Pyrolysis, apparatus for

Gamma, of a photographic emulsion 769 Gas chromatography 235 apparatus for, 235 column packing for, 238 derivatisation in, 236 detectors for, 240 elemental analysis by, 247 of metal chelates 237, 248 pyrolysis, 237... 

Figure 8.45 Apparatus for pyrolysis gas chromatography. A, filament or ribbon-type pyrolyzer and B, Curie-point pyrolyzer. (Reproduced with perm.i ion from ref. 848. Copyright American Chemical society).

The pyrolysis apparatus consists of a vertical, electrically-heated Vycor tube (25 mm. I.D.) packed with 6-mm. lengths of Pyrex tubing (10 mm. O.D.) and mounted in an electric furnace about 45 cm. long (Notes 1 and 2). Attached to the top is a 100-ml. dropping funnel with a pressure-equalizing side arm that has an inlet for nitrogen (Note 3). A thermocouple well inside the tube holds a movable thermocouple and extends to the bottom of the heated section (Note 4). The bottom of the reactor is fitted to a 500-ml. side-arm flask packed in ice. The side arm leads to tw o traps in series cooled in ice and to a final trap cooled in a bath of dry ice and acetone (Note 5). 

A. Pyrolysis of dioyalopentadiene to form oyolopentadiene. Cyclo-pentadiene is prepared from its dimeric form by distillation according to the method of Moffett. The apparatus for the distillation is assembled as shown in Diagram 1. The equipment consists of a 250-mL flask, a Friedrichs condenser fitted with a Haake Model FE hot water circulator, a Cl aisen head, a thermometer, a gas inlet tube, and a collection receiver which Is cooled to -78 C in a dry ice-acetone bath. 

FIGURE 1. Pyrolysis apparatus employed for the synthesis of carbon nanotubes by pyrolysis of mixtures of (a) metallocene + CaHa, (b) Fe(C0)s + C2H2, and (c) metallocene + benzene or thiophene. The numbers 1 and 2 indicated in the figure represents inlet and outlet, respectively.6... 

For larger quantities of substance to be pyrolyzed (e.g., [2.2]paracycloplane), Vogtle et al. developed an apparatus for continuous pyrolysis of sulfones which allows for continuous introduction of starting material and continuous removal of products without breaking the vacuum [20]. 

The rigorously dried 2,4,6-triphenylpyridinium fluorides were heated in a pyrolysis apparatus (with a liquid N 2 cooled trap) at a pressure of 2 Torr or, for lower boiling fluorides, in a micro-Hickman apparatus at 760 Torr. 

R. Reverse, Process and apparatus for the controlled pyrolysis of plastic materials, US Patent 0056214 Al, 2001. 

Figure 15.4 A schematic of a typical continuous stirred tank pyrolysis process. Legend 1 pyrolysis vessel with internal agitator 2 catalyst chamber 3 plastic feedstock hopper 4 char auger to remove solid residue 5 agitator drive motor 6 lower temperature sensor 7 upper temperature sensor 8 burner for furnace 9 feed auger for plastic feedstock 10 condenser cooling jacket 11 condenser 12 oil recovery tank (adapted from Saito, K. and Nanba, M., United States Patent 4,584,421 (1986) Method for thermal decomposition of plastic scraps and apparatus for disposal of plastic scraps )...

T. Yamaguchi, Apparatus for oil production from pyrolysis of waste plastics. JP 0 450, 292 (1992). 

Figure 14.4 Schematic representation of an apparatus for FVP As with all high vacuum work, care must be taken. After all of the substrate has passed through the hot tube, turn off the furnace and allow to cool to room temperature (still under vacuum). Then turn off the pump and admit nitrogen to atmospheric pressure. Remove the traps to a fume cupboard and allow to warm to room temperature, and work up in the usual way. If the desired product is unstable towards air, water, or is simply very reactive, then a more sophisticated pyrolysis system might be required, and more elaborate work up procedures used.

There are several hundreds of papers studying the kinetics of reactions involved in the pyrolysis step (27). Unfortunately for the gasifier modelling there is neither a unified approach nor an overall kinetic equation(s) describing the pyrolysis step for all possible biomass under all possible circumstances. Besides, most of the kinetic studies have been made in thermobalances or related apparatuses with low heating rates (around 25 "C/min), far from the high heating rates in fluidised beds of up to a claimed 1000 C/s or even 10000 C/s. Kinetic equations obtained in thermobalances would provide results very different from the ones in fluidised bed, which is the present case. 

Figure 1. Apparatus for pyrolysis under an autogenous atmosphere.

Scheme 1. General apparatus for flash vacuum pyrolysis and/or flow pyrolysis [10]...

The relatively low thermal stability of the acetylene precursors inspired the search for a more stable, masked ethynyl group that can be quantitatively converted into acetylenes in the gas phase of the pyrolysis apparatus. Presently, the state of the art consists in the substitution of ethynyl groups by chloroethenyl substituents [54b -f, 55,56]). The latter show a higher thermal stability and are conveniently available from acetyl derivatives by reaction with PC15 or from tri-methylsilyl (TMS)-substituted acetylenes by treatment with hydrochloric acid in glacial acetic acid (see Scheme 8). 

The experimental setup consists of a gas dosing system and the DRIFT spectroscopy apparatus. For the pyrolysis experiments KBr was selected as matrix, different to the laser-induced decomposition experiments [141], where SiC was used. KBr was chosen because the emissivity did not increase drastically, as in the case of SiC, where it interfered with the measurements. The Kapton-KBr mixtures are placed in the sample holder of the DRIFT cell and packed using a pressure of 1 MPa as described elsewhere [288, 306]. The sample is heated in an inert gas atmosphere to the desired temperature using a heating rate of 10 K min-1. The spectrum of the Kapton-KBr mixture at a given temperature is collected and used as background spectrum. The following experiments were carried out. 

FIGURE 2. Outline of the short-path pyrolysis apparatus integrated into the PE spectrometer Leybold Heraeus UPG 20012 U is resistive heating, U2 electron impact heating for details see Reference 50... 

Pyrolysis with in situ methylation in the presence of TMAH is now commonly applied for the structural investigation of HS. It has been reported, however, that TMAH not only methylates polar pyrolysate but also assists in bond cleavage. For example, TMAH was found as effective at 300°C as at 700°C for the production of some volatile products from HS, indicating that pyrolysis occurs with equal effectiveness at subpyrolysis temperature of 300°C. It is believed that TMAH pyrolysis is actually a thermally assisted chemolysis rather than pure pyrolysis and it can cause hydrolytic ester and ether bond cleavage even at lower temperature, resulting in some unwanted side reactions, e.g., artificial formation of carboxylic groups from aldehydes. Therefore, TMAH thermochemolysis at low temperature, e.g., 300°C has been proposed. This technique offers several advantages over classical flash pyrolysis or preparative pyrolysis apparatus " ... 

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