CA1216425A - Coal-water dispersion and method of the manufacture thereof - Google Patents
Coal-water dispersion and method of the manufacture thereofInfo
- Publication number
- CA1216425A CA1216425A CA000418903A CA418903A CA1216425A CA 1216425 A CA1216425 A CA 1216425A CA 000418903 A CA000418903 A CA 000418903A CA 418903 A CA418903 A CA 418903A CA 1216425 A CA1216425 A CA 1216425A
- Authority
- CA
- Canada
- Prior art keywords
- dispersion
- coal
- lecithin
- alkylbetain
- weight
- 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
- C10L1/00—Liquid carbonaceous fuels
- C10L1/32—Liquid carbonaceous fuels consisting of coal-oil suspensions or aqueous emulsions or oil emulsions
- C10L1/326—Coal-water suspensions
Landscapes
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Colloid Chemistry (AREA)
- Liquid Carbonaceous Fuels (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
- Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
Abstract
A B S T R A C T
A dispersion is disclosed containing water, pulverized coal and additives including at least one polymer, the coal content ranging from 60 to 85% by weight, characterized in that the dispersion as an additive contains lecithin or an alkylbetain which is adsorbed to the surfaces of the coal particles and which provides repulsion between the coal particles by hydration forces, said polymer co-operating with the lecithin or alkylbetain, respectively and containing segments of hydrophobic as well as hydrophilic character.
A dispersion is disclosed containing water, pulverized coal and additives including at least one polymer, the coal content ranging from 60 to 85% by weight, characterized in that the dispersion as an additive contains lecithin or an alkylbetain which is adsorbed to the surfaces of the coal particles and which provides repulsion between the coal particles by hydration forces, said polymer co-operating with the lecithin or alkylbetain, respectively and containing segments of hydrophobic as well as hydrophilic character.
Description
z~z~
COAL-WATER DISPERS~ON AND METHOD OF THE MANUFACTURE
THEREOF
The present invention relates to a coal-water djspersjon which is very stable in storage and is suitable for transport and direct energy production without precedtng de~atering. More particularly the invention relates to a dispers;on comprising water, pulverized coal and additive, the coal conten~ amount-ing to at least 60 % by weight.
A dispersion of coal is considerably less pollut-ing and can be more easily handled than solid coal and also eliminates some rlsks involved in transport and storage. Such a dispersion is also preferred from an economical point of view.
The reason for using coal dispersions is the planned increased use of coal as a basic energy source in large as well as small plants for producing electricity, steam and heat. The handling of solid coal in this connection is difficult for several reasons and, therefore, the transformation of the coal to liquid form generally is considered an interesting method.
Chemjcal conversion of coal to a liquid productl so--called liquefaction, still cannot compete with oil and it is considered that this method can contribute to the global energy provision only marginally before the year 2000. Chemical conversion of the coal to a gaseous product, so-called gasification, seems to be a more prosperous method of utilizing coal. However, also this method still involves considerable technical difficulties although large resources have been spent on technical development.
Physjcal conversion is another method of transferring the coal into liquid form, and the invention relates to this method. It is practised by dispersing the coal in a liquid which may consist of water as in the case of the ~J
dispersion of the invention, or of some organic fuel such as heat~ng oil, methanol, etc.
The main proble~ of water dispersions of pulverized coal is to make the dispersion stable at low viscosity. The coal particles must not sediment during storage or transport of the coal-water dispersion. More-over, the coal-water dispersion shall have a high pumpability and shall have rheological properties so as to be suitable for burning by conventional technique probably modified to a minor degree.
According to the published international application I~O i31/01152, anionic surfactants and at least one electrolyte among other additives are used to prevent sedimentation and improve rheology. Tests have shown that the sedimentation stability as well as the rheological properties do not satisfy the desired demands.
In the laid open Swedish specifjcation 7805632-2, a coal-water dispersion is disclosed wherein a stabilizing action against sedimentation is obtained by conventional polyelectrolytés, among them poly-phosphate. Also in this case the stability against sedimentation is not satisfactory. The necessary atomization of the fuel when being burnt moreover causes problems e.g. due to formation of agglomerates.
U.S. patent specification 4~242,098 descr;bes a coal-water dispersion wherein the stabilization is obtained by the addition o~ a number of water soluble polymers (polyethyleneoxide, polyacrylamides, etc.).
This dispersion provides an improvement in relation to the dispersions mentioned above but cannot be used directly for energy production without preceding dewatering.
The theory of the stability of dispersions has recently been considerably refined. The theory has been developed to include more concentrated systems but above all a new type of inter-action has been proved. In addition to previously known effects such as electro-static stabilization ~y means of surface-active substances and polyelectrolytes and steric stabiIization by means of polymers there is a further central effect,so-called hydration forces. These forces have recently been demonstrated and have also been explained theoretically. The hydration forces, possibly togetherwith other types of interaction, form the primary basis of the present inventionproviding a long-term stable coal-water dispersion of the type referred to above, which is well suited for direct burning without preceding dewatering by using the techniques available today, possibly with minor modifications.
The dispersion according to the invention is characterized in that the dispersion contains at least one substance adsorbed on the surfaces of the coal particles, which provides repulsion between the coal particles by hydration forces.
Preferably, said substance comprises a zwitterionic amphiphile.
More preferably the substance is a phospholipid such as lecithin or an alkylbetain. It may be zwitterionic or an increased repulsion between coal particles is achieved when this material is partly zwitterionic and partly anionic.
Suitably said substance is present in an amount of about 0.01 to about 0.15 per cent by weight of the total dispersion, preferably about 0.1 per cent by weight of total dispersion.
The invention also provides a method of manufacturing the dispersion, wherein said substance providing the repulsion between the coal particles by hydration forces is supplied to the pulverized coal either dispersed in water ordissolved in an organic solvent.
The dispersion has rheological properties which allow the dispersion to be pumped and transported through pipelines at a greatly reduced friction, and above all has considerably improved stability against flocculation as well as sedimentation. The dispersion moreover has properties such that it can be atomized without forming agglomerates in suitable burner equipment.
When coal-water dispersions which by definition are thermodynamically unstable, are being stabilized the sedimentation and aggregation rates are reduced by creating a barrier which counteracts the particleattraction. This repulsive effect can be achieved by three main principles: electrostatic stabilization, sterical stabilization, and stabilization by means of hydration forces. The ~2~6~5 stabilization changes the energy of the particles and/or creates a high barrier preventing particle attraction. On the basis of these principles it is possibleto stabilize high contents of coal particles in a water medium by the addition of small amounts of organic additives.
In order to create stable colloidal systems it i5 necessary to impart to the system such properties that the attraction forces between the particles are minimized and a replusive barrier against flocculation and subsequent sedimentation is developed. Some form of sterical stabilization by means of hydrophilic polymers provides favourable conditions for a long~term stabilization of coal-water dispersions From studies of lamellar liquid crystalline phases in systems of ionic surface-active substances it has been shown that these phases can swell and incorporate large amounts of water. This is explained by a repulsion over the water layer between adjacent layers of surface-active substance and can be related to electrostatic double-layer forces. For zwitterionic substances such às the phospholipid lecithin the swelling is less pronounced but nevertheless very clear.
This shows that also in the a~sence of a net charge there is a considerable repulsion. This repulsion force, the so-called hydration force, varies approxi-mately exponentially with distance with a characteristic length of 0.2 - 0.3 nm.The force is of a general character and does not vary with the length of the alkyl chain or with the physical condition of the chains (liquid or solid) and is present also when a quantity of charged surface-active substance is included into the systems. ~ydration forces have been shown a]so by directly measuring the forces between surfaces mutually spaced apart by some Angstr~m lmits. A theoretical model for hydration forces has recently been developed, and then it has been possible to relate these forces to the presence of so-called mirror charges overinterfaces where the effective dielectric constant is being changed. Such mirrorcharges with zwitterionic groups should be common in micro- and macro-heterogeneous systems. They are utilized according to the present invention in order to impartdesired properties to a suspension of a low dielectric substance in a high dielectric medium. Thus, a zwitterionic surface-active substance such as lecithin can be adsorbed onto the surfaces of the solid particles. Strong repulsion forces between the particles then exist at short distances. The principle therefore will be particularly useful for concentrated dispersions.
~6~2~
The invention will be descrihed in more detail below with reference to an example.
Example 1. A non-micelle-forming zwitterionic surfactant such as lecithin or an alkylbetain, which is relatively difficult to dissolve in water, is first dissolved in an organic solvent. The solvent can consist of for example octanol, hexadecane or methanol and can be recovered in a suitable manner or can comprise an insigni-ficant portion by weight of the dispersion. Alternatively, the surfactant can be dispersed directly in water probably in the -form of a lamellar liquid crystalline phase, or can be dissolved in water by the addition of an additive having the property of creating soluble mixed aggregates with lecithin.
Preferably the lecithin or alkylbetain is dissolved in water by means of an organic salt as for example an alkali metal salt of a fatty acid or an alkalimetal sorbate.
COAL-WATER DISPERS~ON AND METHOD OF THE MANUFACTURE
THEREOF
The present invention relates to a coal-water djspersjon which is very stable in storage and is suitable for transport and direct energy production without precedtng de~atering. More particularly the invention relates to a dispers;on comprising water, pulverized coal and additive, the coal conten~ amount-ing to at least 60 % by weight.
A dispersion of coal is considerably less pollut-ing and can be more easily handled than solid coal and also eliminates some rlsks involved in transport and storage. Such a dispersion is also preferred from an economical point of view.
The reason for using coal dispersions is the planned increased use of coal as a basic energy source in large as well as small plants for producing electricity, steam and heat. The handling of solid coal in this connection is difficult for several reasons and, therefore, the transformation of the coal to liquid form generally is considered an interesting method.
Chemjcal conversion of coal to a liquid productl so--called liquefaction, still cannot compete with oil and it is considered that this method can contribute to the global energy provision only marginally before the year 2000. Chemical conversion of the coal to a gaseous product, so-called gasification, seems to be a more prosperous method of utilizing coal. However, also this method still involves considerable technical difficulties although large resources have been spent on technical development.
Physjcal conversion is another method of transferring the coal into liquid form, and the invention relates to this method. It is practised by dispersing the coal in a liquid which may consist of water as in the case of the ~J
dispersion of the invention, or of some organic fuel such as heat~ng oil, methanol, etc.
The main proble~ of water dispersions of pulverized coal is to make the dispersion stable at low viscosity. The coal particles must not sediment during storage or transport of the coal-water dispersion. More-over, the coal-water dispersion shall have a high pumpability and shall have rheological properties so as to be suitable for burning by conventional technique probably modified to a minor degree.
According to the published international application I~O i31/01152, anionic surfactants and at least one electrolyte among other additives are used to prevent sedimentation and improve rheology. Tests have shown that the sedimentation stability as well as the rheological properties do not satisfy the desired demands.
In the laid open Swedish specifjcation 7805632-2, a coal-water dispersion is disclosed wherein a stabilizing action against sedimentation is obtained by conventional polyelectrolytés, among them poly-phosphate. Also in this case the stability against sedimentation is not satisfactory. The necessary atomization of the fuel when being burnt moreover causes problems e.g. due to formation of agglomerates.
U.S. patent specification 4~242,098 descr;bes a coal-water dispersion wherein the stabilization is obtained by the addition o~ a number of water soluble polymers (polyethyleneoxide, polyacrylamides, etc.).
This dispersion provides an improvement in relation to the dispersions mentioned above but cannot be used directly for energy production without preceding dewatering.
The theory of the stability of dispersions has recently been considerably refined. The theory has been developed to include more concentrated systems but above all a new type of inter-action has been proved. In addition to previously known effects such as electro-static stabilization ~y means of surface-active substances and polyelectrolytes and steric stabiIization by means of polymers there is a further central effect,so-called hydration forces. These forces have recently been demonstrated and have also been explained theoretically. The hydration forces, possibly togetherwith other types of interaction, form the primary basis of the present inventionproviding a long-term stable coal-water dispersion of the type referred to above, which is well suited for direct burning without preceding dewatering by using the techniques available today, possibly with minor modifications.
The dispersion according to the invention is characterized in that the dispersion contains at least one substance adsorbed on the surfaces of the coal particles, which provides repulsion between the coal particles by hydration forces.
Preferably, said substance comprises a zwitterionic amphiphile.
More preferably the substance is a phospholipid such as lecithin or an alkylbetain. It may be zwitterionic or an increased repulsion between coal particles is achieved when this material is partly zwitterionic and partly anionic.
Suitably said substance is present in an amount of about 0.01 to about 0.15 per cent by weight of the total dispersion, preferably about 0.1 per cent by weight of total dispersion.
The invention also provides a method of manufacturing the dispersion, wherein said substance providing the repulsion between the coal particles by hydration forces is supplied to the pulverized coal either dispersed in water ordissolved in an organic solvent.
The dispersion has rheological properties which allow the dispersion to be pumped and transported through pipelines at a greatly reduced friction, and above all has considerably improved stability against flocculation as well as sedimentation. The dispersion moreover has properties such that it can be atomized without forming agglomerates in suitable burner equipment.
When coal-water dispersions which by definition are thermodynamically unstable, are being stabilized the sedimentation and aggregation rates are reduced by creating a barrier which counteracts the particleattraction. This repulsive effect can be achieved by three main principles: electrostatic stabilization, sterical stabilization, and stabilization by means of hydration forces. The ~2~6~5 stabilization changes the energy of the particles and/or creates a high barrier preventing particle attraction. On the basis of these principles it is possibleto stabilize high contents of coal particles in a water medium by the addition of small amounts of organic additives.
In order to create stable colloidal systems it i5 necessary to impart to the system such properties that the attraction forces between the particles are minimized and a replusive barrier against flocculation and subsequent sedimentation is developed. Some form of sterical stabilization by means of hydrophilic polymers provides favourable conditions for a long~term stabilization of coal-water dispersions From studies of lamellar liquid crystalline phases in systems of ionic surface-active substances it has been shown that these phases can swell and incorporate large amounts of water. This is explained by a repulsion over the water layer between adjacent layers of surface-active substance and can be related to electrostatic double-layer forces. For zwitterionic substances such às the phospholipid lecithin the swelling is less pronounced but nevertheless very clear.
This shows that also in the a~sence of a net charge there is a considerable repulsion. This repulsion force, the so-called hydration force, varies approxi-mately exponentially with distance with a characteristic length of 0.2 - 0.3 nm.The force is of a general character and does not vary with the length of the alkyl chain or with the physical condition of the chains (liquid or solid) and is present also when a quantity of charged surface-active substance is included into the systems. ~ydration forces have been shown a]so by directly measuring the forces between surfaces mutually spaced apart by some Angstr~m lmits. A theoretical model for hydration forces has recently been developed, and then it has been possible to relate these forces to the presence of so-called mirror charges overinterfaces where the effective dielectric constant is being changed. Such mirrorcharges with zwitterionic groups should be common in micro- and macro-heterogeneous systems. They are utilized according to the present invention in order to impartdesired properties to a suspension of a low dielectric substance in a high dielectric medium. Thus, a zwitterionic surface-active substance such as lecithin can be adsorbed onto the surfaces of the solid particles. Strong repulsion forces between the particles then exist at short distances. The principle therefore will be particularly useful for concentrated dispersions.
~6~2~
The invention will be descrihed in more detail below with reference to an example.
Example 1. A non-micelle-forming zwitterionic surfactant such as lecithin or an alkylbetain, which is relatively difficult to dissolve in water, is first dissolved in an organic solvent. The solvent can consist of for example octanol, hexadecane or methanol and can be recovered in a suitable manner or can comprise an insigni-ficant portion by weight of the dispersion. Alternatively, the surfactant can be dispersed directly in water probably in the -form of a lamellar liquid crystalline phase, or can be dissolved in water by the addition of an additive having the property of creating soluble mixed aggregates with lecithin.
Preferably the lecithin or alkylbetain is dissolved in water by means of an organic salt as for example an alkali metal salt of a fatty acid or an alkalimetal sorbate.
2. The surfactant preparation is added to a dispersion of pulverized 'coal or in connection with the pulverization step. For example, the pulverized coal can be produced by wet grinding solid coal, the pulverized coal thus obtained being beneficated and dewatered. In that case the surfactant preparation can be added to the pulverized coal in the process of grinding as a grinding aid or in the process of benefication as a flotation reagent making the coal surface more hydrophobic or after the process of dewatering. Suitable fractions of the coal powder in the final product range from 1 to 200 ,um (preferably ~ 150 ~m) with abroad size distribution (polydispersed coal powder). Optimum packing is obtainedaccording to Fuller. The smaller particle size, the greater stability but it is expensive to grind coal down to submicron particle sizes. The particle concen-tration can be varied within a broad range. Considering economical and technicalaspects the particle concentration should be optimized from one case to the other.
Coal-water dispersions with a dry substance content between 65 and 80 % by weight are of particular interest because these dispersions have a high energy content and good rheological properties for example for transport in pipelines. In orderto obtain the highest coal contents (70 - 80 % by weight) the size distribution must be particularly taken into account. In the normal case this can be done on the basis of simple geometrical considerations as to the minimization of the free volume when packing particles of different sizes. It is also possible to add larger coal particles in the range from 0.5 to 5 mm to a dispersion in orderh - 5 ~
~6~
to obtain in this manner a more energy-rich coal~water dispersion, particularly in view of transporting.
Another possibility according to the invention includes addition of oil to the slurry (0 - 10%) either in the pulverization s~ep or later to improveflame stability when the slurry is Deing burnt, especially in small scale applications.
After the adsorption process one or more of hydrophilic anionic or non-ionic polymers may be added to the dispersion in order to provide some form of a steric barrier and in order to reduce the friction between the particles. For example one can choose between polyethers, polysaccharides, polyalcohols and poly-acrylates. Particularly suitable according to the invention are polyethyleneoxidel copolymers of the polyethyleneoxide~polypropyleneoxide type, carboxymethylcellulose, xanthan gum, guar gum, an alginate and polymers of the type block or graft co-polymers with balanced hydrophilic-lipophilic content. Preferred is a copolymer of polypropylene oxide and polyethylene oxide with a predominant amount of the latter preferably at least 70% by weight. The molecular weight of such copolymer is pre-ferably 5,000 to 50,000, more preferably 8,000 to 15,000. The concentration of polymers in percent by weight based on the total weight can be varied between 0.1 and 5% but is economically optimal at about 0.5%.
For the purpose of making the dispersion more attractive as a non-polluting substitute for oil some alkali metal salts or salts of the alkaline earths can be added to the dispersion suitably in amounts corresponding to the stoichiometric content of sulfur in the fuel in order to obtain the desired reduction in oxides produced when the fuel is utilized. Preferably, the salt is calcium hydroxide or dolomite powder. The salt neutralizes acid gas components generated at the ~xidation of the fuel and can be recovered in a particle percipitator.
In order to prevent the water from evaporating from the coal-water dispersion an agent can be added to the dispersion which forms a monomolecular layer in the interface. Such an agent is cetyl alcohol or hexadecanol, and suitably is added in amount of 1 to 10 ppm by volume.
Preferably the total amount of all additives in the dispersion is less than about 2% by weight.
The invention provides substantial advantages over the prior art technique of stabilizing coal particles in water. Due to an excellent sedime~tation stability combined with favourable rheological properties for pumping, the dis-persion obtained is well suited for transporting coal in an appropriate manner in conduits or pipelines for use for example in the chemical industry or for direct energy production.
Combustion tests in boilers designed for heavy oil have shown that the dispersion is very suitable to replace oil completely or partly.
Coal-water dispersions with a dry substance content between 65 and 80 % by weight are of particular interest because these dispersions have a high energy content and good rheological properties for example for transport in pipelines. In orderto obtain the highest coal contents (70 - 80 % by weight) the size distribution must be particularly taken into account. In the normal case this can be done on the basis of simple geometrical considerations as to the minimization of the free volume when packing particles of different sizes. It is also possible to add larger coal particles in the range from 0.5 to 5 mm to a dispersion in orderh - 5 ~
~6~
to obtain in this manner a more energy-rich coal~water dispersion, particularly in view of transporting.
Another possibility according to the invention includes addition of oil to the slurry (0 - 10%) either in the pulverization s~ep or later to improveflame stability when the slurry is Deing burnt, especially in small scale applications.
After the adsorption process one or more of hydrophilic anionic or non-ionic polymers may be added to the dispersion in order to provide some form of a steric barrier and in order to reduce the friction between the particles. For example one can choose between polyethers, polysaccharides, polyalcohols and poly-acrylates. Particularly suitable according to the invention are polyethyleneoxidel copolymers of the polyethyleneoxide~polypropyleneoxide type, carboxymethylcellulose, xanthan gum, guar gum, an alginate and polymers of the type block or graft co-polymers with balanced hydrophilic-lipophilic content. Preferred is a copolymer of polypropylene oxide and polyethylene oxide with a predominant amount of the latter preferably at least 70% by weight. The molecular weight of such copolymer is pre-ferably 5,000 to 50,000, more preferably 8,000 to 15,000. The concentration of polymers in percent by weight based on the total weight can be varied between 0.1 and 5% but is economically optimal at about 0.5%.
For the purpose of making the dispersion more attractive as a non-polluting substitute for oil some alkali metal salts or salts of the alkaline earths can be added to the dispersion suitably in amounts corresponding to the stoichiometric content of sulfur in the fuel in order to obtain the desired reduction in oxides produced when the fuel is utilized. Preferably, the salt is calcium hydroxide or dolomite powder. The salt neutralizes acid gas components generated at the ~xidation of the fuel and can be recovered in a particle percipitator.
In order to prevent the water from evaporating from the coal-water dispersion an agent can be added to the dispersion which forms a monomolecular layer in the interface. Such an agent is cetyl alcohol or hexadecanol, and suitably is added in amount of 1 to 10 ppm by volume.
Preferably the total amount of all additives in the dispersion is less than about 2% by weight.
The invention provides substantial advantages over the prior art technique of stabilizing coal particles in water. Due to an excellent sedime~tation stability combined with favourable rheological properties for pumping, the dis-persion obtained is well suited for transporting coal in an appropriate manner in conduits or pipelines for use for example in the chemical industry or for direct energy production.
Combustion tests in boilers designed for heavy oil have shown that the dispersion is very suitable to replace oil completely or partly.
Claims (17)
- THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS
CLAIMED ARE DEFINED AS FOLLOWS:
l. A dispersion containing water, pulverized coal and additives, the coal content ranging from 60 to 85% by weight, characterized in that the dispersion contains as an additive lecithin or an alkylbetain which is adsorbed on the surfaces of the coal particles and which provides repulsion between the coal particles by hydration forces, and at least one polymer co-operating with the lecithin or alkylbetain, respectively, and containing segments of hydrophobic aswell as hydrophilic character. - 2. The dispersion as claimed in claim 1 characterized in that the lecithin or alkylbetain is zwitterionic.
- 3. The dispersion as claimed in claim 2, characterized in that an increased repulsion between the coal particles is obtained by the lecithin or alkylbetain being partly zwitterionic and partly anionic.
- 4. The dispersion as claimed in claim 1, characterized in that it contains a polymer which is a block or graft copolymer.
- 5. The dispersion as claimed in claim l, characterized in that said polymer is a copolymer of polypropyleneoxide and polyethyleneoxide with a pre-dominant amount of polyethyleneoxide.
- 6. The dispersion as claimed in claim 5, characterized in that the molecular weight of the copolymer ranges from 5,000 to 50,000.
- 7. The dispersion as claimed in claim 6, characterized in that the copolymer contains at least 70% by weight of polyethyleneoxide and that the molecular weight ranges from 8,000 to 15,000.
- 8. The dispersion as claimed in claim 1, characterized in that it further contains a polysaccharide.
- 9. The dispersion as claimed in claim 8, characterized in that the polysaccharide is xanthan gum or guar gum or an alginate.
- 10. The dispersion as claimed in claim 1, characterized in that the total amount of additive is below 2 % by weight.
- 11. The dispersion as claimed in claim 1, characterized in that it contains 0 to 10% by weight of oil.
- 12. A method of manufacturing the dispersion as claimed in claim 1, characterized in that lecithin or alkylbetain is supplied to the pulverized coal either dispersed in water or dissolved in an organic solvent and at least one polymer is added thereto, which polymer contains segments of hydrophobic as well as hydrophilic character.
- 13. The method as claimed in claim 12, characterized in that lecithin or alkylbetain is supplied to the pulverized coal dissolved in water by means of an organic salt.
- 14. The method as claimed in claim 13 characterized in that the organic salt is an alkali metal salt of a fatty acid or an alkali metal sorbate.
- 15. Method as claimed in claim 12, 13 or 14 wherein the solid coal is pulverized by wet grinding and is then beneficated and dewatered, characterized in that lecithin or alkylbetain is supplied in the process of grinding or benefication or after the process of dewatering.
- 16. The dispersion of claim 1, 2 or 3 characterized in that the additive is present in an amount of about 0.01 to about 0.15 percent by weight of total composition.
- 17. The dispersion of claim 1, 2 or 3 characterized in that the additive is present in an amount of about 0.1 percent by weight of total composition.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE82/00107 | 1982-04-05 | ||
| PCT/SE1982/000107 WO1983000500A1 (en) | 1981-08-03 | 1982-04-05 | Coal-water dispersion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1216425A true CA1216425A (en) | 1987-01-13 |
Family
ID=20345679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000418903A Expired CA1216425A (en) | 1982-04-05 | 1983-01-05 | Coal-water dispersion and method of the manufacture thereof |
Country Status (11)
| Country | Link |
|---|---|
| EP (2) | EP0118440B1 (en) |
| JP (1) | JPS59500520A (en) |
| AU (1) | AU1223183A (en) |
| BR (1) | BR8306789A (en) |
| CA (1) | CA1216425A (en) |
| DK (1) | DK558483A (en) |
| ES (1) | ES519418A0 (en) |
| FI (1) | FI834462A (en) |
| IT (1) | IT1207967B (en) |
| NO (1) | NO834432L (en) |
| WO (2) | WO1983003617A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0118440B1 (en) * | 1982-04-05 | 1988-03-02 | Fluidcarbon International Ab | Coal-water dispersion and method of the manufacture thereof |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT370763B (en) * | 1977-05-31 | 1983-05-10 | Scaniainventor Ab | CARBON SUSPENSION CONTAINING POWDERED COAL, WATER AND DISPERSING AGENTS, AND METHOD FOR THE PRODUCTION THEREOF |
| US4242098A (en) * | 1978-07-03 | 1980-12-30 | Union Carbide Corporation | Transport of aqueous coal slurries |
| US4282006A (en) * | 1978-11-02 | 1981-08-04 | Alfred University Research Foundation Inc. | Coal-water slurry and method for its preparation |
| US4326855A (en) * | 1979-11-08 | 1982-04-27 | Cottell Eric Charles | Process for beneficiating and stabilizing coal/oil/water fuels |
| GB2087862B (en) * | 1980-11-18 | 1984-08-01 | Dearborn Chemicals Ltd | Process for dispersing particulate material in aqueous systems |
| US4358293A (en) * | 1981-01-29 | 1982-11-09 | Gulf & Western Manufacturing Co. | Coal-aqueous mixtures |
| SE436136B (en) * | 1981-08-03 | 1984-11-12 | Fluidcarbon Ab | COOL-WATER DISPERSION WITH ADDITIVE COMPOSITION OF SWITZERIONIC TENSID AND CONNECTING HYDROPHILIC POLYMERS |
| JPS5840392A (en) * | 1981-09-04 | 1983-03-09 | Sumitomo Chem Co Ltd | Coal composition |
| EP0118440B1 (en) * | 1982-04-05 | 1988-03-02 | Fluidcarbon International Ab | Coal-water dispersion and method of the manufacture thereof |
-
1982
- 1982-11-12 EP EP82903239A patent/EP0118440B1/en not_active Expired
- 1982-11-12 WO PCT/EP1982/000244 patent/WO1983003617A1/en active IP Right Grant
- 1982-12-03 IT IT8224584A patent/IT1207967B/en active
-
1983
- 1983-01-05 CA CA000418903A patent/CA1216425A/en not_active Expired
- 1983-01-31 ES ES519418A patent/ES519418A0/en active Granted
- 1983-02-04 AU AU12231/83A patent/AU1223183A/en not_active Abandoned
- 1983-02-04 EP EP83900669A patent/EP0105878A1/en not_active Withdrawn
- 1983-02-04 WO PCT/SE1983/000039 patent/WO1983003618A1/en not_active Application Discontinuation
- 1983-02-04 JP JP58500710A patent/JPS59500520A/en active Pending
- 1983-02-04 BR BR8306789A patent/BR8306789A/en unknown
- 1983-12-02 NO NO834432A patent/NO834432L/en unknown
- 1983-12-05 DK DK558483A patent/DK558483A/en not_active Application Discontinuation
- 1983-12-05 FI FI834462A patent/FI834462A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| NO834432L (en) | 1983-12-02 |
| AU1223183A (en) | 1983-11-04 |
| DK558483D0 (en) | 1983-12-05 |
| BR8306789A (en) | 1984-03-07 |
| ES8402341A1 (en) | 1984-01-16 |
| DK558483A (en) | 1983-12-05 |
| JPS59500520A (en) | 1984-03-29 |
| FI834462A0 (en) | 1983-12-05 |
| IT1207967B (en) | 1989-06-01 |
| FI834462A (en) | 1983-12-05 |
| WO1983003617A1 (en) | 1983-10-27 |
| ES519418A0 (en) | 1984-01-16 |
| EP0105878A1 (en) | 1984-04-25 |
| EP0118440A1 (en) | 1984-09-19 |
| EP0118440B1 (en) | 1988-03-02 |
| WO1983003618A1 (en) | 1983-10-27 |
| IT8224584A0 (en) | 1982-12-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |