THE CENTURY OF PETROL - Petroleum.cz

Preparation of the land for construction of employee housing – today’s Osada quarter in Litvínov
learned that sulphur-resistant catalysts
were needed and that the pressure transformation
of high-boiling-point liquid fractions
produced from the coal material had
to be divided into several technological
stages. These improvements brought about
larger yields of products similar to gasoline
and diesel fuel from different types of petroleum.
Such products were needed mainly
for Otto spark-ignition engines and diesel
engines to drive motor vehicles, which
were already being manufactured at the
time in rapidly increasing quantities.
During the first stage of hydrogenation
(the liquid or heavy phase), a product
containing about 50 % of fractions having
boiling points up to 320 °C was recovered
from the fine-grained coal or tar residues
with a boiling point above 320 °C
by liquid-phase cracking in the presence
of hydrogen and finely dispersed catalyst.
Those fractions were separated by distillation.
The residue and catalyst were then
returned to the heavy phase unit. The distillate
(up to 320 °C) was fractionated by
distillation into petrol with a boiling point
up to 220 °C and a residue. Light cut was
de-phenolised and was passed to the
second-stage hydrogenation unit (called
chamber). The same was done with the
high cut boiling above 220 °C (without
phenol extraction).
The whole distillate had to undergo catalytic
hydrogenation refining in the second
stage (the middle phase) on a solid heterogeneous
metal sulfide catalyst to transform
up to 30 % of the non-hydrocarbon
components. The product obtained in this
way was already very similar to the mixture
of petrol, kerosene and diesel fuel
produced from petroleum. It contained
practically no unsaturated hydrocarbons;
its level of sulphur-, nitrogen- and oxygen-containing
substances had been lowered
to under 0.1 % by weight and the
content of aromatic hydrocarbons was re-
duced to weight 5–15 %. The quantity of
the newly produced light fractions was
small and they consisted largely of hydrogenated
products of oxygen compounds
(phenols).
In the third stage (the so-called light
phase), the petrol content was increased
by hydrocracking of medium distillates,
again using the solid metal sulfide catalyst
(also solid), the quality of both products
being improved as a result of simultaneous
isomerisation of alkanes and cyclanes.
All three stages of tar hydrogenation took
place under a pressure of about 30 MPa
(hydrogenation of hard coal required a
pressure of about 70 MPa) and at temperatures
of 340 – 480 °C in the presence
of catalysts. Catalysts had undergone rapid
improvements. Mathias Pier, leading
research engineer of the German company
I. G. Farbenindustrie, invented the
metal sulfide hydrogenation catalysts
(particularly those based on molybdenum,
tungsten and nickel), as well as the multistage
hydrogenation processes.
Hydroforming was an additional technology
developed for the production of
Construction inspection
of Osada employee settlement
Directive from the imperial minister of air
transport to commence construction of DHD plant
▲
34