CA1137752A - Carbonaceous smokeless agglomerate by oxidizing heat treatment in 3 stages - Google Patents
Carbonaceous smokeless agglomerate by oxidizing heat treatment in 3 stagesInfo
- Publication number
- CA1137752A CA1137752A CA000341519A CA341519A CA1137752A CA 1137752 A CA1137752 A CA 1137752A CA 000341519 A CA000341519 A CA 000341519A CA 341519 A CA341519 A CA 341519A CA 1137752 A CA1137752 A CA 1137752A
- Authority
- CA
- Canada
- Prior art keywords
- stage
- agglomerates
- process according
- hot gas
- stages
- 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
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L5/00—Solid fuels
- C10L5/02—Solid fuels such as briquettes consisting mainly of carbonaceous materials of mineral or non-mineral origin
- C10L5/26—After-treatment of the shaped fuels, e.g. briquettes
- C10L5/28—Heating the shaped fuels, e.g. briquettes; Coking the binders
Abstract
ABSTRACT
Process for manufacturing smokeless agglomerate fuels from agglormerates of carbonaceous material, in particular coal and/or coke particles and a bituminous binder, which comprises subjecting the agglomerates to an oxidizing heat treatment in at least three stages using hot gas and then cooling the agglomerates, the first stage being a heating and drying step, the second stage being an oxidation step, and the third stage being a finishing oxidation step which reduces the tar content to less than 1.4 by weight.
Process for manufacturing smokeless agglomerate fuels from agglormerates of carbonaceous material, in particular coal and/or coke particles and a bituminous binder, which comprises subjecting the agglomerates to an oxidizing heat treatment in at least three stages using hot gas and then cooling the agglomerates, the first stage being a heating and drying step, the second stage being an oxidation step, and the third stage being a finishing oxidation step which reduces the tar content to less than 1.4 by weight.
Description
~13'~ ;2 PROCESS FOR MANU~ACTURING SMOKELESS AGGLOMERA'rE FUELS, SMOKELESS AGGLOMERA~E FUELS ~IIIJS PREPARED AND OVFN FOR
USE IN THIS PROCESS
This invention relates to a process for manufacturing smoke-less agglomerate fuels from agglomerates of carbonaceous material, in particular coal and/or coke particles and a bituminous binder, to smokeless agglomerate fuels thus prepared and to an oven fur use in this process.
Air pollution from various fuels increasingly becomes the object of attention in several countries, and for instance the British "Clean Air Act" has laid down requirements for fuels for domestic heating as regards their smoking properties.
Agglomerates of carbonaceous particles and bituminous binder, e.g., "green briquettes", may burn with evolution of smoke, depending upon the nature and the amount of volatile matter.
Therefore they are usually subjected to some kind of heat treat-ment, e.g., a dry distillation, optionally preceded by an oxidizing treatment. Thus, it is known from French Patent 1,047,584 and its additions 63,415, 66,133 and 67,980 to render smokeless by oxidation small agglomerates of carbonaceous sub-stance. That process comprises two heating stages at different temperatures~ followed by a cooling stage. In this process the reaction rate is mainly controlled by the oxygen content and/or the temperature of the treating gases, thus requiring complicated gas dosing means. Moreo~er, it is not mentioned to which degree the carbonaceous substance is rendered smokeless.
n tihe ~reSeQt invention the problem of controlling the reaction rate has been solved by recognizing that - given a ::~ :
- . ... . ~ , . , .. . . , .. -, .. .. - .. ,- - .. . . . ~.. .......... . ...
~13775~
mass of agglomerates - three variables affect the reaction rate:
the speed, the temperature, and the oxygen content of the treat-ing gas. By maintaining a certain temperature and oxygen content, the gas speed, which is easily regulated by electric fans, governs the reaction rate. Moreover, it has been found that a special sequence of three or more oxidizing stages results in a great flexibility of the process. In addition to considerably low-ering the tar content the mechanical strength, expressed in, e.g., crushing strength, abrasion resistance and resistance to dropping of the agglomerates is substantially improved.
According to this invention, smokeless agglomerate fuels are manufactured from agglomerates of carbonaceous material, in particular coal and/or coke particles and a bituminous binder by subjecting the agglomerates to an oxidizing heat treatment in at least three stages using hot gas and then cooling the agglomerates, the first stage being a heating and drying step, the second stage being an oxidation step, and the third stage being a finishing oxidation step in which third stage the tar content is reduced to less than 1.4% by weight. By smokeless is meant a tar content be-low 1.4%w, which corresponds with the requirements laid down inthe British Clean Air Act for domestic heating.
The process of this invention is now described in more detail.
The agglomerates ofl e.g., coal and/or coke particles and bituminous binder may be in the form of briquettes, extrudates, pellets, etc.,such as the agglomerates disclosed in British Patent Specification 1,498,494 and in French Patent Specification 7,538,325. It is possible to use coal duff, coke breeze, pulver-~) - . , . -, . .
, . . , . :. ~ , . . ..
. .. ~. - - . , :
~ - ~ ~
~L~3~75i52 ized anthracite, or any coal fine, carbonaceous product or waste, pure or mixed with other matter. The binder may be any convention-al bituminous material, such as coal tar pitch, petroleum bitumen or pitch, ethylene cracker residual pitch and so forth. Preferred is a petroleum bitumen, in particular a hard bitumen, penetration, e.g., 1-15 dmm, softening point 80-95C, such as a high vacuum bitumen or a cracked bitumen.
- 2a -..... .
. ~, .
~L~;3 77S;~ :
Semi-blown or fully blown precipitation, in particular propane bitumen, which may contain a fluxing oil, can also be used.
In the first sta~e of the heat treatment the agglomerates are heated up to, e.g., 250 C. ~hey lose their residual water and an exothermic reaction, i.e., the oxidation of the binder, starts. The temperature of the gas just before it strikes the agglomerates is adjusted to about 250-350C, preferably 250-300C, but a lower or higher setting is also possible, provided the residual water is lost and the exothermic reaction is started, respectively no spontaneous combustion of agglomerates occur~.
~he purpose of the gas flow in the first stage is primarily ~o deliver the necessary calories.
Second stage: because of the exothermic reaction the temper-ature of the agglomerates rises, and exceeds the gas inlet temperature. To prevent the agglomerates from catching fire, it is necessary to moderate the conditions, e.g., by lowering the gas inlet temperature or preferably by water-spraying. The purpose of the gas flow is now to take away heat created inside the agglomerates. Accordingly, the gas outlet temperature becomes higher than the inlet temperature. Usually the gas inlet temper-ature is set between 5 and 50C lower, preferably 20C lower than in the first stage, but it is possible to maintain the temperature and moderate the reaction rate by a higher gas speed, a lower oxygen content and/or the addition of water, as will be explained.
~ or every oxygen concentration of the gas there is an e~uilibrium gas speed, where the heat created by the exothermic reaction is carried away by the gas. If the gas speed is lower than this equilibrium speed the exothermic reaction will run out of control and the agglomerates will start burning, while too high a gas speed will result in the agglomerates not being cor-rectly desmoked within a given time, as their core temperature is not sufficiently high. Il is ~so possi~le, and some'imes advisable, to inject water and/or air to slow down the reaction ~,~
: - : , , . , , ; : ~ , , , .. , :, .: . :
s~
rate. In the case of water its evaporation lowers the temper-ature and secondly the resulting steam lowers the partial oxygen concentration, thus slowing the reaction rate in two ways.
The third stage of the heat treatment is meant to desmoke the remaining unreacted parts of the agglomerates. As the exothermic reaction in the second stage proceeds, the rate slows, because the concentration of unreacted material decreases.
Likely the outer layers of the agglomerates already have reacted with oxygen, while the cores yet have to react, because the diffusion of oxygen takes some time. In order to complete the reaction quickly, the inlet gas temperature is raised again~
e.g.,to the same value as in the first stage. Any other te~per-ature is possible, in principle, but the same remarks about this as in the second stage apply.
Sometimes it is necessary to add a fourth, fifth, etc. stage of thermal treatment, to remove or convert the last remnants of potentially smoke-producing matter. The temperature of the last stage will almost always be higher than in the penultimate stage, for reasons discussed above in the third stage. The total treatment time is normally less than 2 hours, usually about 80 minutes, e.g., four stages of 20 minutes each.
Suitable layer thicknesses of the agglomerates are 10 to 50 cm Preferably the gas speed and oxygen content of the hot gas are such that the core temperature of the agglomerates does not exceed 420 C in any of the s-tages, and does not drop below 200 C
in the second or any following stage~ Thus, the oxidizing heat treatment may be carried out in a travelling grate oven, using air and/or fumes as a vehicle to exchange calories with agglomer-ates. In the stages2 and higher the exothermic reaction has tobe controlled by a minimum gas speed through the layer to prevent the agglomerates from catching fire. The gas speed leaving a 40 cm thick layer of egg-shaped br quettes of 30 g must, e.g., exceed 1.6 m/s for an oxygen content of 17 to 18%v. Oxygen S~
contentshigher than 10%v are preferred.
It is obvious that the fumes evolved during the heat treat-ment can be combusted, condensed or recycled to avoid pollution of the environment.
Finally, a cooling step is required for the safe handling, storage and use of the agglomerates. In this way the exothermic reaction is stopped, and catching fire of hot agglomerates is prevented. It is feasible to cool the agglomerates with air and/or water. Air cooling is time- and space-consuming. Spraying with water is also possible, but by far -the quickest and most space-saving method is immersion in a water tank. The temperature of the water and the immersion time can be varied to control the final temperature and the water content of the agglomerates.
When the agglomerates are allowed to cool further in the air, part of the water that was taken up during the immersion will evaporate. Typical but not limitative values are: temperature of hot agglomerates: 350 C, after 7 minutes of water cooling:
110C, temperature of the water tank: 80-85 C.
The apparatus in which the heat treatment is carried out can be derived from any known furnace or oven, operating batchwise or continuously and may be a circulating furnace, a travelling grate oven, a tunnel furnace, etc. A travelling grate oven is preferred. The oven comprises at least 3 zones, preferably 3 separated compartments, being regulated separately with burners, water nozzles, etc., pre~erably in fixed position. A fluidized bed type oven may also be used. If the hot gas is flowing through a horizontal layer of agglomerates from below, it is observed that the agglomerates in the upper layer reach the highest temperatures, because of the generation of heat in the lower l~yers. Of course, this is the reverse of the first stage where the gas is delivering heat and the upper layer will be cooler initially.
~ The resulting agglomerates are particularly suitable for ; domestic use.
.. , , . . .,. . .. ,~ . , . ~,: . . . ; , - , , . : . . . .
~13~ S7~
Examples EXAMPLE I (comparative Example) Ground and dried anthracite was fed into a heated mixer and heated to 70-80 C, then 5.5%w of ~ 80/go bitumen binder (so~tening point 80-goc, penetration 6-15 d~m) at 220C was added to the coal. After mixing ~or 10 minutes at 80 C, the mix-ture was pressed. 46 kg of small briquettes (a~out ~ cm3, 11.2 g, 4.3%w water) were produced. The desmoking was carried out in a two-zone pilot oven without atmosphere control, i.e., in air. The briquettes were put in a metallic basket (70 x 70 x 15 cm), bed thickness was 14 cm. They were heat-treated for 20 minutes in zone 1 at 250C and for 40 minutes in zone 2 at 230C (gas inlet temperatures). The upper layer reached 315 C at the end of the treatment. After forced cooling in air the briquettes were analyzed; weight 10.8 g, water content nil, ', residual tar content 1.6%w and thus do not meet the re~uirement o~ the British Clean Air Act as indicated hereinbefore.
EXAMPLE II
The experiment of Example I was repeated, but the heat 20 treatment consisted of three stages: 20 minutes at 250C, 20 minutes at 230C and 20 minutes at 285 C. The upper layer ~ reached 360C at the end of the treatment. The residual tar i content was 1.2%w.
The rise in temperature at the end of the heat treatment in Example II apparently served to remove 25% more tar in the same time.
EXAMPLE III
The process of the invention was carried out under the conditions tabulated. The mechanical properties of the "green"
vs. the heat-treated briquettes were measured. Quenching was l~ by immersion in water.
I
, , ~, ~ .
Example III A ~xample III B
Composition Binder content, parts per hundred 5,5 6.1 r~ype of binder 85/2 bitumen H 80/go bitumen 5 r~ype of coiql, %w anthracite 60anthracite 100 meager coal 15 steam coal 15 fettlings 10 Pro~erties of ~een briquettes lO Water content, %w 4 5 4.7 Average crushing strength,kg 74 40 Standard deviation ~30 briquettes) kg 7.2 9.8 Resistance to dropping % passing 5 mm sieve after 1 x 5 m 5.8 8.7
USE IN THIS PROCESS
This invention relates to a process for manufacturing smoke-less agglomerate fuels from agglomerates of carbonaceous material, in particular coal and/or coke particles and a bituminous binder, to smokeless agglomerate fuels thus prepared and to an oven fur use in this process.
Air pollution from various fuels increasingly becomes the object of attention in several countries, and for instance the British "Clean Air Act" has laid down requirements for fuels for domestic heating as regards their smoking properties.
Agglomerates of carbonaceous particles and bituminous binder, e.g., "green briquettes", may burn with evolution of smoke, depending upon the nature and the amount of volatile matter.
Therefore they are usually subjected to some kind of heat treat-ment, e.g., a dry distillation, optionally preceded by an oxidizing treatment. Thus, it is known from French Patent 1,047,584 and its additions 63,415, 66,133 and 67,980 to render smokeless by oxidation small agglomerates of carbonaceous sub-stance. That process comprises two heating stages at different temperatures~ followed by a cooling stage. In this process the reaction rate is mainly controlled by the oxygen content and/or the temperature of the treating gases, thus requiring complicated gas dosing means. Moreo~er, it is not mentioned to which degree the carbonaceous substance is rendered smokeless.
n tihe ~reSeQt invention the problem of controlling the reaction rate has been solved by recognizing that - given a ::~ :
- . ... . ~ , . , .. . . , .. -, .. .. - .. ,- - .. . . . ~.. .......... . ...
~13775~
mass of agglomerates - three variables affect the reaction rate:
the speed, the temperature, and the oxygen content of the treat-ing gas. By maintaining a certain temperature and oxygen content, the gas speed, which is easily regulated by electric fans, governs the reaction rate. Moreover, it has been found that a special sequence of three or more oxidizing stages results in a great flexibility of the process. In addition to considerably low-ering the tar content the mechanical strength, expressed in, e.g., crushing strength, abrasion resistance and resistance to dropping of the agglomerates is substantially improved.
According to this invention, smokeless agglomerate fuels are manufactured from agglomerates of carbonaceous material, in particular coal and/or coke particles and a bituminous binder by subjecting the agglomerates to an oxidizing heat treatment in at least three stages using hot gas and then cooling the agglomerates, the first stage being a heating and drying step, the second stage being an oxidation step, and the third stage being a finishing oxidation step in which third stage the tar content is reduced to less than 1.4% by weight. By smokeless is meant a tar content be-low 1.4%w, which corresponds with the requirements laid down inthe British Clean Air Act for domestic heating.
The process of this invention is now described in more detail.
The agglomerates ofl e.g., coal and/or coke particles and bituminous binder may be in the form of briquettes, extrudates, pellets, etc.,such as the agglomerates disclosed in British Patent Specification 1,498,494 and in French Patent Specification 7,538,325. It is possible to use coal duff, coke breeze, pulver-~) - . , . -, . .
, . . , . :. ~ , . . ..
. .. ~. - - . , :
~ - ~ ~
~L~3~75i52 ized anthracite, or any coal fine, carbonaceous product or waste, pure or mixed with other matter. The binder may be any convention-al bituminous material, such as coal tar pitch, petroleum bitumen or pitch, ethylene cracker residual pitch and so forth. Preferred is a petroleum bitumen, in particular a hard bitumen, penetration, e.g., 1-15 dmm, softening point 80-95C, such as a high vacuum bitumen or a cracked bitumen.
- 2a -..... .
. ~, .
~L~;3 77S;~ :
Semi-blown or fully blown precipitation, in particular propane bitumen, which may contain a fluxing oil, can also be used.
In the first sta~e of the heat treatment the agglomerates are heated up to, e.g., 250 C. ~hey lose their residual water and an exothermic reaction, i.e., the oxidation of the binder, starts. The temperature of the gas just before it strikes the agglomerates is adjusted to about 250-350C, preferably 250-300C, but a lower or higher setting is also possible, provided the residual water is lost and the exothermic reaction is started, respectively no spontaneous combustion of agglomerates occur~.
~he purpose of the gas flow in the first stage is primarily ~o deliver the necessary calories.
Second stage: because of the exothermic reaction the temper-ature of the agglomerates rises, and exceeds the gas inlet temperature. To prevent the agglomerates from catching fire, it is necessary to moderate the conditions, e.g., by lowering the gas inlet temperature or preferably by water-spraying. The purpose of the gas flow is now to take away heat created inside the agglomerates. Accordingly, the gas outlet temperature becomes higher than the inlet temperature. Usually the gas inlet temper-ature is set between 5 and 50C lower, preferably 20C lower than in the first stage, but it is possible to maintain the temperature and moderate the reaction rate by a higher gas speed, a lower oxygen content and/or the addition of water, as will be explained.
~ or every oxygen concentration of the gas there is an e~uilibrium gas speed, where the heat created by the exothermic reaction is carried away by the gas. If the gas speed is lower than this equilibrium speed the exothermic reaction will run out of control and the agglomerates will start burning, while too high a gas speed will result in the agglomerates not being cor-rectly desmoked within a given time, as their core temperature is not sufficiently high. Il is ~so possi~le, and some'imes advisable, to inject water and/or air to slow down the reaction ~,~
: - : , , . , , ; : ~ , , , .. , :, .: . :
s~
rate. In the case of water its evaporation lowers the temper-ature and secondly the resulting steam lowers the partial oxygen concentration, thus slowing the reaction rate in two ways.
The third stage of the heat treatment is meant to desmoke the remaining unreacted parts of the agglomerates. As the exothermic reaction in the second stage proceeds, the rate slows, because the concentration of unreacted material decreases.
Likely the outer layers of the agglomerates already have reacted with oxygen, while the cores yet have to react, because the diffusion of oxygen takes some time. In order to complete the reaction quickly, the inlet gas temperature is raised again~
e.g.,to the same value as in the first stage. Any other te~per-ature is possible, in principle, but the same remarks about this as in the second stage apply.
Sometimes it is necessary to add a fourth, fifth, etc. stage of thermal treatment, to remove or convert the last remnants of potentially smoke-producing matter. The temperature of the last stage will almost always be higher than in the penultimate stage, for reasons discussed above in the third stage. The total treatment time is normally less than 2 hours, usually about 80 minutes, e.g., four stages of 20 minutes each.
Suitable layer thicknesses of the agglomerates are 10 to 50 cm Preferably the gas speed and oxygen content of the hot gas are such that the core temperature of the agglomerates does not exceed 420 C in any of the s-tages, and does not drop below 200 C
in the second or any following stage~ Thus, the oxidizing heat treatment may be carried out in a travelling grate oven, using air and/or fumes as a vehicle to exchange calories with agglomer-ates. In the stages2 and higher the exothermic reaction has tobe controlled by a minimum gas speed through the layer to prevent the agglomerates from catching fire. The gas speed leaving a 40 cm thick layer of egg-shaped br quettes of 30 g must, e.g., exceed 1.6 m/s for an oxygen content of 17 to 18%v. Oxygen S~
contentshigher than 10%v are preferred.
It is obvious that the fumes evolved during the heat treat-ment can be combusted, condensed or recycled to avoid pollution of the environment.
Finally, a cooling step is required for the safe handling, storage and use of the agglomerates. In this way the exothermic reaction is stopped, and catching fire of hot agglomerates is prevented. It is feasible to cool the agglomerates with air and/or water. Air cooling is time- and space-consuming. Spraying with water is also possible, but by far -the quickest and most space-saving method is immersion in a water tank. The temperature of the water and the immersion time can be varied to control the final temperature and the water content of the agglomerates.
When the agglomerates are allowed to cool further in the air, part of the water that was taken up during the immersion will evaporate. Typical but not limitative values are: temperature of hot agglomerates: 350 C, after 7 minutes of water cooling:
110C, temperature of the water tank: 80-85 C.
The apparatus in which the heat treatment is carried out can be derived from any known furnace or oven, operating batchwise or continuously and may be a circulating furnace, a travelling grate oven, a tunnel furnace, etc. A travelling grate oven is preferred. The oven comprises at least 3 zones, preferably 3 separated compartments, being regulated separately with burners, water nozzles, etc., pre~erably in fixed position. A fluidized bed type oven may also be used. If the hot gas is flowing through a horizontal layer of agglomerates from below, it is observed that the agglomerates in the upper layer reach the highest temperatures, because of the generation of heat in the lower l~yers. Of course, this is the reverse of the first stage where the gas is delivering heat and the upper layer will be cooler initially.
~ The resulting agglomerates are particularly suitable for ; domestic use.
.. , , . . .,. . .. ,~ . , . ~,: . . . ; , - , , . : . . . .
~13~ S7~
Examples EXAMPLE I (comparative Example) Ground and dried anthracite was fed into a heated mixer and heated to 70-80 C, then 5.5%w of ~ 80/go bitumen binder (so~tening point 80-goc, penetration 6-15 d~m) at 220C was added to the coal. After mixing ~or 10 minutes at 80 C, the mix-ture was pressed. 46 kg of small briquettes (a~out ~ cm3, 11.2 g, 4.3%w water) were produced. The desmoking was carried out in a two-zone pilot oven without atmosphere control, i.e., in air. The briquettes were put in a metallic basket (70 x 70 x 15 cm), bed thickness was 14 cm. They were heat-treated for 20 minutes in zone 1 at 250C and for 40 minutes in zone 2 at 230C (gas inlet temperatures). The upper layer reached 315 C at the end of the treatment. After forced cooling in air the briquettes were analyzed; weight 10.8 g, water content nil, ', residual tar content 1.6%w and thus do not meet the re~uirement o~ the British Clean Air Act as indicated hereinbefore.
EXAMPLE II
The experiment of Example I was repeated, but the heat 20 treatment consisted of three stages: 20 minutes at 250C, 20 minutes at 230C and 20 minutes at 285 C. The upper layer ~ reached 360C at the end of the treatment. The residual tar i content was 1.2%w.
The rise in temperature at the end of the heat treatment in Example II apparently served to remove 25% more tar in the same time.
EXAMPLE III
The process of the invention was carried out under the conditions tabulated. The mechanical properties of the "green"
vs. the heat-treated briquettes were measured. Quenching was l~ by immersion in water.
I
, , ~, ~ .
Example III A ~xample III B
Composition Binder content, parts per hundred 5,5 6.1 r~ype of binder 85/2 bitumen H 80/go bitumen 5 r~ype of coiql, %w anthracite 60anthracite 100 meager coal 15 steam coal 15 fettlings 10 Pro~erties of ~een briquettes lO Water content, %w 4 5 4.7 Average crushing strength,kg 74 40 Standard deviation ~30 briquettes) kg 7.2 9.8 Resistance to dropping % passing 5 mm sieve after 1 x 5 m 5.8 8.7
2 x 5 m 14.2 21.4
3 x 5 m 22.5 31.5 Resistance to abrasion, after 100 revolutions % passing 5 mm sieve 8.8 9.1 r~ar content, %w 3.18 3.39 Weight volume density Conditions of treatmeNt Number of zones 3 4 Gas inlet temperature, C 290-270-310 300-280-300-320 Ox~gen content, %v 17 19.5 Residence time in zones, min. 40-20-20 20-20-20-20 i~
': .;''. .: ' ` ~' ~ '`' . .' 3~i'752 Example III A Example III B
(cont'd) (cont'd) Properties treated briquettes Weight, g 44 . 4 33, 1 Volume, ml 34 . 2 26 . 7 Apparent density, g/ml1.30 1.24 Water content, %w - ~
Average crushing strength, kg 129 79 Standard deviation ( 30 briquettes) kg 12. 7 1 5 . 7 Resistance to dropping % passing 5 mm sieve after 1 x 5 m 1.8 3.0 2 x 5 m 4.5 7.4 3 x 5 m 8.7 11.8 Resis~ance to abrasion, after 100 revolutions % passing 5 mm sieve 4.8 5.0 Tar content, %w 1.0 1.0 These briquettes are virtually smokeless, and show improved mechanical properties.
.
;
': .;''. .: ' ` ~' ~ '`' . .' 3~i'752 Example III A Example III B
(cont'd) (cont'd) Properties treated briquettes Weight, g 44 . 4 33, 1 Volume, ml 34 . 2 26 . 7 Apparent density, g/ml1.30 1.24 Water content, %w - ~
Average crushing strength, kg 129 79 Standard deviation ( 30 briquettes) kg 12. 7 1 5 . 7 Resistance to dropping % passing 5 mm sieve after 1 x 5 m 1.8 3.0 2 x 5 m 4.5 7.4 3 x 5 m 8.7 11.8 Resis~ance to abrasion, after 100 revolutions % passing 5 mm sieve 4.8 5.0 Tar content, %w 1.0 1.0 These briquettes are virtually smokeless, and show improved mechanical properties.
.
;
Claims (13)
PROPERTY OR PRIVILEGE GE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for manufacturing smokeless agglomerate fuels from agglomer-ates of carbonaceous material, and a bituminous binder, which comprises subjecting the agglomerates to an oxidizing heat treatment in at least three stages using hot gas and then cooling the agglomerates, the first stage being a heating and drying step, the second stage being an oxidation step, and the third stage being a finishing oxidation step, in which third stage the tar content is reduced to less than 1.4% by weight.
2. Process according to claim 1, wherein the inlet temperature of the hot gas in the first stage lies between 250 and 350°C.
3. Process according to claim 1, wherein the inlet temperature of the hot gas in the second stage is up to 50°C lower than in the first stage.
4. Process according to claim 1, wherein the inlet temperature of the hot gas in the third stage is higher than in the second stage.
5. Process according to claim 1, wherein the number of stages is four, and wherein the inlet temperature of the hot gas in the fourth stage is higher than in the third stage.
6. Process according to claim 1, wherein hot gas is passed through a layer of agglomerates of a thickness of 10 to 50 cm.
7. Process according to claim l, wherein the gas speed and the oxygen content of the hot gas are such that the core temperature of the agglomerates does not exceed 420°C in any one of the stages, and does not drop below 200°C
in the second stage or any following stage.
in the second stage or any following stage.
8. Process according to claim 1, wherein the oxygen content of the gas is higher than 10%v.
9. Process according to claim 1, wherein the cooling of the agglomerates is effected by water and/or air.
10. Process according to claim 9, wherein cooling of the agglomerates is effected by quenching them in water.
11. Process according to claim 1, wherein the bituminous binder is a petroleum bitumen having a penetration of 1-15 dmm and a softening point of 80-95°C.
12. Process according to claims 1 or 11, wherein the bituminous binder is a high-vacuum bitumen or a cracked bitumen.
13. Process according to claim 1 wherein the agglomerates or carbonaceous material comprise agglomerates of coal and/or coke particles.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7901499A FR2446857A1 (en) | 1979-01-22 | 1979-01-22 | PROCESS FOR THE PREPARATION OF SMOKED FUEL AGGLOMERATES |
| FR7901499 | 1979-01-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1137752A true CA1137752A (en) | 1982-12-21 |
Family
ID=9221017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000341519A Expired CA1137752A (en) | 1979-01-22 | 1979-12-10 | Carbonaceous smokeless agglomerate by oxidizing heat treatment in 3 stages |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5599997A (en) |
| AU (1) | AU527802B2 (en) |
| BR (1) | BR8000323A (en) |
| CA (1) | CA1137752A (en) |
| DE (1) | DE3001776A1 (en) |
| FR (1) | FR2446857A1 (en) |
| GB (1) | GB2040308B (en) |
| HK (1) | HK34083A (en) |
| MY (1) | MY8400158A (en) |
| ZA (1) | ZA80305B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2138441A (en) * | 1983-04-18 | 1984-10-24 | British Gas Corp | Briquetting coal |
| JPS59227979A (en) * | 1983-06-09 | 1984-12-21 | アトランテイツク・リツチフイ−ルド・カンパニ− | Manufacture of dry granular coal fuel with low spontaneous ignitability from granular low grade coal and device using same |
| GB2201423A (en) * | 1987-01-28 | 1988-09-01 | Petrofina | Process for producing smokeless, cured fuel briquettes |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB716537A (en) * | 1952-01-08 | 1954-10-06 | Houilleres Bassin Du Nord | Method of improving coal and pitch base agglomerates, and fuel resulting therefrom |
| GB722495A (en) * | 1952-10-20 | 1955-01-26 | Houilleres Bassin Du Nord | Apparatus for treating agglomerates with a coal and pitch base |
| FR63415E (en) * | 1952-10-20 | 1955-09-13 | Houilleres Bassin Du Nord | Process for improving coal and pitch agglomerates, and resulting fuel |
| FR1047584A (en) * | 1954-07-24 | 1953-12-15 | Houilleres Bassin Du Nord | Process for improving coal and pitch agglomerates, and resulting fuel |
| FR77922E (en) * | 1959-09-10 | 1962-05-11 | Houilleres Bassin Du Nord | Furnace for processing agglomerated fuels |
| FR1410423A (en) * | 1964-08-01 | 1965-09-10 | Fr D Oxy Catalyse Soc | Process and apparatus for producing smoke-free agglomerates |
| FR1559821A (en) * | 1968-01-24 | 1969-03-14 | ||
| BE788782A (en) * | 1971-09-15 | 1973-03-13 | Fmc Corp | COOKING RAW AGGLOMERES IN AIR |
| FR2258458B1 (en) * | 1974-01-18 | 1976-10-29 | Shell France |
-
1979
- 1979-01-22 FR FR7901499A patent/FR2446857A1/en active Granted
- 1979-12-10 CA CA000341519A patent/CA1137752A/en not_active Expired
-
1980
- 1980-01-18 JP JP519280A patent/JPS5599997A/en active Granted
- 1980-01-18 BR BR8000323A patent/BR8000323A/en not_active IP Right Cessation
- 1980-01-18 GB GB8001726A patent/GB2040308B/en not_active Expired
- 1980-01-18 DE DE19803001776 patent/DE3001776A1/en active Granted
- 1980-01-18 ZA ZA00800305A patent/ZA80305B/en unknown
- 1980-01-18 AU AU54742/80A patent/AU527802B2/en not_active Ceased
-
1983
- 1983-09-01 HK HK340/83A patent/HK34083A/en not_active IP Right Cessation
-
1984
- 1984-12-30 MY MY158/84A patent/MY8400158A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2446857B1 (en) | 1983-09-02 |
| FR2446857A1 (en) | 1980-08-14 |
| JPS5599997A (en) | 1980-07-30 |
| GB2040308B (en) | 1983-01-26 |
| MY8400158A (en) | 1984-12-31 |
| HK34083A (en) | 1983-09-09 |
| BR8000323A (en) | 1980-10-21 |
| JPH0229112B2 (en) | 1990-06-27 |
| AU527802B2 (en) | 1983-03-24 |
| DE3001776C2 (en) | 1989-10-05 |
| ZA80305B (en) | 1980-12-31 |
| AU5474280A (en) | 1980-07-31 |
| DE3001776A1 (en) | 1980-07-24 |
| GB2040308A (en) | 1980-08-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |