CA1221654A - Process for cleaning of coke tars with high solids content - Google Patents
Process for cleaning of coke tars with high solids contentInfo
- Publication number
- CA1221654A CA1221654A CA000447670A CA447670A CA1221654A CA 1221654 A CA1221654 A CA 1221654A CA 000447670 A CA000447670 A CA 000447670A CA 447670 A CA447670 A CA 447670A CA 1221654 A CA1221654 A CA 1221654A
- Authority
- CA
- Canada
- Prior art keywords
- tar
- coke
- content
- tars
- cleaning
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10C—WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID
- C10C1/00—Working-up tar
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D37/00—Processes of filtration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D37/00—Processes of filtration
- B01D37/02—Precoating the filter medium; Addition of filter aids to the liquid being filtered
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Working-Up Tar And Pitch (AREA)
- Coke Industry (AREA)
Abstract
PROCESS FOR CLEANING OF COKE TARS
WITH HIGH SOLIDS CONTENT
ABSTRACTS OF THE DISCLOSURE
A method of cleaning coke tars having a high content of contaminating solid matter, which are produced in various crude gas separation processes. The high-solids tar is first centrifuged and then filtered in candle filters, while adding small amounts of, or no, filtering aids and/
or diluting substances, to give the tar a consistency suitable for further processing. The tar to be filtered in the candle filters may be either coke tar coming from a coke oven battery operated with preheated coal and hav-ing a solids content higher than 30%, or even the usual heavy tar. Before filtering, the tar is subjected to centrifuging.
WITH HIGH SOLIDS CONTENT
ABSTRACTS OF THE DISCLOSURE
A method of cleaning coke tars having a high content of contaminating solid matter, which are produced in various crude gas separation processes. The high-solids tar is first centrifuged and then filtered in candle filters, while adding small amounts of, or no, filtering aids and/
or diluting substances, to give the tar a consistency suitable for further processing. The tar to be filtered in the candle filters may be either coke tar coming from a coke oven battery operated with preheated coal and hav-ing a solids content higher than 30%, or even the usual heavy tar. Before filtering, the tar is subjected to centrifuging.
Description
lZ2~654 PROCESS FOR CLEANING OF CO~E TARS
WIT~ ~IG~ SOLIDS CONTENT
FI~I.D AND BACKGROUND OF T~ INVENTION
The present invention relates to a process for the cleaning of coke tars which carry a hi8h content of solids. The tars are produced in various cleaning and cooling processes for crude coke oven gas.
During the high temperature coking of coal which has been charged into coke ovens and which has been predried and/or preheated, a tar is formed which cannot be dehydrated by the usual method of tar decantation and whose solids content is so high, that it does not comply with the required specifications of the tar processing industry. The solids content or QI content (considered as a portion of the quinoline insoluble matter) of such tars is between 10 and 30%. The water content of such tars is between 10 and 20%.
The high solids content is related to the coking conditions (use of predried and preheated coal, higher coking temperature) as well as the increased environmental requirements, which necessitate increased aspiration during the charging process. This leads to a larger carryover into the collecting mains. Experiments for developing improvements in the design of coke ovens and the off-take systems, so far have not achieved the desired results.
During the coking of fine coal in the coke ovens, and also when coal is charged as wet coal, so called heavy tar (approximately 1-2% of the tar) is produced which contains - mls/YE - 1 -~'ZZ1654 approximately 30-50~ solids. With the use of mode~n hioh performance coke ovens, operated at increased Elue temperatures with hlgher charging gas aspiration to accommodate bigger volumes, an increased amount of carryover is created, which results in a higher transfer of coal fines from the coking chamber into the collecting mains. This also decreases the tar quality and leads to an increased yield of heavy tar.
These tars with high solids content cannot be processed in the common tar distillation plants. Only a limited mixing into the coal is possible since homogenization of coal and tar has not yet been achieved because of its high water content. Furthermore, this method only allows a small portion of the tar which has been produced in preheated coal operations (e.g. precarbon process)~to be returned to the coke ovens. Any further use, like combustion, is hindered by the limited pumping ability and the tendency for sedimentation. Therefore, these tars with high solids con-tent are not only without value, but also present an environmental problem.
It is known from U.S. Patent 4,259,171 that tars with high solids content are separated into two liquid streams using centrifuges. One product stream has a reduced, and the other one an increased portion of quinoline insoluble matter. However, this is only a partial solution to the problem since the remaining sludge or second product stream is still difficult to process. Tests for separation in mls/YE - 2 -~Z2~;54 plate filters are indicated in U.S. Patent 2,956,944. They were not successful due to the necessary expensive dilution and the remaining unsatisfactory consistency of the residue.
SUMM~RY OF TEE INVENTION
It therefore is the purpose of this invention, to provide a process for the separation of coke tars which are unduly contaminated with solids, whereby the residues can be used commercially, or at least can be processed without creating environmental problems.
This is accomplished by filtering the coke with hi8h solids content in candle filters, e.g. according to German Patent P
32 12 316, with the addition of little or no filtering aids and/or diluting substances. The filtering is achieved to an allowable degree of purity for further processing.
In addition, from both German 0S 28 28 976 and German Patent P 32 12 316, a candle filter for filtering high viscous liquids is known.
Under this method, the separation of solids is performed by a specially designed bundle of candle filters, whereby the solids are separated at the candle surface and enter t'ne hollow candle center, then the solids are discharged from the filter by means of a special device.
Both above documents and also German 0S 27 06 938 only deal with the process and equipment for filtration of tar, pitch and other consistencies from coal, which occur during coal liqueficatior. These types of tars differ greatly from coke mls/YE _ 3 _ , iZ2~6~4 plant tar in their composition and their ability to be filtered.
Due to practical experience in the past with the candle filters, which are generally made of ceramic materials, it was thought to be impossible to clean hi8h QI contaminated coke tars in such candle filters. The ceramic filters had the inherent problem that the pores of the filter always closed up and could only be freed after irksome work with dissolvents. Surprisingly, it is possible with the new candle filters according to German P 32 12 316, with the addition of only small amounts of filtering aids, and/or dilution, to filter high solids content coke plant tar.
It was also demonstrated that coke plant tar, especially from preheated coal operating coke oven batteries, having a solids content of approximately 10-30%, can be separated in the candle filters. These tars which include very fine solids which formerly could only be processed with great difficulty, or not at all, can now be sufficiently separated with the candle filter invention, even down to a QI content in the filtrate of approximately 0.1%.
It can also be anticipated to separate coke plant tars with a solids content of more than 30% in candle filters. With the help of these candle filters, it is surprisingly possible to handle this type of coke tars. The application of this new process, does not only result in the production of valuable tar, almost completely free of solid particles, but even more so, resolves the residue problem through the mls/YE _ 4 _ X
:
~Z2~654 formation of an easily processable filter cake. According to this invention, it i9 now possible to separate tars from the coke plants in candle filters. Through this method, a filtrate is produced, which can be processed further in any common tar distillation plant and on the other side, a filter cake remains which allows simple handling.
Especially for a large scale commercial application, it has been shown to be useful to centrifuge the tar and to filter the centrifuge sludge only. Just this combination of centrifuging and subsequent candle filtering makes it possible to reasonably size both units. It has to be considered that the centrifuge is designed for very large quantities, but can only remove particles from the tar up to a certain point. The candle filter designed for a very high purity of cleaning, can be sized for a much smaller capacity.
Under realistic design parameters for such a plant, only centrifuge sludge with s solids content of at least 30% is filtered in candle filters.
It has also been demonstrated that the filtration can be accomplished without any type of filtering aids and without any further additives.
Depending upon the actual exact composition of the coke plant tar being recovered, it might be advantageous to use special filtering aids. The invention proposes special filtering aids according to German OS 30 05 246. It is also feasible to mix the high solids content tar, produced in mls/YE _ 5 _ 6~4 colce ovens, witll centrifuge sludge, and the solids of tlle centrifuge sludge will serve as-the f-iltering aids. Also, in this case, an additional filtering aid is not required.
Surprisingly, it was discovered that even tar sludges .~ith a quinoline insoluble content (referred to as QI-value) of 40%, like the heavy tars mentioned and the sludge from the centrifuge, can be filtered with this system.
The invention also suggests the use of coke battery by-products as diluents. Favorable results have been obtaine~
using tar oils as diluents, for instance creosote, in amounts of less than 25%, preferably 15 to 20%. The adding of a diluent almost doubles the absolute filter rate. The utili~ation of the coke oven by-products, such as primary cooler tar, as diluents, is emphasized. This tar can be added to the mixer without much preheating. Under certain conditions, it is also feasible to us part of the filtrate as a diluent in a recycle operation.
The invention suggests the grinding of completely dried filter cake and the blending of it back to the wet or preheated coal to be charged to the coke ovens, to insure a meaningful and economical application of the filter cake from the candle filter. The filter cake, especially after grinding, can easily be blended with the coking coal without the formation of nests in the chamber. Also, an efficient energy recovery through filter cake combustion is feasible.
Another application would be to use the dried filter material for charging the blast furnace.
mls/YE - 6 -~%~
Lastly, the ~ilter cake co~lld be prepared ancl l~sed as bintler material Eor briqllettes. Especially, -in the cerltrifllge-filter combination, the con(litioning of the sludge can be oE
special advantage for a usable consistency.
The invention also suggests the utilization of the Eiltrate for the production of special coke, i.e., needle coke, in addition back-blending with certain portions of non-filtered i.e., non-prepared high solids content tar is feasible, whereby a product with selected solids content will be provided. This allows the tar manufacturer to be flexible and adapt to the demand of the market situation.
Accordingly, an object of the present invention is to provide a method for cleaning coke tar obtained in a coking plant and having a high content of solids, comprising filtering the coke tar in candle filters to separate low solid content tar filtrate from a residue in the filters, the filtering being carried out to a degree of purity suitable for further processing of the filtrate.
A still further object of the invention is to provide a method which is simple and effective to purify otherwise useless coke and other tars.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and mls/YE - 7 -i, ~Z2~654 descriptive matter in which a preferred embodiment of tlle invention is illustrated.
BRIEF DESCRIPTION OF T~E DRAWIN~
The only figure is a process flowsheet illustrating an example of the invention.
DESCRIPTION OF T~E PREFERRED EMBODIMENT
The drawing shows the combination of a centrifuge and candle filter according to one form of the invention. From tar storage container 1 the accumulated coke tar or also only the heavy tar flows through a pipe 2 into a centrifuge 3.
The substantially solid-free tar is removed from the centrifuge at point 4. The centrifuge sludge 5, after possible mixing with a diluent and a filtering aid supplied through a line 6 passes into a candle filter 7. Filter cake 8 and filtrate 9 are discharged separately from the candle filter.
The invention is explained in more detail by the following examples:
Example 1 Coke oven tar from a preheated coal operating batte~y with a water content of 10.1% and QI-value of 15.2% by weight and approximately 50C temperature is mixed in the pressure container with a 5% filtering aid without any diluent, then heated to filtration temperature. The water vapors are exhausted into the atmosphere from the storage container.
Subsequently, the dehydrated tar is cleaned at approximately 160C-170C in the candle filter. The filtration rate had a mls/YE - 8 -lZZ1654 QI-Value o~ onLy 0.03% by weight and 0.02% by welght a~h content.
Example 2 The tar in this test run contained 17% water and a QI-Value of 17.6%. By adding 5% filtering aid and 25% creosote as a solvent, the filtration rate was S0 kg/m2h, and the filtrate obtained had a QI-Value of 0.2% by weight. The filter cake had a QI-Value of S3% by weight.
Example 3 In this case the water content of the tar was 20% by weight and the QI content 19.~% by weight. By adding 5.3% by weight filtering aid and 30% by weight (water free tar) of primary cooler tar, the filtration rate amounted to 63 kg/m2h. The filtrate here also had a QI-content of only 0.2% weight at 0.02 weight % ash.
Example 4 The tar coming from the coke oven battery operated with preheated coal, was first centrifuged whereby the centrifuge sludge had a QI-content of approximately 40%. It was mixed with 20% solvent and obtained a filtration rate of 29 kg/m2h, and a QI content of 1.2 weight % after filtration.
Example 5 A tar obtained at the primary coolers of a coke oven battery and having a QI content of 5.8% by weight and a water content of 3.5% by weight was filtered in the candle filters while adding 3% of flltering aids. The filtering rate was 116 kg/m2h (kg per m2 per hour), and no diluent was added.
The obtained mls/YE - 8a -' . -~221~iS4 filtrate had a QI content of 0.2% by weight.
Example 6 A tar obtained in a coke oven battery operated with wet coaland having a moisture content of 8% and a QI content of 11.6%
by weight was filtered without dilution and at a filtering rate of 37 kg per mZ per hour. The QI content of the filtrate was reduced to 0.5% by weight, and the ash content to 0.03%.
It is noted that where the centrifuge is utilized, a type of centrifuge which is known in the field can advantageously be applied to the invention.
The candle filters comprise a housing or a vessel which is divided into two chambers by a partition wall with one of the chambers storing tar to be filtered and the other the filtered tar. The candle filters are attached to the partition wall and a riser pipe opens out in the chamber for filtered tar and where inlet and outlet lines for tar to be filtered, filtered tar and drying gas as well as an outlet for the filter cake and a beater acting on the partition wall are arranged. An immersion tube serving as an outlet for filtered tar endsimmediately near to or at the elevation of the partition wall with the partition wall having a recess for the end of the immersion tube. The beater is arranged concentrically to the immersion tube and the drying gas inlet relative to the candle filters is arranged in or behind the partition wall level. The filtrate chamber is arranged slidable in the housing with the partition wall being used as a cover. Furthermore, flow pipes pass through the chamber for filtered tar.
i221654 In summary, thus the invention comprises a method cleaning coke tars from a container 1 having a high content of solid matter which comprises centrifuging the coke tars in a centrifuge 3 to separate a low solid content tar on line 'l from a residual sludge on line 5, and filtering the residual sludge in a candle filter 7 to form a filter cake at 8 and a filtrate at 9.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such pr:inciples.
mls/YE
, . . .
, 1: ' .
. , .
- .
WIT~ ~IG~ SOLIDS CONTENT
FI~I.D AND BACKGROUND OF T~ INVENTION
The present invention relates to a process for the cleaning of coke tars which carry a hi8h content of solids. The tars are produced in various cleaning and cooling processes for crude coke oven gas.
During the high temperature coking of coal which has been charged into coke ovens and which has been predried and/or preheated, a tar is formed which cannot be dehydrated by the usual method of tar decantation and whose solids content is so high, that it does not comply with the required specifications of the tar processing industry. The solids content or QI content (considered as a portion of the quinoline insoluble matter) of such tars is between 10 and 30%. The water content of such tars is between 10 and 20%.
The high solids content is related to the coking conditions (use of predried and preheated coal, higher coking temperature) as well as the increased environmental requirements, which necessitate increased aspiration during the charging process. This leads to a larger carryover into the collecting mains. Experiments for developing improvements in the design of coke ovens and the off-take systems, so far have not achieved the desired results.
During the coking of fine coal in the coke ovens, and also when coal is charged as wet coal, so called heavy tar (approximately 1-2% of the tar) is produced which contains - mls/YE - 1 -~'ZZ1654 approximately 30-50~ solids. With the use of mode~n hioh performance coke ovens, operated at increased Elue temperatures with hlgher charging gas aspiration to accommodate bigger volumes, an increased amount of carryover is created, which results in a higher transfer of coal fines from the coking chamber into the collecting mains. This also decreases the tar quality and leads to an increased yield of heavy tar.
These tars with high solids content cannot be processed in the common tar distillation plants. Only a limited mixing into the coal is possible since homogenization of coal and tar has not yet been achieved because of its high water content. Furthermore, this method only allows a small portion of the tar which has been produced in preheated coal operations (e.g. precarbon process)~to be returned to the coke ovens. Any further use, like combustion, is hindered by the limited pumping ability and the tendency for sedimentation. Therefore, these tars with high solids con-tent are not only without value, but also present an environmental problem.
It is known from U.S. Patent 4,259,171 that tars with high solids content are separated into two liquid streams using centrifuges. One product stream has a reduced, and the other one an increased portion of quinoline insoluble matter. However, this is only a partial solution to the problem since the remaining sludge or second product stream is still difficult to process. Tests for separation in mls/YE - 2 -~Z2~;54 plate filters are indicated in U.S. Patent 2,956,944. They were not successful due to the necessary expensive dilution and the remaining unsatisfactory consistency of the residue.
SUMM~RY OF TEE INVENTION
It therefore is the purpose of this invention, to provide a process for the separation of coke tars which are unduly contaminated with solids, whereby the residues can be used commercially, or at least can be processed without creating environmental problems.
This is accomplished by filtering the coke with hi8h solids content in candle filters, e.g. according to German Patent P
32 12 316, with the addition of little or no filtering aids and/or diluting substances. The filtering is achieved to an allowable degree of purity for further processing.
In addition, from both German 0S 28 28 976 and German Patent P 32 12 316, a candle filter for filtering high viscous liquids is known.
Under this method, the separation of solids is performed by a specially designed bundle of candle filters, whereby the solids are separated at the candle surface and enter t'ne hollow candle center, then the solids are discharged from the filter by means of a special device.
Both above documents and also German 0S 27 06 938 only deal with the process and equipment for filtration of tar, pitch and other consistencies from coal, which occur during coal liqueficatior. These types of tars differ greatly from coke mls/YE _ 3 _ , iZ2~6~4 plant tar in their composition and their ability to be filtered.
Due to practical experience in the past with the candle filters, which are generally made of ceramic materials, it was thought to be impossible to clean hi8h QI contaminated coke tars in such candle filters. The ceramic filters had the inherent problem that the pores of the filter always closed up and could only be freed after irksome work with dissolvents. Surprisingly, it is possible with the new candle filters according to German P 32 12 316, with the addition of only small amounts of filtering aids, and/or dilution, to filter high solids content coke plant tar.
It was also demonstrated that coke plant tar, especially from preheated coal operating coke oven batteries, having a solids content of approximately 10-30%, can be separated in the candle filters. These tars which include very fine solids which formerly could only be processed with great difficulty, or not at all, can now be sufficiently separated with the candle filter invention, even down to a QI content in the filtrate of approximately 0.1%.
It can also be anticipated to separate coke plant tars with a solids content of more than 30% in candle filters. With the help of these candle filters, it is surprisingly possible to handle this type of coke tars. The application of this new process, does not only result in the production of valuable tar, almost completely free of solid particles, but even more so, resolves the residue problem through the mls/YE _ 4 _ X
:
~Z2~654 formation of an easily processable filter cake. According to this invention, it i9 now possible to separate tars from the coke plants in candle filters. Through this method, a filtrate is produced, which can be processed further in any common tar distillation plant and on the other side, a filter cake remains which allows simple handling.
Especially for a large scale commercial application, it has been shown to be useful to centrifuge the tar and to filter the centrifuge sludge only. Just this combination of centrifuging and subsequent candle filtering makes it possible to reasonably size both units. It has to be considered that the centrifuge is designed for very large quantities, but can only remove particles from the tar up to a certain point. The candle filter designed for a very high purity of cleaning, can be sized for a much smaller capacity.
Under realistic design parameters for such a plant, only centrifuge sludge with s solids content of at least 30% is filtered in candle filters.
It has also been demonstrated that the filtration can be accomplished without any type of filtering aids and without any further additives.
Depending upon the actual exact composition of the coke plant tar being recovered, it might be advantageous to use special filtering aids. The invention proposes special filtering aids according to German OS 30 05 246. It is also feasible to mix the high solids content tar, produced in mls/YE _ 5 _ 6~4 colce ovens, witll centrifuge sludge, and the solids of tlle centrifuge sludge will serve as-the f-iltering aids. Also, in this case, an additional filtering aid is not required.
Surprisingly, it was discovered that even tar sludges .~ith a quinoline insoluble content (referred to as QI-value) of 40%, like the heavy tars mentioned and the sludge from the centrifuge, can be filtered with this system.
The invention also suggests the use of coke battery by-products as diluents. Favorable results have been obtaine~
using tar oils as diluents, for instance creosote, in amounts of less than 25%, preferably 15 to 20%. The adding of a diluent almost doubles the absolute filter rate. The utili~ation of the coke oven by-products, such as primary cooler tar, as diluents, is emphasized. This tar can be added to the mixer without much preheating. Under certain conditions, it is also feasible to us part of the filtrate as a diluent in a recycle operation.
The invention suggests the grinding of completely dried filter cake and the blending of it back to the wet or preheated coal to be charged to the coke ovens, to insure a meaningful and economical application of the filter cake from the candle filter. The filter cake, especially after grinding, can easily be blended with the coking coal without the formation of nests in the chamber. Also, an efficient energy recovery through filter cake combustion is feasible.
Another application would be to use the dried filter material for charging the blast furnace.
mls/YE - 6 -~%~
Lastly, the ~ilter cake co~lld be prepared ancl l~sed as bintler material Eor briqllettes. Especially, -in the cerltrifllge-filter combination, the con(litioning of the sludge can be oE
special advantage for a usable consistency.
The invention also suggests the utilization of the Eiltrate for the production of special coke, i.e., needle coke, in addition back-blending with certain portions of non-filtered i.e., non-prepared high solids content tar is feasible, whereby a product with selected solids content will be provided. This allows the tar manufacturer to be flexible and adapt to the demand of the market situation.
Accordingly, an object of the present invention is to provide a method for cleaning coke tar obtained in a coking plant and having a high content of solids, comprising filtering the coke tar in candle filters to separate low solid content tar filtrate from a residue in the filters, the filtering being carried out to a degree of purity suitable for further processing of the filtrate.
A still further object of the invention is to provide a method which is simple and effective to purify otherwise useless coke and other tars.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and mls/YE - 7 -i, ~Z2~654 descriptive matter in which a preferred embodiment of tlle invention is illustrated.
BRIEF DESCRIPTION OF T~E DRAWIN~
The only figure is a process flowsheet illustrating an example of the invention.
DESCRIPTION OF T~E PREFERRED EMBODIMENT
The drawing shows the combination of a centrifuge and candle filter according to one form of the invention. From tar storage container 1 the accumulated coke tar or also only the heavy tar flows through a pipe 2 into a centrifuge 3.
The substantially solid-free tar is removed from the centrifuge at point 4. The centrifuge sludge 5, after possible mixing with a diluent and a filtering aid supplied through a line 6 passes into a candle filter 7. Filter cake 8 and filtrate 9 are discharged separately from the candle filter.
The invention is explained in more detail by the following examples:
Example 1 Coke oven tar from a preheated coal operating batte~y with a water content of 10.1% and QI-value of 15.2% by weight and approximately 50C temperature is mixed in the pressure container with a 5% filtering aid without any diluent, then heated to filtration temperature. The water vapors are exhausted into the atmosphere from the storage container.
Subsequently, the dehydrated tar is cleaned at approximately 160C-170C in the candle filter. The filtration rate had a mls/YE - 8 -lZZ1654 QI-Value o~ onLy 0.03% by weight and 0.02% by welght a~h content.
Example 2 The tar in this test run contained 17% water and a QI-Value of 17.6%. By adding 5% filtering aid and 25% creosote as a solvent, the filtration rate was S0 kg/m2h, and the filtrate obtained had a QI-Value of 0.2% by weight. The filter cake had a QI-Value of S3% by weight.
Example 3 In this case the water content of the tar was 20% by weight and the QI content 19.~% by weight. By adding 5.3% by weight filtering aid and 30% by weight (water free tar) of primary cooler tar, the filtration rate amounted to 63 kg/m2h. The filtrate here also had a QI-content of only 0.2% weight at 0.02 weight % ash.
Example 4 The tar coming from the coke oven battery operated with preheated coal, was first centrifuged whereby the centrifuge sludge had a QI-content of approximately 40%. It was mixed with 20% solvent and obtained a filtration rate of 29 kg/m2h, and a QI content of 1.2 weight % after filtration.
Example 5 A tar obtained at the primary coolers of a coke oven battery and having a QI content of 5.8% by weight and a water content of 3.5% by weight was filtered in the candle filters while adding 3% of flltering aids. The filtering rate was 116 kg/m2h (kg per m2 per hour), and no diluent was added.
The obtained mls/YE - 8a -' . -~221~iS4 filtrate had a QI content of 0.2% by weight.
Example 6 A tar obtained in a coke oven battery operated with wet coaland having a moisture content of 8% and a QI content of 11.6%
by weight was filtered without dilution and at a filtering rate of 37 kg per mZ per hour. The QI content of the filtrate was reduced to 0.5% by weight, and the ash content to 0.03%.
It is noted that where the centrifuge is utilized, a type of centrifuge which is known in the field can advantageously be applied to the invention.
The candle filters comprise a housing or a vessel which is divided into two chambers by a partition wall with one of the chambers storing tar to be filtered and the other the filtered tar. The candle filters are attached to the partition wall and a riser pipe opens out in the chamber for filtered tar and where inlet and outlet lines for tar to be filtered, filtered tar and drying gas as well as an outlet for the filter cake and a beater acting on the partition wall are arranged. An immersion tube serving as an outlet for filtered tar endsimmediately near to or at the elevation of the partition wall with the partition wall having a recess for the end of the immersion tube. The beater is arranged concentrically to the immersion tube and the drying gas inlet relative to the candle filters is arranged in or behind the partition wall level. The filtrate chamber is arranged slidable in the housing with the partition wall being used as a cover. Furthermore, flow pipes pass through the chamber for filtered tar.
i221654 In summary, thus the invention comprises a method cleaning coke tars from a container 1 having a high content of solid matter which comprises centrifuging the coke tars in a centrifuge 3 to separate a low solid content tar on line 'l from a residual sludge on line 5, and filtering the residual sludge in a candle filter 7 to form a filter cake at 8 and a filtrate at 9.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such pr:inciples.
mls/YE
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Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of cleaning coke tar having a high content of solid matter, comprising: centrifuging the coke tar to separate low solid contact tar from a residual sludge; and then filtering the centrifugal residual sludge in candle filters to separate a filtrate with low solid content from solid matter of the residual sludge.
2. A method according to claim 1, wherein only centrifuged residual sludge having a solid content of at least 30% is filtered in the candle filters.
3. A method according to claim 1, including using matter of the centrifuged residual sludge as a filtering aid in the candle filters.
4. A method according to claim 3, including admixing the centrifuged residual sludge with the coke tar to be centrifuged.
5. A method according to claim 3, including admixing the centrifuged residual sludge with a mixture of the coke tar and a heavy tar.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3305431A DE3305431A1 (en) | 1983-02-17 | 1983-02-17 | METHOD FOR CLEANING HIGH-SOLID COOKER TARS |
| DEP3305431.2 | 1983-02-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1221654A true CA1221654A (en) | 1987-05-12 |
Family
ID=6191054
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000447745A Expired CA1220438A (en) | 1983-02-17 | 1984-02-17 | Process for cleaning of coke tars with high solids content |
| CA000447670A Expired CA1221654A (en) | 1983-02-17 | 1984-02-17 | Process for cleaning of coke tars with high solids content |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000447745A Expired CA1220438A (en) | 1983-02-17 | 1984-02-17 | Process for cleaning of coke tars with high solids content |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0116956B1 (en) |
| JP (1) | JPS59157178A (en) |
| CA (2) | CA1220438A (en) |
| DE (2) | DE3305431A1 (en) |
| ZA (1) | ZA841046B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3533106A1 (en) * | 1985-09-17 | 1987-03-26 | Ruetgerswerke Ag | ELECTRODE BINDING AGENT |
| DE3702720A1 (en) * | 1987-01-30 | 1988-08-11 | Bergwerksverband Gmbh | CARBONED PECH MATERIAL, METHOD FOR THE PRODUCTION THEREOF AND USE OF THE PECH MATERIAL |
| US5534133A (en) * | 1994-11-17 | 1996-07-09 | Ucar Carbon Technology Corporation | Continuous method for increasing the Q. I. concentration of liquid tar while concurrently producing a Q. I. free tar |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE537330A (en) * | ||||
| FR395738A (en) * | 1908-10-28 | 1909-03-16 | Peter C Reilly | Tar separation process and resulting product |
| DE534644C (en) * | 1928-04-06 | 1931-09-30 | Kohlenveredlung Und Schwelwerk | Process for the preparation of water and dust containing tars |
| US2956944A (en) * | 1958-02-10 | 1960-10-18 | Allied Chem | Process for filtering tar |
| US3595946A (en) * | 1968-06-04 | 1971-07-27 | Great Lakes Carbon Corp | Process for the production of carbon filaments from coal tar pitch |
| DE2706938A1 (en) * | 1977-02-18 | 1978-08-24 | Bergwerksverband Gmbh | PROCESS FOR FILTRATING TARS, PECHING, EXTRACTS OR OILS, FROM COALS |
| DE2810332C2 (en) * | 1978-03-10 | 1982-08-05 | Rütgerswerke AG, 6000 Frankfurt | Process for the separation of quinoline-insoluble constituents from coal tar pitch |
| DE2828976C2 (en) * | 1978-07-01 | 1983-06-01 | Bergwerksverband Gmbh, 4300 Essen | Alluvial candle filter device for dry discharge and method for cleaning the device |
| US4264453A (en) * | 1980-01-10 | 1981-04-28 | Pori International, Inc. | Reclamation of coking wastes |
| DE3005246A1 (en) * | 1980-02-13 | 1981-08-20 | Bergwerksverband Gmbh, 4300 Essen | METHOD FOR PRODUCING A FILTER AUXILIARY |
| DE3212316C2 (en) * | 1982-04-02 | 1988-11-10 | Bergwerksverband Gmbh, 4300 Essen | Filtration apparatus |
-
1983
- 1983-02-17 DE DE3305431A patent/DE3305431A1/en not_active Withdrawn
-
1984
- 1984-02-13 ZA ZA841046A patent/ZA841046B/en unknown
- 1984-02-15 JP JP59025285A patent/JPS59157178A/en active Pending
- 1984-02-16 EP EP84101593A patent/EP0116956B1/en not_active Expired
- 1984-02-16 DE DE8484101593T patent/DE3468121D1/en not_active Expired
- 1984-02-17 CA CA000447745A patent/CA1220438A/en not_active Expired
- 1984-02-17 CA CA000447670A patent/CA1221654A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3468121D1 (en) | 1988-01-28 |
| EP0116956B1 (en) | 1987-12-16 |
| EP0116956A2 (en) | 1984-08-29 |
| JPS59157178A (en) | 1984-09-06 |
| EP0116956A3 (en) | 1985-04-17 |
| DE3305431A1 (en) | 1984-08-23 |
| CA1220438A (en) | 1987-04-14 |
| ZA841046B (en) | 1985-03-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |