JPH09255942A - Oil adsorbent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oil absorbent having excellent oil absorbing properties and sufficient strength by mixing hydrophobic carbonized woody fibers with short polyolefin fibers. SOLUTION: This adsorbent comprises 10-80wt.% hydrophobic carbonized woody fibers such as obtained by carbonizing at a temp. of 200-400 deg.C wood wastes, paper stock chips, chips of lumber from thinning, etc., and 20-90wt.% short polyolefin fibers (e.g. polyethylene, polypropylene). The adsorbent has a B oil adsorption of 6g/g or above and a water absorption of 1g/g or below and is used to treat oils contained in industrial wastewater, oil spilt by accident and to clean up oil mists, etc., produced from domestic life and industrial plants. The waste formed after an oil adsorption work can be easily disposed of.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil adsorbent, and more particularly to the treatment of oil contained in factory wastewater, accidental spilled oil, removal of oil mist generated at home or in a factory. It relates to an oil adsorbent used.

[0002]

2. Description of the Related Art Removal of oil suspended or suspended on the surface of water such as the sea, rivers, lakes and swamps, or removal of oil contained in air discharged from factories, business establishments and ordinary households, and air Therefore, various oil adsorbents have been proposed. Japanese Patent Publication 47-724
No. 2 and Japanese Patent Publication No. 60-6979 disclose oil adsorbents of various shapes such as fibrous, non-woven and bead shapes, which are made of synthetic resin such as polyolefin. However, although these oil adsorbents are effective in treating oil floating on the water surface and oil leaking on the floor, in order to remove suspended oil and oil mist in the air, pressure loss It was necessary to design the product density, shape, etc. in consideration of the above, and it was not possible to sufficiently remove the oil component in such a state. On the other hand, the Asahi Shimbun (July 27, 1994) describes that the hydrophobic carbonized wood fiber exhibited excellent performance as an oil adsorbent in an open test at the Hokkaido Forest Products Research Institute. However, since the hydrophobic carbonized wood fiber is composed of fine fibers, it is necessary to pack it in a mesh bag or the like before use, and the hydrophobic carbonized wood fiber alone is used as an oil adsorbent having sufficient strength. It was difficult to make.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an oil adsorbent having excellent oil absorption properties and sufficient strength.

[0004]

Means for Solving the Problems As a result of intensive studies to solve such problems, the present inventors have found that by adding a polyolefin-based short fiber to a hydrophobic carbonized wood fiber,
The inventors have found that it is possible to obtain an oil adsorbent having sufficient strength without impairing the oil absorption properties of the hydrophobic carbonized wood fiber, and have reached the present invention. That is, the present invention is 10
The gist of the present invention is an oil adsorbent comprising a hydrophobic carbonized wood fiber of 20% by weight to 80% by weight and a polyolefin-based short fiber of 20% by weight to 90% by weight.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
As the hydrophobic carbonized wood fiber used in the present invention, for example,
Examples include those obtained by dry-distilling wood chips such as mushrooms, paper raw material chips, and thinned wood chips such as Todomatsu fiber at a temperature of 200 to 400 ° C. Further, the shape of the hydrophobic carbonized wood fiber used in the present invention is not particularly limited, and for example, the shape of the obtained hydrophobic carbonized wood fiber such as fibrous, powdery, chip-like or the desired oil Various materials can be used depending on the shape of the adsorbent.

The term "hydrophobicity" as used herein means a test of water absorption amount in the oil adsorbent performance test standard of discharged oil control material, that is, 1
A 0 cm × 10 cm test piece was floated on a fresh water surface at 20 ° C. and allowed to stand for 5 minutes, and then left for 5 minutes on a wire mesh woven with a wire having a diameter of 1 mm into a mesh having a mesh length of 17 mm. The weight of the test piece was measured and the water absorption per 1 g of the test piece was measured. As a result, the water absorption is 1 g / g or less.

Examples of the polyolefin short fibers used in the present invention include short fibers made of polyethylene, polypropylene and the like, and sheath-core type composite short fibers made of polyethylene / polypropylene. The fineness of polyolefin short fibers is 1 to 10 denier, and the fiber length is 2 to 50 mm
Are preferred.

In the oil adsorbent of the present invention, the polyolefin-based short fibers have an immobilizing effect on the hydrophobic carbonized wood fibers, and also have an oil absorbing ability. Further, by adding the polyolefin-based short fibers, it becomes possible to impart flexibility to the oil adsorbent.

The mixing ratio of the hydrophobic carbonized wood fiber and the polyolefin short fiber is 10% by weight of the hydrophobic carbonized wood fiber.
~ 80% by weight, polyolefin short fibers 20% by weight ~
90% by weight. If the hydrophobic carbonized wood fiber is less than 10% by weight or the polyolefin short fiber exceeds 90% by weight, the oil adsorbing amount of the oil adsorbent may not be sufficient, and the polyolefin short fiber is less than 20% by weight or hydrophobic. If the content of the carbonized wood fiber exceeds 80% by weight, the strength of the oil adsorbent may decrease.

The shape of the oil adsorbent of the present invention is not particularly limited, but for example, a sheet shape, a mat shape, a roll shape, a ribbon shape, a net shape, a laminate shape, a corrugated structure, a corrugated structure, etc. Is mentioned.

The oil adsorbent of the present invention can be manufactured by a known method. For example, as a method for producing the sheet-shaped oil adsorbent, a papermaking raw material composed of hydrophobic carbonized wood fibers and polyolefin short fibers may be obtained by a papermaking method, and the obtained papermaking raw material may be heat-molded. As a papermaking method, a dry papermaking method, a wet papermaking method or the like can be adopted. Further, when producing a papermaking raw material by a papermaking method, a dispersant, a binder,
You may add additives, such as an antistatic agent. The basis weight of the obtained papermaking fabric is not particularly limited, but is preferably 30 to 600 g / m ² .

Next, the hydrophobic carbonized wood fiber can be prevented from falling off by heat-molding the obtained papermaking original fabric. Examples of the heat molding method include a butte press, a continuous press, heat fusion, heat embossing, and a heat gear pressure bonding method. The temperature at the time of heat molding may be a temperature equal to or higher than the melting point and softening point of the polyolefin short fibers used, and is preferably 120 ° C to 250 ° C. In addition, it is possible to produce an oil adsorbent having a desired thickness by stacking the papermaking original fabrics during heat molding.

The oil adsorbent of the present invention can be obtained by the above-mentioned steps and the like, but the combination of the hydrophobic carbonized wood fiber and the polyolefin-based short fiber to be used, the basis weight of the papermaking paper obtained in the manufacturing step, and the heat-forming The performance of the obtained oil adsorbent can be adjusted by appropriately changing the stacking amount of the papermaking fabric at that time, the conditions at the time of heat molding, and the like. In the evaluation by the oil adsorbent performance test standard of the discharged oil control material, the oil adsorbent having a B heavy oil adsorption amount of 6 g / g or more and a water absorption amount of 1 g / g or less is
Since the amount of water absorption is small, there is no fear that the strength will decrease due to excessive absorption of water, and oil can be efficiently adsorbed, which is particularly preferable.

Here, the amount of B heavy oil adsorbed is measured by the following method. That is, a test piece of 10 cm × 10 cm is put at 20 ° C.
Float on the oil surface of B heavy oil for 5 minutes, and then leave it on a wire mesh woven with a wire with a diameter of 1 mm into a mesh with a mesh length of 17 mm for 5 minutes, and then measure the weight. Then, calculate the adsorption amount per 1 g of the test piece.

The sheet-shaped oil adsorbent can be further subjected to secondary processing such as corrugation processing and wave processing to suppress pressure loss, and can be used for kitchen exhaust, work place oil mist removal, liquid phase or water It can be used as a filter for removing diluted oil.

[0016]

EXAMPLES Next, the present invention will be specifically described with reference to examples. Examples 1 to 3 and Comparative Examples 1 to 3 of Todomatsu fiber were heated at a heating rate of 3 ° C. per minute in a heating furnace.
After heating to 50 ° C and heat treatment at the same temperature for 1 hour,
A hydrophobic wood fiber was obtained by natural cooling. The resulting hydrophobic wood fiber [A], thickness 2 denier, cut length 1
A 0 mm polypropylene short fiber [B] was uniformly dispersed in water at a ratio (% by weight) shown in Table 1 to obtain a dope solution. A basis weight of 200 g / m ² was obtained from the obtained dope solution by a wet papermaking method.
I got the original fabric. Further, the raw fabric was continuously heated and pressed under the conditions of 190 ° C., residence time of 2 minutes, and clearance of 1.5 mm to obtain a planar oil absorbing sheet. The amount of B heavy oil adsorbed and the amount of water absorbed of the obtained sheet-like oil absorbent sheet were measured according to the oil adsorbent performance test standard of the discharged oil control material. Further, the falling state of the hydrophobic wood fibers from the obtained sheet-like oil absorbing sheet was visually determined. Table 1 shows the results.

[0017]

[Table 1]

As is clear from Table 1, a planar oil-absorbing sheet having a small proportion of polyolefin-based short fibers (Comparative Example 2).
Although the oil absorption performance was excellent, the hydrophobic wood fibers were found to have fallen off and did not have sufficient strength. Sheet-shaped oil-absorbing sheet having a low content of hydrophobic wood fibers (Comparative Example 3)
Had an oil absorption performance comparable to that of the product containing no hydrophobic wood fiber (Comparative Example 1). On the other hand, Examples 1 to 3
The sheet-shaped oil-absorbing sheet obtained in No. 1 has the performance of adsorbing B heavy oil of 6 g / g or more and the water absorption of 1 g / g or less without dropping off of the hydrophobic wood fiber, and has sufficient strength and oil absorption performance. I had one.

Comparative Examples 4 and 5 In Example 3, rayon pulp (Comparative Example 4) and papermaking pulp (Comparative Example 5) were used instead of polypropylene short fibers.
Was used to obtain a raw fabric having a basis weight of 200 g / m ² . The obtained raw fabric is dried with a drum dryer at 105 ° C. to obtain a sheet-shaped oil absorbing sheet, and the amount of B heavy oil adsorbed and the amount of water absorbed in the obtained sheet-shaped oil absorbing sheet are used as the oil adsorbent performance test standard of the discharged oil control material. Therefore, it was measured. Table 2 shows the results.

[0020]

[Table 2]

As is clear from Table 2, in Comparative Examples 4 and 5, a planar oil absorbing sheet can be obtained by using pulp instead of the polyolefin-based short fibers, and the obtained planar oil absorbing sheets are Although it had a sufficient oil absorption performance, it had a large amount of water absorption, which could reduce the sheet strength and was unsuitable as a product.

[0022]

The oil adsorbent of the present invention has excellent oil absorption properties and sufficient strength. In addition, it is possible to supply minute hydrophobic carbonized wood fibers that are difficult to handle in the form of products with practical value such as fiber sheets, mats, and secondary processed products.
Further, since the constituent material includes wood fiber, the waste material can be easily treated after the oil absorption work.

Claims (2)

[Claims] 1. An oil adsorbent comprising 10% by weight to 80% by weight of hydrophobic carbonized wood fibers and 20% by weight to 90% by weight of polyolefin-based short fibers. 2. The B heavy oil adsorption amount is 6 g / g or more, and the water absorption amount is 1.
The oil adsorbent according to claim 1, which is g / g or less.