CA2705455A1 - Absorbents and filters for recovering spilled oil and oil in water - Google Patents

Abstract

Oil spills are disastrous to environment and energy resources. Residual oil in produced water after traditional oil/water separation and treatment in oilfield production incurs environmental and energy resource problems too. This invention is on the application of styrofoams, foam peanuts, PE, PET
and related centrifuge, squeezable filters to recover the spilled oil on land and in water, and to recover the residual oil from the oilfield produced water in any process of oil production. This invention will bring enormous benefits to environment protection and energy resource reservation.

Description

Absorbents and Filters for Recovering Spilled Oil and Oil in Water Zhong(Gilbert) Chen Douglas R.Flaig Lucy Pu Amy Chen May, 29th, 2010 T-Win Enhanced Oil Recovery Technologies, Ltd 165 Millrise Close, SW, Calgary, AB, Canada, T2Y 2T4 Specifications The general character and nature of this invention This invention relates to the materials and apparatus to clean and recover the oil from the oil spills on land and in water. Also, this invention relates to the materials and apparatus used to recover the residual oil in produced water in the process of produced fluid separation and treatment in the oilfields.

The background of this invention Nobody doubts that oil spills on land and in water are always notorious disasters threatening the environment and energy resources. We are taught a good lesson again after this year's huge oil spill in the Gulf of Mexico. How to contain the oil spills, recover the huge amount of spilled oil and reduce the environmental affect to the lowest level is what we have been seeking since the birth of oil and gas industry. Another problem hanging on oilfield engineers is the separation of oil from water in the produced fluid. Especially in the processes of chemical flooding and other related enhanced oil recovery processes, even after the costly fluid separation and water treatment, a few hundred ppm residual oil still left in the treated water, which causes chronic environment and resource reservation threats. How to recover the residual oil in the treated water is what the oil and gas industry has been trying to achieve since last century.

On the other hand, with respect to the styrofoams and foam peanuts, different styrofoams and foam peanuts are widely utilized in packaging and insulation purposes. From the statistics data in the presentation by Professor Andrea Kremer, 2003, the annual consumption of styrofoams only in the U.S.A alone reached 1369 tons. Because of the extra light density, styrofoams take 30% of the whole landfill volume. However, it takes over half a millennia for styrofoam to get decomposed.
Incineration is not a good way to dispose the styrofoams either because over 90 hazardous chemicals are released from the burning in vapours and dioxins. In a word, it is troublesome to dispose styrofoams world wide. Some better ways to recycle and re-use styrofoams should be found.

The inventive ideas and tests Oil spill and high residual oil in treated water has been beleaguering me for a long time. I did many oil removal tests using traditional walnut shell grains being applied in oilfield filters to treat produced fluid, feathers, claimed oil only particulates from some related manufacturers and service companies, and styrofoams and foam peanuts during the last two years.
Comparatively, the styrofoams and foam peanuts are far the best to adsorb and remove the oil under complex fluid conditions. At the same time, the wide application of this invention will help the recycle and re-use of the previously troublesome styrofoams and foam peanuts. These test results stimulate me to perform comprehensive patent data base inquiry and file the application for this invention to use styrofoams and foam peanuts to solve those problems.

Previous inventions related to similar articles and processes In order to find related technologies and patented inventions, Canadian Patent Database was inquired by inputing the following key words:

Remove Oil: 76 patents with some related information are listed and compared;
Oil Spill: 90 patents with some related information are listed and compared;
Styrofoam: 154 patents are listed and compared;

Filter: 1000 patents are listed and compared;

Centrifuge Filter: 16 patents from 2,031,727 are listed and compared;
Foam peanuts: 1 patent out of 2,031,727 is listed.

From the comprehensive Patent data base inquiry using those key words, no invention or patent states or claims the utilization of styrofoams and foam peanuts to adsorb oil to solve oil spills and the residual oil problems in oilfield produced water. The following are the patented inventions which are most close to our invention in terms of concepts, materials and apparatus designs:

CA2101573: Filed on 1993-07-29, Issued on 1997-10-07 APPARATUS FOR CLEANING STRIPS BEFORE PRESS FORMING, HAVING DE-OILING ROLLS
AND TACKY ROLLS TO REMOVE OIL AND FOREIGN MATTERS. This patented invention deals with de-oiling rolls and tachky rolls to remove oil and foreign matters, which is quite different from our invention.

CA2085746: Filed on 1990-06-25, Issued on 1996-09-03 APPARATUS AND METHOD FOR REMOVING OIL SPOTS FROM A SURFACE. This patented invention deals with an apparatus to rub some materials on oil contaminated surfaces to remove the oil, which is quite different from our invention.

CA2622814: Filed on 2006-09-18, not issues yet.
REMOVAL OF OILS FROM SOLID SURFACES AND WATER WITH A SUBSTANCE
HAVING A HIGH HUMATE LEVEL. This patented invention deals with using a substance like the manure having a high humate level to remove oil from solid surfaces and water, which is distinctly different from our invention.

CA2192514: Filed on 1996-12-10.
REMOVAL OF OIL FROM COMPRESSED GAS WITH MACROPOROUS POLYMERIC
ADSORBENT The invention talked about using many polymeric adsorbents to remove oil from the compressed gas. The process was stated in the patent and quite different from our processes and utilization areas. In addition, the adsorbents do not include polystyrene based styrofoams and foam peanuts.

CA1074707: Issued on 1980-04-01.
MOVING BELT-TYPE OIL SKIMMER WITH PROPULSION INDUCED FLOW. The invention deals with moveing belt-type oil skimmer design. No claims were stated for the adsorbent materials.

CA2211589: Filed on 1997-08-13.
POLYURETHANE FOAM CLEANING PAD AND ABSORBENT PARTICLES Claimed detergent and clay minerals in the rigid closed wall cell polyurethane foam to adsorb oil, not the polystyrene based styrofoams and foam peanuts.

CA 2072640: Filed on 1990-1-09.
OIL RETRIEVER AND METHOD OF USE THEREFOR
CA1133833: Filed on 1979-09-20.
METHOD AND APPARATUS FOR DEALING WITH OIL SPILLS -Feather bags are the key materials claimed to remove the oil spills.

CA1089659: Filed on 1979-01-25.
ANTI-POLLUTION BOOM. No claims were made on the materials in our invention.
CA2675295: Filed on 2007-12-07.
FLOATING DISPERSANT PASTE
An agent and a method for dispersing spilled oil, particularly on a body of water. The compound is a viscous dispersant liquid comprising a mixture of surfactants and a viscosifying agent.
CA2485279: Filed on 2004-10-19.
METHOD AND APPARATUS FOR OIL SPILL CONTAINMENT. The methods, apparatus, substances are quite different from those in our invention.

CA2102531: Filed on 1992-05-08.
OIL SPILL RECOVERY METHOD AND APPARATUS. Claimed the use of poly-olefin selected from the group consisting of propylene and ethylene polymers and copolymers, which is quite different from our invention.

CA 998622: Filed on 1976-10-19.
OIL SPILL RECOVERY
An article of manufacture for use in the removal and recovery of oil slicks or spills floating on the surfaces of water bodies consisting essentially of an ethylene-alkyl acrylate copolymer having a melt index at least of 800. The invention is quite different from our invention.

CA2248156: Filed on 1997-03-26 OIL-SORBING ARTICLE AND METHODS FOR MAKING AND USING SAME. Cellulose-base material is used as the absorbent. The invention is quite different from our invention.

CA2007534: Filed on 1990-01-10.
OIL ABSORBENT. An oil degradation compound, comprising a mixture of a carrier, namely flour, a first oil-reactive agent, namely dry powdered mustard is used to make a paste to remove oil spill on land. The invention is quite different from our invention.

CA2338309: Filed on 2001-02-26 REMOVAL OF HYDROCARBON POLLUTANTS. Claimed the use of bird feathers. The invention is quite different from our invention.

CA2573212: Filed on 2005-07-18.
WATER PURIFICATION SYSTEM AND METHOD. An oxidation filtration system for cleaning groundwater, the system having an aeration tower and a filtration tank. Within the filtration tank is an upper chamber and a lower chamber. Contained within the lower chamber is a plurality of Styrofoam (tm) filter media. Separating the upper chamber from lower chamber is a filter media mask which keeps the filter media from entering into the upper chamber. The aerated water from the aeration tower enters into the base of the lower filter chamber and rises through the filter media into the upper filter chamber. As the water passes through the filter media, the dissolved solvents fallout of the groundwater and attach themselves to the Styrofoam (tm) media.
An automated back flushing and clarifying process is also provided using a back flush port and a clarification port, a higher level water sensor in the aeration tower and a programmable logic controller. The controller opens and closes the back flush and clarification port depending on the settings within the resident software, the controller interfaces with a remote computer to remotely operate the back flushing, clarification and filtering of the groundwater. The controller receives signals from the sensor to determine emergency back flushing requirements. The controller operates at a minimum one, and maximum five oxidation filtration systems at one time.

The claimed use of Styrofoam is for filtering oxidized solid particulates, solvents in the treatment of groundwater. This has nothing to do with oil adsorption and removal in oil spills or any application to remove residual oil from the treated produced water in the oilfields. Therefore, the invention has nothing to do with our invention either.

In this invention "Absorbents and Filters for Recovering Spilled Oil and Oil in Water", the polystyrene based styrofoams and foam peanuts are used as the absorbents to adsorb the oil on land, on surface of water and in water. The polystyrene styrofoams and foam peanuts have the spectacular characteristics of strong hydrophobicity, very light density to float ever on water surface, recyclable and reusable for the oil adsorption and recovery purposes by squeezing and centrifuging. In order to improve the oil adsorption and recovery efficiency substantially, the styrofoams and foam peanuts can be manufactured into any shape, smaller particle size. In order to prevent those particles floating away, the styrofoam and foam peanuts particles can be packed into any fabrics with small holes to let packed particles contact oil as much as possible. Any shapes are possible: boom, blanket, pad, sheet and so on to adsorb the oil from water bodies. After the oil adsorption, the packed particles can be squeezed and centrifuged to recover the oil. On land, in order to remove the oil contaminating the soil, the styrofoams and foam peanuts, particles, chips of any shapes and sizes can be mixed with the oil contaminated sand or soil to adsorb the oil and any other organic solvents. After that, the mixture of sand, soil and oil saturated particles are dumped into water tank. The low density particles, chips are floating on the surface of water and can be collected to be squeezed and centrifuged to recover the oil and other hydrophobic solvents.
To adsorb and recover the residual oil from the treated produced water in oilfields. The styrofoams and foam peanuts can be designed as skimmer to remove oil from water surfaces in tanks or vessels. The second application method is to replace the traditional walnut shell filter, let the oily water flow through the absorbents, down flow is much better. Of course, up flow is ok too. The filter tank can be designed (Figure 1) with screens at the top and at the bottom to prevent absorbent particles from escaping. At the same time, the screens can be designed as movable contact with pistons to squeeze the absorbents when necessary. The whole filter tank can be designed to rotate to recover adsorbed oil by centrifuging. Furthermore, in order to recover the residual oil and filter out solid particulate in produced fluids in oilfields, absorbents can be packed in a joint pipe with screens on both ends. The joint pipe can be easily replaced when necessary.

Density, adsorption tests and results:
Comparison test materials: Walnut shell grains, foam peanuts, styrofoams.
Quantitative tests were performed for foam peanuts and styrofoam chunks.

Step 1: Density measurement and test (Table 1) For walnut shell grains: Density was not measured. However from picture 1, it is easily seen that walnut shell grain is heavier than water and easily to become water wet and adsorb water on grain surfaces and sink to the bottom (Picture 1).
For foam peanuts and styrofoams:
The density of water at room temperature 22 Celsius degrees is about 133 times to 178 times of the density of the foam peanuts. The density of water at room temperature 22 Celsius degrees is about 30 times to 40 times of the density of the styrofoams.

Step 2 The adsorption tests of water(Table 1) After pushing the styrofoam and foam peanut chunks into water and taking out the chunks, the free water on chunk surfaces was removed. The weight was measured and adsorption ratio rates to the dry weight were calculated. The data in table 1 demonstrated that the water adsorption rates to dry weights of both foam peanuts and styrofoam chunks are lower than 1Ø Namely, one time of chunk weight water can at most be adsorbed on the chunk surfaces (Pictures 2, 3, 4, 5) of the peanuts and styrofoam chunks.

Table 1 Density, water adsorption and oil adsorption rate tests sample Dry Wet Watercup/g Foam pushed Chunk Density 1 i Oil adsorption ratio weight/g weightlg in water/g Volume/cm3 g/em3 Foam 0.06 0.12 110.91 121.50 1059 10.00566 (0.92-0.06)/0.06=14.33 peanut1 P1070770 P1070772 P1070765,1070768 Foam 0.04 0.07 89.62 94.95 5.33 0.0075 (0.75-0.07)/0.04=17 peanut 2 Styrofoam1 0.43 0.59 90.21 104.94 14.73 0.029 (1.52-0.59)/0.43=2.6 Styrofoam2 0.36 0.44 70.32 84.05 13.73 0.026 Not tested Step 3: Static oil adsorption test After obtaining the water adsorption rate for the foam peanut and styrofoam chunks, the chunks were pushed into actual oilfield crude oil. Then the chunks were taken out and free oil on chunk surfaces was removed. Total weights of the chunks with adsorbed oil on surfaces were measured.
The calculated oil adsorption rate for the foam peanut chunk reached 15 to 17 times of the dry weight (Picture 6). For the styrofoam chunk, the oil adsorption rate reached 2-3 times for the big chunk.
For the walnut shell grains, the qualitative tests demonstrated that the walnut shell grains tend to be water wet and can not adsorb crude oil on surfaces as much, or as tight as the foam peanut and styrofoam chunks. Even after agitation the mixed crude oil, walnut shell grains and water in the cups, pictures showed that oil droplets existed between walnut shell grains.
On the surface, you can see the clean walnut shell grains floating beside the crude oil patches. The walnut shell grains do not help adsorb the crude oil from water much (Pictures 7, 8, 9).
Further tests demonstrated that, even placed in complex produced alkali-surfactant-polymer solutions for over three weeks, the adsorbed crude oil on foam peanut and styrofoam chunks were not released from the chunk surfaces. These investigation results proved that foam peanut and styrofoam are far superior to walnut shell grains to adsorb the crude oil. If cut into much smaller particles, the oil adsorption efficiency will be improved by magnitudes because of significant increase of the specific surface ratio of absorbents (Picture 10).
The claimed oil only particulates were used for the qualitative oil adsorption tests too. Results demonstrated that the claimed oil only particulates turned into wet and saturated with water; then sank to the bottom after several hours contact with pure tap water. In complex produced Alkali-surfactant-polymer solutions, the claimed oil only particulates turned into water wet and became water saturated and sank to the bottom in a few minutes. It is worth pointing out that the chemical component of those claimed oil only particulates is polypropylene, which is the same for many other commercial booms, socks and sheets for oil spill removal (Pictures 11, 12).

Step 4: Dynamic filtration and oil adsorption test Qualitative tests were performed by placing dry walnut shell grains, smaller foam peanut chunks and styrofoam chunks into transparent PET bottles. Mixed crude oil and water fluid was poured into the absorbent packed bottles. The test pictures demonstrated that the foam peanuts and styrofoam absorbents trapped the crude oil in the tap water completely, and trapped the residual oil in complex produced alkali-surfactant-polymer solutions at least 95% even though the particle size was not small enough and the absorbents already trapped much oil from the flowing mixed complex fluids (pictures 13, 14, 15, 16, 17, 18). However, for the walnut shell grains, even the dry grains trapped some crude oil; the trapped crude oil was released from the trapped pore space each time when new water solution was added into the filtration bottle. The crude oil was not actually adsorbed on the grain surfaces tightly (pictures 8, 19, 20, 21), but only trapped in the inter-granular pore space. Poorer oil filtration and adsorption is inevitable because of the much higher pressure gradients in actual field situations.

Another discovery found out in the tests of this invention is that the plastic cups, namely the PE, or PET material adsorbed the crude oil very tightly. Adsorbed crude oil stayed on the inside surface very tightly during the several month observation period even in complex surface active solutions (Pictures 22, 23).

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Claims (6)

1. An oil absorbent is used. The key chemical component is one of the polystyrene based foam peanuts and styrofoams, no matter what the shapes and sizes of the substances will be.
These absorbents are applied in the claimed processes in claims 3, 4, 5, 6.

2. An oil absorbent is used. The key chemical component is one of the polyethylene (PE), polyethylene terephthalate (PET, PETE) and their derivative products, no matter what the shapes and sizes of the substances will be. These absorbents are applied in the claimed processes in claims 3, 4, 5, 6.

3. A squeezable or centrifuge filter or any other devices related are used, in which the absorbents claimed in claims 1 or 2, are packed or bedded in those devices.

4. Any one of above absorbents, devices, or any combination of above absorbents, devices is used to clean or recover the oil, solvent spills on land.

5. Any one of above absorbents, devices, or any combination of above absorbents, devices is used to clean or recover the oil, solvents spills in water bodies.

6. Any one of above absorbents, devices, or any combination of above absorbents, devices is used to recover the residual oil from produced liquid solutions in any processes of oil production in oilfields.