 ◽

pp. 177-180

Author(s):

Wen Sheng Linghu ◽

Chun Yan Sun

Keyword(s):

Thermal Decomposition ◽

Mass Loss ◽

Total Mass ◽

Nitrogen Atmosphere ◽

Decabromodiphenyl Ether ◽

Thermogravimetric Analyzer ◽

Total Mass Loss ◽

Air Atmosphere ◽

Tg And Dtg ◽

Bde 209

In this work, the TG/DTA behavior of decabromodiphenyl ether (BDE-209) at nitrogen and air atmosphere by using a thermogravimetric analyzer was investigated. The results showed that both of TG and DTG curves at nitrogen atmosphere are very similarly with that at air atmosphere. About 75 wt% and 25 wt% of total mass loss were observed at the temperature range of about 300-430 °C and about 430-580°C, respectively. It is indicated that the mass loss of BDE-209 during the thermal treamtnet is mainly caused by the evaporation and thermal decomposition.

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Thermal Conversion of Pine Wood and Kinetic Analysis under Oxidative and Non-Oxidative Environments at Low Heating Rate

Proceedings ◽

10.3390/wef-06921 ◽

2020 ◽

Vol 58 (1) ◽

pp. 23

Author(s):

Lelis Gonzaga Fraga ◽

João Silva ◽

Senhorinha Teixeira ◽

Delfim Soares ◽

Manuel Ferreira ◽

...

Keyword(s):

Thermal Decomposition ◽

Mass Loss ◽

Kinetic Analysis ◽

Mass Loss Rate ◽

Thermal Conversion ◽

Inert Atmosphere ◽

Thermochemical Conversion ◽

Pine Wood ◽

Oxidative Atmosphere ◽

Conversion Stage

Atmosphere is one of the most significant factors in the thermal decomposition of biomass. In domestic or industrial biomass boilers, ambient oxygen concentration varies through time, which means that the reaction will change from pyrolysis to combustion. In this way, to analyze and compare each thermochemical conversion process, a simple analytical method, the non-isothermal thermogravimetric analysis, is carried out under oxidative (air) and non-oxidative (argon) environments at 10 °C/min and as a function of different flow rates (2 to 150 mL/min). Additionally, this work was complemented by a kinetic analysis considering a first-order reaction to each conversion stage and using the Coats–Redfern method. The effect of the atmosphere on the thermal decomposition behavior was evident. It was observed that the thermal decomposition of pine wood particles varied from three to two stages when the oxidative or inert atmosphere was applied. The presence of oxygen changes the mass loss curve mainly at high temperature, around 350 °C, where char reacts with oxygen. The maximum mass loss rate from experiments with the oxidative atmosphere is 15% higher than in an inert atmosphere, the average char combustion rate is approximately 5 times higher and the heat released reaches levels 3.44 times higher than in an inert atmosphere. Ignition and combustion indexes were also defined, and results revealed that particles are ignited faster under oxidative atmosphere and that, on average, the combustion index is 1.7 times higher, which reinforces the more vigorous way that the samples are burned and how char is burned out faster in the experiments with air. Regarding the kinetics analysis, higher activation energies, and consequently, lower reactivity was obtained under the oxidative atmosphere for the second stage (~125 kJ/mol) and under the inert atmosphere for the third thermal conversion stage (~190 kJ/mol).

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