вход по аккаунту


Specific Oxidation of Phenols by Dipotassium Nitrosobissulfate.

код для вставкиСкачать
The energy change of penicillin fermentation is as follows
(heats of combustion of raw materials and of the metabolic
products are compared : mechanical energy, e.g. heat generated by stirring of the culture liquor, is not considered):
Energy contained in
I kcal
Residual substances in liquor
Heat of combustion evolved
2 805 000
1923 000
3 147000
Total consumption of energy of the
raw materials
8461 000
Further, every 100 kg of penicillin require: 3000 kWh of
electrical energy (mainly for stirring), 4 tons of steam
(sterilization and sealing), 50000 Nm3 of crude air, 900 m3
of cooling water (cooling of the sterilized solution, removal of
the heat produced by stirring and by biochemicalcombustion).
Costs of penicillin production (exclusive of amortization) can
be divided as follows: for raw materials 50 %, for energy
20 %, for repairs 10 %, personel costs 15 %. other costs 5 %.
These complicated biological processes are very liable to
disturbance and require detailed supervision and exact
analytical control. Even with fermentation processes that
have been well established variations of yield amounting
to % 15 % are to be expected. In general, the following
factors are responsible for this: variation of the penicillium
strain or of the quality of raw materials; infection by foreign
molds; errors in servicing and technical disturbances. The
quality of the raw materials is decisive for fermentation yields,
and as these materials are mostly of natural origin they are
subjected to analytical and biological control.
The sulfur sorption layer can be easily placed o n any platinum
catalyst, including platinum black, e.g. by treatment with
hydrogen sulfide. It is stable at anodic regions up to 600 mV;
oxidation to sulfur dioxide begins only at higher potentials.
The degree of coverage of the platinum surface has a large
effect o n the reaction rate of carbon monoxide or formic
acid; the rate is a maximum when about one third of the
total surface platinum atoms is covered with sulfur.
[VB 6 6 IEI
Lecture at Essen (Germany) on February loth, 1967
German version: Angew. Chem. 79, 477 (1967)
Dr. H. Binder, A. Kohling, and Dr. G. Sandstede
Wiesbadener Str.
6 Frankfurt/Main (Germany)
Specific Oxidation of Phenols by
Dipotassium Nitrosobissulfate
By H.-J. Teuber[*]
Reaction of 2,3-phenanthrenediol with dipotassium nitrosobissulfate, O N ( S O ~ K ) Z , yields 3-hydroxy-1,2-phenanthraquinone, which is obtained as the colorless dimer ( I )
whose UV spectrum corresponds substantially to that of
3,4-dihydro-l(2H)-phenanthrone but not to that of 2,3-dihydro-4(2H)-phenanthrone. The (dimeric) 2-hydroxy-3,4phenanthraquinone is thus not formed.
[VB 57 IEl
Lecture at Frankfurt am Main on October Zlst, 1966
German version: Angew. Chem. 79,478 (1967)
[*I Dr. R. Kreutzfeldt
Farbwerke Hoechst A.G.
6230 Frankfurt/(M)-Hochst, Postfach 70 (Germany)
Electrochemical Oxidation of Formic Acid and
Carbon Monoxide on Platinum Catalysts in Acid
In the formation of p-quinones from monohydric phenols,
substituents may be eliminated from the para-position; not
merely COOH, OCH3, and C1 but even C H 3 may be eliminated, so that blocking of para-positions by methyl
groups cannot always be reliably accomplished :
By H.Binder, A . Kohling, and G. Sandstede[*I
Fuel cells containing acid electrolytes are advantageous for
electrochemical oxidation of carbon-containing fuels because
the resulting carbon dioxide is obtained as a gaseous combustion product, whereas in alkaline electrolytes it remains
dissolved as carbonate. In addition to hydrocarbons and
methanol, other carbon-containing fuels are carbon monoxide (which can be obtained mixed with hydrogen on conversion of hydrocarbons or coal) and also formic acid. Their
use has hitherto been restricted because they poison platinum
catalysts, the electrodes becoming strongly polarized and the
output of the cells lowered. When the platinum surface is
partially covered with sulfur, the anodic oxidation to carbon
dioxide is greatly accelerated. This result could lead to development of fuel cells utilizing either carbon monoxide and
hydrogen, or formic acid.
O n a Raney platinum catalyst that is partially covered with
a monatomic sulfur sorbate, carbon monoxide in 3 N sulfuric acid at 9 0 ° C leads to a potential of 250 mV (at a
current density of 200 mA/cmz) against a hydrogen reference
electrode in the same solution. Anodic oxidation of formic
acid (the hydrate of carbon monoxide) is still more strongly
accelerated, so that under similar conditions a current density of 200 mA/cmz is obtained, even at 30 OC. At 90 OC the
current density reaches a stationary value of ca. 2 A/cmz. At
a n untreated Raney platinum electrode, however, a current
density of less than 1 mA/cmz is obtained.
Angew. Chem. interitat. Edit.
Vol. 6 (1967) / No. 5
Formation of the N-methyliminobissulfate, H~C-N(SO~K)Z,
during demethylating oxidations has been demonstrated.
Lecture at Hamburg on January loth, 1967
[VB 59 IE]
German version: Angew. Chem. 79, 426 (1967)
[*I Prof. Dr. H.-J. Teuber
Institut fur Organische Chemie der Universitat
Robert-Mayer-Str. 719
6 Frankfurt/Main (Germany)
[l] Cf. H.-J.Teuber and G. Steinmetr, Chem. Ber. 98, 666 (1965);
H.-J. Teuber, P. Heinrich, and M. Dietrich, Liebigs Ann. Chem.
696, 64 (1966).
47 1
Без категории
Размер файла
124 Кб
oxidation, nitrosobissulfate, specific, dipotassium, phenols
Пожаловаться на содержимое документа