Pyrolysis carbonization

Pyrolysis. In this context it is relevant to consider initially the effect of hydrogen contents on tar yields during pyrolysis (carbonization). This is particularly so, since, in all coal conversion processes little happens until the coal is at a temperature above that where active thermal decomposition normally sets in. In other words, all coal conversion processes may be regarded as pyrolysis under a variety of conditions which determine the nature of the primary decomposition and the reactions which follow. 

Kamalakaran, R., Lupo, F., Grobert, N., Lozano-Castello, D., Jin-Phillipp, N. Y. and Ruhle, M., In-situ formation of carbon nanotubes in an alumina-nanotube composite by spray pyrolysis , Carbon, 2003, 41, 2737-2741. 

Schmiers, H., Friebel, J., Streubel, P., Hesse, R., and Kopsel, R. 1999. Change of chemical bonding of nitrogen of polymeric N-heterocyclic compounds during pyrolysis. Carbon 37(12) 1965-1978. 

Keywords Intermetallide Ethylene Procatalyst Pyrolysis Carbon nanofiber... 

Flame pyrolysis Carbon source + metallocene catalyst, conventional low pressure pyrolysis reactor 2-3 Low yield, bad quality. Still under development. Plant technology available, large commercialization potential... 

Diacetyltartaric anhydride, acetoxy maleic anhydride and diethyl oxaloacetate all yield carbon suboxide, C3O2 on pyrolysis. Carbon suboxide and protonated carbon suboxide are prominent ions in the mass spectra of all three of these compounds. 

Carbon molecular sieve membranes. Molecular sieve carbons can be produced by controlled pyrolysis of selected polymers as mentioned in 3.2.7 Pyrolysis. Carbon molecular sieves with a mean pore diameter from 025 to 1 nm are known to have high separation selectivities for molecules differing by as little as 0.02 nm in critical dimensions. Besides the separation properties, these amorphous materials with more or less regular pore structures may also provide catalytic properties. Carbon molecular sieve membranes in sheet and hollow fiber (with a fiber outer diameter of 5 pm to 1 mm) forms can be derived from cellulose and its derivatives, certain acrylics, peach-tar mesophase or certain thermosetting polymers such as phenolic resins and oxidized polyacrylonitrile by pyrolysis in an inert atmosphere [Koresh and Soffer, 1983 Soffer et al., 1987 Murphy, 1988]. 

The reference principle for on-line methods has to be different as compared to classic dual-inlet isotope ratio analysis, as it is not possible to introduce sample and reference gas in exactly the same maimer into the mass spectrometer. Reference gas pulses have to be set at different points during one mn, but also laboratory standards with knovm 8-values have to be analysed periodically and exactly in the same manner and under the same conditions as the samples under investigation (identical treatment principle ]13]). A general problem of on-line HPLC and GC methods in isotope ratio analysis is the lack of international reference materials suitable to fulfil the above mentioned requirements. This implies the necessity to establish suitable laboratory standards by EA (elemental analysis) or classic measurements. Meanwhile, also efforts in supplying suitable international organic standards have been overtaken by the IAEA (e.g. caffeine, glutamic acid ]176, 177]). This programme (benzoic acid reference materials with different 8 0-values) will also support the on-line EA and GC 8 0-meas-urement by reductive pyrolysis (carbon reduction) methods (standardisation problems are compiled in ]178]). 

Nitrogen compounds are present partly in the form of ammonia and hydrogen cyanide. The intensity of ammonia formation is high if the pyrolysis (carbonization) temperature is low and if the residence time of the carbonization gas at high temperature levels is short. Here, the equilibrium... 

Fluidised-bed CVD is a special technique to coat nuclear-fuel particles for high-temperature gas-cooled nuclear reactors which was developed in the late 1950s. This technique has also been used in other applications, such as the production of biomedical components (e.g. heart valves deposited by pyrolysis carbon) and some special functional coatings on ceramic particles. 

The ceramization process of poly(Si-isocyanato-Si-methylpolysilazane) (MPZ-6) was investigated by means of the ceramic )deld on pyrolysis, carbon content analysis, and solid-state CPMAS NMR spectra. ... 

Numerous methods of activation are described in the scientific literature,1 2 3 4,5 and hundreds of patents have been issued covering specific procedures.6,7 But for the greater part, the various activation processes are but different mutations of a basic procedure, namely, pyrolysis (carbonization) of the source material—a stage that is usually but not necessarily followed by a stage of controlled oxidation. 

Attempts were made to discover the correlation between the crystalline structure of carbonaceous materials and their capability to reversibly intercalate lithium. This correlation has not been definitely established, but still, one can assume as a certain general principle that the optimum materials would contain an amorphous matrix with inclusions of a mesophase nuclei of graphite crystallites. Such materials are various cokes, pyrographite, and products of pyrolysis (carbonization) of various polymers. For practical purposes, the industry mastered some special materials providing high characteristics of negative electrodes in lithium ion batteries. The most popular material is manufactured by the Japanese company of Osaka Gas Co. under the name of mesocarbon microbeads, MCMB it represents the carbonization product of pitchy resins under a certain temperature regime. 

Charcoal is the solid carbon residue following the pyrolysis (carbonization or destructive distillation) of carbonaceous raw materials, such as coal and wood. Charcoal manufacture is also used in forest management for disposal of refuse. 

Tang MM, Bacon R, Carbonization of cellulose fibers 1. Low temperature pyrolysis. Carbon, 2, 211-220, 1964. 

Jayasankar M, Chand R, Gupta SK, Kunzru D, Vapor-grown carbon-fibers from benzene pyrolysis, Carbon, 33(3), 253-258, 1995. 

Pels JR, Kapteijn F, Moulijn JA, Zhu Q, Thranas KM (1995) Evolutiort of rritrogtar functionalities in carbonaceous materials during pyrolysis. Carbon 33(11) 1641-1653... 

One of the earliest publications on the preparation of carbon molecular sieves was done by Walker et al. [6]. They started from a Saran copolymer, but currently many different raw materials are being used either for research or commercial purposes. The main sources of carbon molecular sieves for commercial applications are coal and coconut shell. An extensive list of the work done in the preparation of carbon molecular sieves can be found elsewhere [7,8]. The typical steps in the preparation of carbon molecular sieves from coal are shown in Fig. 1 [8]. It can be seen that the main steps are oxidation, carbonization, followed either by steam activation or pyrolysis. During steam activation, pores are opened and the resulting carbon molecular sieve can be used in hydrogen purification, while during pyrolysis carbon deposition takes place, and a narrower pore size distribution is achieved. 

Pyrolysis (carbonization) in a steel retort packed with calcined coke in etn inert atmosphere, the cycle consisting of 50 hours to reach 820°C, 20 hours at 820 C and 20 hours cool-down... 

Keywords MCM-41 silica, surface silicon hydride groups, gold and silver in situ reduction, nickel, cobalt, and iron aeetylacetonates, acetylene pyrolysis, carbon nanotubes... 

Galvez, A., Herlin-Boime, N., Reynaud, C., Clinard, C., Rouzaud, J.N., 2002. Carbon nanoparticles from laser pyrolysis. Carbon 40 (15), 2775—2789. 

K. Malladi, C. Wang, M. Madou, Fabrication of suspended carbon microstructures by e-beam writer and pyrolysis. Carbon, 2006,44,2602-2607. 

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