Field of the Invention
[0001] The invention provides an abrasion device (300) for continuously removing coke from
the inner wall of a rotating reactor (110) comprising a cylindrical part (114) and
comprising a base frame (310) with suspensions (311) for mounting auger scrapers (320),
wherein said suspensions (311) are mounted at the base frame (310) and connect an
upper part (312) and a lower part (313) of the base frame (310); said lower part (313)
of the base frame (310) comprises at least one auger scraper (320), wherein said at
least one auger scraper (320) comprises a central roller (321) with an outer auger
helix (322), said at least one auger scraper (320) being rotatably mounted at cross
members (314) at the lower part (313) of the base frame (310) at the ends of the suspensions
(311) that are protruding in direction of the bottom of the cylindrical part (114)
of the rotating reactor (110).
[0002] The invention further provides a system (100) for continuous processing of heavy
fuel oil from recycling waste oil and the processing residues of crude oil into useful
products comprising means for feeding waste oil; at least one hot-gas filter, at least
one condenser, at least one rotating kiln comprising an outer stationary jacket (120)
which forms a heating channel (121), and an inner rotating reactor (110), and the
abrasion device (300) for removing solid coke from the rotating reactor (110).
[0003] The invention further relates to a process for continuous processing of heavy fuel
oil from recycling waste oil and the processing residues of crude oil into useful
products, preferably with the system of the invention.
Background of the Invention
[0004] The heavy oil (residual oil) produced during oil distillation accounts for about
70 percent of the fuel used in shipping worldwide. From 2020 onwards, ships on the
high seas will only be allowed to burn fuel with a Sulphur content of 0.5 percent
or below instead of 3.5 percent allowed so far, or will alternatively have to remove
the Sulphur from the exhaust gases. As a result of the new regulation, which will
be set in force in 2020, environmentally harmful heavy fuel oil cannot be used as
a fuel anymore and a large number of international shipping companies will have to
replace heavy fuel by more environmentally friendly ship diesel. This in turn has
a direct influence on the refineries. There will no longer be a market for their residual
heavy oil products in the future.
[0005] For this reason, methods for re-processing the residual oils produced are needed,
preferably aiming to the recycling of the heavy oils, e.g. by reintegration into production
processes of oils.
[0006] Heavy fuel oil essentially consists of long-chain saturated hydrocarbon compounds
(heavy boilers). In order to generate a usable product, processes are needed to degrade
these long chain hydrocarbons into shorter chains. One suitable method is pyrolysis,
i.e. the so-called "cracking process". The pyrolysis is forced by high temperatures
under exclusion of oxygen. Gases, liquids and solids are produced as pyrolysis products.
[0007] Conventionally, pyrolysis is performed in systems comprising a rotating kiln as reactor,
in which the cracking of the long chain hydrocarbons of the heavy oil takes place.
In the rotating kiln, the heavy oil must be finely atomized and evenly distributed
on the inner wall of the rotating kiln. The necessary reaction temperature is usually
produced by external heating the rotating kiln and the cracking reaction takes place
at the inner wall of the kiln. As a safeguard, the rotating kiln can be purged with
a protective medium such as nitrogen. When the cracking reaction takes place, the
long chain hydrocarbons are converted into gaseous products and coke is produced as
a major byproduct. The coke occurs as a soft coke, which is distributed in the gaseous
phase and which has to be eliminated from the gaseous products before their condensation.
Coke further occurs as solid coke adhering to the inner wall of the rotating kiln.
A growing coke layer at the inner wall of the rotating kiln is disadvantageous, because
it forms a heat insulating layer, which disturbs the cracking reaction. As a result,
the heavy fuel oil cannot reach the reactor wall and the temperature for initiating
the cracking reaction cannot be reached effectively.
[0008] Therefore, several attempts have been made to overcome these disadvantages, and in
particular to remove the solid coke occurring at the reactor wall during the cracking
reaction.
[0009] CA 2926434 concerns a rotary kiln for the treatment of waste oil and other organic waste. The
rotary kiln here is equipped with loosely mounted plates which shall prevent the deposition
of coke in the bottom area of the rotary kiln, or shall lead to the scraping off deposited
coke. However, during the operation, the loosely mounted plates are distributed randomly
within the rotary kiln and after short time of operation, the bottom of the rotary
kiln is blocked by a mixture of plates and coke debris. The material flow in the reactor
is hindered and the coke cannot be discharged quickly enough, which further increases
the size of the bed. This means that the required temperatures cannot be maintained
and the heavy fuel oil is sprayed onto the material on the bottom of the reactor and
the cracking reaction is thereby disturbed. Therefore, a continuous operation of the
rotary kiln as described in
CA 2926434 is not possible.
[0010] The German utility model
DE 29704044 U1 deals with the problem of the formation of solid layers on the inner wall of rotary
kilns resulting from the smoldering of materials containing hydrocarbons, such as
residues from heavy oil and coal hydrogenation. To solve this problem, rolling elements
are used to clean the inner wall of the drum. These rolling elements, however, are
themselves covered with the solid material during operation of the rotary kiln, wherein
their effectivity in cleaning the inner wall of rotary kilns is decreased and the
maintenance efforts of the entire system is increased.
[0011] DE 69732164 T2 concerns processes for removing impurities from oil. In particular, the invention
relates to a device for removing contaminants from used oil, in which device the oil
is subjected to evaporation and pyrolysis to form coke. Contaminants such as heavy
metals remain in the coke, which can then be separated from the oil. The device comprises
a rotating kiln, which is indirectly heated. Also in this device, the problem has
to be solved that coke deposited on the reactor walls has to be removed. To solve
this problem, the reaction chamber is equipped with granular, crude solids (such as
metal chips), which act to chafe and crush coke from the reactor wall. Such system,
however, can only be operated discontinuously, because the granular, crude solids
are mixed with the coke crushed from the reactor wall during operation. This mixture
accumulates in the reactor and needs to be removed regularly from the reactor.
[0012] WO 2020187754 A1 concerns a system for continuous processing of heavy fuel oil from recycling waste
oil and the processing residues of crude oil into useful products, said system comprising
scraper means that are mounted in a rotating kiln, wherein the distance between the
scraper means and the reactor wall is in the range of 0.5 to 2.0 mm. This leads to
the fact the coke still accumulates at the reactor wall as a layer with a thickness
between 0.5 to 2.0 mm.
[0013] Taken together the problem that coke deposits form on the reactor wall and have to
be removed from it during thermal decomposition of heavy fuel oils in rotary reactors
is known in the art.
[0014] To solve this problem, devices for mechanical removal of the coke as described above
have been developed. However, all these solutions are associated with disadvantages
such as no reliable operation, high maintenance efforts as well as the need for discontinuous
removal of materials from the reactor and disposal as waste. Therefore, the solutions
known in the art do not offer the possibility of processing heavy fuel oil in a reliable
continuous process.
Description of the invention
[0015] Accordingly, it was the purpose of the invention to overcome the problems of the
prior art and to provide a simple and reliable system and process for the continuous
pyrolysis of heavy fuel oil.
[0016] To solve this problem, the invention provides in a first aspect an abrasion device.
Said abrasion device comprises a base frame with suspensions for mounting auger scrapers.
The suspensions are mounted at the base frame, connect an upper part and a lower part
of the base frame and are preferably designed to be telescopic and allow a vertical
movement of the lower part of the base frame, which comprises the auger scrapers.
The auger scrapers comprise a central roller with an outer auger helix, which is preferably
made of steel. The auger scrapers are rotatably mounted at cross members at the lower
part of the base frame at the ends of the suspensions that are protruding in direction
of the bottom of the rotating reactor. Preferably, each abrasion device comprises
one, two or three, preferably two, most preferably three auger scrapers. Further preferably,
the rotating reactor of the invention comprises two abrasion devices comprising two
to six auger scrapers, preferably four, most preferably six auger scrapers. The auger
scraper means are aligned with the reactor wall. In a most preferred embodiment, the
auger scrapers are arranged over the entire length of the bottom of the cylindrical
part of the rotating reactor. Further preferably, the auger scrapers are arranged
alternately on the left and right side of the base frame with the telescopic suspensions,
when seen from the top view. This ensures an even load on the telescopic suspensions
by the auger scrapers.
[0017] It is desired to keep the thickness of the layer structure of the coke and thus the
deteriorating heat transfer as low as possible. Preferably, substantially all coke
accumulations at the cylindrical part of the reactor wall shall be removed by the
abrasion device of the invention. In order to achieve this goal, the abrasion device
of the invention comprises at least one, preferably some, most preferably all of the
following further special embodiments:
- i. The base frame of the abrasion device is mounted on a rigid central axis within
the cylindrical part of the rotating reactor such that any axial movement of the abrasion
device is prevented. Only vertical movements of the lower part of the base frame,
which comprises the auger scrapers of the abrasion device, are possible through the
telescopic suspensions.
- ii. The lower part of the base frame further comprises weights to increase the mass
of the lower part of the base frame and to increase the contact pressure of the auger
scrapers on the coke layer on the reactor wall.
- iii. It has been measured by the inventors that the breaking strength of the coke
that accumulates on the inner side of the reactor wall, is in the range of 70 N/mm2 to 90 N/mm2. Accordingly, the mass of the weights was calculated in such a way that the abrasion
device generates a contact pressure of > 70 N/mm2, preferably > 80 N/mm2 or > 90 N/mm2, more preferably 100 N/mm2 to 150 N/mm2, on the inner side of the wall of the cylindrical part of the rotating reactor, wherein
said contact pressure is calculated on the basis of dead weight of the lower part
of the base frame including the auger scrapers and the weights mounted on the lower
part of the base frame and the contact surface area of the auger helix on the inner
wall of the rotation reactor. Best results were achieved when the abrasion device
generates a contact pressure of 120 N/mm2 on the inner side of the wall of the cylindrical part of the rotating reactor. Due
to the telescopic suspensions, the lower part of the abrasion device can always apply
the contact pressure preset by the choice of the mass of the weights to the reactor
wall without obstruction. Best results in this context means that substantially all
of the accumulated coke is scraped from the inner wall of the cylindrical part of
the rotating reactor in a continuous manner.
- iv. Since the auger scrapers are rotatably mounted at cross members at the lower part
of the base frame at the ends of the suspensions that are protruding in direction
of the bottom of the rotating reactor, and due to the preset contact pressure, the
auger scrapers rotate during operation of the rotating reactor. This generates and
ensures a positive movement between the auger scrapers and the inner reactor wall
and further supports the breaking of the accumulated coke at the inner reactor wall
and the scraping-off of the coke by the auger helix.
[0018] To solve the problem of the invention, the invention further provides a system for
continuous processing of heavy fuel from the recycling of waste oil and the processing
of residues from crude oil into useful products comprising
- means for feeding waste oil;
- at least one hot-gas filter,
- at least one condenser,
- at least one rotating kiln comprising an outer stationary jacket which forms a heating
channel, and an inner rotating reactor, and
- means for removing solid coke from the rotating reactor;
wherein the at least one hot gas filter is configured to separate a naphtha/gasoil
fraction after the processing of the heavy fuel oil from a soft coke fraction; and
wherein the rotating reactor is configured to recover a solid coke fraction comprising
high contaminant content;
characterized in that
said system comprises a number of gas burners arranged along the longitudinal direction
and sufficient to evenly and indirectly heat the rotating reactor;
the rotating reactor comprises at least one abrasion device as described in the first
aspect of the invention, said at least one abrasion device comprising auger scraper
means, wherein said auger scraper means are configured to continuously remove accumulated
solid coke from the inner wall of the rotating reactor and converting said accumulated
solid coke into powdery coke;
said means for feeding heavy fuel oil comprises a number of spray lances of different
length and configured to distribute with nozzles said waste oil evenly along the longitudinal
direction within the rotating reactor.
[0019] Said system is preferably configured to operate at a process temperature in the range
of 600 to 650 °C, measured at the inner wall of the rotating reactor.
[0020] The continuous cleaning of the inner wall of the rotating reactor is one of the crucial
points in the construction of the system according to the invention since the heat
transfer is hindered by the layer structure of the coke and thus the cracking process
of the heavy fuel oil on the reactor wall and within the volume of the rotating reactor
is disturbed. It is a great advantage of the abrasion device and system of the invention
comprising said abrasion device that substantially all accumulated coke is removed
from the inner wall of the rotating reactor. Compared to prior art technologies, e.g.
to the technology disclosed in
WO 2020187754 A1, no coke layer is formed the inner wall of the rotating reactor during operation.
So, the heat transfer and energy efficiency of the abrasion device and system of the
invention is greatly improved compared to technologies known in the prior art.
[0021] In a further embodiment, the rotating reactor is equipped at the lower end of the
inclined reactor with a funnel, wherein said funnel comprises auger plates to discharge
the material from the rotating reactor. The funnel and the auger plates are preferably
made of a suitable material, such as iron or steel or stainless steel.
[0022] Accordingly, the rotating reactor comprises a cylindrical part and a funnel with
the auger plates. The cylindrical part has usually a length of 4.50 to 6.00 m. Preferably,
the cylindrical part has a length of 5.00 to 5.50 m. Most preferably, the cylindrical
part has a length of 5.23 m. The funnel has usually a length of 1.50 to 2.50 m. Preferably,
the funnel has a length of 1.80 m to 2.20 m. Most preferably, the funnel has a length
of 2.02 m. The cylindrical part and the funnel together usually have a length of 6.00
m to 8.50 m. Preferably, the cylindrical part and the funnel together have a length
between 6.50 and 8.00 m. Most preferably, the cylindrical part and the funnel together
have a length of 7.25 m.
[0023] The cylindrical part has usually a diameter in the range of 2.40 m to 3.20 m, preferably
in the range of 2.60 m to 3.00 m. Most preferably, the cylindrical part has a diameter
of 2.80 m. The rotating reactor has two barrel rings, i.e. one barrel ring on each
end of the reactor. Each of the barrel rings interacts with a bearing of a frame construction.
When the cylindrical part and the funnel together have a length of 7.25 m, the two
barrel rings have a distance of 7,00 m.
[0024] A known problem of rotating reactors is that a so-called ovality. Ovality is the
degree of deviation from perfect circularity of the cross section of the reactor.
In case of the present invention, the ovality, i.e. the deviation from perfect circularity
of the cross section of the reactor is in the range of ± 3 mm at the barrel rings.
[0025] A further problem is the so-called deflection over the longitudinal axis of the reactor.
The value of the deflection may increase with the length of the reactor. In case of
the present invention, the length of the reactor is relatively short and a value of
1 to 2 mm was calculated for the deflection. However, the rotating reactor of the
present invention comprises at the outer wall of its cylindrical part, means that
ensure that the heating gas is evenly distributed in the heating tunnel (discussed
below). Such means are preferably plates, such as ribbed plates, which are welded
on the outer wall of the cylindrical part. These welded ribbed plates on the outer
wall of the reactor have a further stabilizing effect, which further decreases the
deflection below the value of 1 to 2 mm.
[0026] However, the ovality and deflection of the reactor play a minor role. Deviations
from the "roundness" of the reactor are advantageously compensated by the abrasion
device of the invention, which allows vertical movements of the lower part of the
base frame, which comprises the auger scrapers of the abrasion device, through the
telescopic suspensions.
[0027] The advantage of this construction, in particular the combination of the abrasion
device of the invention with the funnel comprising auger plates is that the scraped
coke is discharged from the rotating reactor continuously in an easy way and without
the need of further constructural means, simply by gravity. The discharge of the scraped
coke by gravity is further supported by the arrangement of the rotating reactor, which
is inclined in direction of the lower end, i.e. towards the funnel comprising auger
plates. Preferably, the rotating reactor is inclined at an angle between 2 und 8°,
preferably 3 to 6°, most preferably 4 to 5°.
[0028] In a further embodiment, the system of the invention comprises downstream components
such as a diverter, double pendulum dampers and screws for discharging the scraped
coke. Preferred downstream elements comprise a diverter, a mill or a grinder, rotary
valves or double sluice gates, a hot-rolling screw conveyor and a cooling screw conveyor.
The solids are conveyed from the rotating reactor into the diverter. In the subsequent
downstream elements, the coke must be cooled from the process temperature down to
a temperature of e.g. 60 °C in the cooling screw. After passing the cooling screw,
the scraped coke may be filled in big bags or other types of containers for storage
and further handling. Accordingly, the system of the invention comprises in a further
embodiment downstream means for filling the scraped coke into containers, such as
Big Bags.
[0029] In order to promote the cracking reaction, the rotating reactor must be heated to
reach and maintain the process temperature, which is suitably in the range of 400
to 700°C, preferably between 550 and 700°C, more preferably between 600 and 650°C.
In a preferred embodiment, the rotating reactor is heated indirectly. This has the
advantage that the occurrence of hotspots or punctual heat in the reactor wall is
prevented, which could occur with direct heating. Indirect heating is realized preferably
by an outer jacket, which forms a housing and heating channel around the rotating
reactor. External burners, such as external gas burners, that are placed outside of
the rotating reactor and outside of the housing, are used to produce heat that is
blown into the heating channel (the space between the rotating reactor and the outer
jacket) of the system of the invention. A further challenge is to apply the required
heat evenly over the whole body of the rotating reactor. This problem is solved in
the preferred embodiment of the invention in that and number of burners, such as gas
burners are arranged to apply indirect heat along the entire length of the rotating
reactor. In a further preferred embodiment, 2 to 6 gas burners are used for indirect
heating, more preferably 3 to 5 gas burners most preferably 4 gas burners. The number
of gas burners, however, may be adopted in accordance with the dimensions of the rotating
reactor. Moreover, the gas burners must have an output sufficient to support the cracking
reaction in the rotating reactor. The total output of the gas burners is preferably
between 500 and 2,000 kW, more preferably between 750 and 1,500 kW, most preferably
between 950 and 1.250 kW. In a further preferred embodiment of the invention, the
burners are mounted to the heating tunnel via a pre-combustion chamber. In order to
prevent heat loss, the pre-combustion chamber and the heating tunnel are insulated.
[0030] To ensure that the heating gas is evenly distributed in the heating tunnel, means
are provided on the outer wall of the rotating reactor. Such means are preferably
plates, such as ribbed plates, which are made from a suitable material, such as iron,
steel or stainless steel. These means increase the surface of the reactor wall and
ensure a turbulent flow of the heating gas as well as a more efficient heat transfer
into the rotating reactor. The system of the invention therefore comprises in a further
embodiment ribbed plates for supporting the distribution of the heated air, wherein
said ribbed plates are mounted on the outer wall of the rotating reactor. The number
and the dimensions of these ribbed plates are configured in accordance with the dimensions
of the system of the invention, i.e. of the rotating reactor.
[0031] The system of the invention further comprise holes in the jacket for directing the
heating gas into the space between housing and reactor wall of the rotating reactor.
[0032] A further challenge, which has been solved by the system of the invention, is the
even distribution of the heavy fuel oil over the entire length of the rotating reactor.
For this reason, the heavy fuel oil is not distributed into the rotating reactor with
one spray lance only. The number of spray lances has been rather increased in accordance
with the length of the rotating reactor, especially in accordance with the length
of the cylindric part of it. Accordingly, the system of the invention comprises more
than one, e.g. 2 to 8, preferably 3 to 5, most preferably 4, evenly most preferred
3 spray lances, which guarantee even distribution of the sprayed heavy fuel oil with
in the rotating reactor. The spray lances have different lengths in order to distribute
the heavy fuel oil with defined parts or areas of the rotating reactor, whereby it
is advantageous that the length of the spray lances is selected in order to prevent
overlapping spray pattern.
[0033] In this regard, the design of the nozzles, which are mounted at the end of the spray
lances in the rotating reactor, has also been optimized. The nozzle used are as fine
as possible and do not have a too large spray cone. This construction has the advantage
that an overlapping spray pattern is prevented. The use of a flat spray nozzles is
not recommended, as these are only to be used for coarse spray patterns. In a preferred
embodiment of the invention, the nozzles used at the end of the spray lances have
a spray cone with a spray angle at the outlet of the nozzle of approx. 45°. This construction
ensures that not too much material is sprayed onto a too small area, because this
would deteriorate the heat transfer within the rotating reactor and therefore disturb
the cracking reaction.
[0034] Solids, such as coke, are continuously scraped from the rotating reactor wall during
its operation, forming a bed of debris in the certain area on the bottom of the rotating
reactor. This bed of debris detonates the heat transfer on the reactor wall and into
the rotating reactor at least locally. Spraying the heavy fuel oil on the bed of the
breeze would lead to an incomplete cracking reaction. In a further embodiment of the
invention, the direct action of the nozzles is therefore arranged to spray the heavy
fuel oil on areas of the wall of the rotating reactor, which is free of debris of
solids and coke.
[0035] The remaining solids, such as soft coke and dust, in the gas stream need also to
be separated downstream. The quality of the purified gas is decisive for the stability
of the further process. The system of the invention therefore comprises in a further
embodiment means for removal of the remaining solids from the gas stream. Suitable
means for the removal of the remaining solids from the gas stream are for example
cyclones or hot gas filtration systems. Most preferred in accordance with the invention
are hot gas filtration systems. A suitable hot gas filtration system comprises e.g.
fibre-ceramic filter cartridges. Such a hot gas filter may comprise rigid filter elements,
which are suspended in an insulated container with a conical dust collection chamber,
wherein the filter cartridges made of robust ceramic fibes are resistant to temperatures
up to 850 °C and chemicals. Suitable fiber ceramic materials for this purpose are
available in the art. In a further preferred embodiment, the hot gas filter is equipped
with means for cleaning the filter cartridges. Such means are e.g. selected from jet
valves, which are opened in short intervals (fractions of a second), whereby the filter
cartridges are purged with an inert purge gas, such as nitrogen gas at high pressure.
[0036] In a further embodiment, the system of the invention comprises seals between the
rotating reactor and the inlet and outlet housings, and a seal between the heating
channel and the reactor. In particular, the seals between the rotating reactor and
the inlet and outlet housings are important for operating the process of the invention
and a reliable manner.
[0037] The system of the invention is in further embodiment equipped with heat exchanger.
This has the advantage that the pyrolysis and flue gases can be used for heat recovery,
i.e. the thermal energy of the flue gases is used to preheat the combustion air required
for the gas burners in order to ultimately save natural energy, i.e. natural gas,
and also to reduce the output size of the burners as far as possible. Surprisingly,
if the pyrolysis gas is fed via a heat exchanger for residual heat utilization, heat
energy can be obtained between 120 and 170 MJ/h at efficiencies between 0.5 and 0.7
with the system of the invention. Accordingly, the system of the invention can be
operated in an environmental-friendly manner.
[0038] In a further embodiment, the system of the invention comprises a condenser for separating
the heavy boiling hydrocarbons, aqueous phase and inert gas fraction from the dust-free
pyrolysis gas. The condenser is suitably arranged in the system after the hot gas
filter.
[0039] To ensure the inert environment within the system during continuous operation, the
system is operated under slight overpressure in an oxygen free atmosphere.
[0040] In order to facilitate the cracking process in the rotating reactor and to ensure
a reliable operation in a continuous manner, the system of the invention is configured
to prevent any cold bridges and to keep the temperature of and in the rotating reactor
including parts that are connected to the rotating reactor, in the range of the process
temperature as described above.
[0041] In a further aspect, the invention provides a process for continuous processing of
heavy fuel oil from the recycling of waste oil and the processing of crude oil, into
useful products comprising the steps of
- thermal cracking of heavy fuel oil in system according to the invention;
- discharging the process gas from the rotating reactor via the hot-gas filter for separation
of soft coke particles and thereafter via the condenser;
- scraping coke from the rotating reactor (110) with the abrasion device (300) according
to the invention;
- discharging the powdery coke from the rotating reactor;
- partial condensation of the process gas in a condenser and drain off the resulting
naphtha/gas oil mixture into storage tanks for further processing.
[0042] The process of the invention can be described in a general manner as follows: The
thermal cracking (pyrolysis) takes place in the rotating reactor of the invention.
Feed pumps convey the starting product (heavy fuel oil) from the storage tank to the
subsequent subsystems. The oil is mixed with steam on the input side, preferably under
ratio control, and injected into the rotating reactor. The pyrolysis takes place in
a temperature range between 400 to 700°C, preferably between 450 and 600°C, more preferably
between 600 and 650°C, measured at the inner wall of the rotating reactor. The temperature
in the inner volume of the reactor is preferably between 450°C and 500°C, most preferably
450°C. The long-chain hydrocarbon compounds are degraded and pyrolysis coke and pyrolysis
gas are produced. The coke adheres to a great extent to the reactor wall and forms
solid coke, which disturbs thermal flow from the heating channel of the system of
the invention into the rotating reactor. The solid coke is therefore removed by auger
scrapers and discharging means and conveyed out of the rotating reactor by gravity.
[0043] The pyrolysis gas produced contains a not inconsiderable proportion of solids. These
are to be removed directly from the hot gas stream, preferably by means of a hot gas
filter, which in a more preferred embodiment of the invention comprises fiber-ceramic
filter cartridges. The quality of the purified gas is decisive for the stability of
the further process.
[0044] The solids-free pyrolysis gas is a mixture of heavy boiling hydrocarbons, low boiling
hydrocarbons and water in the presence of inert gas components which are separated
by condensation. The resulting hydrocarbon liquids from heavy boiling hydrocarbons
and water are discharged from the system of the invention via defined service lines
in a storage tank for further use. The remaining non-condensed gases (low boilers)
serve as fuel for the gas heaters of the system of the invention.
[0045] The separated solids are fed to a Big Bag filling system via a hot-rolling screw
conveyor and a cooling screw conveyor. The Big Bags are e.g. temporarily stored in
a small warehouse before they are shipped for recycling by truck. Recycling of the
separated solids may e.g. be done by use as fuel for blast furnaces.
[0046] The specific features of the process of the invention are described in connection
with figure 10 below.
[0047] In a further aspect, the invention relates to the use of the gas oil / naphta produced
with the system and/or the process of the invention for manufacturing useful products,
such as fuel, base oil and base oils products.
[0048] Moreover, the invention relates to the use of the powdery coke produced with the
system and/or the process of the invention as fuel in blast furnaces.
[0049] The advantage of this aspect of the invention is that almost any products as well
as waste products resulting from the process of the invention are re-usable or recyclable.
[0050] The invention is further illustrated in more detail by eight figures, wherein
- Figure 1
- shows a cross-sectional view of the system of the invention;
- Figure 2
- shows cross-sectional view of the funnel of the rotating reactor;
- Figure 3
- shows a side-view on and into an embodiment of the system of the invention;
- Figure 4
- shows another side-view on and into an embodiment of the system of the invention;
- Figure 5
- shows a cross-sectional view on an embodiment of the diverter of the system of the
invention;
- Figure 6
- illustrates the principle, how the direction of rotation and the spraying is coordinated;
- Figure 7
- shows an embodiment of the heating tunnel with burners and pre-combustion chamber;
- Figure 8
- shows an embodiment the heating tunnel with burner and pre-combustion chamber;
- Figure 9
- visualizes the hot gas filter;
- Figure 10
- shows an embodiment of the abrasion device of the invention in a top view (Fig. 10A),
front view (Fig. 10B) and a side view (Fig. 10C); and
- Figure 11
- represents a flowsheet of the process of the invention.
[0051] Figure 1 shows a cross-sectional view of the system
100 of the invention. The system
100 comprises a rotating reactor
110, which is equipped with an abrasion device
300 in the cylindrical part
114 of the rotating reactor. Said abrasion device
300 comprises a base frame
310 with suspensions
311 for mounting auger scrapers
320. The suspensions
311 are mounted at the base frame
310, connect an upper part
312 and a lower part
313 of the base frame
310 and are telescopic thereby allowing a vertical movement of the lower part
313 of the base frame
310, which comprises the auger scrapers
320. The auger scrapers
320 comprise a central roller
321 with an outer auger helix
322, which is made of steel. The auger scrapers
320 are rotatably mounted at cross members
314 at the lower part
313 of the base frame
310 at the ends of the suspensions
311 that are protruding in direction of the bottom of the cylindrical part
114 of the rotating reactor
110. The embodiment shown in Figure 1 comprises two abrasion devices
300, wherein each abrasion device
300 comprises three auger scrapers
320. The auger scrapers
320 are aligned with the inner wall of the rotating reactor
110 and are arranged over the entire length of the bottom of the cylindrical part
114 of the rotating reactor
110. The auger scrapers
320 are arranged alternately on the left and right side of the base frame
310 with the telescopic suspensions
311, when seen from the top view. This ensures an even load on the telescopic suspensions
311 by the auger scrapers
320.
[0052] In order to remove substantially all coke accumulations from the cylindrical part
114 of the inner wall of the rotating reactor
110, the abrasion device
300 of the system
100 shown in Figure 1 is characterized by the following further special embodiments:
- i. The base frame 310 of the abrasion device 300 is mounted on a rigid central axis 113 within the cylindrical part 114 of the rotating reactor 110 such that any axial movement of the abrasion device 300 is prevented. Only vertical movements of the lower part 313 of the base frame 310, which comprises the auger scrapers 320 of the abrasion device 300, are possible through the telescopic suspensions 311.
- ii. The lower part 313 of the base frame 310 further comprises weights 330 to increase the mass of the lower part 313 of the base frame 310 and to increase the contact pressure of the auger scrapers 320 on the coke layer on the inner wall of the rotating reactor 110.
- iii. The mass of the weights 330 was calculated in such a way that the lower part 313 abrasion device 300, which comprises the auger scrapers 320, generates a contact pressure 120 N/mm2 on the inner side of the wall of the cylindrical part 114 of the rotating reactor 110, wherein said contact pressure is calculated on the basis of dead weight of the lower
part 313 of the base frame 300 including the auger scrapers 320 and the weights 330 mounted on the lower part 313 of the base frame 300 and the contact surface area of the auger helix 322 on the inner wall of the rotation reactor 110. Due to the telescopic suspensions 311, the lower part 313 of the base frame 310 of the abrasion device can always apply the contact pressure preset by the choice
of the mass of the weights 330 to the wall of the rotating reactor 110 without obstruction. The breaking strength of the accumulated coke at the inner wall
of the rotating reacting reactor 110 was determined to be in the range between 70 N/mm2 and 90 N/mm2. Substantially all of the accumulated coke is scraped from the inner wall of the
cylindrical part 114 of the rotating reactor 110 in a continuous manner, when the abrasion device 300, in particular the lower part 313 of the base frame 310 with the auger scrapers 320 generates a contact pressure of 120 N/mm2 on the inner wall of the cylindrical part 114 of the rotating reactor 110.
- iv. Since the auger scrapers 320 are rotatably mounted at cross members 314 at the lower part 313 of the base frame 310 at the ends of the suspensions 311 that are protruding in direction of the bottom of the rotating reactor 110, and due to the preset contact pressure, the auger scrapers 320 rotate during operation of the rotating reactor 110 without an additional drive unit, i.e. the rotation of the auger scrapers 320 is driven by the rotation of the rotating reactor 110.
- v. This generates and ensures a positive movement between the auger scrapers 320 and the inner wall of the rotating reactor 110 and further supports the breaking of the accumulated coke at the inner wall of the
rotating reactor 110 and the scraping-off of the coke by the auger helix 322.
[0053] The rotating reactor
110 shown in this embodiment comprises a cylindrical part
114 and a funnel
115 with the auger plates
116. The cylindrical part
114 has a length of 5.23 m and diameter of 2.80 m. The cylindrical part
114 and the funnel
115 together have a length of 7.25 m. The ovality, i.e. the deviation from perfect circularity
of the cross section of the rotating reactor
110 is in the range of ± 3 mm. The value of the deflection over the length of the rotating
reactor
110 was calculated with 1 to 2 mm, which is further decreased by the ribbed plates
122, which are welded on the outer wall of the cylindrical part
114.
[0054] The rotating reactor
110 is inclined at an angle of 4°, which further supports the transport of the scraped
solids by gravity into the direction of the funnel
115. The funnel
115 is located at the lower end of the inclined reactor
110 and comprises auger plates
116. The funnel
115 with the auger plates
116 supports the transport of the scraped solids out of the reactor
110 into a diverter (not shown), from which the solids are removed from the system
100 via an outlet
172 through a mill
175 and a doble sluice gate
176.
[0055] Figure 2 shows cross-sectional view of the funnel
115 of the rotating reactor
110, which is equipped with auger plates
116 supports the transport of the scraped solids out of the reactor
110 into a diverter (not shown). For introducing the heavy fuel oil into the reactor,
the reactor comprises in the central axis
113 spray lances
150 with nozzles
151.
[0056] Figures 3 and 4 show embodiments of a side-view on and into the system
100 of the invention. The system
100 comprises an outer jacket
120 which forms a housing of the system
100. Between the housing
120 and rotating reactor
110, a heating channel
121 is formed. Four gas burners
130 are mounted in a pre-combustion chamber
140 outside the rotating reactor and outside the housing and are connected to the heating
channel
121 via connecting pipes
123. With this construction, an indirect heating of the reactor
110 is achieved. The indirect heating prevents the formation of punctual heat or hot
spots, which otherwise may occur upon direct heating. To ensure an even heat distribution
within the heating channel
121, the rotating reactor
110 is equipped with ribbed plates
122, which are fixed on the outer wall of the reactor
110. The system
100 comprises four spray lances
150 with nozzles
151. In figures 3 and 4, the spray cones
152 of the nozzles
151 are indicated. It can be seen from figures 3 and 4 that the spray cones
152 show non-overlapping pattern in order to support an even distribution of the heavy
fuel oil sprayed into the reactor
110 and to prevent local overdosing of heavy fuel oil in the reactor
110. The system
100 further comprises the abrasion device
300 of the invention (not shown in Figures 3 and 4).
[0057] In
Figure 5, it is shown that the funnel
115 of the rotating reactor
110 protrudes into the diverter
170. Figure 5 shows a cross-sectional view of an embodiment of the diverter
170. The diverter
170 comprises at the lower end a funnel
171 with an outlet
172 for the solids, which fall through a mill (not shown) into a double sluice gate (not
shown) by gravity and are discharged thereby from the system
100. On the upper end, the diverter
170 comprises an outlet for the pyrolysis gas, which is connected to the hot gas filter
(not shown). The diverter
170 further comprises a maintenance opening
174.
[0058] Figure 6 illustrates the principle, how the direction of rotation (indicated by the arrow)
and the spraying is coordinated in the reactor
110. During operation of the system
100, a debris of scraped solids
153 is formed, which accumulates at a certain position in the reactor
110 due to the rotation of the reactor
110. The nozzles
152 are oriented such that spraying of the heavy fuel oil into the direction of the accumulated
debris
153 is prevented, i.e. the heavy fuel oil is sprayed on areas of the inner wall
114 of the reactor
110, which are free from debris
153 of solids. This construction ensures that the heavy fuel oil sprayed into the reactor
110 contacts the inner wall
114 of the reactor
110 directly, wherein the reactor wall
114 has the required reaction temperature of 600 to 650 °C.
[0059] Figures 7 and 8 show embodiments of the housing
120 of the system
100, which forms the heating chamber
121. Four gas burners
130 are connected via connector pipes
123 to the heating chamber
121. The heating pipes
123 are part of a pre-combustion chamber
140. Further shown in
Figure 8 is the seal
160 of the central axis
113 and a bearing
190 of the rotating reactor
110. The housing further comprises an opening
160 for exhaust gas.
[0060] Figure 9 shows the hot gas filter
180 comprising a filter housing
181 and pressure lines
182 for introducing purge gas into the hot gas filter
180 via purge gas inlet
186. The cleaning of the filter cartridges
184 with purge gas, such as nitrogen, is controlled by jet valves
182. The pyrolysis gas is introduced into the hot gas filter via inlet
185. The hot gas filter
180 comprises at the lower end a conical form, which ends with an outlet
188 for the solids that are removed from the pyrolysis gas. The solids fall into the
diverter
170 by gravity. The hot gas filter
180 further comprises an outlet
189 for the solids-free pyrolysis gas into direction of the condenser (not shown). For
proper operation, the hot gas filter
180 comprises a backflush tank
187.
[0061] Figure 10 shows an embodiment of the abrasion device
300 of the invention with the features as detailed in Fig. 1, wherein Fig. 10A is a top
view, Fig. 10B is a front view and Fig. 10C is a side view of the abrasion device
300. In addition to the features detailed in Fig. 1, the weights 330 are covered by a
roof
340, which prevents the accumulation of off-scraped coke powder on the weights of the
abrasion device
300, which supports the maintenance of the contact pressure of 120 N/mm
2 on the inner side of the wall of the cylindrical part
114 of the rotating reactor
110 exerted by the lower part
313 of the base frame
310 with the auger scrapers
320, which comprise a central roller
321 and an auger helix 322. The lower part
313 of the base frame
310 comprises a further frame
315 to increase the stability of the lower part
313 of the base frame
310.
[0062] Figure 11 represents a flowsheet of the process of the invention. The process according to
Figure 10 can be described as follows:
200
[0063] The system
100 of the invention is fed with the heavy fuel oil from storage tanks via a pump and
a pressure line. In order to ensure a reliable process, a second pump may be kept
in reserve. The pressure line to the rotating reactor 110 is electrically heated with
an operation temperature in the range of 50 to 80 °C, preferably 60 to 70 °C, most
preferably of 65 °C, because a lower temperature results in an increase in viscosity
of the heavy fuel oil and thus in increased pressure losses.
[0064] The heavy oil must be finely atomized, coated with a protective medium and evenly
distributed on the inner wall
114 of the rotating reactor
110. In the rotating reactor
110 the cracking reaction takes place.
210
[0065] As described for the system
100 of the invention above, the heavy fuel oil is fed into the rotating reactor
110 via a number of spray lances
150 comprising nozzles
151 in order to achieve a uniform spray pattern but to also to prevent an overlapping
spray pattern of the individual nozzles
151. For example, for a rotating reactor
110 of approx. 4 m length and with a diameter of 2.8 m, four nozzles
151 are used to meet the prerequisites of the spray pattern. In order to decouple the
nozzles
151 hydraulically from each other and to be able to lock and flush them individually
in the event of an operational malfunction, they are fed individually into the reactor
110 via separate spray lances
150 of different length. The input feed is thus divided into four identical partial feeds.
The required protective film is achieved by dosing steam in a ratio of approx. 1:
10 with controlled quantities. Static mixers are used to achieve a largely homogeneous
mixture of oil and steam.
[0066] The required operating temperature of 500 to 600°C at the inner wall
114 of the rotating reactor
110 is achieved by four gas burners
130 with a 250 kW output, operated with natural gas or recycled pyrolysis gas. In a heat
exchanger, the combustion air is preheated with the hot flue gases according to the
counterflow principle.
[0067] Coke adhering to the rotating reactor wall
114 is removed by scraping and conveyed due to the inclined position rotating reactor
110 towards the outlet of the reactor
110 into the diverter. The solid material accumulates at the lower end of the diverter
and is discharged by a separating system via a mill and double sluice gate. The gas
flow is discharged at the upper outlet of the diverter. The diverter as well as the
downstream system components between reactor
110 and condenser are electrically heated at a holding temperature of
550°C. The temperature of the diverter is determined by the temperature of the reactor
110. The high temperatures are important to prevent condensation in the system components
before the condensation stage in order to prevent sticking and clogging of the system
components.
220
[0068] Solid particles contained in the gas stream are filtered in the downstream hot gas
filter 180.
[0069] Rigid filter elements
184 are suspended in an insulated container
181 with a conical dust collection chamber at the lower end, which comprises filter cartridges
184 made of robust ceramic fibers resistant to temperatures up to 850 °C and chemicals.
The pyrolysis gas is introduced laterally in the lower part of the filter via inlet
185, where the dust containing gas is deflected in such a way that larger particles are
already separated here as a result of gravity forces. The pyrolysis gas, which is
still loaded with fine dust, now flows through the filter elements
184 suspended in the filter container from the outside to the inside, whereby the dust
is separated on the surface of the filter cartridges
184. The now dust-free pyrolysis gas reaches the gas outlet
189 via the filter head and is still at a temperature level sufficient for the subsequent
condensation.
[0070] The filter elements
184 located in the hot gas filter
180 are grouped into several filter groups, which can be shut off separately towards
the outlet. Differential pressure and/or time-controlled, one chamber at a time is
decoupled from the gas cleaning process, while the gas filtration continues to run
normally via the filter elements
184 of the remaining chambers. To clean the filter elements, jet valves
182 of the shut-off chamber are opened one after the other for fractions of a second,
whereby purge gas (N
2 / 300°C) flows into the interior of the filter cartridges
184 at high pressure via pressure lines
183. This short rinsing impulse is sufficient to blow off the filter cake. The "offline"
cleaning process means that the dust is not immediately drawn back onto the filter
elements
184, but falls downwards into a dust collection chamber. Since only small quantities of
purge gas are used for pulse cleaning, there is no temperature reduction in the gas
and dust collection chamber of the filter
180, which is also sufficiently heat-insulated and electrically heated (500 °C). The dust
falls into the diverter
170 and is discharged by the operation of the mill and the double sluice gate, which
is also used for discharging the scraped coke from the lower end of the rotating reactor
110.
520
[0071] The dust-free pyrolysis gas is fed to the condensation stage via the shortest possible
route at 550°C process temperature. In the condenser, heavy boiling hydrocarbons,
aqueous phase and inert gas fraction are separated. The essential condensation products
are gas oil/naphtha and water. These are collected in a storage container and, after
a certain dwell time, separated in a level-controlled manner and transported to downstream
plants or storage tanks for further use.
[0072] The non-condensable residual gas flow is fed into an exhaust system.
240
[0073] In the regular operation of the system
100 of the invention the low-boiling hydrocarbons (methane, ethane, propane, butane,
pentane) comprised in the produced gas, are fed as fuel to the gas burners
130 to heat the rotating rector
110.
250
[0074] The coke produced exits the diverter
170 and the hot gas filter
180 at 550 °C process temperature. With a mill and a double sluice gate, the coke is
discharged under gas-tight conditions to the downstream equipment. A hot-rolling screw
conveyor collects the material flow and conveys it to a cooling screw conveyor. The
coke is cooled down to a temperature of 60 °C in the cooling screw. Subsequently it
is filled into Big Bags. The Big Bags are inflated with nitrogen prior to filling,
which in turn inertises the conveying and cooling screws in counterflow to the coke.
The Big Bags are preferably dustproof and conductive.
Advantages of the invention
[0075] The system and process of the invention have several advantages compared to the conventional
systems and processes. One main problem associated with cracking of heavy fuel oil
is the formation of coke which adheres at the reactor wall at one hand and which is
partly distributed in the gaseous reaction products as soft coke and dust. With the
system and process of the invention, it is possible for the first time to operate
a pyrolysis reactor in a reliable and continuous manner over long time periods, because
means and methods are provided to effectively remove the coke from the reactor wall
as well as from the gaseous reaction products continuously. The system further solves
problems like the prevention of hot spots in the reactor by indirect heating of the
rotating reactor with a hot gas stream produced by external gas burners outside the
pyrolysis reactor. Moreover, the entire system is temperature controlled to prevent
cold points and undesired condensation in the reactor and associated assemblies.
[0076] The system of the invention further fulfills today's environmental requirements.
Almost any products resulting from the process of the invention are further used or
recycled, such as gas oil /naphta for the production of fuel and recycling oils, such
as base oil and base oil products. In a heat exchanger, the combustion air is preheated
with the hot flue gases according to the counterflow principle. The pyrolysis gas
produced with the method of the invention is re-used for producing the required process
heat with the gas burners of the system. The scraped coke is further used as fuel
for blast furnaces.
List of Reference numerals
[0077]
- 100
- System of the invention
- 110
- Rotating reactor
- 113
- Central axis, rigid central axis
- 114
- Cylindrical part of the rotating reactor
- 115
- Funnel
- 116
- Auger plates
- 120
- Outer jacket, housing
- 121
- Heating channel
- 122
- Ribbed plates
- 123
- Connection between heating channel and pre-combustion chamber
- 130
- Gas burner
- 140
- Pre-combustion chamber
- 150
- Spray lance
- 151
- Nozzle
- 152
- Spray cone of a nozzle
- 153
- Debris of scraped coke
- 160
- Seal
- 170
- Diverter
- 171
- Funnel for solids
- 172
- Outlet to double sluice gate
- 173
- Outlet for pyrolysis gas to hot gas filter
- 174
- Maintenance opening
- 175
- Mill, grinder
- 176
- Double sluice gate
- 180
- Hot gas filter
- 181
- Filter housing
- 182
- Jet valves
- 183
- Pressure lines for purge gas
- 184
- Filter cartridges
- 185
- Inlet for pyrolysis gas
- 186
- Inlet for purge gas
- 187
- Backflush tank
- 188
- Outlet for solids
- 189
- Outlet for pyrolysis gas in direction to the condenser
- 190
- Reactor bearing
- 200
- Feed
- 210
- Reactor
- 220
- Hot-gas filtration
- 230
- Condensation
- 240
- Gas exhaust
- 250
- Solids handling
- 300
- Abrasion device
- 310
- Base frame
- 311
- Suspension
- 312
- Upper part of base frame
- 313
- Lower part of base frame
- 314
- Cross member
- 315
- Frame
- 320
- Auger scraper
- 321
- Central roller
- 322
- Auger helix
- 330
- Weights
- 340
- Roof
1. An abrasion device (300) for continuously removing coke from the inner wall of a rotating
reactor (110) comprising a cylindrical part (114) and comprising a base frame (310)
with suspensions (311) for mounting auger scrapers (320),
wherein said suspensions (311) are mounted at the base frame (310) and connect an
upper part (312) and a lower part (313) of the base frame (310);
said lower part (313) of the base frame (310) comprises at least one auger scraper
(320), wherein said at least one auger scraper (320) comprises a central roller (321)
with an outer auger helix (322), said at least one auger scraper (320) being rotatably
mounted at cross members (314) at the lower part (313) of the base frame (310) at
the ends of the suspensions (311) that are protruding in direction of the bottom of
the cylindrical part (114) of the rotating reactor (110).
2. The abrasion device (300) of claim 1, wherein said suspensions (311) are telescopic,
thereby allowing a vertical movement of the lower part (313) of the base frame (310)
which comprises the at least one auger scraper (320).
3. The abrasion device 300 of claim 1 or 2, wherein said abrasion device 300 comprises
three auger scrapers (320).
4. The abrasion device 300 according to any one of claims 1 to 3, wherein said auger
scrapers 320 are arranged alternately on the left and right side of the base frame
310 with the telescopic suspensions 311, when seen from the top view.
5. A system (100) for continuous processing of heavy fuel oil from recycling waste oil
and the processing residues of crude oil into useful products comprising
• means for feeding waste oil;
• at least one hot-gas filter,
• at least one condenser,
• at least one rotating kiln comprising an outer stationary jacket (120) which forms
a heating channel (121), and an inner rotating reactor (110), and
• means for removing solid coke from the rotating reactor (110);
wherein the at least one hot gas filter is configured to separate a naphtha/gasoil
fraction after the processing of the heavy fuel oil from a soft coke fraction; and
wherein the rotating reactor (110) is configured to recover a solid coke fraction
comprising high contaminant content;
characterized in that
said system (100) comprises a number of gas burners (130) arranged along the longitudinal
direction and sufficient to evenly and indirectly heat the rotating reactor (110);
the rotating reactor (110) comprises at least one abrasion device (300) according
to any one of claims 1 to 3, wherein said at least one abrasion device (300) is arranged
inclined and are configured to continuously remove accumulated solid coke from the
inner wall (114) of the rotating reactor (110) and converting said accumulated solid
coke into powdery coke;
said means for feeding heavy fuel oil comprises a number of spray lances (150) of
different length and configured to distribute with nozzles (151) said waste oil evenly
along the longitudinal direction within the rotating reactor (110).
6. The system (100) of claim 5, wherein said system (100) comprises one or two abrasion
devices (300), wherein each of said abrasion devices (300) comprises one, two or three,
preferably three auger scrapers (320), and wherein said auger scrapers are aligned
with the inner wall of the rotating reactor (110) and are arranged over the entire
length of the bottom of the cylindrical part (114) of the rotating reactor (110).
7. The system (100) according to any one of claims 5 or 6, wherein a lower part (313)
of a base frame (310) of the abrasion device (300), which comprises the auger scrapers
(320), is movable in vertical direction through telescopic suspensions (311) of the
base frame (310).
8. The system (100) according to claim 7, wherein the lower part (313) of the base frame
(310) further comprises weights (330), wherein said weights (330) increase the mass
of the lower part (313) of the base frame (310) and increase the contact pressure
of the auger scrapers (320) on the coke layer on the inner wall of the rotating reactor
(110).
9. The system according to claim 8, wherein the lower part (313) of the base frame (310)
of the abrasion device (300), which comprises the auger scrapers (320), exerts a contact
pressure in the range of 100 N/mm2 to 150 N/mm2, preferably 120 N/mm2 on the inner wall of the rotating reactor (110).
10. The system (100) according to any one of claims 5 to 9, wherein the auger scrapers
(320) rotate during operation of the rotating reactor (110) and wherein the rotation
of the auger scrapers (320) is driven by the rotation of the rotating reactor (110).
11. The system (100) according to any one of claims 5 to 10, wherein the rotating reactor
(110) is inclined at an angle between 2° and 8°, preferably at 4 ° in order to continuously
discharge the powdery coke from the rotating reactor (110) by gavity.
12. The system (100) of any one of claims 1 to 11, characterized in that said system (100) further comprises a funnel (115) comprising auger plates (116)
for discharging powdery coke form the rotating reactor (110).
13. The system (100) of any one of claims 1 to 12, characterized in that said system (100) comprises four spray lances (150) of different length, said spray
lances (150) comprising nozzles (151) which project the heavy fuel oil evenly into
the rotating reactor (110) volume and onto the inner wall (114) of the rotating reactor
(110.
14. The system (100) of any one of claims 5 to 13, characterized in that the rotating reactor (110) is heated indirectly by gas burners (130), which are mounted
to the heating channel (121) via a pre-combustion chamber (140).
15. A process for continuous processing of heavy fuel oil from the recycling of waste
oil and the processing residues of crude oil, into useful products comprising the
steps of
• thermal cracking of heavy fuel oil in a system (100) according to any of claims
5 to 14;
• discharging the process gas from the rotating reactor (110) via a diverter and a
hot-gas filter for separation of soft coke particles and thereafter by a condenser;
• scraping coke from the rotating reactor (110) with the abrasion device (300) according
to any one of claims 1 to 4;
• discharging the scraped powdery coke from the rotating reactor (110);
• partial condensation of the process gas in condensers and drain off a resulting
naphtha/gas oil mixture into storage tanks for further processing.