JPS5864103A - Method and apparatus for separating oil from water - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This E! The present invention relates to a method and apparatus for separating oil from AFi water.

The present invention comprises passing a water stream containing preferably 1000 p% or less oil on a weight basis through an oil-absorbing bed, the absorbing bed having at least a perforated body through which water passes; The oil-absorbing coating has an oil-absorbing coating on the surface.
The latex particles generally consist of deposits of absorbent latex particles, which are oil-swellable and oil-insoluble;
A# The amount of the oil-swellable latex particle coating film is such that when swollen with oil, its volume is sufficient to block all internal gaps in the porous body and prevent passage of water flow. be.

This BAFi is also permeable to the water that lies horizontally in the water flow and Ochoba canal, but it is in a sealed connection with the headrace, so the water flowing in the canal has no choice but to pass through it. 1000J water flow based on the weight of the pore absorption bed
lptx i In an apparatus for removing oil from an oil-containing water stream that does not exceed i, the coating has a latex coating of an oil-absorbing polymer on the surface of a porous body, and the coating is in contact with the oil and has a wet film volume of 2.
The present invention provides an improved device in which the coating film is swollen by a factor of 50 to 50, and the swelling amount is sufficient to block the perforated body and prevent water flow from passing through. 'Oil' generally refers to organic liquids that are immiscible with water or do not dissolve more than 2 weight parts by weight in water at 25°C and atmospheric pressure. Such oils include, for example, kerosene, lubricating oil, gasoline, jet fuel, and There are petroleum oils such as fuel oil.Other oils include benzene, toluene, xene/, ethylbenzene; aliphatic hydrocarbons such as hexane, octane, dodecane, eicosa/, their positional isomers; cyclic hydrocarbons, e.g. cyclohexane, ethylcyclohexane; keto/classes e.g. 2-oftenone, 4-dobcenone: and chlorinated solvents e.g. 1,
1.1-) 'J dichlorothane and 0-dichlorobenzene.

The features and advantages of the present invention will become more apparent from the accompanying drawings and associated specification.

FIG. 1 is a schematic diagram of a filtration device according to the invention.

Figure 2IIIi is a partial cross-sectional view of a perforated body used in the apparatus of Figure 1;

FIG. 1 shows a device 10 according to the invention. Attachment, [1
0d has an integrated headrace or means 11 for dividing all the waterways. Headrace lit;! It has a vertically extending branch or means 12 which opens to the atmosphere and exhibits a corresponding pressure drop, and a thickened p-legal retainer 13t. A water flow 14 flowing in the direction of the arrow passes through the water conduit 11 . Water flow 141;j 1 million capacity parts of water! It is preferable to contain 71,000 parts by weight or less of oil or organic compound. The water conduit 11 is far from the branch pipe 12 at an enlarged portion 13
There are 15 exits at 9 positions next to the Multiple perforated filter elements 17
l) generally within the enlarged portion 13 of the headrace 11
It is in a sealing relationship with the leg portion of the enlarged portion 13 of. Adjacent to the branch pipe 12 is a perforated filtration holding net 18 such as a wire mesh. The second support net 19 is generally adjacent to the outlet section 15. As shown in FIG. 1, the perforated filter element 17 is generally disc-shaped and allows all of the water to flow therethrough.

Each perforated element 17 has a surface coating (not shown) of oil-absorbing latex which is oil-swellable, oil-insoluble and which covers the unswollen coating volume. It swells 2 to 50 times.

FIG. 2 illustrates a partial cross-section of filter element 25Q. The contact element 25 consists of a perforated body 26 with a number of narrow holes 427 and a number of internal gaps 28. Element 25 consists of a porous matrix 29 that is generally insoluble in water. Substrate 29 has an oil-absorbing coating 31t on its surface.

The oil-absorbing coating film 31 is an oil-swellable latex coating film having the aforementioned oil-swellability t. In operation of the apparatus and in carrying out the method of the invention, a water stream containing a small amount of oil passes through the water conduit 11, as indicated by the arrow in FIG. The water flow is discharged from the F;iM element 1 foot and the outlet 15 of the conduit. A small amount of oil in the water stream is latex # like coating film 31! Absorbed by one membrane.

Paint! When oil is added to it, s31 swells into a large number of swollen latex particles which aggregate into viscous droplets and are passed downstream of the filter element 17 to contact the unswollen coating. When the unswollen coating comes into contact with the highly swollen particles, it then takes up some of the oil and becomes agglomerated droplets or globules of viscous, oil-swollen latex particles of sufficient size to fill the PA's element, i.e. The internal gaps are sufficiently filled to allow water to pass through. P groove element 17 19 If the water head in the branch pipe 12 rises and reaches a certain height, the water flow end is closed or the filter element 17 is unswollen latex coating film t toward another similar filter.
Exchange with the element that has. Book.

A wide variety of materials can be used as substrates for supporting oil-absorbing latex coatings in the practice of the invention. Preferred materials are flexible synthetic resins 7 ohms, such as continuous air polyurethane 7 ohms: polyethylene foam, polypropylene 7 ohm, polybutene foam, polyvinyl chloride foam, polybutadiene foam, polyurethane 7 ohm, etc. Continuously creeping polyolefin forms and other rubber forms. Other materials useful as substrates for coating with oil-absorbing latex include sand, vermiculite, bagasse, straw, sawdust, granulated petroleum and charcoal, coke, shredded car and truck tires, metal granules, glass granules and glass 7 ohms. There is. Woven or non-woven fabrics of natural or synthetic fibers are also suitable as substrates. For many uses, my text #'i is contained within a water stream.
A substrate that is not affected by organic liquids is desirable. This is especially true if the absorbent bed is exposed to a contaminated water stream for a relatively long period of time.

However, in many cases it is also possible to use substrates that are gradually disturbed by organic matter in the water stream. A typical example of this use is a filter, which constantly checks the pressure drop through the filter and quickly replaces the filter if it becomes clogged. It is generally important that the rate of swelling of the latex polymer coating is substantially greater than the rate of swelling or dissolution of the substrate. 7. For applications where substrates that are sensitive to machine fluids are used, it is generally desirable that the swellable latex polymer swell at least twice the rate of swelling or dissolution of the substrate.

Latex polymer latexes useful in the practice of this invention may be any polymeric latex that swells on contact with mineral oil. Convenient latex polymers swell upon contact with water. However, further swelling is required when it comes into contact with the oil or organic material to be removed. The choice of polymer for use in the oil or organic liquid can be easily determined by examining the swelling index in the particular liquid in which the latex polymer particles are immersed or absorbed. This swelling index can be conveniently determined by immersing the latex polymer in the desired oil or organic liquid and measuring the total volume per unit weight of the latex polymer after 30 minutes in water and oil. The volume ratio per unit weight with organic liquid and without oil or organic liquid is the swelling index. 1 if the polymer dissolves
The 1N index becomes infinite. If the swelling index is greater than 1.2, the polymer particles are suitable for practical use in the present invention. A swelling index of at least L5, preferably 3 or higher, is desirable for most applications. It is important in the practice of this invention to use cross-linked polymers that swell but do not dissolve. Polymers are suitable for use in the present invention if they swell in the presence of organic liquids and water. However, in most cases the swelling index is between 1.5 and 50,
It is desirable to use polymers that are sufficiently cross-linked, preferably having a cross-linking ratio of 3 to 50. A variety of polymeric materials are conveniently used, including styrene and substituted styrenic polymers: polyvinyl chloride copolymers of vinyl chloride, such as copolymers of 60% by weight vinyl chloride and 40% by weight vinyl acetate; Polymers and copolymers of vinylidene chloride, including copolymers of 75-vinylidene chloride and 25-acrylonitrile; acrylic polymers such as methyl methacrylate, ethyl acrylate, etc. be. Generally the chemical composition of the polymer is not critical. The polymers need to exhibit significant swelling properties, i.e., they need to increase in volume by at least 20% in at least 10 minutes in the organic liquid that the polymer must accommodate under the desired operating temperature and pressure conditions. be. Particularly good materials that are compatible with a wide variety of organic liquids are styrenic polymers, such as polystyrene and polymers of styrene and up to 10% by weight divinylbenzene. Alkylstyrene polymers and copolymers are particularly advantageous for general use of aliphatic and aromatic hydrocarbons. The alkylstyrene polymers swell very quickly on contact with aliphatic and/or aromatic hydrocarbons. Generally, the faster a polymer swells, the faster it shuts off when it comes into contact with a liquid. Usually alkylstyrene polymers and copolymers exhibit substantial swelling within one minute when contacted with so-called muk diesel oil.

Cross-linked polymers and copolymers of styrenes, especially tertiary-alkylstyrenes, are preferably used as absorbent latex polymers in the process of the invention. All of these polymers are readily available alkylstyrenes containing 4 carbon atoms.
Those having an alkyl group having 20 to 20, preferably 4 to 12 t-groups, such as tertiary-alkylstyrenes, n-alkylstyrenes, 2-alkylstyrenes, in-alkylstyrenes, and copolymers thereof. There is.

Particularly preferred for use in the practice of this invention are alkylstyrenes such as those described above and cross-linked copolymers with alkyl esters made from Cl-024 alcohol and acrylic or methacrylic acid or mixtures thereof. .

Suitable monomers that can be used as comonomers with alkylstyrenes include, for example, vinylnaphthalenes, styrene, vinyltoluenes, α-methylstyrene, ring f-substituted &-methylstyrenes, halostyrenes, aryl-styrenes, etc. and alkaryl styrenes: methacrylic esters, acrylic esters, 7-maleate esters and half-esters, maleate esters and half-esters, itaconate esters and half-esters, vinylbiphenyls, These include vinyl esters of aliphatic carboxylic acids, alkyl vinyl esters, alkyl vinyl ketones, α-olefins, isoolefins, butadiene, imprene, dimethylbutadiene, acrylonitrile and methacrylonitrile.

The latex polymers used in the method of the present invention include
Preferably, the amount of crosslinking agent is 0.01 to 2% by weight. The most effective absorption of oil and organic liquid impurities occurs when the cross-linking agent is present at less than 1% because the polymer readily swells and absorbs substantially all of the organic material by volume. When water containing an organic liquid is passed through an absorption bed with a T-25 volume Thilatex polymer coating, up to 2% cross-linking can be avoided since such an operation allows for a low volume of organic material to be absorbed into the polymer. Agents are also suitable.

Cross-linking agents that can be used to prepare absorbent latex polymers suitable for use in the present invention include, for example, divinylbenzene,
Diethylene glycol dimethacrylate, diisopropenylbenzene, diisopropenyl diphenyl, diallyl maleate, diallyl phthalate, allyl acrylates, allyl methacrylates, allyl heptamalates, allyl heptamalates, alkyd resin types, butadiene or Crosslinking in polyethylene unsaturated compounds such as isoprene polymers, cyclooctadiene, methylene norbornylene, divinyl 7-thaleates, vinylisopropenylbenzene, divinylbiphenyl, and vinyl adduct compositions of these polymers. There are other di- or poly-reactive compounds known to be used as agents. Latex polymers containing cross-linkers usually swell due to absorbed organic substances. If there is an excess of crosslinker, absorption will take an unreasonably long time and the latex polymer will not be able to absorb enough organic liquid to fill the interior spaces of the filter bed.

If the absorbing polymer contains too little of the cross-linking agent, the polymer will eventually dissolve in the organic material, e.g., forming a continuous non-particulate mass of polymer-rich organic liquid, which effectively blocks water flow. It will not stop.

The polymers for use in the present invention are prepared by emulsion polymerization techniques, preferably polymerized with free radical catalysis. For most applications, the latex used in the practice of this invention should have a particle size reaction force of 2000 A, although latex with smaller and larger particle sizes can also be used.

Example 3 70% by weight of butyl styrene, 20% by weight of 2-ethylhexyl acrylate, 10% by weight of mixed methacrylate esters of alcohols from cetyl to eicosyl.
0.075 parts by weight of a 1:1 mixture by weight of divinylbenzene and diethylbenzene based on the above 3 parts by weight - 0.5 parts by weight of potassium persulfate based on the weight of active monomers (ROM) Weight part, same ROM
1 weight of sodium bicarbonate on a weight basis - 1 weight of a mixed long-chain sodium chloride surfactant based on the weight of the same ROM 2 weight of a surfactant St - 70 parts by weight of water containing oil absorbency Manufactured latex tube. The polymerization reaction was carried out as follows: 20% water containing potassium persulfate and sodium bicarbonate and 2 weights of the total monomer mixture were added to the reactor.

Stir the reactor and heat to 80°C for 30. It was heated for a minute. At this point, the remaining monomers and a 1N aqueous solution of potassium persulfate and sodium bicarbonate were added at a constant rate over 5 hours. After the addition was complete, the reaction mixture was further stirred at 80° C. for 1 hour. The container and contents were then cooled to T-35C. The reaction mixture was filtered to remove coagulum. Particle size approximately 100011-4 solid 2
8.2% latex was obtained. This latex has a diameter of 3
v2 inch (8,9cm), thickness rabbit inch (0B3Sc
nl) was used to coat a number of continuous air #1 polyurethane plates. The board was soaked in latex, the excess latex was squeezed out, and the board was dried at 80° C. for 16 hours to form a coating. Various coating weights were applied onto the polyurethane foam by repeating the dipping, pressing and drying method. Polyurethane foam is 1.7 bonds/cubic foam) (27,234/j
) with a density of 41 ± 5 holes per inch (2,54 m) and a water pressure of A inch (1,27 CI11).
inch square (25,8m), A inch (0,635eN
1) 8 cubic feet/min (22 & 5:
A number of experiments were carried out using urethane boards with various latex coating weights and uncoated boards having an air flow rate t of 1/min). The equipment used is generally as shown in Figure 1, and the waste water that is passed through is water containing fuel oil. The test equipment was fed with 25 gal hours (94,64 tons) of mercury and 25 mg/hour of A2 fuel oil. Water-oil mixture is mixed with water and oil using a propeller-type stirrer to finely disperse the oil in the water before entering the seven-hole filter plate. The experiment was terminated if the oil rose to a height of 9z) or if the oil clearly passed through the offshore plate. A 7-ohm urethane plate without a urethane coating was first used. The water head after 1 hour in branch 12 was approximately 3 inches (7,6261+) high, at which point surface oil appeared in the drain water. Using a board with a coating weight of 23.8 inches of Queen Latex, the initial wood head was approximately 5 inches (12.7 inches).
cIl), but after 2.5 hours the tree head was about 6 inches (
Surface oil appeared in 15 and 24 countries). Then the latex body 59.7 weight 133.5 weight - and 55.5 weight
Three types of plates with a membrane weight t of % by weight were used. Approximately 3 hours 1
Utex solids 59.7 and 55.5 weight after 0 minutes - 31 water without passage of fuel oil in the coating plate! [48 inches (
121.9aw). 33.5 gb of latex solids coated urethane 7 ohm was mixed with 1 g of water a little over 3 hours ago.
48 inches 0■, 9a11). In all cases a small but unmeasurable amount of DuPont Oil Red A (
Oil-soluble dyes) were added to the fuel oil to aid in measuring the oil distribution in the coated foam slabs.In each case when the water passed through the latex coated foam sample, no oil was observed and 9, i.e., throughout the red IIi filter bed. It did not spread and no oil was detected in the wastewater either by odor or taste.

Since there are a wide variety of organic materials, oil-absorbing latexes, and substrates that can be separated from water using the present invention, if you wish to test the suitability of combinations of organic materials, latex and substrates, and latex coating weights, A convenient method for determining the suitability of combinations is to add organic liquids, which are removed from a stream of water, by dropwise addition to a 6 inch (15,25 um) thick coated bed. It is convenient to add dyes to such experiments that readily indicate the presence of organic liquids in the bed. 6 inches (15,2
The combination is suitable for the practice of the present invention, provided that the organic liquid is not passed through a filtration bed of 4 m) and a Freundsch (15,24 m) head.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a filtration device according to the present invention. 11...- Water conduit, 12... Branch pipe, 13-
...-Legal holding section, 14.--Water flow, 17.
...-filtering element, FIG. 2 shows a partial sectional view 1 of a perforated body used in the device of the invention. 25...Filtering element, 26-...Porous body, 2
g ------- Internal gap, 29... Porous substrate, 31... Oil-absorbing coating film.

Claims (1)

[Claims] 1. Passing a water stream containing not more than 1 OOOP% of organic liquid or oil on a weight basis through an oil-absorbing bed, the absorbing bed having at least a basic perforated absorbing bed through which water can pass. The porous body has an organic liquid or oil-absorbing coating on its surface, the coating consisting mainly of deposits of latex particles, the latex particles being organic liquid or oil-swellable and containing an organic liquid or an oil-absorbing coating. Fox skeleton latex particles made of oil-insoluble cross-linked polymers are capable of swelling in an organic liquid or oil to 2 to 50 times their unswollen volume, and the organic liquid or oil-swollen latex coating is The amount of the membrane is such that when swollen with the organic liquid or mineral oil, its volume is sufficient to close the internal gaps in the pores and prevent the passage of water flow. How to remove oil. λ The method according to claim 1, wherein the porous body is a non-granular body. 3. The method according to claim 1, wherein the porous body is a granular body. 4. The method according to claim 1, comprising the step of monitoring the pressure drop through the perforated body t. 5. The method according to claim 2, wherein the perforated body is a continuous plastic foam. 6. A water flow channel and a foundation that is located laterally within the channel, is permeable to water, and is in a sealed connection with the water channel, so that water flowing within the channel must pass through it. The porous body constituting the absorbent bed has an organic liquid or oil-absorbing coating on its surface. 2-50 of volume
It consists of a latex coating of an organic liquid or oil-absorbing polymer that swells to double, the amount of which is sufficient to block the porous body and prevent water flow when swollen. water flow, preferably l 99023 m on a weight basis
Apparatus for removing organic liquids or oils from water streams containing the following organic liquids or oils: 7. The device according to claim 6, wherein the porous body is a non-granular body. 8. The device according to claim 6, wherein the porous body is a granular body. 9. The device of claim 6, further comprising means for indicating the pressure drop through the perforated body. 10. The device of claim 6, wherein the perforated body is a 7 ohm plastic material.