L0118 – Use of TMA to predict deposition behaviour of biomass fuels
Deposits formation on boiler heat transfer surfaces is one of the main operational problems associated to biomass co-combustion. This paper proposes a novel method to rank deposition propensity of biomass fuels. The method combines thermo-mechanical analysis (TMA) with ash leaching procedures and is applied here to a set of biomass fuels. Based on the TMA penetration and shrinkage traces obtained for the original and the leached ashes, the fuels are classified regarding their deposition tendencies. The results have been successfully
validated with chemical analysis of the liquid fraction from ash leaching. Initial results for the behaviour of coal–biomass mixtures are also presented
B3348 – Hybrid organic–inorganic materials as coatings for protecting wood
A new coating based on organic–inorganic materials was prepared using concurrent sol–gel and polymerization techniques, and applied to wood using a dip coating method. Vinyl-functionalized zirconium oxoclusters were co-polymerized with vinyltrimethoxysilane on wood. The coating process was examined, also assessing the specific weight of hybrid polymer left on the wood after one or two coating steps. The efficacy of the process in consolidating and protecting the wood was investigated using high-temperature differential scanning calorimetry (DSC), environmental scanning electron microscopy (ESEM), infrared spectroscopy and solid state NMR spectroscopy. The coating did not affect the morphology and appearance of the wood. However, it did modify its behavior on exposure to fire and preliminary accelerated biological tests with the brown rot fungus Coniophora puteana showing an improved resistance to the fungal attack.
B3183 – Manufacture of fibrous reinforcements for biocomposites and hemicellulosic oligomers from bamboo
Autohydrolysis of bamboo (treatments with hot, compressed water) resulted in liquors containing mainly hemicellulose-derived products (oligo- and mono-saccharides), and in spent solids (enriched in cellulose and lignin) with potential utility as a reinforcement for composites. Autohydrolysis of bamboo was carried out under a variety of operational conditions, and the resulting solid and liquid phases were assayed for composition. Kinetic models (based on pseudo-homogeneous, first-order, and irreversible reactions) were developed for data interpretation. Under selected conditions, 62.6% of the initial hemicelluloses present in the raw material were converted into oligosaccharides. The solid phase from the treatment leading to the maximal concentration of oligomeric compounds derived from hemicelluloses was employed as a fibrous reinforcement for polylactic acid (PLA)-based biocomposites. For comparative purposes, other three types of reinforcements from bamboo were also employed for making PLA-based composites: bamboo flour, short bamboo fibers, and large bamboo fibers. Compared to neat PLA, reinforcement with bamboo-derived materials resulted in increased stiffness and lower strain at break, whereas little effects were caused in tensile strength. Additional information on thermal analysis and surface morphological characteristics of biocomposites is also provided.
B2890 – Safety Evaluation and Cause Investigation of the Fire in Various Solid Biomass Fuels and Organic Rubble Pile Using High Sensitivity Calorimeters
Recent proposed various biomass fuels are reviewed from safety aspects. Many biomass materials are proposed to use as fuel, such as RDF (=Refuse derived fuel), wood chip. And these fuels have high energy and possibility to make fires, explosion or other incidents. We experienced many incidents of biomass materials, such as biomass fuel, rubble produced from destroyed houses by the great earthquake in March 2011, in Japan. Rubble includes various organic materials, and sometimes causes fire, which is used for fuel of power plants. It is very difficult to extinguish fire of biomass fuel in storage facilities. Here current studies on heat generation for these materials and proposed an evaluation test method for these new developing materials in Japan are introduced, which is to use high sensitive calorimeters such as C80, MS80, or TAM, and gas emission test. And cause investigation work for post-earthquake fires by rubble, conducted by author is introduced. High sensitive calorimeters can detect small heat generation between room temperature and 80 ?, due to fermentation or other causes. This heat generation sometimes initiated a real fire, and produced some combustible gas, which may explode if fuel is stored inside silo or indoor storage
B2666 – Microcalorimetric qualitative analysis of biofilm development in porous media used in wastewater treatment by constructed wetland
In wastewater treatment by constructed wetland, the biodegradation capability of the biomass developed in the soil is one of the most important factors. For this kind of treatment unit, soil properties are studied to improve its filtration capacity and hydraulic residence time of the wastewater. The impact of soil properties like porosity and soil components on biomass development and biodegradation capacity seem to be less studied certainly due to the complexity of microbial identification techniques currently used. The study presented here is a preliminary work to validate that calorimetric technique could be a tool in the understanding of biodegradation capacity of wastewater treatment processes. Biofilm is preliminary
developed in columns filled with different porous materials of well known porosity and constitutive components. These columns are fed with the same continuous flow of synthetic
solution (C, N, and P) as a substrate amending during 3 weeks. Then each week, 2 mL samples of porous media from these columns are analyzed in isothermal calorimeter for 48 h. Net heat flow is recorded before and after substrate injection. This work results in the definition of the procedure for batch experiments in calorimeter for wastewater process efficiency. The results of these experiments show that the microbial reaction due to substrate amendment is highly depending on the porous material used for biofilm growth. Indeed calorimetric signals recorded lead to conclude that biofilm grown on plastic beads has a faster and more intensive reaction to glucose amendment than biofilm grown on glass beads. At least, two glass beads samples analyzed in the calorimeter after the same duration of feeding with synthetic solution have very different response to glucose or synthetic solution.
B2662 – Evaluation of danger from fermentation-induced
spontaneous ignition of wood chips
Recently we conducted investigations in biological wastes because large pile-up storage of waste wood chips and others caused many fires in Japan. This paper shows the experimental results on wood chips with thermal analysis, by using a Thermogravimetry–differential thermal analysis (TG–DTA) and micro calorimeters, and as well with spontaneous ignition measurements, such as a UN wire mesh cube tester and a spontaneous ignition tester (SIT). Exothermic reaction of wood chips was observed during 45–60 ?C only by the high sensitive microcalorimeters, TAM and MS 80. This reaction is far apart from the second major reaction by oxidation and is not easy to be recognized by the conventional detectors, like
the TG–DTA and the wire mesh cube tester, because their sensitivity cannot meet the strict requirement. Correspondingly, experimental results under the adiabatic condition in the SIT confirmed this theory, in which the onset temperature of spontaneous ignition of wood chips was measured as 50–80 ?C. This implies that the weak initial reaction at ambient temperatures mainly results from microbial fermentation in the presence of its inherent moisture and possibly gives rise to the further intense combustion sustained by a chemical reaction if the heat cannot be removed from the large scale storage of wood chips.
B2578 – Evaluation of Various Solid Biomass Fuels Using Thermal Analysis and Gas Emission Tests
Various recently proposed biomass fuels are reviewed from the point of view of their safety. Many biomass materials are proposed for use as fuels, such as refuse derived fuel (RDF), wood chips, coal-wood mixtures, etc. However, these fuels have high energy potentials and can cause fires and explosions. We have experienced many such incidents. It is very difficult to extinguish fires in huge piles of biomass fuel or storage facilities. Here current studies on heat generation for these materials and proposed evaluation methods for these new developing materials in Japan are introduced, which are consistent with measurements using highly sensitive calorimeters such as C80, or TAM, and gas emission tests. The highly sensitive calorimeters can detect small heat generation between room temperature and 80 °C, due to fermentation or other causes. This heat generation sometimes initiates real fires, and also produces combustible gases which can explode if fuel is stored in silos or indoor storage facilities.
B2420 – Contributions of hemicellulose, cellulose and lignin to the mass and the porous properties of chars and steam activated carbons from various lignocellulosic precursors
In this study, contributions of hemicellulose, cellulose and lignin to the mass and the porous properties of chars and activated carbons from various lignocellulosic materials were studied. A predictive calculation was established using the experimental results obtained for the three components separately to evaluate the carbonization and activation yields and their respective contributions to the chars and to the subsequent activated carbons of various precursors in term of weight fraction. These equations were validated.
The results showed that lignin can be considering as being the major contributor of all chars and activated carbons. Besides, the evolution of the mean pore size versus the specific porous volume showed that each component contributes to the porosity of chars and activated carbons whatever is its weight contribution.
B2398 – Pyrolysis of the waste biomass
The paper summarises results of several thermogravimetric experiments performed with a selected group of eight different waste biomaterials under heating rates from 2 to 50 K min –1 . The enthalpy of materials tested in the experiments varied from around 180 up to almost 700 kJ kg–1 . Certain conclusions concerning mainly the dependence of the heat exchange under the chosen conditions of the pyrolysis are drawn on the basis of measured values.
B2383 – Calorimetric determination of the effect of ammonium-iron(II) phosphate monohydrate on Rhodic Eutrudox Brazilian soil
The fertilizer NH4FePO4·H2O (AIP) was synthesized under mild hydrothermal conditions to be applied on soils to prevent iron deficiencies. The effect of the addition of AIP on soil microbial activity was studied by calorimetry, determining both basal respiration and carbon mineralization by means of the addition of an external carbon source. Thermal analyses (TG and DSC) were also used to provide additional soil properties. The effect of different amounts of AIP on soil microbial activity was quantitatively analyzed by a mass and energy balance performed via the analysis of the power–time curves. These balances allowed determination of the impact of AIP on soil more rapidly than conventional methodologies. The increase in the amount of added AIP leads to a less efficient metabolism, probably due microbial competition for the nitrogen source provided by the AIP and for the carbon source.
B1429 – Formation of charcoal from biomass in a sealed reactor
Samples of cellulose, hemicellulose, lignin, and nine species of whole biomass were pyrolyzed in sealed
reactors. Very high charcoal yields (e.g., 40% from cellulose, 48% from Eucalyptus gurnrnifera)
were obtained. Higher sample loading (sample mass per unit reactor volume) increased charcoal
yield and the associated exothermic heat release and lowered the reaction onset temperature. These
effects were induced by the vapor-phase concentrations of the volatile products, and not the system
pressure. Addition of water catalyzed the reaction and increased the char yield. These observations
suggest that charcoal formation is autocatalyzed by water, an initial pyrolysis product. When whole
biomass was used as a feedstock, higher charcoal yields were obtained from species with high lignin
and/or low hemicellulose content.
B1193 – Calorimetric study of the bioremediation of a polluted soil.
The calorimetric cells of a Setaram BT 2.15 flux calorimeter have been modified, in order to measure the heat production associated with microbial growth, with a continuous flow of gas and liquid through the sample. Good conditions for the growth of the microorganisms present in a polluted soil were determined and the possibility of the bioremediation examined. It was shown that the biodegradation of hydrocarbons adsorbed for a long time in the soil is a very slow process difficult to study with calorimetry. On the contrary, sodium succinate and different C14 hydrocarbons were easily biodegradated, producing a large quantity of heat.
B1176 – Thermogravimetric study of the pyrolysis of waste wood.
A thermogravimetric study of the pyrolysis of three different types of waste wood (forest wood, old furniture and used pallets) is carried out in a TGA equipment using dynamic and isothermal techniques. Isothermal runs were carried out at two temperature levels, one between 225° and 325°C (low range) and the other, between 700° and 900°C (high range). Results show a good agreement between the kinetic parameters obtained from either dynamic or isothermal techniques. It must be remarked that the own chemical composition of each type of wood together with the compounds added to the wood for each application, play a fundamental role in the kinetic behavior of their thermal decomposition.
B1152 – Analyse de la pyrolyse ménagée du bois par un couplage TG-DSC-IRTF.
B0424 – Effects of pressure on biomass pyrolysis. II. Heats of reaction of cellulose pyrolysis.
A Setaram DSC in conjunction with stainless steel pressure vessels was used to investigate the effects of pressure and purge gas flow rate (gas phase residence time) on the heat demands of cellulose pyrolysis. High pressure and low flow rate reduce the heat of pyrolysis and increase char formation. Experiments were conducted to investigate the pyrolysis reactions of anhydrocellulose and levoglucosan, the two major intermediate products in cellulose pyrolysis. Separate models for the degradation of each intermediate were postulated and combined to form a detailed mechanistic model for cellulose pyrolysis. The model explains all the observed effects of pressure and flow rate.
B0423 – Effects of pressure on biomass pyrolysis. I. Cellulose pyrolysis products.
A three phase research program, using a tubular, laminar flow, micro reactor system, was undertaken to study the effects of pressure on biomass pyrolysis. Results of the first two phases indicate that increasing pressure increases the yields of char and CO2, and decreases the yields of CO, CH4, C2H6 and C3H6. Increased volatile residence time favors the formation of char, and increases yields of C2H6 at the expense of CO and C3,'s. The addition of small amounts of O2 reduces the yields of all hydrocarbons, but has little effect on char formation.
A2374 – Mechanical, barrier, and biodegradability properties of bagasse cellulose whiskers reinforced natural rubber nanocomposites
Cellulose whiskers were isolated from bleached sugar cane bagasse kraft pulp. The length of the isolated whiskers was in the range 84–102 nm while the width was in the range 4–12 nm. They were used as reinforcing elements in natural rubber (NR) matrix. The effect of whiskers loading on tensile properties, thermal properties, moisture sorption, water vapor permeation, and soil biodegradation was studied. Significant improvement of Young's modulus and tensile strength was observed as a result of addition of whiskers to the rubber matrix especially at high whiskers’ loading. Dynamic mechanical thermal analysis (DMA) and differential scanning calorimetry (DSC) results showed no change in the glass transition temperature (Tg) of the rubber matrix upon addition of cellulose whiskers but at softening of rubber, cellulose whiskers have reinforcing effect on the rubber. Presence of bagasse whiskers resulted in an increase in moisture sorption of rubber films up to 5% whiskers loading while at higher whiskers’ loading the moisture sorption tended to decrease. Barrier properties to water vapor decreased on increasing cellulose whiskers up to 7.5% whiskers loadings then increased with further increase in whiskers loading. Presence of cellulose whiskers increased the rate of degradation of rubber in soil.
A2349 – Mechanical durability and combustion characteristics of pellets from biomass blends
Biofuel pellets were prepared from biomass (pine, chestnut and eucalyptus sawdust, cellulose residue, coffee husks and grape waste) and from blends of biomass with two coals (bituminous and semianthracite). Their mechanical properties and combustion behaviour were studied by means of an abrasion index and thermogravimetric analysis (TGA), respectively, in order to select the best raw materials available in the area of study for pellet production. Chestnut and pine sawdust pellets exhibited the highest durability, whereas grape waste and coffee husks pellets were the least durable. Blends of pine sawdust with 10–30% chestnut sawdust were the best for pellet production. Blends of cellulose residue and coals (<20%) with chestnut and pine sawdusts did not decrease pellet durability. The biomass/biomass blends presented combustion profiles similar to those of the individual raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends.
A2342 – Kinetic study on the thermal degradation of a biomass and its compost: Composting effect on hydrogen production
Compost from vegetable residues is usually used as an organic amendment to soil; however, their thermal degradation characteristics show that it could be used as raw material in air gasification facilities. According to the obtained data, hydrogen production is positively affected by composting, increasing hydrogen concentration in the raw gas from 15.2 to 22.6 vol%. This effect is related with physicochemical changes that occur during thermophilic stage of composting. After this step it does not observes any progress on hydrogen production. On the other hand, in order to compare thermal degradation of a biomass (Leucaena leucocephala) and two composts with different maturation levels, non-isothermal thermogravimetric analysis (TGA) has been used. Under inert atmosphere, data have been adequately simulated assuming three fractions (hemicellulose, cellulose and lignin) in both biomass and composts. However, under air atmosphere we have used a simplified model that assume two components in biomass (holocellulose and lignin) and three in composts (including humic substances). Using nth-order kinetic equations to describe component degradations, we have calculated a set of kinetic parameters which do not differ of the reported for other lignocellulosic materials. This procedure allows obtaining an approximate composition of samples
A2334 – The importance of thermal behaviour and petrographic composition for understanding the characteristics of a Portuguese perhydrous Jurassic coal
The perhydrous Batalha coal (Portugal) is found in the Cabaços and Montejunto Formation of the Oxfordian–Kimeridgian, Upper Jurassic age. From the macroscopic point of view, its appearance is similar to other perhydrous coals. Microscopically, the maceral group of huminite is the main organic component (96%), ulminite being the most important petrographic component, followed by textinite with resinite (4%) lumina filled. The huminite random reflectance is 0.33%. This coal is characterized by high H/C atomic ratio, and anomalous physical and chemical properties that are characteristic of perhydrous coals such as: (i) the absence of any correlation between reflectance and the chemical rank parameters; (ii) a lower real density than that of non-perhydrous coals; (iii) a high hydrogen content; and (iv) suppressed reflectance. Using its calorific value (moist, ash-free basis) as rank parameter, Batalha coal must be considered a subbituminous A coal. Hydrogen enrichment due to the presence of resinite has influenced the technological properties of this coal, namely: (i) reduction of the thermostability and decrease in the temperature of initial thermal decomposition due to, among other reasons, the existence of aliphatic structures with low dissociation energy bonds resulting from the presence of resinite; (ii) from the DTG profile, the volatile matter combustion and char combustion is not evident; (iii) development of chars made up of isotropic particles with angular edges, which is typical of a low rank coal; (iv) the evolution trend of gaseous compounds (CO, CO2 and CH4) during pyrolysis; and, (v) an increase in its calorific value due to its hydrogen content. The study of this coal which is interbedded in Jurassic formations in the Lusitanian Basin of Portugal is a new contribution to the assessment of the evolution of organic matter in this area.
A2317 – Integral use of pepper stems
Pepper stems were treated for its integral utilization. Characterization of original pepper stems (63.4% holocellulose, 23.3% hemicelluloses, 25.6% lignin) was done according to standards methods. In this work, the valorisation of these components was studied. Hemicelluloses fraction recovered from the hydrolsated pepper stems presented xylose and glucose as the main simple sugars, representing 39% and 19.9% of total sugars content in the autohydrolysis hydrolysates and 59.8% and 16% in the acid hydrolysates respectively. Physical properties of paper sheets formed with soda pulp from pre-hydrolysated pepper stems were measured with high 76 °SR value, and cellulose and lignin fractions from pulp and black liquor were recovered respectively. Cellulose was characterized by ATR-IR to complete the chemical structure analysis. Lignin isolated from the liquid was submitted to ATR-IR, 1H NMR, GPC and TGA in order to suggest suitable applications based on its physicochemical properties.
A2290 – Hydrothermal carbonization as an effective way of densifying the energy content of biomass
Hydrothermal carbonization processes were studied under different conditions using two different biomass materials: walnut shell and sunflower stem. Coalification under mild conditions was promoted with the aim of increasing the calorific value of the solid hydrochar. Hydrocarbonization processes brought up an increase on the heating value of the materials up to 28.9 and 29.3 MJ kg? 1, for sunflower stem and walnut shell, respectively, which corresponds to an increase of 1.75 and 1.50 fold when compared with the natural biomass. Also, regarding the variables studied it was found that temperature and water/biomass ratio were more influent on the hydrocarbonization process than residence time. The hydrochars show negligible N2 adsorption at 77 K and interesting surface morphology, characterized by the formation of microspheres which grow as temperature increases. Moreover, hydrochars are acid in nature and present several oxygen functionalities, as observed from FT-IR and pzc analysis.
A2180 – Polyol production by chemical modification of date seeds
Polyol production from chemical modification of date seeds has been investigated through oxypropylation and liquefaction techniques (using organic solvents in the presence of a catalyst). The obtained products were characterized using infrared spectroscopy analysis, 1H NMR, thermogravimetric analysis and other parameters such as hydroxyl number (IOH) and viscosity. Results showed that 93% of the solid substance was converted into polyol in the oxypropylation reaction at the date seeds/propylene oxide ratio of 0.25 and 10% potassium hydroxide at 160 °C. The oxypropylated product has IOH of 779 mg KOH/g and viscosity of 6.9 Pa s. Regarding the liquefaction technique, results show that a yield of 95% was obtained at the date seeds/liquefying solvent ratio of 0.25 in 60 min of reaction at 160 °C. The liquefied product shows IOH of 336 mg KOH/g and viscosity of 0.9 Pa s.
A2179 – Polyols obtained from solvolysis liquefaction of biodiesel production solid residues
In this study, the possibilities of solvolysis liquefaction of the main solid residue generated in the rapeseed biodiesel production process into a liquid form were investigated by using polyhydric alcohols [polyethylene glycol (PEG #400) and glycerol] and their ensuing polyols obtained were evaluated. The influences of some liquefaction parameters on the residue content, such as mass/solvent ratio, liquefaction temperature and time, were discussed. The results show that the biopolyols production from rapeseed cake residue under different liquefaction conditions is completely feasible. The Fourier transform-infrared (FT-IR) of the liquefied product showed that cellulose, hemicellulose and lignin are almost decomposed in the liquefaction reaction. To open new avenues of exploitation of liquefied product, several physical and chemical characteristics of polyols were determined and the detailed chemical compositional analysis was performed by gas chromatography–mass spectrometry (GC–MS). The GC–MS analysis showed that the chemical components can be divided into several groups, i.e., glycols, acids, ester and ether compounds. The OH number and viscosity in the polyol were 505 mg of KOH/g and 0.4 Pa s, respectively; being values found in the range of those current petroleum-based polyols used as precursor in polyurethane synthesis.
A2163 – Thermogravimetric analysis as a new method to determine the lignocellulosic composition of biomass
Biomass energy uses organic matter such as wood or plants - lignocellulosic biomass - for creating heat, generating electricity and producing green oil for cars. Modern biomass energy recycles organic leftovers from forestry and agriculture, like corn stovers, rice husks, wood waste and pressed sugar cane, or uses special, fast-growing “energy crops” like willow and switchgrass, as fuel. Biomass is composed of three major components: cellulose, hemicelluloses, and lignin. Their differences in chemical structures lead to different chemical reactivities, making the relative composition in cellulose, hemicelluloses and lignin in the biomass a crucial factor for process design. In this paper thermogravimetric analysis is investigated as a new method to obtain lignin, hemicellulose and ?-cellulose contents in biomass. It is shown that this alternative method lead to comparable results than common methods used for the determination of the ?-cellulose content, with an enhancement of the accuracy in the determination of the hemicellulose content. Unfortunately, this method cannot be adopted for the determination of the lignin amount.
A2140 – Kinetic modelling of steam gasification of various woody biomass chars: Influence of inorganic elements
A study was performed on the influence of wood variability on char steam gasification kinetics. Isothermal experiments were carried out in a thermobalance in chemical regime on various wood chars produced under the same conditions. The samples exhibited large differences of average reaction rate. These differences were linked neither with the biomass species nor age and may be related to the biomass inorganic elements. A modelling approach was developed to give a quantitative insight to these observations. The grain model was used on one biomass of reference for temperatures between 750 and 900 °C and steam partial pressures between 0 and 0.27 bar. The model was applied to the other samples through the addition of an integral parameter specific to each sample. A satisfactory correlation was found between this parameter and the ratio potassium/silicium. This result highlighted the catalytic effect of potassium and inhibitor effect of silicium on the reaction.
A2132 – Acylation de la cellulose par le chlorhydrate de chlorure de 3-pyridinoyl : application dans l’adsorption du plomb Pb2+
Le chlorhydrate de chlorure de 3-pyridinoyl (ou chlorhydrate de chlorure de nicotinoyl), qui possède un anneau pyridinique susceptible d’adsorber des polluants cationiques a été greffé sur de la cellulose « Kraft » dans des conditions douces. Différentes analyses (FTIR, ATG, MEB et analyse élémentaire) ont permis de vérifier que le greffage a bien eu lieu et qu’il augmente largement les propriétés de rétention de la cellulose vis-à-vis de cations Pb2+ (quantité adsorbée : 14,50 mg/g contre 3,26 mg/g, temps d’équilibre : 60 minutes contre 150 minutes). La cinétique d’adsorption est correctement décrite par un modèle de pseudo-deuxième ordre et le phénomène est bien modélisé par une isotherme de Langmuir. Par ailleurs, la détermination des paramètres thermodynamiques montre que la réaction est spontanée et exothermique, ce qui ouvre des perspectives intéressantes du point de vue du recyclage du matériau adsorbant puisque le cation pourrait être désorbé à températures élevées.
A2124 – Charcoal Production via Multistage Pyrolysis
Interests in charcoal usage have recently been re-ignited because it is believed that charcoal is a much better fuel than wood. The conventional charcoal production consumes a large amount of energy due to the prolonged heating time and cooling time which contribute to the process completing in one to several days. Wood pyrolysis consists of both endothermic and exothermic reactions as well as the decomposition of the different components at different temperature range (hemicellulose: 200–260 °C; cellulose: 240–350 °C and lignin: 280–500 °C). In this study we propose a multistage pyrolysis which is an approach to carry out pyrolysis with multiple heating stages so as to gain certain processing benefits. We propose a three-stage approach which includes rapid stepwise heating stage to a variable target temperatures of 250 °C, 300 °C, 350 °C and 400 °C, slow and gradual heating stage to a final temperature of 400 °C and adiabatic with cooling stage. The multi-stage pyrolysis process can save 30% energy and the processing time by using a first temperature target of 300 °C and heating rate of 5 °C·min?1 to produce a fixed-carbon yield of 25.73% as opposed to the base case with a fixed-carbon yield of 23.18%.
A2095 – Characterization of Punica granatum L. peels and quantitatively determination of its biosorption behavior towards lead(II) ions and Acid Blue 40
In this study, a waste biomass of Punica granatum L. (P. granatum L.) peels was firstly characterized by means of Brunauer-Emmett-Teller (BET) surface area, elemental analysis, FT-IR, thermogravimetric (TG) analysis and zeta potential measurement techniques. FT-IR results indicated that the mechanism involved in the biosorption of lead(II) ions and AB40 onto biosorbent was mainly attributed to lead(II) ions and dye binding of amino, carboxylic, hydroxyl and carbonyl groups. The biosorption abilities of P. granatum L. peels for lead(II) ions and Acid Blue 40 (AB40) were then investigated. Biosorption equilibrium and kinetic data fit well by the Langmuir isotherm and the pseudo-second-order kinetic models, respectively. The maximum biosorption capacities were 193.9 mg g(-1) for lead(II) ions and 138.1 mg g(-1) for AB40. Biosorption processes were spontaneous and endothermic in nature according to the thermodynamic results and the equilibrium was attained within 50 min. The validity of used kinetic models in this study can be quantitatively checked by using a normalized standard deviation ?q(%). Finally, the biosorption procedure was adopted to treat the real and simulated wastewaters including several metal salts and dyes. The wastewater applications have shown that the biosorbent indicated a reasonable biosorption capability to remove lead(II) ions (98.07%) and AB40 (94.76%) from industrial wastewaters
A2064 – Usability of terebinth (Pistacia terebinthus L.) fruits as an energy source for diesel-like fuels production
This study examined the effects of varying pyrolysis parameters, including final temperature, heating rate, particle size, and nitrogen flow rate, on the yields of terebinth as a source of bio-oil. The maximum bio-oil yield of 58.99 wt.% was almost equal to diesel fuel in terms of its major fuel properties (H/C = 1.73, 38.50 MJ/kg, 0.954 g/cm3, and flash point of 59 °C). The GC–MS and 1H-NMR analysis results showed that bio-oil predominantly comprised aliphatic hydrocarbons with high heating value and other valuable compounds with potential added value. The results show that the bio-oil can be used as a feedstock for the production of the diesel-like fuels or refined chemicals
A2047 – Kinetic models for the oxy-fuel combustion of coal and coal/biomass blend chars obtained in N2 and CO2 atmospheres
The thermal reactivity and kinetics of five coal chars, a biomass char, and two coal/biomass char blends in an oxy-fuel combustion atmosphere (30%O2–70%CO2) were studied using the non-isothermal thermogravimetric method at three heating rates. Fuel chars were obtained by devolatilization in an entrained flow reactor at 1273 K under N2 and CO2 atmospheres. Three nth-order representative gas–solid models – the volumetric model (VM), the grain model (GM) and the random pore model (RPM) – were employed to describe the reactive behaviour of the chars. The RPM model was found to be the best for describing the reactivity of the high rank coal chars, while VM was the model that best described the reactivity of the bituminous coal chars, the biomass char and the coal-biomass blend char. The kinetic parameters of the chars obtained in N2 and CO2 in an oxy-fuel combustion atmosphere with 30% of oxygen were compared, but no relevant differences were observed. The behaviour of the blend of the bituminous coal (90%wt.) and the biomass (10%wt.) chars resembled that of the individual coal concealing the effect of the biomass. Likewise, no interaction was detected between the high rank coal and the biomass chars during oxy-fuel combustion of the blend.
A2046 – FTIR quantitative analysis technique for gases. Application in a biomass thermochemical process
The present work proposes a novel and alternative FTIR calibration method to quantify gases. Unknown concentrations are deducted from calibration curves, obtained by combining a dilution flow with another flow of the gas of interest. Both streams are controlled by accurate flow meters. In the present case the method is used to quantify the main light gaseous products (CO, CO2 and CH4) from the pyrolysis of several biomasses. Pyrolysis is reached by thermogravimetric analysis (TGA) forming the well-known tandem TG-FTIR, relating in this way weight loss with the spectra in a given time. In addition, it has been studied the effects of parameters such as chemical composition, temperature and heating rate, on the emissions of these pyrolysis products
A2025 – Determination of the specific heat of biomass materials and the combustion energy of coke by DSC analysis
The accurate determination of the thermal properties of biomass materials is particularly important when studying biomass combustion processes. This paper reports a method for the determination of the maximum sampling error and the confidence intervals of thermal properties obtained from TG-DSC analysis. Special care must be taken with the sampling procedure to achieve an acceptable degree of error and low statistical uncertainty. The obtained levels of uncertainty and error demonstrate that the properties evaluated by the analysis were representative of the fuels. A study of the trends and time correlations was performed to ensure that the observed correlations arise from completely random causes. The obtained results are particularly interesting for biomass energy applications.
A1998 – Conversion of lignin to aromatic-based chemicals (L-chems) and biofuels (L-fuels)
Conversion of lignin into chemicals and biofuels was performed using the commercial Kraft lignin, Indulin AT. Lignin was depolymerised in an aqueous alkaline solution using a continuous flow reactor generating four fractions. First is the gas fraction (mainly CO(2)), the second includes methanol, acetic acid and formic acid, thus defined as small organic compounds and third one (up to 19.1 wt.% of lignin) is mostly composed of aromatic monomers. The fourth fraction (45-70 wt.%) contains oligomers (polyaromatic molecules) and modified lignin. Pyrocatechol was the most abundant product at high severities (315°C) with selectivity up to 25.8%. (31)P NMR showed the loss of almost all aliphatic OH groups and apparition of catechol groups during depolymerisation.
We describe the mechanical defibrillation of bacterial cellulose (BC) followed by the dry-cast generation of reconstituted BC films (RBC). Xyloglucan (XGT), extracted from tamarind seeds, was incorporated into the defibrillated cellulose at various compositions, and new films were created using the same process. Microscopy and contact angle analyses of films revealed an increase in the microfibre adhesion, a reduced polydispersity in the diameters of the microfibrils and increased hydrophobic behaviour as a function of %XGT. X-ray diffraction analysis revealed changes to the crystallographic planes of the RBC and the biocomposite films with preferential orientation along the (1 1 0) plane. Compared with BC, RBC/XGT biocomposite with 10% XGT exhibited improvement in its thermal properties and in Young’s modulus. These results indicated a reorganisation of the microfibres with mechanical treatment, which when combined with hydrocolloids, can create cellulose-based materials that could be applied as scaffolding for tissue engineering and drug release.
A1986 – Characterization of the different fractions obtained from the pyrolysis of rope industry waste
A study of the possibilities of pyrolysis for recovering wastes of the rope’s industry has been carried out. The pyrolysis of this lignocellulosic residue started at 250 ?C, with the main region of decomposition occurring at temperatures between 300 and 350 ?C. As the reaction temperature increased, the yields of pyrolyzed gas and oil increased, yielding 22 wt.% of a carbonaceous residue, 50 wt.% tars and a gas fraction at 800 ?C. The chemical composition and textural characterization of the chars obtained at various temperatures confirmed that even if most decomposition occurs at 400 ?C, there are some pyrolytic reactions still going on above 550 ?C. The different pyrolysis fractions were analyzed by GC–MS; the produced oil was rich in hydrocarbons and alcohols. On the other hand, the gas fraction is mainly composed of CO2, CO and CH4. Finally, the carbonaceous solid residue (char) displayed porous features, with a more developed porous structure as the pyrolysis temperature increased.
A1964 – Production and characterisation of activated carbon from wood components in powder: Cellulose, lignin, xylan
The aim of this work was to characterise the activated carbon produced from wood and its basic components: cellulose, lignin and xylan (hemicelluloses). Two ways of activation were tested: simple pyrolysis under N2 and thermal treatment of the material impregnated with KOH (KOH-activation). Concerning the pyrolysis, simultaneous measurements of DTA-TGA allowed to compare the heat of reaction and the decomposition rate of the 3 wood components. Moreover it was shown that only the char from cellulose has a significant BET-surface area of pores. The KOH-activated carbons from wood and wood components were characterised by their BET surface area, their spectra in temperature programmed desorption (TPD) up to 1173 K and by their capacity to adsorb pollutant compounds in aqueous phase such as phenol and methylene blue. It was shown that the theoretical models of Langmuir and Freundlich satisfactorily fit to the adsorption isotherms of these pollutants, moreover most of the parameters of these theoretical models rank as the BET-surface area of pores.
A1877 – Devolatilization behaviour and pyrolysis kinetic modelling of Spanish biomass fuels
The basic pyrolysis behaviour of eight different biomass fuels has been tested in a thermogravimetric analyser under dynamic conditions (5, 20 and 50 °C min-1 heating rates) from room temperature up to 1,000 °C. Their decomposition was successfully modelled by three first-order independent parallel reactions, describing the degradation of hemicellulose, cellulose and lignin. Hemicellulose would be the easiest one to pyrolyse, while lignin would be the most difficult one. Experimental and calculated results show good agreement. The reactivity of the different biomass type functions of various thermal, kinetic and composition parameters are discussed. The effect of the heating rate on pyrolysis behaviour was studied, and a comparison between slow and fast heating rate reveals a small displacement of the DTG profiles to higher temperatures. The heating rate not only affects the highest mass loss rate temperature but also influences the mass loss rate value.
A1744 – An investigation of the pyrolysis kinetics of some aliphatic amino acids
The thermal behavior of some aliphatic amino acids, including alanine, valine, leucine, isoleucine, and proline was investigated by thermogravimetry (TG) in the range of temperatures within 30–400 8C. Pyrolysis of these amino acids was performed at various heating rates under inert (non-oxidative) conditions. The kinetic analysis was carried out using a composite procedure involving the iso-conversional method and the master plots method. The iso-conversional method indicated that the pyrolysis reaction should conform to single reaction model. The master plots method suggested that the phase boundary reaction models best describe the pyrolysis of alanine, valine, leucine and isoleucine, while the pyrolysis of proline should conform to the simple order reaction model. Also, for each amino acid, the kinetic parameters, such as activation energy and pre-exponential factor, were determined, respectively.
A1743 – Sol–gel derived TiO2 wood composites
The sol–gel process was applied to enhance properties of pine sapwood. For this purpose wood prisms were soaked in nanoscaled precursor solutions prepared from titanium(IV) n-butoxide and titanium(IV) iso-propoxide, respectively, using vacuum impregnation technique. The wet composites were cured by special program with final heat treatment at 103 °C. Weight percent gains (WPG) of the wood specimen in the range of 19–25% were obtained due to these procedures. SEM investigations show that precursor solutions penetrate into the whole wood body and the titania formed after heat treatment in the composites is deposited in the pores (lumen) and partly in the cell walls of the wooden matrix. The moisture sorption was investigated in long term tests for a period of some months by storage at 20–23 °C in humid air (relative humidity of 99%) and ambient atmosphere (relative humidity 40–60%), respectively. For untreated reference samples the moisture sorption results in increasing of mass and volume according to saturation values of 24 and 13%, respectively, after about 15 days. The incorporation of titania reduces the saturation values of the moisture sorption by up to 12% in mass and by up to 5% in volume at a relative humidity of 99%. Thus, an enhancement of the dimensional stability of about 60% is obtained at best. The results demonstrate that modification of wood with sol–gel derived precursors can enhance its dimensional stability, which prevents the formation of cracks. Because of that reduced moisture sorption biological attacks should be delimited. Additionally, thermal analyses show a retarded combustion of the wood matrix due to titania infiltration.
A1609 – Thermal lag analysis on a simulated TGADSC device
A ThermoGravimetric Analyser with Differential Scanning Calorimeter (TGADSC) has been simulated to evaluate the influence of different parameters on thermal lag. Two virtual materials with selected properties were created and combined with two heating rates. A threedimensional mesh was created based on measurements in the actual TGADSC. Specific models have been applied and boundary conditions have been configured, including a programmed Proportional Integral Derivative (PID) controller to regulate temperature. The results showed that a sample with a lower thermal diffusivity had greater temperature differences when compared to the furnace temperature than a sample with a higher thermal diffusivity. Biot number has also been computed to analyse temperature differences within the sample. Thermal diffusivity and Biot number effects were miniscule compared to the heating rate, which increased sample emperature instability and temperature differences within the sample.
A1579 – The effect of some wood preservatives on the thermal degradation of Scots pine
Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.
A1571 – Threecomponents organic–inorganic hybrid materials as protective coatings for wood: Optimisation, synthesis, and characterisation
The present work explores new solutions for the development of functional flameresistant hybrid coatings for wood, by using oxoclusterreinforced hybrid materials. Hybrid coatings and bulk materials were produced by photopolymerisation of 3methacryloxypropyltrimethoxysilane (MAPTMS) with methylmethacrylate (MMA) in the presence of the dimeric oxocluster (Zr6O4(OH)4(OOCCH2CHCH2)12(nPrOH)] 2·4(CH2CHCH2COOH), (Zr12), characterised by the presence of 12 vinylacetate groups for each molecules. The molar ratios among silane, MMA monomer and oxocluster were changed to optimise the best performing formulation. The final molar ratio chosen for the spray deposition of the coatings under inert atmosphere and for the preparation of the bulk specimens was MAPTMS:MMA:Zr12 = 1:3:0.008. Attenuated Total ReflectanceFourier Transform Infra Red (ATRFTIR) spectroscopy and Differential Scannig
Calorimetry (DSC) were used in timeresolved fashion to optimise the photopolymerisation time, resulting to be 20 min. The polymerisation of the organic part and the condensation of the siloxane groups were investigated by the combined use of DSC, Fourier Transform InfraRed (FTIR) and solid state Nuclear Magnetic Resonance (NMR) spectroscopies, showing that, whereas a complete organic polymerisation degree was reached, the condensation of the silica component was not completed. Dynamical Mechanical Spectroscopy (DMS) evidenced that: (1) the copolymerisation of the silane with the Zr12 oxocluster without MMA yields materials with very poor mechanical thermoproperties; (2) the Zr12 oxocluster copolymerised with MMA gives very stiff but fragile hybrids; (3) the ternary system yields instead flexible materials, which are endowed with outstanding thermomechanical properties. The optimised formulation was used for the deposition of coatings on wood (Larex), which were analysed by Scanning Electron Microscopy (SEM), contact angles measurements and tested toward flameresistance.
A1562 – Chemical aspects of wood modification by sol–gel-derived silica
It has been shown that tetraethoxysilane-derived precursors are suitable solutions for impregnating pine sapwood to improve its dimensional stability. Tailored sol–gel syntheses result in precursors with nano-scaled silica species which are able to penetrate into the cell walls of wood. The physical fixation of those species inside the cell walls was verified by ESEM/EDX investigations. There is evidence that the silica species are chemically bonded to wood components. Non-reacted alkoxy groups can exist in the wood composites after impregnation. The
amount of these organic residues depends on the composition of the precursors, especially their condensation degree and reactivity. Treatments for finishing the composites after the impregnation step to get clean products and stable properties are discussed in this context. An explanation of the complex relationship between solids content in the impregnation solutions and percentage weight gain and bulking of the composites is given. It can be demonstrated that high WPG values ([20 %) are pre-conditions for an effective protection of the resulting composites but they only guarantee efficient improvements if connected with the incorporation of the inorganic component inside the cell walls. Therefore, the sol–gel syntheses have to
be carried out in such a manner that very small (2 nm) as well as reactive species are sufficiently available. This demands syntheses using sub-stoichiometric water contents (H2O/TEOS4, better2).
A1545 – Kinetic models comparison for nonisothermal steam gasification of coal–biomass blend chars
The nonisothermal thermogravimetric method (TGA) was applied to a bituminous coal (PT), two types of biomass, chestnut residues (CH) and olive stones (OS), and coal–biomass blends in order to investigate their thermal reactivity under steam. Fuel chars were obtained by pyrolysis in a fixedbed reactor at a final temperature of 1373K for 30 min. The gasification tests were carried out by thermogravimetric analysis from room temperature to 1373K at heating rates of 5, 10 and 15Kmin?1. After blending, no significant interactions were detected between PT and CH during cogasification, whereas deviations from the additive behaviour were observed in the PT–OS blend. However, for the two coal–biomassblends, the gasification behaviour resembled that of the individual coal, as this component constituted the larger proportion of the blend. The temperatureprogrammed reaction (TPR) technique was employed at three different heating rates to analyze noncatalytic gas–solid reactions. Three nthorder representative gas–solid models, the volumetric model (VM), the grain model (GM) and the random pore model (RPM)
were applied in order to describe the reactive behaviour of the chars during steam gasification. From these models, the kinetic parameters were determined. The best model for describing the reactivity of the PT, PT–CH and PT–OS samples was the RPM model. VM was the model that best fitted the CH sample, whereas none of the models were suitable for the OS sample.
A1543 – Influence of torrefaction on the grindability and reactivity of woody biomass
The use of biomass to produce energy is becoming more and more frequent as it helps to achieve a sustainable environmental scenario. However the exploitation of this fuel source
does have drawbacks that need to be solved. In this work, the torrefaction of woody biomass (eucalyptus) was studied in order to improve its properties for pulverised systems. The
process consisted in a heating treatment at moderate temperature (240, 260, 280 °C) under an inert atmosphere. The grindability of raw biomass and the treated samples was
compared and an improvement in the grindability characteristics was observed after the torrefaction process. Thermogravimetric analysis of the samples was carried out in order to
study their reactivity in air. The DTG curves of the torrefied biomass showed a double peak nature. The kinetic parameters were calculated for each reaction stage. The torrefaction
process was found to influence the parameters of the first stage, whereas those corresponding to the second remained unaffected.
A1542 – Influence of storage time on the quality and combustion behaviour of pine woodchips
The current situation in the energy sector suggests the possibility of using biomass in co-combustion systems as an alternative to other fuels. In the case of the North of Spain the amount of forest residues that is generated guarantees it as a valuable source of energy for the future. However, an effective exploitation of these residues must first overcome a number of serious problems such as transport, storage, handling and pre-treatment, to meet the requirements of the power plants. The aim of this work is to study the influence of storage time on the moisture content and chemical and combustibility properties of pine woodchips. Their combustibility behaviour was evaluated by means of the following tests: heating value, ash composition, slagging/fouling indices, and the combustion profiles obtained from TG analysis. As a result of the weather conditions in the North of Spain open-air storage in the area under study is not suitable for dry pine woodchips, although their combustion behaviour remains practically unaltered.
A1539 – Thermal behaviour and kinetics of coal/biomass blends during co-combustion
The thermal characteristics and kinetics of coal, biomass (pine sawdust) and their blends were evaluated under combustion conditions using a non-isothermal thermogravimetric method (TGA). Biomass was blended with coal in the range of 5–80 wt.% to evaluate their co-combustion behaviour. No significant interactions were detected between the coal and biomass, since no deviations from their expected behaviour were observed in these experiments. Biomass combustion takes place in two steps: between 200 and 360 °C the volatiles are released and burned, and at 360–490 °C char combustion takes place. In contrast, coal is characterized by only one combustion stage at 315–615 °C. The coal/biomass blends presented three combustion steps, corresponding to the sum of the biomass and coal individual stages. Several solid-state mechanisms were tested by the Coats–Redfern method in order to find out the mechanisms
responsible for the oxidation of the samples. The kinetic parameters were determined assuming single separate reactions for each stage of thermal conversion. The combustion process of coal consists of one reaction, whereas, in the case of the biomass and coal/biomass blends, this process consists of two or three independent reactions, respectively. The results showed that the chemical first order reaction is the most effective mechanism for the first step of biomass oxidation and for coal combustion. However, diffusion mechanisms were found to be responsible for the second step of biomass combustion.
A1513 – CFD analysis of the modification of the furnace of a TG–FTIR facility to improve the correspondence between the emission and detection of gaseous species
A Fourier transform infrared spectrometer (FTIR) was coupled to thermogravimetric (TG) experimental equipment to determine the products of the thermal decomposition of several biomass samples both qualitatively and quantitatively. Working conditions for the TG device were simulated in a CFD model to analyse gas flux difficulties, embedding different models included in ANSYS FLUENT 12.1.4, including programming temperature control and devolatilisation kinetics, through User-Defined Functions. Based on the CFD results, an improvement to the experimental equipment was designed, simulated and implemented. A comparison between data from the original and the improved equipment was performed, including both experimental and simulated data.
The objective of this study was to develop a methodology for the determination of the maximum sampling error and confidence intervals of thermal properties obtained from hermogravimetric analysis (TG), including moisture, volatile matter, fixed carbon and ash content. The sampling procedure of the TG analysis was of particular interest and was conducted with care. The results of the present study were compared to those of a prompt analysis, and a correlation between the mean values and maximum sampling errors of the methods were not observed. In general, low and acceptable levels of uncertainty and error were obtained, demonstrating that the properties evaluated by TG analysis were representative of the overall fuel composition. The accurate determination of the thermal properties of biomass with precise confidence intervals is of particular interest in energetic biomass applications.
A1455 – Catalytic effects of Fe, Al and Si on the formation of NOX precursors and HCl during straw pyrolysis
The catalytic effects of iron, aluminum or silicon on the formation of NOX precursors (HCN, NH3 and HNCO) and HCl during wheat straw pyrolysis were studied using a thermogravimetric analyzer (TG) coupled with a Fourier transform infrared (FTIR) spectrometer in argon atmosphere. The results show that the presence of iron, aluminum or silicon decreases conversion of straw-N into NH3 with the sequence of Fe[Si[Al. The iron or silicon addition suppresses N-conversion into HCN and HNCO, and the aluminum addition has no notable influence on HCN emission during pyrolysis. The share of N-conversion to NH3 and HCN increases, but that to HNCO and NO decreases a little in the presence of added iron, aluminum or silicon. The addition of SiO2 results in the highest HCl removal efficiency.
A1443 – Characterization of the thermal degradation and heat of combustion of Pinus halepensis needles treated with ammonium-polyphosphate-based retardants
The thermal degradation behavior of P. halepensis needles treated with two ammonium-polyphosphate-based commercial retardants was studied using thermal analysis (DTG) under nitrogen atmosphere. Moreover, for the same experimental material, the heat of combustion of the volatiles was estimated based on the difference between the heat of combustion of the fuel and the heat contribution of the charred residue left after pyrolysis. The heat of combustion of the volatiles was exponentially related to the retardant concentration of the samples. In the range of
retardant concentrations from 10 to 20% w/w the mean reduction percentage of the heat of combustion of the volatiles, with respect to untreated samples, was 18%
A1387 – Production of Calcium Carbide from Fine Biochars
Carbon is the most abundant source of energy and chemicals on the earth. Biomass produced from photon-activated conversion of atmospheric CO2, and biomass fossils such as
coal and petroleum are all carbon-rich sources. In around only one century of heavy industrial use of petroleum, this hydrocarbon source has already depleted to a point of a
widespread concern over its scarcity in the decades to follow. Biocarbon, also known as biochar, can be readily produced from a vast sustainable supply of lignocellulosic
biomass through pyrolysis. It is often in fine form and characterized by low mechanical strength and high activity in comparison to coal-derived chars. The ability to use biochar
for the production of chemicals with high energy efficiency will largely alleviate our dependence on shrinking petroleum feedstock. Herein, we show reaction of fine biochars with fine
CaO for the production of CaC2, an important starting material for production of many commodity chemicals. The process offers the potential to redirect the carbon conversion
A1386 – Pyrolysis gases released during the thermal decomposition of three Mediterranean species
The aim of this work is to improve the understanding of the pyrolysis of species involved in fires of Mediterranean vegetation and to propose a description and a quantification of the gases released during their degradation. TG–MS and FTIR analyses were performed with three Mediterranean species: Cistus creticus, Myrtus communis and Genista corsica. The pyrolysis behaviour of these plants was studied. TG curves show differences between plants. Then, the evolution of the pyrolysis gases was investigated. The main gases released were H2O, CO2, CO, CH4 and H2. The use of FTIR and mass spectrometry allowed identifying the different stages of the gas formation. The last part of the study was devoted to the gas quantification
from the results obtained with the TG–MS. The results showed variations of the gas composition in function to the temperature and of the plant species
A1385 – Combustion and pyrolysis characteristics of Tunçbilek lignite
In this study, thermal characteristics and kinetic parameters of cleaned Tunçbilek lignite were determined by using a Setaram Labsys DTA/TG/DSC thermal analysis system both for combustion and pyrolysis reactions. Experiments were performed at a heating rate of 10°C min–1 under reactive (air) and inert (nitrogen) gases up to 1000°C. Non-isothermal heating conditions were applied and reaction intervals were determined for combustion and pyrolysis reactions from obtained curves. The combustion properties were evaluation by considering the burning profile of the lignite sample. Burning temperatures and rate of combustion were determined from TG/DTG curves. Calorific value of the lignite sample was measured by DSC curve and compared with the adiabatic bomb calorimeter result. In addition to investigation of the combustion properties, pyrolysis characteristics of the lignite sample were investigated
based on TG/DTG/DSC curves. Activation energy (E) and pre-exponential factor (A) were calculated from the TG data by using a Coats–Redfern kinetic model both for combustion and pyrolysis reactions of cleaned Tunçbilek lignite.
A1384 – Influence of some minerals on the cellulose thermal degradation mechanisms. Thermogravimetic and pyrolysis-mass spectrometry studies
The influence of different inorganic salts (MgCl2, ZnCl2, NiCl2 and H2PtCl6) on the primary mechanisms of cellulose thermal degradation has been conducted by using thermogravimetric (TG-DTG) and pyrolysis-mass spectrometry (Py-MS) analysis at low heating rate (10°C min–1 ) from ambient temperature to 500°C. The results clearly demonstrate that the used salts influence the primary degradation mechanisms. Furthermore, we can assume that some inorganic salts could be considered as specific catalysts and some others as inhibitors. MgCl2 promotes selectively initial low temperature dehydration as observed both by TG and Py-MS. ZnCl2 strongly changes the thermal behaviour of impregnated sample. The maximum mass loss rate temperature is shifted to lower temperature and on the basis of our results we can conclude that ZnCl2 acts as catalyst in all primary degradation mechanisms. NiCl2
and H2PtCl6 do not modify significantly the cellulose thermal behaviour but change the composition of both produced gases and liquids suggesting that these minerals catalyse some secondary reactions.
A1383 – Thermal degradation of lignins isolated from wood
The lignin preparations isolated from pine and beech wood were subjected to a thermogravimetric analysis (TG). The lignin preparations were also used to obtain samples of different degrees of thermal degradation characterised by mass-losses in the interval from 10 to 60% of their initial mass. These samples were subjected to elementary analysis and the content of methoxy groups. It was observed that the content of these functional groups declined in products in which the degree of thermal degradation exceeded 30%, which corresponds to temperatures over 450°C.
A1381 – Uncertainty Determination Methodology, Sampling Maps Generation and Trend Studies with Biomass Thermogravimetric Analysis
This paper investigates a method for the determination of the maximum sampling error and confidence intervals of thermal properties obtained from thermogravimetric analysis (TG analysis) for several lignocellulosic materials (ground olive stone, almond shell, pine pellets and oak pellets), completing previous work of the same authors. A comparison has been made between results of TG analysis and prompt analysis. Levels of uncertainty and errors were obtained, demonstrating that properties evaluated by TG analysis were representative of the overall fuel composition, and no correlation between prompt and TG analysis exists. Additionally, a study of trends and time correlations is indicated. These results are particularly interesting for biomass energy
A1031 – Pyrolysis characteristics and global kinetics of coconut and cashew nut shells
Coconut and cashew nut shells are two typical biomass wastes abundant in most of the tropical countries. However, despite their enormous
potential as energy sources, they are hardly studied and their thermal characteristics are still not well known. In this study, both biomasses are
thermally degraded through thermogravimetry and their characteristics such as devolatilisation profiles and kinetics are analyzed, from 250 to 900°C,
in an inert atmosphere, at two different heating rates, and compared with wood pellets. The results show that their pyrolysis profiles are different from
that of the commonly studied woody biomass. In fact, they present two different peaks instead of the one overlapping peak, for hemicellulose and
cellulose. In addition, they present activation energies ranging from that are slightly above the commonly known maximum for biomass. At 10 and
20°C/min the activation energy varied from about 130 to 174 and 180 to 216 kJ/mol, for cashew and coconut shells, respectively.
A0828 – Pyrolysis of wood impregnated with phosphoric acid for the production of activated carbon: Kinetics and porosity development studies
The pyrolysis of impregnated wood for the production of activated carbon is investigated. Laboratory experiments are performed in a TG for
heating rates of 10°C/min and 20°C/min and a mathematical model for the kinetics of the pyrolysis process is developed and validated. The effect
of the temperature and of the time duration of the pyrolysis process on the specific surface of the activated carbon is examined on the basis of
experiments conducted in a crossed bed reactor. Results indicate that the temperature and the residence time in the pyrolysis reactor may be
optimised. Indeed, it is found that the maximum specific surface of the end product is obtained for pyrolysis processes conducted at a temperature
of 400°Cfor a time period of 1 h.
A0797 – Thermogravimetric study of the pyrolysis of biomass residues from tomato processing industry
There is an increasing concern with the environmental problems associated with the increasing CO2, NOx and SOx emissions resulting from the
rising use of fossil fuels. Renewable energy, mainly biomass, can contribute to reduce the fossil fuels consumption. Biomass is a renewable
resource with a widespread world distribution. Tomato processing industry produces a high amount of biomass residue (peel and seeds) that could
be used for thermal energy and electricity. A characterization and thermogravimetric study has been carried out. The residue has a high HHVand
volatile content, and a low ash, and S contents. A kinetic model has been developed based on the degradation of hemicellulose, cellulose, lignin
and oil that describe the pyrolysis of peel, seeds and peel and seeds residues.
A0565 – Production and characterisation of activated carbon from wood components in powder: Cellulose, lignin, xylan
"The aim of this work was to characterise the activated carbon produced from wood and its basic components: cellulose, lignin and xylan
(hemicelluloses). Two ways of activation were tested: simple pyrolysis under N2 and thermal treatment of the material impregnated with
KOH (KOH-activation). Concerning the pyrolysis, simultaneous measurements of DTA-TGA allowed to compare the heat of reaction and the
decomposition rate of the 3 wood components. Moreover it was shown that only the char from cellulose has a significant BET-surface area of
pores. The KOH-activated carbons from wood and wood components were characterised by their BET surface area, their spectra in
temperature programmed desorption (TPD) up to 1173 K and by their capacity to adsorb pollutant compounds in aqueous phase such as
phenol and methylene blue. It was shown that the theoretical models of Langmuir and Freundlich satisfactorily fit to the adsorption isotherms
of these pollutants, moreover most of the parameters of these theoretical models rank as the BET-surface area of pores."
A0512 – Combustion and pyrolysis characteristics of tunçblek lignite
In this study, thermal characteristics and kinetic parameters of cleaned Tunçbilek lignite were determined by using a Setaram Labsys DTA/TG/DSC thermal analysis system both for combustion and pyrolysis reactions. Experiments were performed at a heating rate of 10°C min-1 under reactive (air) and inert (nitrogen) gases up to 1000°C. Non-isothermal heating conditions were applied and reaction intervals were determined for combustion and pyrolysis reactions from obtained curves. The combustion properties were evaluation by considering the burning profile of the lignite sample. Burning temperatures and rate of combustion were determined from TG/DTG curves. Calorific value of the lignite sample was measured by DSC curve and compared with the adiabatic bomb calorimeter result.
In addition to investigation of the combustion properties, pyrolysis characteristics of the lignite sample were investigated based on TG/DTG/DSC curves. Activation energy (E) and pre-exponential factor (A) were calculated from the TG data by using a Coats-Redfern kinetic model both for combustion and pyrolysis reactions of cleaned Tunçbilek lignite.
A0510 – Thermal analysis (TG-DTA) and drift spectroscopy applied to investigate the evolution of humic acids in forest soil at different vegetation stages
Humic acids (HAs) extracted from soils developed under two Norwegian spruce (Picea abies, (L.) Karst) subalpine forests of northern Italy were characterized using chemical, thermal (TG-DTA) and spectroscopic (DRIFT) analyses. The samples were taken from five sites which differed in orientation (northern and southern exposure) and vegetal cover at different old age: grassland, regeneration, immature and mature stands. In general, the thermal patterns of HAs were similar (three exothermic reactions appeared around at 300, 400 and 500°C) in both sites in grasslands and regeneration while a considerable modification appeared in HA from stands of different age at northern and southern exposure site. DRIFT spectroscopy confirmed the differences observed through TG-DTA analysis. In particular the main structural changes were ascribed to modification of carbonyl group and of CH stretching in aliphatic components in each HAs from different sites.
A0502 – Thermogravimetric analysis and kinetics modeling of isothermal carbonization of olive wood in inert atmosphere
The kinetics of olive wood carbonization is investigated by means of isothermal thermogravimetric analysis method. Measurements were carried out in a thermobalance for different fixed temperatures between 498 and 648 K. A two-stage semi-global kinetic model consisting of four sequential steps was proposed to derive kinetic parameters. The olive wood is classified in three pseudo-components. For the first two, similar thermal degradation mechanisms take place in a single reaction step. For the third, the thermal degradation takes place in two consecutive steps. The isothermal conditions allow the kinetic constants (activation energy and pre-exponential factors) to be estimated by means of the analytical solution of the mass conservation equations. An overall good agreement was obtained with activation energy values available in the literature.
A0461 – Investigation on the effects of fire retardants on the thermal decomposition of wood-derived rayon fiber in an inert atmosphere by thermogravimetry-mass spectrometry
The effects of three retardants, NH4Cl, (NH4)2SO4 and NH4H2PO4, on the thermal decomposition of wood-derived rayon fiber have been investigated by thermogravimetry-mass spectrometry (TG-MS) analysis. The main thermal decomposition of pure wood-derived rayon fiber, like other cellulosic materials, takes place rapidly over a narrow temperature range. When wood-derived rayon fiber is impregnated with the fire retardants, there is a shift in the temperature of maximum rate of weight loss to the values lower than 300°C, while the amount of char residue formed is increased. The fire retardants have resulted in the increase of the intensity (peak area) of m/z=18 and 28 MS signals, but the decrease of the intensity of m/z=44 MS signals. Furthermore, it appears with a relative decrease of the intensity of m/z=60 and 68 MS signals, which means that low levels of levoglucosan and levoglucosenone are recorded in the presence of the fire retardants. Finally, the relationship between char residue formation and the relative quantity of levoglucosan is determined.
A0452 – Assessment of various kinetic models for the pyrolysis of a microgranular cellulose
The kinetics of pyrolysis of a micro-crystalline cellulose in nitrogen were studied from TGA and DTG data, obtained with two different modes of heating: a dynamic mode at constant heating rates between 1 and 11°C/min and an isothermal mode at various temperatures, kept constant between 280 and 320°C. In isothermal mode, it appeared very clearly that the mass depletion shows a sigmoid profile characteristic of an auto-accelerated reaction process. This behaviour is consistent with kinetics of nuclei-growth, well represented by the models of Avrami-Erofeev (A-E) and of Prout-Tompkins (P-T) type. All the other kinetic models commonly applied to the thermal decomposition of solids revealed unsatisfactory. The TGA and DTG data were, thus, found ideally simulated from a reaction scheme consisting in two parallel reactions, termed 1 and 2, each one described by the kinetic law: dx/dt=-A-E/RTxn(1-0.99x)m. Reaction 1 is related to the bulk decomposition of cellulose and is characterised by the set of parameters: E1=202 kJ/mol; n1=1; m1=0.48. Reaction 2 is related to the slower residual decomposition, which takes place over approximately 350°C and affects only 16% by weight of the raw cellulose. With m2 constrained to 1, the optimised parameters of this reaction were: E2=255 kJ/mol; n2=22. Finally, the proposed model allowed to correctly fit not less than to 10 sets of ATG-DTG data, isothermal and dynamic.
A0431 – Chemical and thermal analysis of the biopolymers in thyme (Thymus vulgaris)
Thyme (Thymus vulgaris) has been known, long time ago, for its aromatic properties. It contains essential oils and polymers such as cellulose (mixture of hemicellulose and cellulose) and lignin. The thyme, studied in this work, was gathered from the same place, in the period from November 1999 to October 2000. The chemical analysis (water, total ash, essential oils, extractive substances, cellulose, holocellulose and lignin) can be used roughly in the characterisation of the four periods that correspond to the four seasons of the year. The cellulose level was found to be more than lignin level in the wet periods (growth of the plant). The opposite was found in the dry periods. The total ash and essential oil levels were found to be high during the period of high pluviometry. The thermal decomposition of cellulose and holocellulose was found to fit well with the first-order kinetics. The activation energy, under air flow, was 185 and 196 kJ mol-1 for cellulose and holocellulose, respectively. The maximum decomposition rate and thermal analysis heating rate of lignin were found to have a direct linear relationship.
A0382 – Kinetic study of the thermal decompositions of biopolymers extracted from various plants
A knowledge of the kinetics of decomposition of biopolymers on heating is important mainly in two domains: forest fires and the incineration of biomass for the production of electric energy. For the study by thermogravimetry of biopolymers (cellulose, holocellulose and lignin), samples of several Mediterranean plants were used.
A0374 – Decomposition of bio-polymers of some mediterranean plants during heating.
Forest fires are a plague for all countries in the world. Many factors can induce them. The organic matter (fuel) in the plant, is often responsible for the start of the fire. The bio-polymers and mainly the cellulose decompose at about 300°C with flammable evolved gas. This decomposition is first order, and the activation energy is about 180 kJ mol-1. On the other hand, the degradation of the lignin seems more complex, but we observed on many samples, a linearly decomposition of the lignin vs. the heating rate (in the interval close to the start of the forest fire, 300 to 3000°C h-1). The decomposition of the plant during the heat is mainly dependent on the cellulose level. This degradation is also slightly dependent on the lignin level mainly if the lignin present in this plant is less stable
A0353 – Etude comparative de cinq végétaux méditerraneens par analyses thermique et chimique
The comparative thermal and chemical study was done on five mediterranean plants: Acacia dealbata, Quercus coccifera, Rosmarinus officinalis, Thymus vulgaris, Ulex parviflorus. Results were independent of the drying way of samples (110°C, 60°C or lyophilisation). The correlation between the maximum decomposition rate at about 300°C and the content of cellulose was confirmed. The samples cut on the same foot of Ulex parviflorus, in spring, produced, for the thorns and sprigs, a minimum in cellulose content, and a maximum in lignine content. The results were inverse in winter.
A0352 – Application de la spectroscopie infra rouge à l’étude du comportement thermique de la cellulose. Partie I
In this work, we describe and evaluate the use of the Fourier transform infra red (FTIR) spectroscopy in DRIFT mode (diffuse reflectance infra red Fourier transform) in an environmental device to follow the functional evolution of cellulose during thermal treatments. The potentialities (and difficulties) of the technic are given.
A0349 – Etude comparative par analyses thermique et chimique de quelques végétaux méditerranéens.
Thermal analysis can be used for the behaviour of plants during heating and most particularly in the risk prevention of forest fire. Cellulose, holocellulose and lignin are the most important compounds determinated by analytical procedures in six mediterranean vegetals: Acacia dealbata, Pinus halepinsis, Quercus coccifera, Rosmarinus officinalis, Thymus vulgaris, Ulex parviflorus. TG-DTA is applied to the powders obtained after drying (110°C), pounding and sifting. The rate of pyrolysis about 300°C allows a semi-quantitative estimate of the cellulose present in the vegetal and its flammability.
A0342 – Analyse thermique de la cellulose et de quelques dérivés etherifiés et estérifiés.
The cellulose and its derivatives are used more and more, especially like excipients in pharmaceutical industry.The identification of cellulose and some of its derivatives: cellulose acetophthalate, hydroxy-propylmethylcellulose acetosuccinate, sodium carboxymethylcellulose, hydroxysthylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, hydroxypropylmethyl-cellulose phthalate, is possible by thermal analysis (simultaneous DTA-TG). For that reason, one consider the temperature of the DTA maximum peaks and the DTG minimum peaks. This identification is easy when these products are a majority in pharmaceutical specialities.
A0335 – Etude par analyse thermique de quelques végétaux méditerranéens.
Thermal analysis can be used for the study of the behaviour of plants during heating, and most particularly in the risk prevention of forest fire.Simultaneous thermal analysis (DTA-TG) of some mediterranean vegetals (needles of Pinus halepensis, leaves of Quercus coccifera; leaves of Rosmarinus officinalis; prickles, flowers and branchs of Ulex parviflorus; leaves and branchs of Acacia dealbata; leaves of Cistus albidus) shows the presence of several exothermic peaks. The first one, about 300°C, is responsible for a brutal ignition of the evolved gas. We compare the different samples by using the DTA and DTG peak temperatures and the weight loss by volatilization at 300°C.
A0329 – Caractérisation par analyse thermique de la lignine, de la cellulose et de quelques uns de ses dérivés éthérifiés.
Cellulose and its derivatives (methyl cellulose, sodium carboxymethyl cellulose, hydroxymethyl cellulose and hydroxypropyl cellulose) used as excipients in pharmaceutical industry can be characterised by simultaneous thermoanalytical (DTA and TG) methods, based on the temperatures of exothermic peaks. Lignine cellulose can be identified by taking into account the difference in temperature between the first exothermic DTA peak and the corresponding DTG peak.
A0315 – Décomposition thermique des grignons d’olive. Influence des différents paramètres
A0313 – Comportement thermique de quelques végétaux méditerranéens
Thermal analysis can be used for the study of the behaviour of plants during heating, and
most particularly in the risk prevention of forest fire.
Simultaneous thermal analysis (DTA-TG) of some mediterranean vegetals (needles of Pinus
halepensis, leaves of Quereus eoeeifera; leaves of Rosmarinus offieinalis; prickles, flowers and
branehs of Ulex parviflorus; leaves and branehs of Acacia dealbata; leaves of Cistus albidus)
shows the presence of several exotherrnie peaks. The first one, about 300°C is responsible for a
brutal ignition of the evolved gas. We compare the different samples by using the DTA and DTG
peak temperatures and the weight loss by volatilization at 300°C