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Kinetics of Fast Thermal Reactions in Bituminous Coal.

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i
H32'
9
8
8
H32
H62'
Fig. I . Perhydrodibenzo[l,2,3,6,7,81hewathiecin ( I ) : Projection on t h e CI-C2-CI* (C2*) plane.
T h e a t o m s marked with a n asterisk a r e symmetry-equivalent to t h e unmarked (i). T h e b o n d lengths (A) a n d angles (") were averaged accordus-c:
ing t o t h e full symmetry of t h e molecule (2/m). S t a n d a r d deviations of t h e bond lengths a n d angles (without averaging): as-s,
as-c-c:
0.1-0.3";
ac-c-c:
0.3-0.4";
OS-C-H.
0.001-0.004.&; UC-C: 0.005-0.007 A; aC-H: 0.04-0.06A; r3s-S-s. 0s-S-c.
aC-c-H:
3 "; aH-c-H:
4". T h e dihedral angles in t h e ten-membered ring and i n t h e six-membered ring a r e also given.
formation in the cyclodecane skeleton. A larger deviation
from the ideal value would have led to a greater degree of
flattening of the cyclohexane ring.
The C- S (1.86 A) and S--S (2.05 A) bond lengths are indiangle (109.5') corcative of single bonding. The S-S-S
responds to a tetrahedral angle while the angle at S1 is about
4.5" smaller. All intermolecular distances are equal to (or
greater than) the sum of the van der Waals radii. It can be
concluded, therefore, that crystal packing has little influence
on the conformation of the molecule.
Received: J a n u a r y 28, 1970
[Z 162 IE]
G e r m a n version: Angew. C h e m . 92, 319 (1970)
[*I Prof. Dr. F. Fehtr and Dr. F. Lemmer
Institut fur Anorganische Chemie der Universitat
5 Koln 1, Zulpicher Strasse 47 (Germany)
I**] Prof. Dr. W. Hoppe, Dr. A. Gieren, and
Dr. S. Hechtfischer
Abteilung fur Rontgenstrukturforschung
am Max-Planck-Institut fur EiweiR- und Lederforschung
8 Munchen 15, Schillerstrasse 44-46 (Germany)
[I] This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie and
Badische Anilin- C Soda-Fabrik.
[2] F. Feher and B. Degen, Angew. Chem. 79, 689 (1967);
Angew. Chem. internat. Edit. 6, 703 (1967).
[3] Cf. F. Lemmer, Dissertation, Universitat Koln 1969.
[4] W. Hoppe, S. Hechtfircher, and K . Zechmeister, Tagungsber. Sekt. Kristallkunde, dtsch. mineralog. Ges., Bern, 3.-5.
Oct. 1968, p. 23; S. Hechtfischer, W . Steigemann, and W . Hoppe,
Acta crystallogr., in press.
[ 5 ] E . Huber-Euser and J . D . Dunitz, Helv. chim. Acta 49, 1821
(1966); 44, 2027 (1961); J . D. Dunitz and K . Venkatesan, ibid.
44, 2023 (1961).
C 0N F E RE N C E R E PO RTS
Kinetics of Fast Thermal Reactions in Bituminous
Coal
By Werner Peters *I
The by-product oven, grate firing, and fixed bed generators
are used in the traditional processes for the utilization of coal.
Recent developments initiated by the introduction of fluidized-bed gasification by Winkler in the early 1920's had the
aim of improving reactor performance by increasing the reaction rates. This aim is still pursued nowadays in projects at
the Bergbau-Forschung, Essen, that are just starting or are
already in progress on, e.g. continuous coking processes,
magnetohydrodynamic energy conversion, and dust gasification with process heat from nuclear reactors.
The starting point for the study of the kinetics of fast thermal
reactions is based o n the fact that a pyrolysis reaction, whose
rate depends primarily o n the temperature and thus on the
heat and mass transfer, precedes heterogeneous reactions of
gasification and combustion. If the physical conditions
remain constant it is possible t o analyze the kinetics due only
to the chemical processes in specifically designed apparatus.
Since the duration of a reaction is only a few hundredths of a
314
second at heating rates of up t o 105 "C/min the instruments
must have a high resolving power with regard t o time. High
speed photography (40000 frames/s) and time-of-flight mass
spectrometry (10000 analyses/s) have proved effective in
such work.
The curves for gas evolution which were recorded at linear
heating rates afford activation energies and frequency factors
for the products of individual components which are valid
for the relevant pyrolysis reactions. The kinetic data recorded
for coals at very different heating rates (10-3 t o lo5 "Cjmin)
show that the same decomposition reactions take place both
during carbonification on the geological time scale and during
the very fast reactions occurring in a dust flame. The experimentally determined kinetic results for pyrolysis permit
deduction of the combination of pyrolysis and reaction with
the gasification agent. Measurements confirm the calculated
data.
Lecture a t D o r t m u n d on January 21, 1970
[VB 231 E l
G e r m a n version: Angew. Chem. 82, 297 (1970)
[*I Prof. Dr. W. Peters
Bergbau-Forschung GmbH
43 Essen-Kray, Frillendorfer Strasse 351 (Germany)
Angew. Chem. internat. Edit. Vol. 9 (1970) J No. 4
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