WO2012136225A1 - Method for oil spill collection on water - Google Patents
Method for oil spill collection on water Download PDFInfo
- Publication number
- WO2012136225A1 WO2012136225A1 PCT/DK2012/050116 DK2012050116W WO2012136225A1 WO 2012136225 A1 WO2012136225 A1 WO 2012136225A1 DK 2012050116 W DK2012050116 W DK 2012050116W WO 2012136225 A1 WO2012136225 A1 WO 2012136225A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pumice
- collected
- water surface
- oil
- stones
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
- B63B35/32—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for for collecting pollution from open water
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
- B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
- B01J20/28004—Sorbent size or size distribution, e.g. particle size
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
- B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
- B01J20/28011—Other properties, e.g. density, crush strength
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/68—Treatment of water, waste water, or sewage by addition of specified substances, e.g. trace elements, for ameliorating potable water
- C02F1/681—Treatment of water, waste water, or sewage by addition of specified substances, e.g. trace elements, for ameliorating potable water by addition of solid materials for removing an oily layer on water
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B15/00—Cleaning or keeping clear the surface of open water; Apparatus therefor
- E02B15/04—Devices for cleaning or keeping clear the surface of open water from oil or like floating materials by separating or removing these materials
- E02B15/041—Devices for distributing materials, e.g. absorbed or magnetic particles over a surface of open water to remove the oil, with or without means for picking up the treated oil
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B15/00—Cleaning or keeping clear the surface of open water; Apparatus therefor
- E02B15/04—Devices for cleaning or keeping clear the surface of open water from oil or like floating materials by separating or removing these materials
- E02B15/046—Collection of oil using vessels, i.e. boats, barges
- E02B15/047—Collection of oil using vessels, i.e. boats, barges provided with an oil collecting boom arranged on at least one side of the hull
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/40—Devices for separating or removing fatty or oily substances or similar floating material
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
- C02F2101/32—Hydrocarbons, e.g. oil
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/007—Contaminated open waterways, rivers, lakes or ponds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2303/00—Specific treatment goals
- C02F2303/16—Regeneration of sorbents, filters
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B15/00—Cleaning or keeping clear the surface of open water; Apparatus therefor
- E02B15/04—Devices for cleaning or keeping clear the surface of open water from oil or like floating materials by separating or removing these materials
- E02B15/048—Oil collectors moved over the water skimming the water surface
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/20—Controlling water pollution; Waste water treatment
- Y02A20/204—Keeping clear the surface of open water from oil spills
Definitions
- the present invention concerns a method for collecting petroleum products from a polluted water surface, where pumice is used for laying upon a contaminated water surface.
- the fact that the pumice stones are so small implies that when the pumice stones are attempted collected, a very fine mesh net is required, which due to the fine meshes will push the water in front of it, the water thus forming a wave in front of the fine mesh net, and the pumice stones be impacted by this wave to be moved and whirled around in the water, and oil as well a pumice will evade collection.
- the cleaning method or the way in which the pumice beads are cleaned in US 7,517,831 B2 is not expedient as very special conditions are required in order to burn off the collected oil as well as the fact that the such a burning of cannot readily be performed with a clean combustion as result, leaving something to be desired as the pollution is not just to be moved from the water and to the air.
- the oil- filled pumice beads can be collected in containers and brought ashore after which they can be burned off under optimal conditions.
- this inexpedient as it requires a considerable storage capacity for contaminated pumice beads as well as for clean pumice beads, since immediate reuse of the pumice beads thus cannot be applied. Therefore, several unsuitable conditions have been acknowledged by the prior art methods where pumice beads are used for collecting a pollution of oil on water.
- the invention concerns a method for collecting petroleum products from a contaminated water surface, where pumice is used for laying upon a contaminated water surface.
- the new feature of a method according to the invention is that the pumice has an average particle size between 15 and 80 mm, preferably between 30 and 50 mm, where the pumice has a density between 200 and 400 kg/m 3 by a water content below 10 weight-%.
- the relatively large size of the pumice stones provide a markedly greater advantage in connection with handling of these pumice stones by storing as well as in application but in particular when applied for collecting an oil pollution on water.
- the particularly great advantage of pumice stones of this size is due to the fact that it has appeared to be much easier to collect the pumice stones when they have an appreciable dimension compared to that which has been previously used. At the same time, it is advantageous that the density is somewhat lower than the previously used types of pumice.
- the advantage of the lower density means that the pumice stones lie higher in the water surface, thus allowing the petroleum to attach to the surface and the open pores of the pumice stones in a surprisingly efficient way.
- the surface of the individual pumice stones will be covered by a layer of oil with a thickness of up to several millimetres.
- pumice stones with a size as indicated above of 40 mm in diameter compared with pumice stones with a size of 8 mm in diameter.
- both pumice stones are regarded as perfect spheres in the following examples.
- the relationship between the two diameters 40 mm and 8 mm is 5 which is also the above calculated relationship with the same relation. Since the buoyancy, or in other words the position of the pumice stone in the water surface, is directly dependent on the density of the individual pumice stone with or without oil, respectively, the relationship between volume and area are rather decisive for how easy it is to collect the pumice stones again.
- a small and relatively heavy pumice stone with a diameter of 8 mm and with an oil layer of 2 mm will lie deeply in the water whereas a large and relatively light pumice stone with a diameter of 40 mm and an oil layer of 2 mm will lie more superficially in the water.
- a pumice stone with a diameter of 8 mm may collect about 0.004 litres of oil whereas a pumice stone with a diameter of 40 mm may collect about 0.01 litres of oil. If, for example, supposing that the oil to be collected weighs 900 g/1, and the used pumice weighs 400 g 1, this can be approximated to:
- pumice stone with small diameter in principle can collect more oil but that the density of a pumice stone with oil is also significantly higher than when comparing with a larger and far more easily handled pumice stone with oil.
- the oil is so to say lifted more easily off the water surface as a larger part of the individual pumice stones is over the water surface.
- pumice stones with a size between 15 and 80 mm, and particularly if the size is over 30 mm as the surfaces on e.g. a ship by which the oil coated pumice stones are to be handled can be made of a kind of grate or with meshes carrying the pumice stones without substantial contact with the surfaces. In that way it is avoided that a large part of the collected oil is deposited on these surfaces, providing a clear advantage in connection with cleaning of the actual equipment after use. It is therefore advantageous to use the pumice stones in the sizes indicated here as they can be collected and handled more easily.
- the method according to the invention includes at least the following steps: the pumice is laid upon a contaminated water surface; the pumice is collected by machine; the pumice is cleaned entirely or partially of the collected petroleum or oil; and the pumice is transported to storage or laying out again.
- Laying can occur on open sea but may also be done at littoral areas, in harbour areas, on rivers or lakes, whereby an oil pollution is prevented from hitting the coast or the lakeshore.
- pumice is laid out upon a contaminated water surface as an aggregate to a flow of water where water and pumice are discharged together via a jet pipe.
- it can be a water cannon which via a pump pumps water out of a spray nozzle.
- a connection to a container with loose and clean pumice stones can be arranged, producing a vacuum caused by the water flow whereby the pumice stones are sucked into the flow and transported by the water.
- pumice can be laid at a given distance from a vessel while at the same time the vessel is working at capacity with collecting and cleaning already laid pumice stones.
- clean pumice stones are supplied to a container directly communicating with the seawater under the vessel.
- a container directly communicating with the seawater under the vessel.
- Such a container can readily be established such that there is direct access to the sea from the bottom of the container or sides, only delimited by a kind of grate with holes/meshed with a size which is less than that of the pumice stones.
- Laying of pumice stones upon a contaminated water surface can also be performed in that they are supplied with a flow of air where air and pumice are discharged together via a kind of nozzle. In principle, it may be a solution as described above but without using water that may worsen the pollution by splashing down into the oil.
- pumice can be laid out upon a contaminated water surface from an aircraft, e.g. an airplane or a helicopter.
- an aircraft e.g. an airplane or a helicopter.
- This can e.g. be effected in that a container of suitable type is provided in an airplane or under a helicopter which then flies over the area and releases an opening mechanism on the container, whereby the content of pumice is released and laid upon the contaminated surface.
- the laid pumice can be collected by a conveyor, the conveyor extending from a vessel and down at least a distance below the water surface from where the pumice is collected, where the conveyor includes one or more endless conveyor belts provided with meshes, e.g. constituted by a wire mesh, the meshes of the wire mesh having a dimension which is less than the particle size of the applied pumice, preferably having a dimension between 10 and 45 mm.
- the conveyor belt of the collecting conveyor is provided with relatively larges meshes, yet ensuring good collection of the laid pumice stones, there is achieved the decisive advantage that it is possible to sail with appreciable speed without forming a wave in front of the collecting conveyor.
- a conveyor for collecting pumice stones can be divided into sections and have a collecting width of up to 30 metres or more. This can be effected by a single wide conveyor, but several juxtaposed conveyors may also be applied. Moreover, a kind of guide plates or a kind of grabbing arms guiding pumice stones in direction towards the conveyor can be arranged with advantage, whereby they are lifted off the water and on board a vessel for cleaning or alternatively for storage.
- the above mentioned grabbing arms may advantageously be a kind of conveyor with a conveyor belt with meshes where, as mentioned above, the conveyor belt is arranged more or less vertically, along the sides of and out from the sides of the overall conveyor lifting the pumice off the water, where vertical conveyor belt itself during operation more or less guides and follows the respective pumice stones during the collecting.
- the collecting action may readily be performed at a speed that cause the pumice stones to lie in up to a plurality of layers as they are easily distributed in a single layer by a subsequent more rapidly running conveyor.
- treatment and cleaning of the collected pumice stones is effected onboard the vessel as the collected pumice stones are heat treated by hot air, steam or water, whereby hydrocarbons are released from pores in the pumice and collected in the form of liquid or vapour.
- a kind of cooker hood can be arranged above the conveyor belt for collecting possible evaporated petroleum residues.
- the cleaning itself is performed best and most efficiently with the pumice stones in a single layer in a more or less closed system such that the steam pressure causes the pumice stones to be circulated and cleaned efficiently on the entire surface prior to being laid out again.
- the collected oil which has been cleaned off as mentioned above is deposited, advantageously in a tank from where the oil can be unloaded later on.
- a tank may advantageously be adapted such that the contents of the tank can be heated by heating bodies arranged and suited for the purpose.
- the oil may advantageously be pumped into a towed floating container which after filling either can be towed on or simply be left for later pickup.
- a container can be made in the style of a closed rubber dinghy and in an alerting colour and possibly with a kind of transmitter that enables easy localisation at sea.
- pumice stones After cleaning the pumice stones, these are in principle ready for being moved directly on to laying again on the polluted water surface by one of the above mentioned methods.
- the collected and cleaned pumice stones can be moved to a storage container which is often at the end of clean-up after an oil pollution.
- a particularly preferred way of performing a method according to the invention is that the laid-out pumice is collected by a vessel which is navigated with circling movements at the outskirts of the contaminated area, and that the vessel is navigated in a spiralling movement towards the centre of the contaminated area as the laid pumice is collected.
- Such a circling and spiral-shaped movement can occur with one or more vessels, having the advantage that continuously monitoring or moving around at all sides of an oil pollution is performed, and therefore it is easier to ensure that wind and weather do not move the oil pollution without it being noticed.
- An oil pollution may in some cases extend across a small area why a clean-up can be performed rapidly and relatively easily.
- the invention therefore also describes a method for collecting oil from a water surface wherein the collected and cleaned pumice stones are re-laid in the area around which a vessel is navigated with circling, spiralling movements. It is thus possible to circle around the pollution and to lay clean pumice stones in an area closer to the centre of the pollution while simultaneously collecting pumice stones covered with oil from the edge of the oil pollution.
- Fig. 1 shows a vessel circling in a spiral around an oil pollution.
- Fig. 1 is seen an oil pollution 1 and a vessel 2 heading in direction of the arrow around the oil pollution 1 in spiral shape.
- a conveyor 3 which extends to a level below the water surface and which is made with a conveyor belt of wiremesh or similar.
- a first conveyor belt which extends from the water and to the vessel and which has a conveyor device along the vessel 2.
- a transverse conveyor belt which conveys the not shown collected pumice stones onboard the vessel.
- the collecting mechanism with a conveyor can be designed in innumerable other ways.
- the surfaces upon which the oil-coated pumice stones are handled are made of e.g. a wiremesh of steel or similar which can easily be cleaned.
- a jet 5 which here illustrates laying of pumice stones on the part of the oil pollution 1 which has not yet been collected. By a subsequent passage with the vessel 2, these laid pumice stones will be collected.
- Fig. 1 only serves the purpose of illustrating the principle of how laying and collecting of pumice stones can take place. 11
Abstract
The invention concerns a method for collecting petroleum products from a contaminated water surface, where pumice is used for laying upon a contaminated water surface. The new feature of a method according to the invention is that the pumice has an average particle size between 15 and 80 mm, preferably between 30 and 50 mm, where the pumice has a density between 200 and 400 kg/m3 by a water content below 10 weight-%. The particularly great advantage of pumice stones of this size is due to the fact that it has appeared to be much easier to collect the pumice stones when they have an appreciable dimension compared to that which has been previously used. At the same time, it is advantageous that the density is somewhat lower than the previously used types of pumice. The advantage of the lower density means that the pumice stones lie higher in the water surface, thus allowing the petroleum to attach to the surface and in the open pores of the pumice stones in a surprisingly efficient way.
Description
METHOD FOR OIL SPILL COLLECTION ON WATER Field of the Invention
The present invention concerns a method for collecting petroleum products from a polluted water surface, where pumice is used for laying upon a contaminated water surface.
Background of the Invention
It is commonly known that in connection with spilling of hydrocarbons in the form of various types of oil or petroleum product on water, different kinds of collecting equipment are used. For example, collecting equipment where a floating barrier is drawn by two vessels around the actual pollution and where collection of e.g. oil from the water surface is performed by e.g. a third vessel is prior art. This collecting and encircling of the pollution, which is typically a kind of oil, is effected by special equipment which is most suited to be applied under weather conditions where it is not too windy and thus where the waves are not so high.
From US 7,517,831 B2 is known another method for collecting oil from a water surface. Here is used beads of a particular type of pumice with a carbon content between 5 and 15% by weight. This particular pumice has a density between 500 and 700 kg/m , and the pumice beads have a particle size between 3 and 8 mm. It is thus relatively small pumice beads which are disclosed by the invention in US 7,517,831 B2 and provided on a polluted water surface. Due to their nature with closed cells in the central part and open cells at the surface of the pumice stones, the pumice beads will absorb oil from the water surface. The small pumice beads are then collected and subjected to combustion whereby the collected oil is burned and removed from the pumice beads, which then can be reused.
A similar solution is also known from DE 31 42 275 Al where small pumice beads or granulate with a particle size between 1 and 16 mm is used as well, but where the particle size however is preferably between 2 and 8 mm.
By this method of collecting a contaminated petroleum-based liquid from water there are, however, some inexpediencies as it is associated with some difficulties to collect the small pumice beads from the water surface. This is particularly difficult in connection with breaking sea and wind as the pumice beads are easily dispersed and at the same time require a fine mesh net to be moved in the water surface. The fact that a fine mesh net or other suitable collecting tool is required entails a considerable resistance between tool and water, which influences the speed at which the pumice can be collected in negative direction. In principle, this means that the collecting itself largely means a very comprehensive challenge where very small pumice stones are to be collected by a kind of equipment which in principle shovels water and pumice onboard a vessel, after which a similarly difficult handling of the small pumice stones take place. The fact that the pumice stones are so small implies that when the pumice stones are attempted collected, a very fine mesh net is required, which due to the fine meshes will push the water in front of it, the water thus forming a wave in front of the fine mesh net, and the pumice stones be impacted by this wave to be moved and whirled around in the water, and oil as well a pumice will evade collection.
Another drawback by using relatively small pumice stones as indicated in US 7,517,831 B2 and in DE 31 42 275 Al is that a single stone of this modest size may bind an appreciable amount of oil in relation to its weight and thereby in relation to its buoyancy, why such a pumice stone will lie deeper in the water and thus become even more difficultto collect.
Moreover, the cleaning method or the way in which the pumice beads are cleaned in US 7,517,831 B2 is not expedient as very special conditions are required in order to burn off the collected oil as well as the fact that the such a burning of cannot readily be performed with a clean combustion as result, leaving something to be desired as the pollution is not just to be moved from the water and to the air. Alternatively, the oil- filled pumice beads can be collected in containers and brought ashore after which they can be burned off under optimal conditions. However, this inexpedient as it requires a considerable storage capacity for contaminated pumice beads as well as for clean pumice beads, since immediate reuse of the pumice beads thus cannot be applied.
Therefore, several unsuitable conditions have been acknowledged by the prior art methods where pumice beads are used for collecting a pollution of oil on water.
Object of the Invention
It is the object of the invention to indicate a new and improved method for collecting an oil pollution on water where pumice with a suitable and manageable size is used, and where the collected oil can be processed for recycling.
Description of the Invention
As mentioned in the introduction, the invention concerns a method for collecting petroleum products from a contaminated water surface, where pumice is used for laying upon a contaminated water surface.
The new feature of a method according to the invention is that the pumice has an average particle size between 15 and 80 mm, preferably between 30 and 50 mm, where the pumice has a density between 200 and 400 kg/m3 by a water content below 10 weight-%. The relatively large size of the pumice stones provide a markedly greater advantage in connection with handling of these pumice stones by storing as well as in application but in particular when applied for collecting an oil pollution on water. The particularly great advantage of pumice stones of this size is due to the fact that it has appeared to be much easier to collect the pumice stones when they have an appreciable dimension compared to that which has been previously used. At the same time, it is advantageous that the density is somewhat lower than the previously used types of pumice. The advantage of the lower density means that the pumice stones lie higher in the water surface, thus allowing the petroleum to attach to the surface and the open pores of the pumice stones in a surprisingly efficient way. When the pumice stones have been sloshing around in the water surface in the oil pollution for some time, e.g. some minutes or several hours, the surface of the individual pumice stones will be covered by a layer of oil with a thickness of up to several millimetres.
Experiments have shown that a layer with a thickness between 2 and 4 mm readily can be attached to a pumice stone with a diameter about 40 mm. If by calculation the pumice stone is regarded as a sphere with a coating thickness of only 2 mm and a diameter of 40 mm, this will mean that one pumice stone can bind about 0.01 litre oil,
corresponding to 100 pumice stones each with a diameter of 40 mm binding about 1 litre oil to the surfaces, which is surprising and considerably more than what is possible to bind and collect by the prior art types of pumice. This is highly due to the density of the pumice stones but also the size of the individual pumice stones have influence.
For example, by simple calculation of volume in relation to surface area it may quickly be realised that there are obvious advantages by using pumice stones with a size as indicated above of 40 mm in diameter compared with pumice stones with a size of 8 mm in diameter. For the sake of simplicity both pumice stones are regarded as perfect spheres in the following examples.
Volume = 4/3 π r3 => V8 = 268 mm3 V8 = 33,510 mm3
Area = 4 π r2 => A8 = 201 mm2 A40 = 5,027 mm2
The relationship between the two diameters 40 mm and 8 mm is 5 which is also the above calculated relationship with the same relation. Since the buoyancy, or in other words the position of the pumice stone in the water surface, is directly dependent on the density of the individual pumice stone with or without oil, respectively, the relationship between volume and area are rather decisive for how easy it is to collect the pumice stones again. A small and relatively heavy pumice stone with a diameter of 8 mm and with an oil layer of 2 mm will lie deeply in the water whereas a large and relatively light pumice stone with a diameter of 40 mm and an oil layer of 2 mm will lie more superficially in the water.
A pumice stone with a diameter of 8 mm may collect about 0.004 litres of oil whereas a pumice stone with a diameter of 40 mm may collect about 0.01 litres of oil. If, for example, supposing that the oil to be collected weighs 900 g/1, and the used pumice weighs 400 g 1, this can be approximated to:
Mass of oil M8 ou = 3,6 g M40 oii = g
Mass of pumice stone M8 pUmice = 0.11 g M40 pUmice = 13.4 g
Mass increase in % M8 % = 3273 % M40 % = 67 %
It appears clearly from the above that pumice stone with small diameter in principle can collect more oil but that the density of a pumice stone with oil is also significantly higher than when comparing with a larger and far more easily handled pumice stone with oil. When using the markedly larger pumice stones, the oil is so to say lifted more easily off the water surface as a larger part of the individual pumice stones is over the water surface.
Hereby, several advantages are achieved. Among others, there is no need for using collecting equipment extending so far down in the water and at the same time equipment with larger meshes can be used, meaning that a wave is not formed and pushed in front of the collecting equipment and which can whirl pumice stones and oil around and possibly release oil from the pumice stones. Furthermore, there are significant and obvious advantages to the further handling during laying, collecting as well as cleaning, all being advantages associated with the size of the pumice stones.
In that connection it is to be mentioned that relatively small pumice stones with a particle size between 1 and 16 mm are only laid out upon a water surface with difficulty as the wind will carry them with them. A similar problem will arise by laying by helicopter where small and light pumice stones will be whirled around such that it is impossible to determine where they are laid.
At the same time, there are additional advantages of using pumice stones with a size between 15 and 80 mm, and particularly if the size is over 30 mm as the surfaces on e.g. a ship by which the oil coated pumice stones are to be handled can be made of a kind of grate or with meshes carrying the pumice stones without substantial contact with the surfaces. In that way it is avoided that a large part of the collected oil is deposited on these surfaces, providing a clear advantage in connection with cleaning of the actual equipment after use. It is therefore advantageous to use the pumice stones in the sizes indicated here as they can be collected and handled more easily.
The method according to the invention includes at least the following steps: the pumice is laid upon a contaminated water surface; the pumice is collected by machine;
the pumice is cleaned entirely or partially of the collected petroleum or oil; and the pumice is transported to storage or laying out again.
Laying can occur on open sea but may also be done at littoral areas, in harbour areas, on rivers or lakes, whereby an oil pollution is prevented from hitting the coast or the lakeshore.
In a preferred variant of a method according to the invention, pumice is laid out upon a contaminated water surface as an aggregate to a flow of water where water and pumice are discharged together via a jet pipe. In principle it can be a water cannon which via a pump pumps water out of a spray nozzle. At the same time, a connection to a container with loose and clean pumice stones can be arranged, producing a vacuum caused by the water flow whereby the pumice stones are sucked into the flow and transported by the water. In this way pumice can be laid at a given distance from a vessel while at the same time the vessel is working at capacity with collecting and cleaning already laid pumice stones.
In a preferred variant of the invention, clean pumice stones are supplied to a container directly communicating with the seawater under the vessel. Hereby, ample amounts of water are present all the time for keeping the pumice afloat and ready for laying. Such a container can readily be established such that there is direct access to the sea from the bottom of the container or sides, only delimited by a kind of grate with holes/meshed with a size which is less than that of the pumice stones. Laying of pumice stones upon a contaminated water surface can also be performed in that they are supplied with a flow of air where air and pumice are discharged together via a kind of nozzle. In principle, it may be a solution as described above but without using water that may worsen the pollution by splashing down into the oil.
Alternatively, pumice can be laid out upon a contaminated water surface from an aircraft, e.g. an airplane or a helicopter. This can e.g. be effected in that a container of suitable type is provided in an airplane or under a helicopter which then flies over the
area and releases an opening mechanism on the container, whereby the content of pumice is released and laid upon the contaminated surface.
In a particularly preferred variant of a method according to the invention, the laid pumice can be collected by a conveyor, the conveyor extending from a vessel and down at least a distance below the water surface from where the pumice is collected, where the conveyor includes one or more endless conveyor belts provided with meshes, e.g. constituted by a wire mesh, the meshes of the wire mesh having a dimension which is less than the particle size of the applied pumice, preferably having a dimension between 10 and 45 mm. As the conveyor belt of the collecting conveyor is provided with relatively larges meshes, yet ensuring good collection of the laid pumice stones, there is achieved the decisive advantage that it is possible to sail with appreciable speed without forming a wave in front of the collecting conveyor. This is particularly due to the fact that the conveyor does not act as a sealed plate moved in the water but allows a large through-flow of water while at the same time retaining pumice stones and moving them on board the vessel. A conveyor for collecting pumice stones can be divided into sections and have a collecting width of up to 30 metres or more. This can be effected by a single wide conveyor, but several juxtaposed conveyors may also be applied. Moreover, a kind of guide plates or a kind of grabbing arms guiding pumice stones in direction towards the conveyor can be arranged with advantage, whereby they are lifted off the water and on board a vessel for cleaning or alternatively for storage.
The above mentioned grabbing arms may advantageously be a kind of conveyor with a conveyor belt with meshes where, as mentioned above, the conveyor belt is arranged more or less vertically, along the sides of and out from the sides of the overall conveyor lifting the pumice off the water, where vertical conveyor belt itself during operation more or less guides and follows the respective pumice stones during the collecting. The collecting action may readily be performed at a speed that cause the pumice stones to lie in up to a plurality of layers as they are easily distributed in a single layer by a subsequent more rapidly running conveyor.
In a particularly efficient variant of the method according to the invention, treatment and cleaning of the collected pumice stones is effected onboard the vessel as the collected pumice stones are heat treated by hot air, steam or water, whereby hydrocarbons are released from pores in the pumice and collected in the form of liquid or vapour. By subjecting the more or less oil-covered pumice stones to a temperature of 80 to 90°C, there is achieved the effect that the oil becomes easy flowing and thus more or less runs off the individual pumice stones by itself. However, lower or higher temperatures can be used as well according to need or to circumstances. In order to increase the speed in the cleaning process, hot air, water or steam can be blown on the pumice stones, thus tearing the oil from the pumice at rather high speed whereby the capacity of a cleaning station is increased. Such a cleaning will typically occur in a more or less closed compartment where pumice stones rest on a grate or a conveyor belt with meshes where collecting means are arranged under the conveyor belt and where oil and other liquids and solid particles are collected. Moreover, a kind of cooker hood can be arranged above the conveyor belt for collecting possible evaporated petroleum residues." By conveying the oil-coated pumice stones on a wire grate or similar, there is further achieved the advantage that a substantial amount of heat is not transmitted to the part of the conveyor moving through the hot part of the cleaning station.
In a particularly preferred variant of the invention, there is preformed cleaning of pumice stones by steam having a temperature up to 120°C whereby the oil is rapidly and efficiently detached and thereby separated from the pumice stones. The cleaning itself is performed best and most efficiently with the pumice stones in a single layer in a more or less closed system such that the steam pressure causes the pumice stones to be circulated and cleaned efficiently on the entire surface prior to being laid out again.
The collected oil which has been cleaned off as mentioned above is deposited, advantageously in a tank from where the oil can be unloaded later on. In a variant of a vessel with which to perform the invention, such a tank may advantageously be adapted such that the contents of the tank can be heated by heating bodies arranged and suited for the purpose. Hereby is achieved possibility of working with collecting oil at temperatures at which the oil is not fluid enough to flow/be pumped. When such
a container for the collected oil is filled, the oil may advantageously be pumped into a towed floating container which after filling either can be towed on or simply be left for later pickup. Such a container can be made in the style of a closed rubber dinghy and in an alerting colour and possibly with a kind of transmitter that enables easy localisation at sea.
After cleaning the pumice stones, these are in principle ready for being moved directly on to laying again on the polluted water surface by one of the above mentioned methods. Alternatively, the collected and cleaned pumice stones can be moved to a storage container which is often at the end of clean-up after an oil pollution.
A particularly preferred way of performing a method according to the invention is that the laid-out pumice is collected by a vessel which is navigated with circling movements at the outskirts of the contaminated area, and that the vessel is navigated in a spiralling movement towards the centre of the contaminated area as the laid pumice is collected. Such a circling and spiral-shaped movement can occur with one or more vessels, having the advantage that continuously monitoring or moving around at all sides of an oil pollution is performed, and therefore it is easier to ensure that wind and weather do not move the oil pollution without it being noticed.
An oil pollution may in some cases extend across a small area why a clean-up can be performed rapidly and relatively easily. However, there are also examples of extremely large oil pollutions where it will not be possible immediately to cover the entire area with pumice stones. The invention therefore also describes a method for collecting oil from a water surface wherein the collected and cleaned pumice stones are re-laid in the area around which a vessel is navigated with circling, spiralling movements. It is thus possible to circle around the pollution and to lay clean pumice stones in an area closer to the centre of the pollution while simultaneously collecting pumice stones covered with oil from the edge of the oil pollution. By a relatively modest amount of pumice one may thus work inwards towards the centre of the pollution as the same pumice stones can be laid out, collected and cleaned repeatedly. Therefore there is no need for an infinitely amount of pumice but it is possible to work with an amount which readily can be stored on a vessel adapted for this type of work.
Regardless of using one or the other method for collecting an oil pollution, it is important to act as quickly as possible such that the least possible damage occurs on the environment, and less spreading of the oil pollution is to be preferred at any time. Equipment for performing a method according to the invention may therefore advantageously be packed in an emergency container which can be rigged rapidly, after which laying and collecting oil can be commenced.
Description of the Drawing
The invention is described in the following with reference to the drawing, wherein: Fig. 1 shows a vessel circling in a spiral around an oil pollution.
Detailed Description of Embodiments of the Invention
In Fig. 1 is seen an oil pollution 1 and a vessel 2 heading in direction of the arrow around the oil pollution 1 in spiral shape. At one side of the vessel 2 is seen a conveyor 3 which extends to a level below the water surface and which is made with a conveyor belt of wiremesh or similar. In the shown variant there is a first conveyor belt which extends from the water and to the vessel and which has a conveyor device along the vessel 2. At the end of the first conveyor belt is arranged a transverse conveyor belt which conveys the not shown collected pumice stones onboard the vessel. This is just an example, and the collecting mechanism with a conveyor can be designed in innumerable other ways. However, it is particularly advantageous that the surfaces upon which the oil-coated pumice stones are handled are made of e.g. a wiremesh of steel or similar which can easily be cleaned. Furthermore, it is an advantage that particularly the part of the conveyor 3 which extends down into the water, is as penetrable as possible since this greatly influences the speed at which the vessel 2 can be moved.
At the side of the vessel 2 is furthermore seen a jet 5 which here illustrates laying of pumice stones on the part of the oil pollution 1 which has not yet been collected. By a subsequent passage with the vessel 2, these laid pumice stones will be collected.
Fig. 1 only serves the purpose of illustrating the principle of how laying and collecting of pumice stones can take place.
11
Claims
1. A method for collecting petroleum products from a contaminated water surface, where pumice is used for laying upon the contaminated water surface, characterised in that the pumice has an average particle size between 15 and 80 mm, preferably between 30 and 50 mm, and where the pumice has a density between 200 and 400 kg m by a water content less than 10 weight-%, the method comprising at least the following steps:
the pumice is laid out upon a contaminated water surface;
- the pumice is collected by machine;
the pumice is cleaned entirely or partially of the collected petroleum;
the pumice is transported to storage or for laying out again.
2. Method according to claim 1, characterised in that pumice is laid out upon a contaminated water surface as an aggregate to a flow of water where water and pumice are discharged together via a jet pipe.
3. Method according to claim 1, characterised in that pumice is laid out upon a contaminated water surface as an aggregate to a flow of air where air and pumice are discharged together via a kind of nozzle.
4. Method according to claim 1, characterised in that pumice is laid out upon a contaminated water surface from an aircraft, e.g. an airplane or a helicopter.
5. Method according to any of claims 1 to 4, characterised in that pumice is collected by a conveyor, the conveyor extending from a vessel and down at least a distance below the water surface from where the pumice is collected, where the conveyor includes one or more endless conveyor belts provided with meshes, e.g. constituted by a wire mesh, the meshes of the wire mesh having a dimension which is less than the particle size of the applied pumice, preferably having a dimension between 10 and 45 mm.
6. Method according to any of claims 1 to 5, characterised in that the collected pumice is heat treated by hot air, steam or water, whereby hydrocarbons are released from pores in the pumice and collected in the form of liquid or vapour.
7. Method according to claim 6, characterised in that the collected and cleaned pumice is immediately further transported for re-laying on the contaminated water surface.
8. Method according to claim 6, characterised in that the collected and cleaned pumice is transported to a storage container.
9. Method according to any of claims 1 to 8, characterised in that the laid-out pumice is collected by a vessel which is navigated with circling movements at the outskirts of the contaminated area, and that the vessel is navigated in a spiralling movement towards the centre of the contaminated area as the laid pumice is collected.
10. Method according to any of claims 1 to 9, characterised in that the collected and cleaned pumice is re-laid in the area around which a vessel is navigated with circling, spiralling movements.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP12767720.1A EP2694742A4 (en) | 2011-04-06 | 2012-04-10 | Method for oil spill collection on water |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
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DKPA201170161 | 2011-04-06 | ||
DKPA201170161 | 2011-04-06 | ||
DKPA201170749 | 2011-12-22 | ||
DKPA201170749 | 2011-12-22 |
Publications (1)
Publication Number | Publication Date |
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WO2012136225A1 true WO2012136225A1 (en) | 2012-10-11 |
Family
ID=46968625
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/DK2012/050116 WO2012136225A1 (en) | 2011-04-06 | 2012-04-10 | Method for oil spill collection on water |
Country Status (2)
Country | Link |
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EP (1) | EP2694742A4 (en) |
WO (1) | WO2012136225A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8968570B2 (en) | 2012-11-06 | 2015-03-03 | Oil Clear Europe Ltd. | Floatable oil absorber, its uses, and its method of manufacture |
US9719226B2 (en) | 2012-05-04 | 2017-08-01 | Oil Clear Europe Ltd. | Floatable oil absorber |
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US3734294A (en) * | 1971-01-15 | 1973-05-22 | J Zerbe | Pollutant recovery system |
US3752762A (en) * | 1971-04-05 | 1973-08-14 | J Cincotta | Apparatus for removing oil from oil contaminated water |
DE3142275A1 (en) * | 1981-10-24 | 1983-05-05 | Aktiengesellschaft für Steinindustrie, 5450 Neuwied | Environmentally friendly method of collecting and separating oil from water surfaces |
US5490940A (en) * | 1994-04-08 | 1996-02-13 | Exxon Production Research Company | Method for forming mineral solids-oil floccules |
US20030225211A1 (en) * | 1997-01-10 | 2003-12-04 | Rink Glenn R. | Process of forming oil-absorbent bodies |
Family Cites Families (3)
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DE2046395A1 (en) * | 1970-09-19 | 1972-03-30 | Strabit-Werke Gmbh, 5450 Neuwied | Binder for oil and organic solvents and process for their preparation |
FR2870753B1 (en) * | 2004-05-28 | 2007-04-20 | Camp Jean Pierre | PIERRE PONCE WITH CARBON CONTENT, PROCESS FOR PRODUCING THE SAME AND APPLICATIONS THEREOF |
FR2936960B1 (en) * | 2008-10-13 | 2012-10-05 | Ecopomex S A M | ADSORBENT PRODUCT FOR THE DEPOLLUTION OF HYDROCARBONS, IN PARTICULAR IN WATER PLANTS, AND METHOD OF OBTAINING AND USING THE SAME |
-
2012
- 2012-04-10 WO PCT/DK2012/050116 patent/WO2012136225A1/en active Application Filing
- 2012-04-10 EP EP12767720.1A patent/EP2694742A4/en not_active Withdrawn
Patent Citations (5)
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US3734294A (en) * | 1971-01-15 | 1973-05-22 | J Zerbe | Pollutant recovery system |
US3752762A (en) * | 1971-04-05 | 1973-08-14 | J Cincotta | Apparatus for removing oil from oil contaminated water |
DE3142275A1 (en) * | 1981-10-24 | 1983-05-05 | Aktiengesellschaft für Steinindustrie, 5450 Neuwied | Environmentally friendly method of collecting and separating oil from water surfaces |
US5490940A (en) * | 1994-04-08 | 1996-02-13 | Exxon Production Research Company | Method for forming mineral solids-oil floccules |
US20030225211A1 (en) * | 1997-01-10 | 2003-12-04 | Rink Glenn R. | Process of forming oil-absorbent bodies |
Non-Patent Citations (1)
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9719226B2 (en) | 2012-05-04 | 2017-08-01 | Oil Clear Europe Ltd. | Floatable oil absorber |
US8968570B2 (en) | 2012-11-06 | 2015-03-03 | Oil Clear Europe Ltd. | Floatable oil absorber, its uses, and its method of manufacture |
Also Published As
Publication number | Publication date |
---|---|
EP2694742A4 (en) | 2015-11-25 |
EP2694742A1 (en) | 2014-02-12 |
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