Investigation of fast-heating pyrolysis of sapropelitic coals by mass-spectrometric thermal analysis

The products of the fast-heating pyrolysis of two sapropelitic coals, from Taymalyr and Budagovo, in a helium flow were studied by differential mass-spectrometry (in the mass number range from 2 to 110). Equations describing the kinetics of the process under different conditions were produced. The mass-spectra of the sapropelitic coals are similar to those of switch oil evaporation products, which indicates the similarity of their chemical structures. The results obtained allowed the conclusion that the fundamental chemical structure of sapropelitic coals is a polycyclic hydrocarbon matrix of CH₂ and CH groups with joinednalkane chains containing end-capping CH₃ and COOH groups.

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Zusammenfassung Mittels Differential-Massenspektroskopie im Massenzahlbereich von 2 bis 110 wurden die Produkte einer in einem Heliumstrom vollzogenen Schnellheizpyrolyse von Faulschlammkohle aus Taymalyr und Budagovo untersucht. Zur Beschreibung der Kinetik des Prozesses unter verschiedenen Bedingungen wurden Gleichungen entwickelt.Die Massenspektren der Faulschlammkohlen gleichen dennen von Verdampfungsprodukten aus Schalterölen, was auf die Ähnlichkeit ihrer chemischen Struktur hinweist. Die erhaltenen Ergebnisse erlauben den Schluß, daß die grundlegende chemische Struktur der Faulschlammkohlen eine polycyclische Kohlenwasserstoffmatrix aus CH₂- und CH-Gruppen ist, von der n-Alkanketten mit endständigen CH₃- und COOH-Gruppen abzweigen.

     

餐饮垃圾热解制取生物燃油的实验研究

主要研究温度、餐饮垃圾种类以及催化剂对餐饮垃圾热解所制生物燃油的产率和品质的影响。结果表明,猪肉和米饭的最佳产油温度均为410℃,白菜的最佳产油温度为450℃。米饭、白菜、猪肉的产油率分别为45.02%、25.60%、71.26%。采用氧弹热量计对其热值进行测定,米饭和白菜热解油的高位热值较低,分别为18.30MJ/kg和17.49MJ/kg;而猪肉热解油的高位热值为36.57 MJ/kg, 并且黏稠度较高。催化剂Co-MCM-41的催化效果明显,使餐饮垃圾的产油率由41.99%提高到66.30%,同时使热解油中的含氧化合物明显降低,而烷烃类和烯烃类的含量明显增加,高位热值由30.30MJ/kg提高到32.74MJ/kg。通过物理吸附仪对新制备的和使用一次后再生的催化剂Co-MCM-41进行表征,结果表明,催化剂Co-MCM-41再生后孔容、孔径和比表面积变化不大,性质基本不变,活性依然存在。
     

A thermal analysis study of the pyrolysis of Victorian brown coal

The pyrolysis in a nitrogen atmosphere of three run-of-mine samples and a suite of lithotype samples of Victorian brown coal has been investigated using simultaneous TG/DTG/DTA. The TG, DTG curves provide parameters which represent the pyrolysis properties of coal. The pyrolysis profiles can also be used as fingerprints of brown coal lithotypes and hence are of value in the context of the broad characterization of coal.

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Zusammenfassung Mittels Pyrolyse in Stickstoff wurden unter Anwendung simultaner TG, DTG und DTA drei Förderproben und eine Reihe von Lithotypenproben von Viktoriabraunkohle untersucht. Die TG und DTG Kurven liefern Parameter, die für die Pyrolyseneigenschaften von Kohle charakteristisch sind. Die Pyrolysenprofile können auch als Fingerabdruck von Braunkohlenlithotypen benutzt werden und sind deshalb im Zusammenhang mit einer umfassenden Charakteristik der Kohle von Bedeutung.

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The Coal Corporation of Victoria, is acknowledged for the provision of the brown coal samples and the corresponding proximate and ultimate analysis data.     

The examination of bromine-containing fire retardants in unsaturated polyester resins by means of pyrolysis residue analysis

A method has been developed for following the bromine and weight losses of fire retarded UPE as a function of temperature. The results obtained by this method indicate that those bromine–containing fire retardants which exhibit a linear LOI–bromine concentration relation, the bromine concentration in the pyrolytically produced fuel remains more or less constant, while for those materials which deviate positively from the linear relation (that is they are more efficient), the bromine concentration in the fuel tends to peak at certain temperatures. When this effect is combined with variation in composition of the pyrolytic fuel, a situation can arise where a high bromine concentration coincides with a fuel particularly sensitive to flame quenching by bromine. Such a combined effect may be the reason why some brominated fire retardants are far more effective than others.     

Evaluation of the thermal stability of biodiesel blends of castor oil and passion fruit

The diversity of raw materials and technological routes employed in the biodiesel production has resulted in products with different chemical properties. This non-uniformity in the biodiesel composition may influence to the fuel quality. The aim of this study was to evaluate biodiesel blends of passion fruit and castor oil in different proportions and their thermal stability. Biodiesel blends of passion fruit and castor oil presented parameters in the standards of the Petroleum, Natural Gas and Biofuels National Agency. The TG curves indicated that castor oil biodiesel was more stable. Passion fruit biodiesel has a high content of oleic and linoleic acids, which are more susceptible to oxidation. Biodiesel blend of passion fruit and castor oil 1:1 increased the thermal stability in relation to passion fruit biodiesel. Biodiesel blend of passion fruit and castor oil 1:2 presented higher thermal stability, because castor oil has a high content of ricinoleic acid.     

Evaluation of four ABS resins by thermal analysis

Four new commercial grades of rubber toughened ABS (acrylonitrile-butadienestyrene) terpolymers were characterized by differential scanning calorimetry (DSC), mechanical analysis and gel permeation chromatography (GPC). These rubber toughened ABS molding compounds were manufactured by a new blended technology to yield resins which offer a broad range of flow properties and levels of toughness. Based upon DSC estimates of the level of rubber included, the four ABS compounds can be divided into two groups; the first has about 11 wt.% butadiene and the second near 18 wt.%. In addition, two styrene-acrylonitrile copolymers with different average molecular weights were found blended within each ABS group. By this blending process four resins are produced with impact strengths ranging from below three to near seven ft-lb in^–1. These analytical results show that a resin's impact strength is enhanced not only by increasing the level of rubber particles in a given ABS compound but also by raising the molecular weight of the SAN which is blended into the terpolymer.Dedicated to Professor Bernhard Wunderlich on the occasion of his 65th birthdayThe authors acknowledge useful discussions with L. L. Blyler, Jr., X. Quan and L. Shepherd and A. Hale for his scanning electron microscopy results. GPC results were carried out by Jordi Associates.     

Evaluation of the combustion behaviour of perhydrous coals by thermal analysis

Summary Perhydrous coals are characterized by a high hydrogen content and exhibit a modified composition and physico-chemical properties in comparison with normal coals. These modifications affect the behaviour of perhydrous coals during pyrolysis and, therefore, may have an influence on the subsequent combustion process. In this work the combustibility behaviour of a series of perhydrous coals was evaluated in order to study the effect of hydrogen enrichment during the thermal treatment of the coals in an oxidant atmosphere. To this end temperature programmed combustion tests for the coals, and air isothermal (500°C) reactivity tests for their chars, were carried out in a thermogravimetric analyser. A clear relationship between the combustion behaviour of the perhydrous coals, and the aromatic to aliphatic hydrogen ratio was found.     

Determination of kinetic parameters for pyrolysis of cellulose and cellulose treated with ammonium phosphate by differential thermal analysis and thermal gravimetric analysis

Activation energy E, pre-exponential factor k₀, and reaction order n for the pyrolysis of α-cellulose and cellulose modified with dihydrogen ammonium phosphate were determined by means of TGA and DTA. The results obtained are E = 53.5 kcal./mole, k₀ = 10^18.8 min.^?1, n = 1 for α-cellulose and E = 32 kcal./mole, k₀ = 10¹² min.^?1, n = 1 for modified cellulose. A new theory of DTA was also developed. This theory, in which it is concluded that the peak value of DTA curve coincides with the maximum rate of reaction, may be used not only for the present work but is generally applicable to DTA studies. Detailed procedures of experiment and theory are described.     

Evaluation of a glycerol derived biofuel by thermal analysis

This work describes thermal analysis evaluation of a glycerol derived compound (fatty acid esters of (2,2-dimethyl-1,3-dioxolan-4-yl) methanol) developed to work as a biofuel. Mixtures of these ketal–glyceryl esters with fatty acid methyl esters typical of soybean biodiesel were prepared and evaluated in relation to biodiesel critical thermal properties such as temperature of crystallization, thermal stability and volatilization measured by differential scanning calorimetry and thermogravimetric analysis. The volatility of the products containing fatty acid methyl esters and (2,2-dimethyl-1,3-dioxolan-4-yl) methyl esters could be predicted by thermogravimetric analyses conducted in nitrogen that avoided time consuming distillation and greatly reduced material expenditure.     

Sinterability enhancement in semicokes obtained by controlled pyrolysis of a petroleum residue

Self-sintering semicokes were prepared by pyrolysis of an aromatic petroleum residue at 460–480 °C and pressures of 0.1–1.0 MPa. The evolution of gases and thermoplasticity from resultant semicokes were monitored by TGA and TMA, respectively. Sintering behaviour of the semicokes is extremely sensitive to pyrolysis conditions which determine contents of volatile matter and binder phase. Semicokes produced at 1.0 MPa have high volatile contents with excessive plasticity. Changes of temperature and soak time, used to reduce volatile matter contents induce reductions to the plasticity and sintering. A lower pyrolysis pressure has a similar effect. Although the operational window is narrow, heat-treated compacts (2500 °C) can be made with high density (1.9 g cm⁻³) and bending strengths >75 MPa. Using high-temperature pyrolysis (460 °C) with a post-treatment at 350–400 °C eliminates light components, without decreasing sintering properties. Compacts from these powders also exhibit high density (1.9 g cm⁻³) with higher bending strengths >90 MPa, comparable or superior to mesocarbon microbeads (MCMB) obtained from the same precursor.     

Differential thermal analysis of some fibers containing chlorine

The differential thermal analysis curves of four fibers containing chlorine (Saran, Cordelan, Teklan and Kanekalon), and their blends, are influenced by experimental conditions, although not to the same extent as those of poly(vinyl chloride) resin in powder form. The curves were determined using two different (Du Pont) cells, and are discussed in terms of sample holder geometry and material composition. The importance of procedural variables in “fingerprint” applications of thermal analysis for routine fiber identification is re-emphasised.     

Evaluation of PCM/diatomite composites using exfoliated graphite nanoplatelets (xGnP) to improve thermal properties

This paper deals with the thermal performances of shape-stabilized phase change materials (SSPCM) for energy saving in various fields. This study enhanced thermal properties of SSPCM using exfoliated graphite nanoplatelets (xGnP). SSPCM, which contains the xGnP, was prepared by mixing and melting techniques for high dispersibility, thermal conductivity, and latent heat storage. In the experiment, we used hexadecane, octadecane, and paraffin as phase change materials (PCMs), and they have 254.7, 247.6, and 144.6 J g^?1 of latent heat capacity, and melting points of 20.84, 30.4, and 57.09 °C, respectively. The characteristics of SSPCMs were determined using SEM, DSC, FTIR, TG, TCi, and Energy simulation. SEM morphology showed homogenous dispersion of PCM and xGnP in the porous diatomite. DSC analysis results showed the latent heat capacity of SSPCM and SSPCM/xGnP composites, and TG analysis results showed the thermal reliability of the samples. Also, we checked the thermal conductivity of the SSPCM that contains xGnP, by TCi analysis.     

Investigation of pyrolysis of chinese coals using thermal analysis/mass spectrometry

TA/MS (thermal analysis coupled with mass spectrometry) was applied to the pyrolysis of Chinese coals with different ranks. A total of 13 Chinese coals were investigated. The samples were deliberately chosen to represent the 13 types of Chinese coals according to the Chinese coal classification system. The experiments were carried out in an argon atmosphere with a flow rate of 150 ml min^-1. The samples were heated from 40 up to 1200°C with a constant heating rate of 10 k min^-1. The main evolved pyrolysis products were identified through the on-line recorded mass spectra. The thermal and evolution behavior was compared between the coals. The results showed a strong thermal and evaluation behavior dependence on the coal rank. Different aliphatic fragments and also some aromatic substances, which are of environmental concern (BTX, PAHs), were found to be released depending on the different types of coal. This revised version was published online in July 2006 with corrections to the Cover Date.     

A study of the mixture of coal and residue of the vacuum distillation of crude oil by thermal analysis

Thermal analysis was used for investigating the effect of the addition of the residue obtained from crude oil vacuum distillation on the carbonization process of brown coal. The kinetic analysis of the experimental TG curves was carried out by using the Coats-Redfern equation and then to select the most likely mechanism (functiong (α)) for particular decomposition stages of brown coal and its mixture with the residue. In the brown coal carbonization process the nucleation of a new solid phase is predominant. In the temperature range of the decomposition of coal (620–820 K) the addition of residue results a change in the mechanism of the thermal decomposition process — in the mixture three-dimensional diffusion processes and one-dimensional diffusion occur, depending on the composition. Above 730 K (secondary carbonation processes) the most likely mechanism involves the nucleation of a new solid phase as well as diffusion processes.     

Evaluation of thermal analysis experimental data

The possibilities of the THERMOKIN software package for evaluation of experimental data of solid state thermal decomposition are described. The software package makes it possible to simulate the solid state reactions, to evaluate the results of various thermal analysis methods such as TG/DTG, DSC., evolved gas analysis etc. The software enabled us to choose the adequate model of solid state reactions, to calculate the parameters of reactions and the errors of the parameters. Using this software package the interpretation of the results obtained by various methods of thermal analysis as well as the determination of the optimal experimental conditions for the studied substances can be made.

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Zusammenfassung Die Möglichkeiten des Softwarepaketes THERMOKIN zur Auswertung experimenteller Daten von thermischen Feststoffzersetzungen werden beschrieben. Das Softwarepaket ermöglicht die Simulation von Feststoffreaktionen, die Auswertung der Ergebnisse von verschiedenen thermoanalytischen Methoden, wie z.B. TG/DTG, DSC., Analyse der entstehenden Gase usw. Durch das Softwarepaket wurde es ermöglicht, ein adäquates Modell für die Feststoffreaktion auszuwählen und die Reaktionsparameter sowie deren Fehler zu berechnen. Unter Anwendung dieses Softwarepaketes können einerseits die Ergebnisse aus den verschiedensten thermoanalytischen Verfahren interpretiert und andererseits die optimalen Reaktionsbedingungen für die jeweiligen untersuchten Substanzen ermittelt werden.

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Dedicated to Prof. Dr. H. J. Seifert on the occasion of his 60^th birthday     

Evaluation of the stability of substituted InF3 glasses by differential thermal analysis

The thermal properties and devitrification behaviour of substituted InF₃ glasses were studied by means of differential thermal analysis. A comparison of various simple quantitative methods to assess the level of stability of multicomponent fluoride glass systems was also made. Most of these methods are based on critical temperatures. In this paper, a new parameter,k _d(T), is introduced to the stability criteria. The stabilities of several substituted InF₃ glasses were evaluated experimentally and correlated with the activation energies of crystallization via this new kinetic criterion and compared with those evaluated by other criteria.     

Catalytical and thermal pyrolysis of polyolefins

Polyolefins have a high potential for alternative oil production since they contain only carbon and hydrogen atoms. By pyrolysis of these materials up to 95% can be obtained as oil and gas. Upgrading the products by catalytic cracking of polyolefins is a subject of growing interest in the last years as less energy is needed for the pyrolysis and more valuable products are formed. Numerous studies have been reported in which a variety of catalysts such as zeolites, silica-alumina, mesoporous MCM-41, solid acids and reaction conditions have been investigated. In our studies we used Lewis acids and mixtures of Ziegler–Natta catalyst such as TiCl₄, AlCl₃ to pyrolyse polypropylene. Experiments were carried out in a batch reactor as well as in a fluidized bed process. The pyrolysis temperature can be decreased by 100 °C compared to runs without catalysts. A drastic increase in the amount of low boiling compounds (C4 hydrocarbons) can be observed by the use of the catalysts instead of longer chained hydrocarbons.