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Showing papers on "Pyrolysis published in 1975"


Journal ArticleDOI
D. W. van Krevelen1
01 Aug 1975-Polymer
TL;DR: In this paper, it was shown that the amount of char and the incombustible gases that may be formed in thermal decomposition are very important quantitative measures of flame resistance.

855 citations


Journal ArticleDOI
TL;DR: The authors showed that partial pyrolysis at a lower temperature increases the char yield subsequently obtained after 1 h at 370°C at inert medium or in air, and that two competing sequences of cellulose pyrolys reactions are initiated by intermolecular dehydration and a char-free depolymerization leading to flaming combustion.

246 citations


Journal ArticleDOI
01 Apr 1975-Fuel
TL;DR: In this article, the thermal decomposition of the organic material in Colorado oil shale is analyzed and the rate constants and activation energies for two consecutive first-order reactions are deduced.

137 citations


Journal ArticleDOI
01 Jun 1975-Carbon
TL;DR: In this paper, the pyrolysis behavior of different commercially available polyimides has been studied by means of thermoanalysis, dilatometry and analysis of the gaseous pyrolys products.

133 citations



Patent
Allan Sass1
10 Nov 1975
TL;DR: In this article, the second pyrolysis zone is maintained substantially free of free oxygen by transferring heat from a heating media to the char products produced in the first pyroglobalization zone.
Abstract: Carbonaceous material is gasified in a first pyrolysis zone substantially in an absence of free oxygen by heating with a solid heating media. The carbonaceous material is conducted through the first pyrolysis zone in turbulent flow to provide for the rapid transfer of heat to effect the gasification. Gaseous products are recovered while char products are introduced into a second pyrolysis zone for additional gasification. The second pyrolysis zone is maintained substantially free of free oxygen. Gasification in the second pyrolysis zone is effected by the transfer of heat from a heating media to the char products produced in the first pyrolysis zone. Gaseous products from the second pyrolysis zone are recovered. The char products from the second pyrolysis zone can be heated to a temperature sufficient for use as a solid heating media. The gaseous product from the first pyrolysis zone, after separation from the char product, can be cooled to a lower temperature to condense a liquid product therefrom. Liquid products produced can be recycled to the pyrolysis zones to produce additional gaseous products. The gaseous product from the second pyrolysis zone can be used as a conveying gas for the carbonaceous feed, char products, and recycle char. A portion of the char product and the gaseous product can be converted to methane for the production of pipeline gas.

94 citations


Patent
23 Oct 1975
TL;DR: In this paper, an approach for pyrolysis of waste material such as old tyres in which cuttings of the waste material are fed to a reactor vessel and heated under sub-atmospheric pressure by an outside heat source, the decomposition products being given off mainly in the form of gases.
Abstract: Apparatus and method for the pyrolysis of waste material such as old tyres in which cuttings of the waste material are fed to a reactor vessel and heated under sub-atmospheric pressure by an outside heat source, the decomposition products being given off mainly in the form of gases. Some of the gas is burnt to provide the heat.

75 citations


Journal ArticleDOI
01 Jun 1975-Carbon
TL;DR: In this article, the kinetics of the deposition of laminar graphite on nickel by the pyrolysis of methane, ethane and ethylene at temperatures from 700-1000° has been studied.

40 citations


Journal ArticleDOI
TL;DR: In this article, the thermal degradation of linear poly-2-hydroxyethyl methacrylate and of its acetyl and methoxy derivatives was investigated by the Curie-point pyrolysis gas chromatography.

38 citations


Patent
13 Mar 1975
TL;DR: In this paper, an approach for the thermal decomposition of organic material is described, in which the waste solids concentrates are first mixed in a fluidizing tank with fluidizing oil to form an appropriate mixture which is then dehydrated to remove water from the waste and oil mixture.
Abstract: Apparatus and a proccess for the thermal decomposition of organic material is disclosed wherein the waste solids concentrates are first mixed in a fluidizing tank with a fluidizing oil to form an appropriate mixture which is then dehydrated to remove water from the waste and oil mixture. Subsequently, the waste solids and oil are separated. The resultant dehydrated, substantially oil free organic waste material is then pyrolized within a temperature range of approximately 700° F. to 1800° F. by which lower molecular weight organic compounds are distilled off as organic vapors and gases while a residue of char and ash remain.

36 citations


Journal ArticleDOI
TL;DR: In this article, the pyrolysis of native jack pine bark has been studied from 200 to 340°C by thermogravimetric (TG), and isothermal weight-loss methods.
Abstract: The pyrolysis of native jack pine bark has been studied from 200 to 340°C by thermogravimetric (TG), and isothermal weight-loss methods. The effects of particle size, solvent extraction and additions of zinc (II) and iron (III) chlorides on the pyrolysis behaviour have also been examined. The bark was characterized by infrared spectroscopy and low-temperature gas adsorption. Residues were analysed for CHN contents and structural changes which occurred on heating were examined by optical and scanning electron microscopy. The TG characteristics were not affected by solvent extraction or particle size variation while the metal chloride additions inhibited the loss of volatile materials from the bark probably by stabilizing chemical bonding in the bark components. Isothermal decomposition data were found to fit established kinetic expressions associated with inorganic decompositions. The physical mechanics of pyrolysis have been interpreted on the assumption that pyrolysis is initiated through the formation of planes of lateral strain which are sites for decomposition and which decrease in number inversely with time. It is suggested that these sites are produced by an oxidation mechanism which may be rate-controlling in the pyrolysis. This hypothesis is supported by the observation that the data fit a reaction rate compensation curve, often associated with oxidation processes but more generally with heterogeneous catalytic reactions. The compensation curve also relates the kinetic parameters found by other workers for a large variety of wood-derived materials.


Patent
24 Dec 1975
TL;DR: In this article, a light gas oil, consisting predominantly of alkylated naphthalenes plus minor amounts of thiophene, quinoline, indan, and related Naphthalene type carbonaceous compounds, derived from the liquid by-product from olefin production by pyrolysis in steam of a hydrocarbon fraction, is converted to mononuclear aromatic hydrocarbons by a two stage process in which said naphthene types are first hydrogenated at tetralinizing conditions saturating only one of the two aromatic rings of the feedstock
Abstract: A light gas oil, consisting predominantly of alkylated naphthalenes plus minor amounts of thiophene, quinoline, indan, and related naphthalene type carbonaceous compounds, derived from the liquid by-product from olefin production by pyrolysis in steam of a hydrocarbon fraction, is converted to mononuclear aromatic hydrocarbons by a two stage process in which said naphthalene type carbonaceous compounds are first hydrogenated at tetralinizing conditions saturating only one of the two aromatic rings of the feedstock. Said first stage hydrogenation also hydrodesulfurizes and hydrodecontaminates said feedstock. The tetralanized desulfurized normally liquid effluent from the first stage hydrogenation is hydrocracked in the second stage, said hydrocracking being in the presence of a catalyst featuring a stabilizing metal component on an acid-modified mordenite having a silica to alumina unit mol ratio within the range from 15 to 70 as a result of acid leaching of mordenite.

Patent
25 Aug 1975
TL;DR: In this paper, waste water containing dissolved acid-gas and ammonia impurities is processed for separate recovery of the acid gas, ammonia and recycle water for pyrolysis gas.
Abstract: Waste water containing dissolved acid-gas and ammonia impurities is processed for the separate recovery of the acid gas, ammonia and recycle water. In a further aspect, a purified pyrolysis gas is produced by treating a raw pyrolysis gas product stream utilizing the aforementioned recycle water and a pair of coupled acid-gas-absorber and acid-gas-stripper columns.


Journal ArticleDOI
TL;DR: In this article, a stationary substrate technique was used for the chemical vapor deposition of SiC from pyrolysis of CH3SiCl3 and a relatively large amount of excess carbon was co-deposited even in H2, which was explained on the basis of a competition between gas phase and solid surface formation of carbon in comparison with silicon.

Journal ArticleDOI
TL;DR: In this article, Curie point pyrolysis in combination with low voltage mass spectrometry has shown that humic acids extracted from three typical Indian soils have similar structures which resemble that of a fungal "humic acid" rather than that of lignin.
Abstract: Curie point pyrolysis in combination with low voltage mass spectrometry has shown that humic acids extracted from three typical Indian soils have similar structures which resemble that of a fungal ‘humic acid’ rather than that of a lignin.


Journal ArticleDOI
TL;DR: In this paper, the pyrolysis reaction has been found to be of first order, and activation energies have varied with concentration of the alkyl germanium compound.
Abstract: Thin films of Ge produced by the pyrolysis of alkyl germanium tetramethyl germanium and tetraethyl germanium compounds have been studied for their rates of deposition, crystallinity, and carbon contamination. The pyrolysis reaction has been found to be of first order, and the activation energies have been found to vary with concentration of the alkyl germanium compound between the limits of 25–30 kcal/mole for both tetramethyl and tetraethyl germanium. The morphology and crystallinity of the films vary with the chemical and crystalline structure of the substrate. Good quality and uniform films are produced on monocrystalline germanium substrates preetched in situ with gas. The carbon contamination is found to be strongly dependent on the substrate material, and it varies between 25 ppm for germanium and 200–50,000 ppm for tungsten substrates.

Journal ArticleDOI
TL;DR: In this paper, the authors showed that when tobacco is heated in nitrogen at heating rates comparable to those in a smouldering cigarette, 27 % of the carbon content of the tobacco is converted to carbon oxides, and the relative proportions of the two oxides are strongly dependent on heating rate.
Abstract: Abstract Flue-cured Virginia tobacco has been heated in nitrogen and nitrogen/oxygen mixtures under flow conditions, and the rate of formation of carbon monoxide and carbon dioxide has been determined as a function of temperature, heating rate, and proportion of oxygen in the gas. When the tobacco is heated in nitrogen at heating rates comparable to those in a smouldering cigarette, 27 % of the carbon content of the tobacco is converted to carbon oxides. Both carbon oxides show two distinct formation regions: a low-temperature region (about 100°-450°C), and a high-temperature region (about 550°-900°C). These temperature limits are almost identical to those predicted from studies on the combustion coal of a cigarette burning in air. When tobacco, or the carbonaceous residue remaining after the pyrolysis experiments, is heated in nitrogen / oxygen mixtures, the total amount of carbon converted to carbon monoxide and carbon dioxide is independent of heating rate, but the relative proportions of the two oxides are strongly dependent on heating rate. At the lower heating rate, proportionally less carbon monoxide, and more carbon dioxide, is produced. Under oxidation conditions, about 70 % of both carbon oxides formed in the low-temperature region (100°-450°C) are produced by tobacco decomposition reactions, whereas in the high-temperature region about 10-20 % of the carbon monoxide, and 2-9 % of the carbon dioxide, are produced by tobacco decomposition.



Patent
31 Jan 1975
TL;DR: In this paper, measured sample quantities of sulfureous matter are introduced into a sealed chamber where the samples are pyrolyzed to form sulfur dioxide and sulfur trioxide gases and to oxidize organic substances to form carbon dioxide gas.
Abstract: Measured sample quantities of sulfureous matter are introduced into a sealed chamber where the samples are pyrolyzed to form sulfur dioxide and sulfur trioxide gases and to oxidize organic substances to form carbon dioxide gas. The gases are then passed through a free sulfur-absorbing packing and into a scrubbing zone wherein transition metal amine complex is used to remove sulfureous compounds without reaction with the carbon dioxide gas. The scrubbed gases are then analyzed to determine the carbon dioxide content thereof.

Journal ArticleDOI
TL;DR: In this article, pyrolysis of phenyltrimethylsilyldiazomethane with carbonyl compounds gave styrene derivatives, whilst pyrolynsis with 2,3dimethylbuta-1,3-diene gave silacyclohexene derivatives together with benzosila-cyclopentene and the dimerization product of silyl-carbene.
Abstract: Pyrolysis of phenyltrimethylsilyldiazomethane with carbonyl compounds gave styrene derivatives, whilst pyrolysis with 2,3-dimethylbuta-1,3-diene gave silacyclohexene derivatives together with benzosila-cyclopentene and the dimerization product of silyl-carbene; the reaction probably involve methyl migration from silicon to carbenic carbon in the silylphenylcarbene followed by 2 + 2 and 2 + 4 reactions with the carbonyl compounds and butadiene.

Journal ArticleDOI
01 Jan 1975
TL;DR: In this article, thermogravimetric analysis, pyrolysis and flame structure studies were performed on polyolefin samples and the results showed that polyethylenes (low and high density) and polypropylene give stable counterdiffusion and diffusion flames for which temperature and species profiles can be determined with excellent reproducibility.
Abstract: Polyolefin samples were subjected to thermogravimetric analysis, pyrolysis and flame structure studies. Polyethylenes (low and high density) and polypropylene give stable counterdiffusion and diffusion flames for which temperature and species profiles can be determined with excellent reproducibility. Low oxygen indices and mass burning rates were measured for these materials, whereas the tendency of polystyrene to char limits the application of these methods. Evidence is given for the composition of the gaseous phase generated by the pyrolysis process. The flames are fed by the flammable mixture produced by the pyrolysis reaction mixed with traces of oxygen that appear to be present in the “feeding space” between the flame and the polymer melt. Complete analysis and profiles are given. The limitations of the Low Oxygen Index determination as a practical test are discussed and its validity questionned.

Patent
06 Oct 1975
TL;DR: The pyrolysis of hydrocarbons to produce light olefins is accomplished in a reactor-quench system employing a common molten metal medium and forced circulation risers in both the reactor and quench zones as discussed by the authors.
Abstract: The pyrolysis of hydrocarbons to produce light olefins is accomplished in a reactor-quench system employing a common molten metal medium and forced circulation risers in both the reactor and quench zones.

Journal ArticleDOI
TL;DR: In this paper, the authors reported on some experimental activated carbon fabric prepared by pyrolysis and activation of a phenolic fabric, but the small sample size of their product precluded an extensive characterization.
Abstract: In a recent article we reported on some experimental activated carbon fabric prepared by pyrolysis and activation of a phenolic fabric [1). The small sample size of our product precluded an extensive characterization. Now we have successfully prepared activated carbon fabric on a much larger scale. Since the technology of activated carbon textiles is progressing at an accelerated rate, it appears appropriate at this time to

Patent
30 May 1975
TL;DR: Granular activated carbon is produced from a waste tire pyrolysis residue by kneading homogeneously the residue, a wooden carbonaceous material, and a carbonaceous binder under heat, extruding the resulting mixture by an extruder under certain heating conditions, and carbonizing and activating the extruded material as mentioned in this paper.
Abstract: Granular activated carbon is produced from a waste tire pyrolysis residue by kneading homogeneously the residue, a wooden carbonaceous material, and a carbonaceous binder under heat, extruding the resulting mixture by an extruder under certain heating conditions, and carbonizing and activating the extruded material.