Title of Invention

AN IMPROVED METHOD FOR FLASH DISTILLATION OF RESIDUAL OIL

Abstract An invention relates to a residual oil from the processing of curde oil, natural bitumen or oil sand is mixed in a mixer with granular, hot coke as heat carrier (heat carrier coke) in a weight ratio of 1:3 to 1:30, where on the granules of the heat carrier coke there is first of all formed a liquid residue film which partly evaporates in the mixer. Gases and vapours and moist, sticky coke are withdrawn from the mixer. The mixer of coke and residual oil is introduced into a subsequently connected stirred tank in which the mixture slowly moves downwards while being stirred mechanically at a temperature of 450 to 600°C. and preferably at 480 to 550°C. Dry, flowable coke is withdrawn from the stirred tank. Usually, the dwell time of the heat carrier coke in the stirred tank is 1 to 30 minutes.
Full Text Description
This invention relates to a process for the gentle flash dis-
tillation of a residual oil from the processing of crude oil,
natural bitumen or oil sand, wherein the residual oil is
mixed in a mixer with granular, hot coke as heat carrier
(heat carrier coke) in a weight ratio of 1:3 to 1:30, and due
to the mixing process in the mixer a liquid residue film is
first of all formed on the granules of the heat carrier coke,
which residue film partly evaporates in the mixer. The gases
and vapors formed are withdrawn from the mixer.
Such process is known from DE-A-197 24 074, wherein one or
several mixers are employed, which have intermeshing screws
rotating in the same directioxi. It was found out that in this
process it is complex or difficult to achieve solid dwell
times of more than 120 seconds.


It is the object underlying the invention to develop the
known process and to produce a rather high yield of product
oil of the best quality possible in an inexpensive way. In
accordance with the invention this is achieved in that the
mixture of coke and residual oil formed in the mixer is in-
troduced into a subsequently connected stirred tank in which
the mixture slowly moves downwards while being stirred me-
chanically at a temperature of 450 to 600°C and preferably at
480 to 550°C, and that dry, flowable coke is withdrawn from
the stirred tank. This flowable coke is largely free from
liquid residual oil and therefore exhibits a good flow behav-
ior.

In the process in accordance with the invention, the dwell
times of the heat carrier coke in the mixer usually are 1 to
120 seconds and in the stirred tank 1 to 30 minutes. As
mixer, there is advantageously used one with two or more
horizontal intermeshing screws, which is already known. This
mixer can be built with a relatively short length, so that
the dwell times of the gases and vapors in the mixer are also
short and usually amount to 0.5 to 5 seconds.
Coke-containing solids from the mixer, which are still moist
and sticky, are charged into the subsequently connected
stirred tank. The content of residual oil in the mixer, which
residual oil is charged into the stirred tank, still is 5 to
90 wt-% and mostly 10 to 70 wt-% of the amount of residual
oil supplied to the mixer. The stirred tank in which the sol-
ids gradually move downwards may have a single impeller shaft
or also several impeller shafts. Thorough mixing promotes the
withdrawal of the gases and vapors released, which are with-
drawn from the stirred tank and, like the gases and vapors
withdrawn from the mixer, are supplied to a condensation.
Stirring in the stirred tank is necessary because the resid-
ual oil is a bituminous binder which leaves a coke residue,


and it must be prevented that the solid particles agglomerate
to form large lumps. Lumps formed are broken again by the
stirrer, so that the flow property of the heat carrier is
maintained. In the stirred tank, long dwell times can easily
be achieved, whereas with equal dwell times mixers with hori-
zontal, intermeshing screws would have to be built with too
much length, which on the one hand would be mechanically dif-
ficult and on the other hand complex and expensive.
Embodiments of the process will be explained with reference
to the accompanying drawing, "wherein:
Fig. 1 shows a flow diagram of the process,
Fig. 2 shows a diagram indicating yields as a function of
the reaction temperature, and
Fig. 3 shows a diagram indicating pollutants in the prod-
uct oil as a function of the reaction temperature.
In the mixer 1 of Fig. 1, hot heat carrier coke is introduced
through line 2, and the residual oil to be processed is in-
troduced through line 3. The heat carrier coke has tempera-
tures in the range from 500 to 700°C, and heat carrier coke
and residual oil are supplied to the mixer 1 in a weight ra-
tio of 3:1 to 30:1. In the present case, the mixer 1 has a
plurality of horizontal, intermeshing screws, as is known per
se. In the mixer 1, temperatures in the range from 450 to
600°C and mostly 480 to 550°C are obtained. Gases and vapors
formed leave the mixer 1 after a short dwell time in the
range from 0.5 to 5 sec through the discharge duct 5 and are
introduced into a condensation 6. From this condensation,
gases are separately withdrawn through line 7, and crude
product oil is withdrawn through line 8, which crude product
oil can be supplied to a further treatment not represented.
The coke-containing solids mixture, which has passed through
the mixer 1 and has arrived at the outlet passage 10, still

has a residual content of residual oil of 5 to 90 wt-%, based
on the amount supplied through line 3. Therefore, the mixture
still is moist and sticky, so that there is expediently used
a mechanical cleaning device 11 (e.g. screw, scraper), in or-
der to avoid deposits and agglutinations in the passage 10.
In the stirred tank 12, the mixture of solids and residual
oil is stirred mechanically while it moves downwards, the
temperatures being maintained in the range from 450 to 600°C
and mostly in the range from 480 to 550°C. The dwell times of
the solids in the stirred tank lie in the range from 1 to 30
min and preferably amount to at least 3 min. Hence it is pos-
sible to also use rather low temperatures in the stirred
tank, in order to convert the residual oil to oil vapor, gas
and coke. In the present case, gases and vapors formed flow
upwards through the passage 10 and along with the gases and
vapors from the mixer 1 reach the condensation 6 through the
discharge duct 5.
It may be expedient to introduce a stripping gas (e.g. steam,
C4~hydrocarbon gas or nitrogen) into the lower portion of
the stirred tank 12, as is indicated by the broken line 13.
When the coke reaches the lower portion of the stirred tank
12, it is dry and flowable. This coke is withdrawn through
line 14 and supplied to a pneumatic conveyor 15. Combustion
air, which is preferably preheated, is introduced through
line 16 into the pneumatic conveyor, and it is also possible
to introduce additional fuel. In the conveyor 15, the addi-
tional fuel and/or part of the coke is burnt, the remaining
coke is heated and introduced into the collecting bin 17. Ex-
haust gases leave the collecting bin through line 18, and the
hot coke, which has temperatures in the range from 500 to
700°C, accumulates in the lower portion of the bin 17. From
here, it is supplied as heat carrier coke through line 2 into
the mixer 1 in the manner already described above. A partial


stream of 1 to 30 wt-%, based on the total amount of heat
carrier coke supplied to the distillation, can be supplied
through line 4 to the end of the mixer 1. This additional
heat carrier coke will then chiefly become effective in the
solids mixture introduced into the stirred tank 12. By means
of this second addition of coke the mixture of coke and re-
sidual oil in the stirred tank can additionally be heated,
which accelerates the conversion of the residual oil on top
of the coke. In contrast to the representation of Fig. 1, the
heat carrier coke supplied through line 4 can also be intro-
duced into the vertical portion of the discharge duct 5,
where the hot heat carrier coke removes accretions and recir-
culates the same to the mixer 1. Excess coke can be withdrawn
from the coke circuit through line 2a.
Explanations on Figs. 2 and 3: Experiments performed revealed
that with decreasing reaction temperature (T) both the yield
of product oil and the quality of the product oil are in-
creasing.
In Fig. 2, the formed amounts (in wt-%) of coke (C), product
oil (PO) and gases (G) up to C4 are represented on the Y-
axis. The valuable range is that of the product oil.
In Fig. 3, the Z-axis indicates the percentage (wt-%) of
various pollutants in the product oil, based on the initial
content in the treated residual oil, namely for sulfur (S),
nitrogen (N), Conradson residue (CCR) and the sum of nickel
and vanadium (Ni+V).
It can be seen that at a low reaction temperature both the
yield of product oil is higher and the content of pollutants
in the product oil is lower. However, at decreasing tempera-
tures the reactions require longer dwell times of the solids,
which only with the combination of mixer 1 and stirred tank
12 can be achieved in an economic way.


Example:
In an arrangement corresponding to Fig. 1, 10 t/h of a vacuum
residue obtained in the distillation of crude oil are in-
jected into the mixer 1 with a temperature of 330 °C and mixed
with 80 t/h heat carrier coke of 570°C. The vacuum residue
contains 20 wt-% CCR, 3 wt-% sulfur, 200 mg/kg vanadium and
100 mg/kg nickel. In the mixer, a reaction temperature of
500°C is obtained. After about 30 seconds, the still oil-
containing heat carrier coke is dropped from the mixer into a
stirred tank 12. The residual content of residual oil still
is 25 wt-%, based on the amount of residue supplied. Within
another 5 minutes, the mixture is reacted in the stirred tank
to obtain dry coke (1.2 t/h) as well as oil vapor and gas.
The mixture of oil vapor and gas is withdrawn through the
ducts 10 and 5 and supplied to a condensation 6. Correspond-
ing to Figs. 2 and 3, there are obtained 8.3 t/h product oil
(C5+) with 4 wt-% CCR, 2.1 wt-% S, 7 mg/kg V and 3.5 mg/kg
Ni as well as 500 kg/h gas (C4-). The heat carrier coke (80
t/h) as well as the coke freshly formed on its surface are
withdrawn from the stirred tank largely free from liquid con-
stituents and thus dry and flowable.


WE CLAIM
1. An improved method for flash distillation of a residual oil from an on-going
processing of crude oil, natural bitumen or oil sand, comprising the steps
of:
- mixing in a mixer with granular, hot coke as heat carrier (heat
carrier coke) in a weight ratio of 1:3;
• forming a liquid residue film on the granules of the heat carrier
coke in course of mixing the heat carrier coke with the residue oil
in a mixer, residue film partly evaporating in the mixer;
- withdrawing the gases and vapors formed in the forming step from
the mixer; and
- withdrawing the so produced moist, sticky coke from the mixer, the
improvement is characterized in that the mixture of coke and
residual oil is introduced into a subsequently connected stirred
tank, in which the mixture slowly moves downwards while being
stirred mechanically at a temperature of 450 to 600°C and
preferably at 480 to 550°C, and in that, a dry, flowable coke left in
the stirred tank.

2. The method as claimed in claim 1, wherein the dwell time of the heat
carrier coke in the mixer is 1 to 120 seconds.
3. The method as clamed in claim 1, wherein the dwell time of the heat
carrier coke in the stirred tank is 1 to 30 minutes.
4. The method as claimed in claim 1 or 2, wherein fresh heat carrier coke is
added to the coke-containing mixture, which is introduced into the stirred

tank with a residual content of residual oil of 5 to 90 wt-%, based on the
amount of residual oil charged into the mixer.
5. The method as claimed in any of the preceding claims, wherein a
mechanical cleaning device is disposed on a passage between the mixer
and the stirred tank.


An invention relates to a residual oil from the processing of curde oil, natural
bitumen or oil sand is mixed in a mixer with granular, hot coke as heat carrier
(heat carrier coke) in a weight ratio of 1:3 to 1:30, where on the granules of the
heat carrier coke there is first of all formed a liquid residue film which partly
evaporates in the mixer. Gases and vapours and moist, sticky coke are
withdrawn from the mixer. The mixer of coke and residual oil is introduced into a
subsequently connected stirred tank in which the mixture slowly moves
downwards while being stirred mechanically at a temperature of 450 to 600°C.
and preferably at 480 to 550°C. Dry, flowable coke is withdrawn from the stirred
tank. Usually, the dwell time of the heat carrier coke in the stirred tank is 1 to 30
minutes.

Documents:

385-cal-2000-abstract.pdf

385-cal-2000-assignment.pdf

385-cal-2000-claims.pdf

385-CAL-2000-CORRESPONDENCE 1.1.pdf

385-CAL-2000-CORRESPONDENCE.1.1.pdf

385-cal-2000-correspondence.pdf

385-cal-2000-description (complete).pdf

385-CAL-2000-DRAWINGS 1.1.pdf

385-cal-2000-drawings.pdf

385-cal-2000-examination report.pdf

385-CAL-2000-FORM 1 1.1.pdf

385-cal-2000-form 1.pdf

385-cal-2000-form 18.pdf

385-CAL-2000-FORM 2 1.1.pdf

385-cal-2000-form 2.pdf

385-CAL-2000-FORM 3 1.1.pdf

385-cal-2000-form 3.pdf

385-CAL-2000-FORM 5 1.1.pdf

385-cal-2000-form 5.pdf

385-cal-2000-form 6.pdf

385-cal-2000-gpa.pdf

385-CAL-2000-GRANTED-ABSTRACT.pdf

385-CAL-2000-GRANTED-CLAIMS.pdf

385-CAL-2000-GRANTED-DESCRIPTION (COMPLETE).pdf

385-CAL-2000-GRANTED-DRAWINGS.pdf

385-CAL-2000-GRANTED-FORM 1.pdf

385-CAL-2000-GRANTED-FORM 2.pdf

385-CAL-2000-GRANTED-SPECIFICATION.pdf

385-CAL-2000-PA.pdf

385-cal-2000-priority document.pdf

385-cal-2000-reply to examination report.pdf

385-cal-2000-specification.pdf

385-cal-2000-translated copy of priority document.pdf


Patent Number 249746
Indian Patent Application Number 385/CAL/2000
PG Journal Number 45/2011
Publication Date 11-Nov-2011
Grant Date 08-Nov-2011
Date of Filing 07-Jul-2000
Name of Patentee LURGI LENTJES AG
Applicant Address DANIEL-GOLDBACH-STRASSE 19, D-40880, RATINGEN
Inventors:
# Inventor's Name Inventor's Address
1 WEISS HANS-JURGEN MUHLENWEG 41, D-61440 OBERURSEL
2 ZENTNER UDO BRUCKNERSTRASSE 9, D-64347 GRIESHEIM
3 DREHER INGO ROSENGARTCHEN 62, D-61440 OBERURSEL
PCT International Classification Number C10G 9/28
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 19959587.9 1999-12-10 Germany