Bojan Janković

Vinča Institute of Nuclear Sciences | VIN · Department of Physical Chemistry

Thermal decomposition (pyrolysis) of coal bottom ash (collected after lignite combustion in coal-fired power plant TEKO-B, Republic of Serbia) was investigated, using the simultaneous TG-DTG techniques in an inert atmosphere, at various heating rates. By using the XRD technique, it was found that the sample (CBA-TB) contains a large amount of anort...

Agricultural and waste biomasses present viable solutions for utilization in the energy sector, achieving sustainable and long-term transformation into energy and fuel. However, it is important to carefully evaluate the competing applications for these feedstocks, considering both short- and long-term stability. Biomass for biogas production in agr...

The aim of this study is to explain the consequences of the occurrence of enthalpy–entropy compensation (EEC) and isoequilibrium relationship during slow pyrolysis of cigarette butt filters (CBFs), consisting cellulose acetate (AC) as the main component. By using model-free and model-based kinetic methods and thermodynamic calculations, the complet...

This study is focused on the detailed examination of the combustion properties and kinetic analysis of a cellulose acetate fibrous bundle (CAFB), separated from used cigarette filters. It was shown that the faster rate of CAFB heating allows a large amount of heat to be supplied to a combustion system in the initial stages, where the increase in he...

This work examined the possibilities and limitations of model-free and model-based methods related to decrypting the kinetic complexity of multi-step thermo-oxidative degradation processes (as a testing system, a [4-(hydroxymethyl)phenoxymethyl] polystyrene resin was used), monitored by thermal analysis (TGA-DTG-DTA) techniques. It was found that i...

Developing efficient methods for Mn separation is the most challenging in exploring innovative and sustainable acid mine drainage (AMD) treatments. The availability and capacity of certain waste materials for Mn removal warrant further exploration of their performance regarding the effect of process factors. This study addressed the influence of AM...

Thermo-chemical conversion via the pyrolysis of cigarette butt (CB) filters was successfully valorized and upcycled in the pre-carbonization and carbonization stages. The pre-carbonization stage (devolatilization) of the precursor material (cellulose acetate filter, r-CAcF) was analyzed by micro-scale experiments under non-isothermal conditions usi...

Brassinosteroids (BRs) are a class of plant hormones that play important roles in regulating various physiological and developmental processes in plants. One of the most effective BRs involved in modulating crop growth is 24-epibrassinolide (24-EBL). The effects of different concentrations of 24-EBL on various biochemical and biophysical parameters...

This work provides detailed mechanistic analysis of thermo-oxidative degradation behavior of vitamin D3—Ca (CaCO3 form) solid state supplement formulation. Analytical techniques such Attenuated Total Reflection Fourier-transform Infrared (ATR-FTIR) spectroscopy and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) were used f...

A powdered PVA/CaCO3 nanocomposite carrier was successfully fabricated for effective loading of small bioactive molecules, such as vitamin D3 (VD3). Generation of, namely, VD3/PVA/CaCO3 nanocomposite scaffold was carried out through an adsorption mechanism as a loading route of an active compound onto a powder carrier. Developed composites were cha...

This work provides insight into possibilities of maximum utilization of C3-C4 energy crops for thermo-chemical conversion (slow pyrolysis) into high value biochemicals, platform chemicals, drop-in fuels and combustible gases, using coupled kinetic and thermodynamic analyses. In order to examine the kinetics of decomposition of lignocellulosic compo...

Thermo-chemical conversion of cigarette butt filters (CBFs) waste was investigated using various thermal analysis techniques (simultaneous TG-DTG-DTA and DSC methods) at different heating rates in an inert atmosphere. Thermo- and thermophysical properties of waste material were discussed, from the point of view of chemical structure and the influen...

The actual paper analyses the performance of different energy crop biomasses, Miscanthus x giganteus Greef et Deu (EC-1) and Arundo donax L. (EC-2) stems, during slow pyrolysis process monitored by simultaneous TG-DTG-MS techniques, through chemical exergy analysis. In addition to considering the physical and chemical characteristics of given feeds...

With the increased popularity of using wood stoves for household heating in recent years, numerous experimental research projects have been launched with the goal of generating cleaner and more efficient stove designs. This work is focused on mathematical modeling of combustion process in low-power residential heating appliance (small-scale stove)...

The presented paper deals with the influence of the heating rate on combustion characteristics (reactivity and reactivity evaluation, ignition index (D i), burnout index (D f), the combustion performance index (S), and the combustion stability index (R W)) of the protective coronavirus face masks. Two types of commonly used face masks in different...

The essence of this study is synthesis of a newly developed and efficient heterogeneous catalyst based on aluminum oxide support promoted with potassium iodide (KI) as active dopant responsible for pronounced catalyst activity. Modified sol–gel, reflux and hydrothermal method were used for synthesis of aluminum-oxide support using aluminum isopropo...

The pyrolysis of [4-(hydroxymethyl)phenoxymethyl]polystyrene (Wang) resin was studied by dynamic simultaneous thermogravimetric analysis (TGA) and derivative thermogravimetry techniques. The studied resin is used as the most commonly polymer supports in the peptide synthesis. A developed experimental master plots (exp-MP) model is presented that ca...

Sustainable development and mitigation of the climate changes are one of the main challenges of the circular economy, while the use of food industry residues could make an important contribution in tackling these challenges. In order to improve energy efficiency aspects of the industry residue treatment, generally, the drying process as the first s...

Thermal decomposition of hydrous volcanic glass occurs through the release of different water species under overlapping processes over wide temperature range. Its investigation is of practical interest since it constitutes integral processing part towards its valorization as source for the production of high-quality porous material for various appl...

This paper provides insights into understanding the physical and chemical changes that take place during re-heating process of Poplar fluff bio-char derived by carbonization at high operating temperature (850 °C). Bio-char re-heating experiments were performed by simultaneous TGA-DTG-DSC techniques in N2 atmosphere at 5, 10, 15 and 20 °C min⁻¹. Kin...

This study presents the experimental results of the mechanical and thermophysical properties of wood pellet samples important for their utilization in pellet stoves and boilers for heat production. The impact of operational parameters during the production process on a single pelletizer unit for three typical domestic commercial wood pellet samples...

This paper provides in-depth knowledge about the evolved gas analysis interpretation via newly proposed semi-quantitative approach, arising from thermogravimetric analysis (TGA) – mass spectrometry (MS) coupled measurements, for studying pyrolysis behavior of three kinds of biomass waste materials (spent coffee grounds, beech sawdust and wheat stra...

This study provides new information on the thermal stability and kinetics of pyrolysis of commonly used resins in solid-phase peptide synthesis. Pyrolysis process of 4-benzyloxybenzyl alcohol resin was monitored by simultaneous TGA-DTG measurements in a nitrogen atmosphere, at four different heating rates (5, 10, 20 and 30 K min⁻¹). Kinetic computa...

The issue of accumulated seashell waste has been increasingly addressed in the studies of its applicability as a secondary source of calcium carbonate. In this work, the mechanism of the thermo-oxidative degradation of two types of mollusk shells (Dosinia exoleta—DE and oyster Ostrea edulis—OE) was investigated using simultaneous thermal analysis....

The preliminary thermogravimetric studies of co-pyrolyzed low-rank coals (lignites Kostolac (KSL) and Kolubara (KLB)) with waste materials (spent coffee ground (SCG) and tire rubber granulate (WRG)) in a form of blends have been performed. Thermal analysis (TA) measurements of blend samples were carried out in a nitrogen (N2) atmosphere at three di...

Despite many advantages of the utilization of biomass as a renewable energy source, certain bottlenecks during biomass plant operation can be identified. Transport and collection of biomass as well as non-uniform material characteristics are issues related to decreasing efficiency of logistics and fuel manipulation which can also cause economic pro...

Thermally accelerated oxidative degradation of wolfberry pulp was kinetically monitored using model-free and model-based approaches. Kinetic calculations were performed based on simultaneous thermal analysis measurements in an air at four different heating rates. From kinetic analysis, new developed mechanistic scheme which is responsible for wolfb...

Rhyolite is an extrusive, igneous rock of aluminosilicate composition that upon rapid cooling forms obsidian. Obsidian is amorphous and contains limited water portions (< 2 mass%); however, secondary hydration turns it either to perlite (H2O ≈ 2–5 mass%) or pitchstone (> 5 mass%). In the current study, kinetics of hydrous rhyolite dehydration were...

As representative among biomass feedstocks, Poplar fluff was chosen to analyze the pyrolysis properties of this new biofuel. Thermogravimetry under inert (argon) atmosphere at the heating rates of 5, 10, 15, and 20 °C min−1 was employed in the investigation of thermal processing of studied biomass. The determination of kinetic parameters and estima...

The aim of this research was to obtain a carbon solid residue by the carbonization process of biomass in an inert atmosphere which, through physical activation and chemical treatment (using TEOS - tetraethyl orthosilicate) would allow creation of highly porous and spatially distinct ordered bio-SiC ceramics. The results of carbonization experiments...

Thermo-oxidative degradation of mollusk shells to CaO through intermediate phase of CaCO3 has been investigated using various analytical techniques. Powders of shells species (Dosinia exoleta and Ostrea edulis), with particle size fractions of 0.045 – 0.125 mm, 0.125–0.2 mm, and 0.2–1 mm, were subjected to degradation at the various heating rates (...

In order to clarify relationship between apricot kernel shell biomass slow pyrolysis mechanism and its main constituents (viz. hemicelluloses, cellulose and lignin), the reactivity effects of main constituents on pyrolysis characteristics were determined by the non-isothermal simultaneous thermal analysis. It was found that four-step (parallel) rea...

Simultaneous thermal analysis (TG–DTA) of low-rank coals from different annual periods (2015 and 2018) which originate from Kolubara and Nikola Tesla A (TENT A) coal-fired power plants was studied to identify their combustion characteristics and self-ignition risks. In order to investigate kinetics of thermo-oxidative degradation, model-free models...

During the utilization of coal in large power plants, one of the major logistical issues is related to spontaneous ignition of the coal. This characteristic of coal depends on the rank and type of the coal, the content of the moisture and volatile matter as well as particle size distribution. This paper presents the novel approach for determination...

Goal of this work is to establish technical feasibility and fundamentals of producing activated carbon from plane tree seeds biomass for porous materials derivation. Bio-chars produced via carbonization from plane tree seeds precursor were activated in CO2 at 750 and 850?C, during various residence times. Their surface area and porosity were charac...

The detailed kinetic analysis of slow pyrolysis process of apricot (Prunus armeniaca L.) kernal shells has been estimated, under non-isothermal conditions, through thermogravimetric analysis and derivative thermogravimetry. Thermal decomposition was implemented using four different heating rates (5, 10, 15, and 20?C per minute), with consideration...

The combustion reactivity of plane tree seeds biomass feedstock was studied using the thermogravimetry. The effects of atmosphere (O2/Ar) and different oxygen concentrations (O2/Ar = 20:80% and O2/Ar = 50:50%) on the combustion characteristics were investigated. When combustion atmosphere changes from O2/Ar = 50:50% to O2/Ar = 20:80% (reducing oxyg...

In this work, plane tree seed-based activated carbons were characterized in detail for a variety of applications. The particularly important area of application would be in the artificial photosynthesis. After carbonization process of biomass precursor at 650°C, the resulting preliminary activated carbons were activated at various temperatures. The...

Apricot kernel shells are naturally available source of biomass with potential for conversion to clean energy through a thermo-chemical process such as pyrolysis. To facilitate further process development, an advanced mathematical model which represents the process kinetics is developed and validated on the thermal decomposition studies using simul...

As waste biomass from fruit processing industry, apricot kernel shells have a potential for conversion to renewable energy through a thermo-chemical process such as pyrolysis. However, due to major differences of biomass characteristics as the well-known issue, it is extremely important to perform detailed analysis of biomass samples from the same...

Thermo-analytical characterization of selected biomasses (agricultural waste and wood biomass feedstock) through the pyrolysis process was performed under dynamic conditions. Slow pyrolysis (carbonization) regime (with a heating rate below 50 °C min−1) was selected because it favours the residual solid (bio-carbon/bio-char) in the higher yields (ch...

Slow pyrolysis characteristics of agricultural residue feedstocks (corn brakes, wheat straw, and hazelnut shell) were investigated by simultaneous thermal analysis (STA–TG–DTG–DSC), coupled with mass spectrometry (MS). Thermal decomposition of agricultural residues was divided into three stages, corresponding to removal of water, devolatilization,...

Slow pyrolysis characteristics of different biomasses (hazelnut shell (HS), sawdust (Beech), and sawdust chemically treated (SDCT)) were investigated by simultaneous thermal analysis (STA), coupled with mass spectrometry (MS). Thermal decomposition of these samples was divided into three stages corresponding to removal of water, devolatilization, a...

This paper investigates the ability of waste apricot (Prunus armeniaca) kernel shells (AKS) bio-char prepared by single-step carbonization process at 850 °C (residence time of 1 h) for possible removal of toxic elements and organic micro-pollutants. The experiment that was performed as well as parameters used proved to be optimal for bio-char produ...

Thermal and kinetics behaviors of the low-rank coals from different annual periods (Kolubara (2015)/(2018) and TENT A (2015)/(2018)) during combustion process in air atmosphere, using simultaneous TGA-DTG-DTA-MS measurements were investigated. The FTIR spectroscopy was used to gain additional information on coals structures. Kolubara and TENT A coa...

The application of various allelochemicals in agricultural production is carried out primarily to increase the quantity and quality of crop yield. These allelochemicals, which include brasssinosteroids (BRs), can reinforce the resistance of crops to abiotic stresses or increase their competitive ability against other organisms (biotic stresses). In...

Dielectric relaxation spectra of three representatives of the class of hydroxyethylammonium carboxylate protic ionic liquids (PILs), namely 2-hydroxyethylammonium formate [2-HEAF], 2-hydroxyethylammonium propionate [2-HEAP] and 2-hydroxyethylammonium butanoate [2-HEAB], were recorded over a wide frequency range (0.05 ≤ ν(GHz) ≤ 50) at 25 °C. The th...

The pyrolysis process of various types of biomass (agricultural and wood by-products) in non-isothermal conditions using simultaneous thermal analyses (STA) was investigated. Devolatilization kinetics was implemented through combined application of model-free methods and DAEM (distributed activation energy model) using Gaussian distribution functio...

This paper describes the pyrolysis of Poplar fluff (from Populus alba) using on-line apparatus, and carbonization process at 850 °C using the fixed bed reactor. Characteristics of pyrolysis products were examined. Elemental and chemical analyses were shown that Poplar fluff has higher energy content characterized by increased content of fibrous str...

This paper describes the pyrolysis of Poplar fluff (from Populus alba) using on-line apparatus, and carbonization process at 850 °C using the fixed bed reactor. Characteristics of pyrolysis products were examined. Elemental and chemical analyses were shown that Poplar fluff has higher energy content characterized by increased content of fibrous str...

Proposed approach enables a reliable determination of kinetic and thermodynamic behaviors for thermal degradation of polymers. As a model polymer, poly(ethylene oxide) with average molecular weight Mv ~ 100.000 (PEO100) was used. Two-component continuous distribution kinetics best describes PEO100 thermal degradation, involving two main reactions w...

Slow pyrolysis characterization and kinetic modeling study of five different biomasses (corn brakes (CB), wheat straw (WS), hazelnut shell (HS), sawdust (Beech), and sawdust chemically treated (SDCT)) were performed in this work, using STA-MS techniques. Thermal decomposition of these samples was divided into three stages corresponding to removal o...

Kinetic and thermodynamic analysis of non-isothermal decomposition of super-fine kaolin powder was examined. It was established that the decomposition process proceeds through liberation of adsorbed water, the loss of the water of hydration and dehydroxylation process, which produces highly disordered metakaolin. By applying the distributed reactiv...

Combustion characteristics (reactivity and reactivity evaluation, ignition index (Di), burn-out index (Df), combustion performance index (S) and combustion stability index (RW)) and thermo-oxidative degradation kinetics of plane tree seeds (PTS) were investigated. Oxidation analysis shows that PTS exhibits stable and high combustion activity, where...

Kaolins are used in a multiplicity of industries because of unique physical and chemical properties. Relationships between thermal and radioactivity properties are discussed in its application as a building material. Super-fine kaolin powder with particle sizes about 30 μm was analyzed. Simultaneous TGA/DTA analysis was performed on powder samples...

Raw and pyrolyzed samples of the plane tree seeds (PTS) were tested by various advanced analytical techniques including simultaneous TG-DSC technique, FTIR analysis, X-ray diffraction (XRD) analysis, Raman spectroscopy analysis, GC–MS (gas chromatography–mass spectrometry) analysis and scanning electron microscope analysis, for its characterization...

Slow pyrolysis (gradual heating over a wide range of temperatures) characteristics of various biomasses (corn brakes, wheat straw, and hazelnut shell) were investigated by simultaneous thermal analysis (STA-TGA-DTG-DSC), coupled with mass spectrometry. Thermal decomposition of these samples was divided into three stages corresponding to removal of...

The oscillatory behavior is not the only interesting nonlinear phenomena that appeared in the Briggs–Rauscher (BR) reaction. The BR reaction containing malonic acid may undergo a sudden transition from low (the state I) to high iodide and iodine (the state II) concentration states. This paper focuses on the mixture with an immutable [CH2(COOH)2]0/[...

Proposed distributed reactivity model of dehydration for seedling parts of two various maize hybrids (ZP434, ZP704) was established. Dehydration stresses were induced thermally, which is also accompanied by response of hybrids to heat stress. It was found that an increased value of activation energy counterparts within radicle dehydration of ZP434,...

The pre-exponential factors used for computation procedure performed for studied systems. (DOCX)

In this work, plane tree seed-based activated carbons (AC) were used for possible application in carbon dioxide capture and storage (CCS) technology. After carbonization process at 850 °C, resulting preliminary AC’s were activated at various temperatures. The high levels of the growth in basal planes of graphite structure in carbonized sample were...

Kinetics of degradation for Aronia melanocarpa fresh fruits in argon and air atmospheres were investigated. The investigation was based on probability distributions of apparent activation energy of counterparts (εa). Isoconversional analysis results indicated that the degradation process in an inert atmosphere was governed by decomposition reaction...

In the process of macromolecule cross-linking, the choice of type and quantity of the both, components and experimental condition, are important to obtain the new cross-linked materials with better mechanical and chemical characteristics. The mechanism of cross-linking depends on of the rubber type and structure. That is an intermolecular cross-lin...

Thermal and thermo-oxidative kinetics of Aronia melanocarpa fresh samples was investigated. The current investigation was based on the application of kinetic triplets and geometrical characteristics of thermal analysis curves in identifying the main bioactive compounds that govern the thermal and thermo-oxidative degradation mechanisms. From establ...

The thermal and thermo-oxidative processes in Aroniamelanocarpa (black chokeberry) were investigated using combined thermo-analytical (TG-DTA) and spectroscopic (FTIR) experimental techniques. Isoconversional analysis revealed that the process in an inert (argon) atmosphere was probably governed by chlorogenic acid degradation, where autocatalysis...

In this work, the thermal stability, the non-isothermal cure kinetics and distributed reactivity model (DRM) for fiber reinforced resin matrix composite (T800H/3900-2 prepreg) have been systematically analyzed using combined phenomenological and partially fundamental approaches. It has been shown that the proposed actual kinetic model (expressed th...

In these study, influence of wide range of 24-epibrassinolide (24-EBL) on early growth potential of two maize hybrids (ZP 434 and ZP 704) was examined. Paper concerns germination, seedling biomass, important chlorophylls content, and redistribution of elements (heavy metals and microelements), in a seedlings of the maize hybrids, as influenced by d...

In this paper, bismuth ferrite (BFO) particles synthesized by controlled hydrothermal process, where the particles of small sizes and with high purity were obtained. Structural analysis showed that non-annealed powder can be perfectly fitted to rhombohedral space group R3c and contains a very small amount of secondary phase, whereas the final produ...

Isoconversional analysis and accurate determination of lifetime properties for thermal and thermo-oxidative degradation processes of Aronia melanocarpa were examined. The Šesták–Berggren (SB) autocatalytic model was found as best model to describe degradation process of A. melanocarpa in inert atmosphere. It has been found that autocatalysis may oc...

In the present study, the pyrolysis process under dynamic conditions of swine manure solids collected from rearing farm was investigated. Tested type of biomass feedstock was analyzed from the point of view of technological exploitation in order to obtain the highest possible quality and yields of bio-oil and bio-char. Furthermore, char gasificatio...

The on-line dynamic pyrolysis kinetics of swine manure solid samples was investigated in this paper. It has been found that the model which includes combined Friedman’s isoconversional and multi-distributed reactivity approaches can best describe the pyrolysis process. Pyrolysis kinetics of swine manure samples proceeds through two major pyrolysis...

Bayesian inference was used to test the powdered cellulose pyrolysis, under the isothermal experimental conditions. A completely new procedure that was based on obtaining the reliable distribution functions of the effective (apparent) activation energy (E a ) values by the statistical derivation of prior and posterior functions was introduced. It h...

Crystallization process of Gd2Ti2O7 precursor’s powder prepared by Pechini-type polymerized complex route has been studied under isothermal experimental conditions in an air atmosphere. It was found that the crystallization proceeds through two-parameter Šesták-Berggren (SB) autocatalytic model, in the operating temperature range of 550 °C≤T≤750 °C...

Isothermal decomposition process of chemically transforming indium tin oxide (ITO) powders into indium (III) hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanically activated. It has been found that in the case of activated sample, shorter induction periods appear, which permits growth of smaller...

Pyrolysis process of coffee paper cup samples was investigated in a flow stream of nitrogen at different heating rates (10, 20, 30 and 40 degrees C min(-1)), using thermo-analytical techniques. It was found that second pyrolysis stage can be described by Sestak-Berggren (SB) autocatalytic model, with mechanism function f(alpha) = alpha(0.011)(1 - a...

This work deals with the isothermal pyrolysis of Pine and Beech wood samples and kinetic studies, using the thermo-analytical technique, at five different operating temperatures. Pyrolysis processes were investigated by using the distributed apparent activation energy model, which involves the complex mixture of different continuous distribution fu...