Showing papers on "Pyrolysis published in 1971"

Studies of the Pyrolysis of Triglycerides

Abstract: The pyrolysis of triglycerides (trilaurin and tripalmitin) in an atmosphere of nitrogen at 300–700°C has been attempted. Fatty acids, acrolein, ketones, and olefins have been identified as pyrolysis products. As intermediates of the pyrolysis, unsaturated glycol difatty acid esters and acid anhydrides were also detected. These results suggest a reaction mechanism of the pyrolysis involving the above compounds.

Carbon, carbides, and methane in an apollo 12 sample.

Abstract: Total carbon in the Apollo 12 sample 12023 fines was 110 micrograms per gram of sample with a carbon isotopic abundance delta(13)C (relative to the Pee Dee belemnite standard) of +12 per mil. Hydrolysis of the fines with deuterium chloride yielded undeuterated methane along with deuterated hydrocarbons, thus confirming the presence of 7 to 21 micrograms of carbon per gram of sample as carbide and about 2 micrograms of carbon per gram of sample as indigenous methane. After vacuum pyrolysis of the fines to 1100 degrees C the following gases were detected in the relative abundance: carbon monoxide carbon dioxide methane. Variations of the delta(13)C value with the pyrolysis temperature indicated the presence of carbon with more than one range of isotopic values. The observed delta(13)C value of +14 per mil for lunar carbide is much higher than that of carbide in meteorites. These results suggest that lunar carbide is either indigenous to the moon or a meteoritic contribution that has been highly fractionated isotopically.

Pyrolysis–gas chromatographic analysis of poly(vinyl chloride). II. In situ absorption of HCl during pyrolysis and combustion of PVC

Abstract: A pyrolysis–gas chromatographic technique for measuring the amount of hydrogen chloride released during the high temperature pyrolysis of poly(vinyl chloride) resins, plastisols, copolymers and compounds containing inert fillers has been developed. The technique, which is also applicable to the analysis of chlorinated polyethylene and chlorinated poly(vinyl chloride), is based on the use of a standard precursor of HCl, poly(vinyl chloride) homopolymer. The analysis has been successfully used to measure the degree of in situ absorption of HCl during pyrolysis by certain basic fillers [K2CO3, CaCO3, CaO, MgO, Al(OH)3, Na2CO3, Al2O3 and LiOH] dispersed in a poly(vinyl chloride)–o-dioctyl phthalate matrix. Combustion of a number of combustion residues (chloride determination) revealed that the amount of HCl absorbed by the basic filler was independent of the method of degradation (pyrolysis or combustion). Flammability measurements of those matrices having the same composition indicate that in situ absorption of HCl during combustion has little effect on the overall flammability of these materials.

Method and apparatus for the destructive decomposition of organic wastes without air pollution and with recovery of chemical byproducts

Abstract: Organic material, such as kraft black liquor, wood residues, organic fuels and garbage or other organic wastes, is destructively distilled and pyrolyzed at elevated temperatures and for a time sufficient to break down the material to non-combustible solids and a stable, clean-burning gaseous fuel. Said destructive distillation and pyrolysis steps can be effected in a single stage, though preferably they are conductive in successive stages. Valuable organic products can be recovered from the first stage effluent by condensation or otherwise between these stages. The temperature during pyrolysis is maintained at a high enough level and for a time sufficient to preclude undesirable recombination of intermediate products, formed during pyrolysis, to compounds which would otherwise pollute the atmosphere. A controlled amount of oxygen, which can take the form of malodorous emission gases such as those engendered in the operation of a kraft mill or other industrial plant, for example, is continuously introduced during pyrolysis to provide energy by exothermic oxidative reactions. However, the oxygen so employed is insufficient to effect stoichiometric or, in other words, complete combustion of the reaction mixture. Further, the content of water vapor in the pyrolysis zone where cracking is occurring is maintained at a level high enough to insure that carbon particles in said zone will react with water to form hydrogen and carbon monoxide.

Upgrading low rank coals as fuel

Abstract: A process in which lumps of sub-bituminous or lower rank coal are heated to pyrolysis temperatures of up to about 1,000* F. by contact, preferably countercurrent, with an inert hydrogen-poor hydrocarbonaceous heat transfer fluid, preferably a coal-derived oil, thereby transforming the coal to a char product in lump form of upgraded calorific value, such product, moreover, being less pyrophoric than a char product produced by pyrolysis at the same temperatures in an inert gaseous (nitrogen) atmosphere.

Pyrolysis and analysis system

Abstract: A METHOD AND APPARATUS FOR DIRECTLY SELECTIVELY ANALYZING ORGANIC CARBON OR OTHER PREDETERMINED COMPOUNDS IN A SAMPLE-CONTAINING FLUID SUCH AS WASTEWATER. THE ORGANIC CARBON IN THE WASTEWATER SAMPLE IS EITHER OXIDATELY PYROLYZED TO CARBON DIOXIDE OR REDUCTIVELY PYROLYZED TO METHANE, WHICH PRODUCTS ARE THEN ANALYZED. PRIOR TO PYROLYSIS, THE INORGANIC CARBONATE AND BICARBONATE SALTS PRESENT IN THE WATER ARE REMOVED BY ACIDIFICATION TO CARBONIC ACID AND VAPORIZATION OF THE CARBON DIOXIDE COMPONENT IN A VOLATILIZATION ZONE. THE VAPORS, INCLUDING CERTAIN VOLATILE ORGANIC CARBON COMPOUNDS, ARE DIRECTED IN A CARRIER GAS THROUGH A PACKED DETENTION COLUMN FOR SORPTION OF THE ORGANIC CARBON COMPOUNDS ON THE PACKING WHILE THE CARBON DIOXIDE IS VENTED. THEREAFTER THE CARRIER GAS FLOW IS REVERSED AND THE SORBED COMPOUNDS ARE DESORBED AND CONVEYED TO A PYROLYSIS ZONE WHEREIN THEY ARE PYROLYZED ALONG WITH THE UNVAPORIZED SAMPLE AND CONVERTED TO A GASEOUS PYROLYSIS PRODUCT WHICH IS QUANTITATIVELY ANALYZED. THE WASTEWATER MAY BE SUPPIED IN A BOAT TO THE VOLATILIZATION ZONE AND THE BOAT MOVED INTO THE PYROLYSIS ZONE DURING PYROLYSIS.

Coking a feedstock comprising a pyrolysis tar and a heavy cracked oil

Abstract: THE PROCESS FOR THE PRODUCTION OF A HIGH QUALITY PETROLEUM COKE WHICH CAN BE GRAPHITIZED TO OBTAIN A GRAPHITE HAVING A DESIRABLY LOW COEFFICIENT OF THERMAL EXPANSION, COMMONLY REFERRED TO AS NEEDLE GRAPHITE, IS DESCRIBED. THE METHOD COMPRISES THE COKING OF A BLEND OF A THERMALLY OR CATALYTICALLY CRACKED HEAVY OIL HAVING A HIGH AROMATIC CONTENT AS A RESULT OF THE THERMAL OR CATALYTIC CRACKING WITH A QUANTITY OF A PYROLYSIS TAR WHICH IS OBTAINED AS A BYPRODUCT FROM THE HIGH TEMPERATURE, DILUENT CRACKING OF PETROLEUM DISTILLATES TO PRODUCE OLEFINS. IT HAS BEEN OBSERVED THAT A SYNERGISM EXISTS BETWEEN THE PYROLYSIS TAR AND CRACKED HEAVY OIL SO THAT THE PYROLYSIS TARS CAN BE USED IN MUCH GREATER QUANTITIES THAN WOULD BE PREDICTED FROM THE CHARACTERISTICS OF THE COKES PRODUCED BY THE COKING OF THE INDIVIDUAL COMPONENTS. IN A TYPICAL EMBODIMENT, A BLEND COMPRISING FROM 20 TO 60 PERCENT OF PYROLYSIS TAR AND 40 TO 80 PERCENT OF A DECANT OIL FROM CATALYTIC CRACKING IS THERMALLY COKED BY HEATING TO A TEMPERATURE FROM 850* TO ABOUT 1000*F. AND PASSING THE HEATED STOCK TO A DRUM AND PERMITTING THE STOCK TO CRACK TO FORM VAPORS AND COKE THEREIN AT TEMPERATURES OF FROM 830* TO ABOUT 875*F.

Diesel odor and the formation of aromatic hydrocarbons during the heterogeneous combustion of pure cetane in a single-cylinder diesel engine

Abstract: Experimental facilities and methods, based on combined gas-chromatographic and mass-spectrometric techniques, which can be employed for the qualitative analysis of odoriferous and carcinogenic compounds formed during the heterogeneous combustion of pure hydrocarbon fuels are described. Exhaust-gas samples from a lightly loaded, CFR diesel engine operating on a lean, pure cetane-air mixture at a compression ratio of 14 to 1 have been collected and analyzed. A number of species including saturated and unsaturated aldehydes, alcohols and acids, both homo- and heterocyclic compounds and aromatic compounds have been qualitatively identified. The significance of these results are discussed in conjunction with both the diesel-odor problem and the possible biological activity of diesel exhaust. Since commercial lubricating oil contains significant quantities of cyclic compounds, the pyrolysis and partial oxidation of any oil blow-by was investigated as a possible source of the aromatics. Additional engine experiments showed that aromatics were still present in the exhaust when the commercial oil was replaced by an oil that did not contain any cyclic compounds. The combustion products of pure cetane-air mixtures burning at atmospheric pressure, in an air-aspiring spray burner, were also found to contain aromatic hydrocarbons. Based on these experiments, it can be concluded that a large number of aromatic hydrocarbons are synthesized during the heterogeneous combustion of pure cetane-air mixtures, and that any blow-by of lubricating oil that occurs in a diesel engine enhances the production of aromatic hydrocarbons.

Pyrolysis of Organomercury Compounds: Investigation by the Method of Matrix Isolation

Abstract: The method of matrix isolation has been used to investigate mechanisms of gas-phase chemical reactions, in particular the pyrolysis of some organomercury compounds. A molecular beam of pyrolysis products was condensed simultaneously with a large excess of rare gas at temperatures from 5 to 15°K to form a matrix that was subsequently studied by infrared spectroscopy. In the case of C6H5HgCCl3, we found that pyrolysis in the temperature range 220-400°C produced mainly dichlorocarbene. In addition, some trichloromethyl radical was observed and increased in relative importance at increased temperatures. Another identified product of pyrolysis was C6H5HgCl. In general, the same reactive intermediates, CCl2 and CCl3, were found from pyrolysis of Hg(CCl3)2 in the temperature range 250-500°C, along with CCl3HgCl and HgCl2. The identity of CCl2 and CCl2 was demonstrated by measurement of the relative intensities and isotopic splittings of stretching vibrations due to the chlorine isotopes. Isotopic patterns found for CCl2 are: v3 (745.8, 744.0, 741.8 cm-1), v1 (719.5, 717.0, 714.9 cm-1) and for CCl3 are: v3 (897.8, 896.4, 895.2, 893.9 cm-1). Less dilution with the rare gas or warming of the matrix produced a decrease of CCl2 and CCl3 spectral bands and an increase of bands due to C2Cl4, C2Cl6, and other products. These results show the usefulness of matrix isolation in the study of such reactive species as CCl2 produced by pyrolysis in the gas phase.

Thermolysis of 18O labelled ethyl acetate

Abstract: There was only minor scrambling of the oxygen in the unpyrolysed 18O labelled ethyl acetate when heated to pyrolysis temperatures in a carefully deactivated reactor.

Chloroprene removal from pyrolyzed 1,2-dichlorethane

Abstract: In a process for treating the raw gaseous products of the pyrolysis of 1,2-dichlorethane to form vinyl chloride, a procedure for eliminating chloroprene involving the steps of cooling the raw gaseous product coming from the pyrolysis reaction under a pressure above atmospheric to obtain a gaseous phase and a liquid phase, and treating the liquid phase with chlorine in an amount of between 0.01 and 5 percent by weight with respect to the 1,2-dichlorethane not converted during the pyrolysis. After such treatment, the resulting mixture is separated into individual components.

Process for the production of incombustible carbonaceous material

Abstract: A carbonaceous material is obtained by bringing a mixture of one or more substances selected from the group consisting of molecular phosphorus, inorganic phosphorus-containing compounds and organic phosphorus-containing compounds and organic compounds into contact with a substrate heated at a temperature of 600*1,500*C thereby depositing the resulting carbon formed by pyrolysis on the substrate. Alternatively, an organic phosphoruscontaining aromatic compound is brought into contact with a substrate heated at a temperature of 600*-1,500*C thereby depositing the resulting carbon formed by pyrolysis on the substrate. A shaped article coated with said carbonaceous material is obtained by effecting such pyrolysis and deposition on a shaped article made of metal, ceramics glass or carbon. The carbonaceous materials obtained according to this invention are composed of 80-99.9% of carbon and 0.1-20% of phosphorus and are imcombustible having excellent oxidation-resisting properties in addition to the intrinsic properties of carbon.

Pyrolysis of poly(methyl methacrylate co ethyl acrylate)

Abstract: An investigation of the behavior of poly(methyl methacrylate co ethyl acrylate) with a commercially available filament-type pyrolysis unit and gas chromatogaph was conducted. It has been hypothesized that the quantity of ethyl acrylate monomer produced under the conditions of the experiment is dependent upon the number of ethyl acrylate–methyl methacrylate bonds contained in the copolymer. These observations were made possible by a standardized samples-handling technique in which a uniformsize disk was pyrolyzed at a maximum pyrolysis temperature of 600°C. This enabled reproducible pyrolysis gas chromatograms to be obtained and permitted pyrolysis products of copolymers containing different ratios of ethyl acrylate and methyl methacrylate to be compared. An examination of sequence distribution data, obtained with the aid of a sequence distribution program for copolymers, showed sufficient agreement with the pyrolysis data to support the hypothesis. It has been demonstrated that pyrolysis gas chromatography may be applied to experimentally determine the sequence distribution of copolymers.

Method for the depolymerization of polytetrafluoroethylene

Abstract: High yield monomeric tetrafluoroethylene may be recovered from polytetrafluoroethylene and polytetrafluoroethylene composites by pyrolyzing the polymer in the presence of high temperature steam. The steam acts as a condensable carrier gas for the low molecular weight pyrolysis products and should be present in an amount such that the mole ratio of steam to pyrolysis products is at least one to one. The steam also acts as a means for heating the polymer to the necessary decomposition temperatures.