WO2008046660A1

WO2008046660A1 - Treatment process and unit for carrying out the process

Info

Publication number: WO2008046660A1
Application number: PCT/EP2007/009150
Authority: WO
Inventors: Christian Widmer; Edward Kosior
Original assignee: Christian Widmer
Priority date: 2006-10-20
Filing date: 2007-10-22
Publication date: 2008-04-24
Also published as: DE102007049962A1

Abstract

Treatment process for plastic waste floating on the sea surface or on other waters having the steps: skimming off the plastic waste; mechanical treatment of the plastic waste; dewatering the plastic waste; discharging interfering matter; pollutants such as DDT, PCB and materials of value such as PET; liquefaction and/or material utilization of the plastic fraction which is substantially freed from pollutants and materials of value.

Description

Description of the method of preparation and installation for carrying out the method

The invention relates to a treatment process for floating on the sea surface or other waters plastic waste and a system for performing this method.

The problem underlying the invention is described in a GEO article of March 2004, which is quoted below for the sake of simplicity:

"Between California and Hawaii, an almost closed, three million-tonne plastic carpet about the size of Central Europe has been produced, from world-wide production of 125 million tons of plastic annually." In this area of the North Pacific, Charles Moore of the Algalita Marine has According to the Research Foundation, every kilo of animal plankton now produces six kilograms of plastic waste, which is primarily found in the upper layers of the water, as is zooplankton, whose plant-based food the sun needs.

The reason for the garbage flood far away from human settlements are circular currents of wind and water. Climatically, the world's largest ocean between Japan and California is determined by trade winds: at the equator, hot air rises, is deflected by the earth's rotation westward, sinks cold again at about 30 degrees north latitude and flows back east in a compensatory movement. The circulating airflow also moves the water, slowly but steadily. A gentle vortex of gigantic proportions revolves around a center about 2000 kilometers northwest of Hawaii. According to the National Oceanic and Atmospheric Administration (NOAA), the garbage driving off the coasts of Asia and America is trapped in the Pacific mega-vortex for at least 16 years.

Not long enough to be decomposed; So far, most of the conventional plastics are not degraded by microorganisms. It can take up to 500 years before UV radiation and oxidation break down a toy duck into its molecules. Packaging remnants, coke bottles and plastic fishing nets are more than just an aesthetic problem. Animals erroneously consume smaller pieces of food and swallow the garbage. Especially seabirds, such as Laysan albatrosses, have often been seen stifling indigestible pieces of plastic. In addition, water-insoluble toxic substances such as DDT or PCB, which reach the sea via rivers, preferably accumulate on the surfaces of the floating material. Hideshige Takada, a geochemist at the University of Tokyo, found that the concentration of these substances on floating plastic particles is one million times higher than in the surrounding water. When fish "cull" the garbage for prey, they also ingest the toxins with the food. The higher the animals are in the food chain, the more the poison accumulates in the organism - and thus also ends up in people's food. "

In view of the problem described in this article, the invention has for its object to provide a treatment process to reduce a floating layer of plastic waste with reasonable effort. Furthermore, a facility for carrying out this treatment process is to be created.

This object is achieved in terms of the treatment process by the combination of features of claim 1 and with respect to the system by the combination of features of the independent claim 13.

According to the invention, according to the inventive concept, the plastic waste floating on the sea surface or other bodies of water is first of all skimmed off and mechanically processed. This mechanical treatment may include, for example, comminution, pre-dewatering and compaction of the plastic waste. In a further process step, the waste is dried and then or before it discharged pollutants, contaminants and recyclables such as PET-containing waste.

The remaining plastic waste, freed from pollutants and recyclables, is either recycled or liquefied and, for example, further processed into fuel.

In the case where the waste plastics from the sea surface are skimmed off, it is necessary to free the waste of salts or the like, in order to prevent the formation of chlorides or other in the further processing

To prevent pollutants. This "desalting" is preferably carried out by a washing process in which the washing water circulated and cleaned and desalted by a treatment plant. This wastewater treatment plant can also be used to clean condensate or press water from the drainage of waste.

The pollutants contained in the waste water, condensate or press water can be bound and disposed of by suitable methods, for example by sorption on activated carbon.

The resulting in plastic liquefaction fuel (heating oil, diesel ....) and non-condensable gases can be used to supply energy used in the treatment process plants, such as combustion of pollutants or in the mechanical treatment of waste, so that the treatment plant largely self-sufficient can be operated.

When skimming it may happen that living things, especially sea creatures is skimmed - these creatures are diverted via a separate sorting step and preferably returned to the water. In principle, these could also be used for further recycling - for example processing into foods.

The dewatering step described initially preferably contains in addition to a pre-dewatering, drying, which is performed at reduced pressure and relatively low temparature in the range between 100 and 200 ⁰ C, so that the risk of the formation of chlorides or other pollutants is minimized.

According to the invention it is preferred if the waste by means of a variety of

Skimmers or floating facilities are skimmed off and then forwarded for further processing to one or more floating or arranged on the mainland central stations on which the actual processing takes place.

The products resulting from the treatment, such as diesel, heating oil or recyclable plastics, are then transported away from the central station for further use.

Other advantageous developments of the invention are the subject of further

Dependent claims.

In the following, a preferred embodiment of the invention is explained in more detail with reference to schematic drawings. Show it: - A -

Fig. 1 basic idea of the process steps which are necessary to the

To remove plastic waste from the oceans and to recycle it without pollutants returning to the water;

2 shows a process model in which, after skimming and dewatering, a further treatment on the water as well as on the mainland can take place;

Fig. 3 shows an overall process, which has floating treatment plants with

Tank storage and storage bunker for solid recyclables includes. The produced liquid fuel, as well as the solid recyclables are then taken up by floating between the floating processing plants and the mainland transport vessels at sea and cleared ashore, and

Fig. 4, the problem solution for receiving and recycling the floating in the ocean mixed plastics (1). By rotation (1.1), the recovery fleet consisting of vessels with skimming, Vorentwässerungs-, and Vorzerkleinerungsvorrichtungen (2 and 3), positioned so that the plastic carpet always flows to the collecting fleet. The positioning can change seasonally and is supported by satellite monitoring through detection and GPS control. The precompressed material is stored in the ship bunkers and transported to one of the floating central processing stations (3.7). By docking (3.8) to the central station (4) the pretreated mixed plastics are handed over. The closed oval plastic garbage currently has a length of 3 ¹ 000 km and a width of about 2'00O km. For example, the recovery fleet (2 - 3.6) consists of approximately 12 vessels and at least 3 floating central stations (4 - 15) and covers a width of approximately 150 km and a length of approximately 400 km. Between the central stations (4 - 15) commute

Transport vessels (16) which transfer the recovered materials (10.1 / 5 and 7) to the mainland (17) and carry them to recycling (18). Plastic waste in the ocean contains mixed plastics such as:

PS, polystyrene mainly from packaging materials

PE, polyethylene and gas cylinders, canisters, containers, toys, PP, polypropylene transport baskets, packaging nets, pipes, shoes, sandals, foils etc.

Nylon, Perlon mainly present as fishing nets and garments

PVC Since PVC is heavier than water, most parts sink to the ground. But as composites, closed hollow bodies, as well as wrapped with other plastics, they remain in the plastic carpet as Schwimmgut.

PET Predominantly as a beverage bottle, this material is heavier than water and sinks filled with water. Since most bottles are closed, they drive along the water surface.

For plastic liquefaction, PVC has to be sorted out, as this material releases chlorides when melted and has highly corrosive properties, which can destroy the equipment and prevent the fuel from being used as fuel in the form of diesel fuel.

PET is not suitable for liquid fuel production, but as a raw material in recycling it is a sought after and valuable material with a high value added potential (for example for recycling as bottles for the beverage industry).

If there are sorted fractions when sorting PS, PE and PP, they could also be used as raw materials to create new products. However, these would have to be totally cleaned beforehand and the salt and chemical substances such as DDT or PCB should be removed. In the drawings:

1.1 Rotational movement of floating plastic waste.

2 Floating device for the removal of plastics from the sea.

Here, for example, the following options could be mentioned:

- Large-scale vessels from the fishery, equipped with trawl nets and intake bridges for the collection and pre-dewatering of mixed plastics.

- Extraction snorkel over cyclones which separate the plastic material from the water.

A catching device attached to the bow of the ship, comprising the plastic material introduced, e.g. with an elevator in the ship promotes and drains over the elevator (which consists of Lochsiebelementen), at the same time.

- Large-volume crane grab, which bring in the plastic waste from the ship.

- In 2003, when test images were taken with grippers attached to the helicopter, the plastic carpet was torn apart by the rotor pressure.

2.1 The brought in marine animals are sorted out and go:

2.2 Back to the water

2.3 In the recovery as food. However, this is not recommended in this environment with high levels of pesticides and toxins (see Geo Report, last paragraph).

3 Pre-treatment on the collecting vessel for drainage and reduction of the volume from approx. 200kg / m3 to 400kg / m3 and thus to increase the transport capacity by:

3.1 Reduction eg via rotor shears 3.2 Compaction eg in a baling press with the simultaneous effect that the mixed plastics are additionally dehydrated.

3.3 The waste water mixed with small plastic parts is subjected to sieving (3.4).

3.4 Screening system for the press water. In this case, plastic parts (3.5) are returned to the compaction (3.2).

3.5 Return of the plastic parts after the Waschwassersieb ung.

3.6 The salt water is returned to the sea after the sieving cycle.

3.7 Transport of plastic materials to a floating central station

3.8 docking to the transfer device and transfer of the plastic mixture e.g. with a device similar to a hay blower or Kornabsaugvorrichtung means of a centrifugal fan via a flexible pipe that blows or sucks plastic chips in the bunker.

4 Floating central station with treatment plant for the contaminated mixed plastics. From the intermediate bunker, the material is preferably supplied via a, not shown here suction treatment steps.

4.1 Crushing on preferably palm-sized pieces.

4.2 Washing in commercially available washing drums or washing systems, which are used in particular for the cleaning of plastic parts in a continuous process.

4.3 The drying is preferably carried out in a vacuum dryer at a process temperature of 100 to 200 ⁰ C at a negative pressure of up to 50 mbar. Through locks in the entrance and the exit area, this can

Drying process quasi be driven continuously. With a residence time of between one and three hours, not only the residual moisture is removed under the influence of temperature and negative pressure, but also the adhering pollutants such as chlorides and toxins pass through the vapor phase after cooling into the condensate.

4.4 In the separation of pollutants / recyclables the pollutants, such as wood, metal composites, by hand sorting and with electronic detection,

Aluminum, metal parts and cardboard separated and sorted material, so that the recyclable substances separated into:

5 PET material which is preferably compacted in a baler.

6 mixed plastics for recycling or conversion to liquid fuels.

7 mixed plastics which are recycled and compacted for transport in a baling press.

8 Storage of compact mixed plastics (7) and PET (5) in bunkers.

9 plastic liquefaction in a plant such as e.g. in the patent application DE 10 2006 039 824.6 is described. Their revelation is fully included in the

Disclosure of the present application. In this method, the mixed plastics (6) are melted by heat from 300 to 350 ⁰ C and the liquid supplied to a cracking reactor in which at 420-450 ⁰ C, the cracked plastics are expelled gaseous and cooled after passing through a distillation column via a quench and the resulting condensate is present as liquid fuel.

10 storage tank for the bunkering of the liquid fuel.

10.1 Supply of liquid fuel into the pollutant combustion plant

11 Seawater desalination plant for the production of washing water for the washing process (4.2)

12 Waste water treatment for the purification of waste water loaded with molten and pollutants from the laundry (4.2) and the condensate from the drying process (4.3) The toxic substances are bound to activated carbon, which is disposed of pollutant-free after reaching saturation in the incineration plant (14) , 12.1 Pollutants from the wastewater treatment plant (12)

12.2 Waste water from the washer (4.2) and the condensate from drying (4.3)

12.3 Return of purified water to the washing process (4.2)

13 Dirty and pollutant interim storage facilities from wastewater treatment (12.1) and pollutants (12.2) from the separation of pollutants / recyclables (4.4)

13.1 Contaminants and pollutants from the separation of pollutants / recyclables (4.4)

13.2 Supplying the pollutants of (13) into the combustion (14)

14 combustion of pollutants and supply of gases and liquid fuel from the storage tank (10) at a temperature of over 1,400 ⁰ C for residue-free combustion of all pollutants.

15 waste heat recovery from the incinerator (14) for the production of saturated steam (11.3) and hot water (11.2)

15.1 Supply of hot gases from combustion (14)

15.2 Hot water for the washing process (4.2)

15.3 saturated steam of 200 ⁰ C for the supply of plastic liquefaction (9) and their ancillary equipment with additional energy.

16 Transfer of liquid fuels (10.1) and compacted recyclables (8) from the floating central station (4) to transport vessels.

17 Transport to the mainland and unloading of liquids (10.1) and recyclable materials (5 and 7).

18 Recycling on the mainland of:

- liquid fuels (10.1)

- Plastics (5 and 7) In the middle of 2006, the weight of the plastic carpet was enriched to nearly five million tons. It is estimated that between 200,000 and 400,000 tons are washed in each year. In order to reduce this flotsam to one fifth within a realistic period of 15 years, 600,000 tons would have to be deducted per year. 600 million liters of liquid fuels could be produced from this annual amount (equivalent to 4.3 million barrels of heating oil at a raw-market price of more than € 344 million per year). With an operating time of 320 days / a, each of the twelve vessels (3 - 3.8) would have to fish around 160 tonnes per day and feed it to the floating central station, which has a

Processing capacity of min. 640 tons. Surprising calculations show that the construction of such a fleet, consisting of conversion of existing ships, will pay for themselves within five years and that the operating and maintenance costs will be around 150 million Euro / a. This means that gross profit will exceed € 2 billion over the next ten years of operation (excluding rising crude oil prices).

- 1

LIST OF REFERENCES

1 plastic waste in the ocean

1.1 Rotational motion, Megastrudel

2 skimming device

2.1 marine animals

2.2 Sea animals back into the water

2.3 Sea animals for food

3 pretreatment, drainage

3.1 Crushing

3.2 compaction

3.3 Sewage screening

3.4 Screening plant

3.5 plastic recycling

3.6 saltwater return

3.7 Transport to the central station

3.8 Material return

4 Floating central station

4.1 Crushing

4.2 Plastic laundry

4.3 Vacuum drying

4.4 sorting plants

5 PET material

6 mixed plastics for liquefaction

7 mixed plastics for recycling

8 Storage PET and mixed plastics

9 plastic liquefaction

10 storage tank

10.1 Liquid fuel

11 Seawater desalination plant

12 wastewater treatment

12.1 pollutants

12.2 Wastewater

12.3 Purified water

13 pollutant storage

13.1 Contaminants

13.2 Contaminants in combustion

14 pollutant combustion plant 15 waste heat recovery

15.1 hot gases

15.2 hot water

15.3 saturated steam

16 transport ship

17 Transport to the mainland

18 recovery on the mainland

Claims

claims

1. Treatment processes for plastic waste floating on the sea surface or in other waters, comprising the following steps:

- Skimming the plastic waste

- Mechanical treatment of plastic waste

- Dewatering the plastic waste

- Removal of contaminants, pollutants such as DDT, PCB, and recyclables such as PET

- liquefaction and / or recycling of the largely freed of pollutants and recyclables plastic fraction.

A dressing process according to claim 1, wherein the waste plastics are washed prior to dewatering to rid them of impurities and salts or the like.

3. Processing method according to claim 2, wherein the washing water is desalted and circulated.

4. Processing method according to claim 2 or 3, wherein the washing water and / or obtained in the dewatering condensate or press water is purified in a wastewater treatment plant.

5. Processing method according to one of claims 2 to 4, wherein contaminants contained in the contaminated wastewater, condensate or press water are bound and disposed of.

6. Processing method according to one of the preceding claims, wherein the liquefied plastic is mainly processed into fuels.

7. Processing method according to claim 6, wherein fuels and non-condensable gases are used for energy supply in a combustion of the pollutants or in the mechanical treatment of the waste.

8. Processing method according to one of the preceding claims, with the step:

- Sorting out of living things, in particular sea creatures, and return to the water, or reuse.

9. treatment process according to any one of the preceding claims, wherein the dehydration comprises a drying at reduced pressure and a temperature of less than 250 ⁰ C, preferably in the range between 100 and 200 ⁰ C.

10. The method according to any one of the preceding claims, wherein the waste plastics are skimmed off by means of one or more ships or floating facilities.

11. The method of claim 10, wherein the skimmed plastic waste is transferred to a floating central station for processing according to one of the above-described steps.

12. A method according to claim 10 or 11, wherein the ships or floating means are positioned so that the plastic waste moves towards them due to ocean currents.

13. Plant for carrying out the method according to one of the preceding claims, with

- a variety of floating equipment for skimming and pre-dewatering / compaction of the waste and with

- At least one central station for the treatment of waste, with a mechanical treatment stage, a washing device with wastewater treatment, a drying plant, a pollutant / waste material separation plant, a Kunststoffverflüssigungsanlage and storage for the processed and resulting materials.