JP3263351B2 - Oil recovery device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for treating a waste liquid containing a volatile oil produced in a factory or the like to render the distillation residue harmless, reusing the recovered raw volatile oil, and further removing the volatile oil. TECHNICAL FIELD The present invention relates to an oil recovery device that does not discharge an aqueous solution containing urea.

[0002]

2. Description of the Related Art Conventionally, when the oil content of a volatile oil-containing waste liquid is small, it is entrusted to an industrial waste contractor and treated by combustion. Toxic substances such as dioxin are generated and have become a problem worldwide. Illegal dumping continues to pollute groundwater and destroy the ozone layer, and has been raised as a social issue. In addition, a large amount of waste liquid is used to separate a water-based aqueous substance having a relatively high oil content, and the oil is treated by distillation under reduced pressure or atmospheric pressure. The problem of remaining harmful substances in the residue is always left in the processing within the regulation value. Finally, it is burnt and treated as industrial waste while containing harmful substances. This is because volatile oil remains in the still space at the end of distillation.

[0003] A method using steam distillation is used for producing essential oils from plants and the like, but a method using heated steam is not used because the essential oil components are deteriorated. Recovery of oil content in waste liquid by heating steam has not yet been known.

[0004] Furthermore, the content of volatile oil dissolved in the water layer is high and may not be discarded as it is for environmental sanitation. Complicated treatment such as reducing the content is required. This water layer has never been returned to the steam generator for reuse.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to an oil recovery system in which heated steam is sent to a waste liquid containing volatile oil, and the volatile oil is removed by steam distillation to render the distillation residue harmless. An apparatus is provided. That is, by using a volatile waste liquid by heating steam, the temperature of the waste liquid is raised to 100 ° C. or higher, and the volatile oil is easily distilled.
In addition, the waste liquid can be efficiently treated without increasing the temperature as the temperature of the waste liquid rises to the extent that the waste liquid is converted into resin. The toxic volatile oil can be removed to make the distillation residue harmless, and the recovered volatile oil can be reused.

Further, the present invention separates a volatile oil layer and an aqueous layer obtained by steam distillation in the above apparatus, removes the oil layer outside the system, and returns the aqueous layer containing volatile oil to a steam generator for volatilization. Provided is an oil recovery device characterized in that an aqueous layer containing a volatile oil is not discharged out of the system. By using this apparatus, it is possible to prevent the risk of environmental pollution and the like when the volatile oil is highly toxic because the volatile oil does not go out of the system.

The components include a distillation still, a steam generator, a cooler, a liquid separator, a thermometer, a steam regulating valve, a liquid level sensor, an adsorption tank, a waste liquid feed pump, and a distillate discharge pump. it can. The above components are appropriately selected depending on the type and amount of the oil component in the waste liquid. The apparatus of the present invention may be either a batch type or a continuous type. further,
The above components may include a water layer circulation pump for returning the water layer to the steam generator. However, the return of the water layer containing volatile oil to the steam generator can be returned by head.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The waste liquid applicable to the apparatus of the present invention can be applied to all kinds of waste liquid as long as the oil contained therein is volatile. Distillation pots are known and are commercially available in various containers such as glass and metal. Containers with special specifications are available and available. Steam generators are also readily available commercially. In a factory or the like, surplus steam can be used. The heating steam has an absolute pressure of 1 to 5 kg / cm ² , preferably about 1 to 3 kg / cm ² , and at this time, the temperature in the distillation still is about 100 to about 103.
℃. The time required for distillation depends on the scale depending on the throughput.

[0009] There are various types of coolers on the market. Separators are readily available on the market. Various types of thermometers such as analog and digital are commercially available. Level sensors are readily available on the market. Various types of steam regulating valves are available from manual to automatic. In the adsorption tank, both containers made of glass and metal are easily available on the market, and a large number of adsorbents, such as activated carbon, are also commercially available. Pumps having various capabilities can be obtained for the waste liquid feeding / distillate removal and water layer circulation pumps. The above components of the oil recovery apparatus of the present invention are appropriately selected depending on the type and amount of the oil in the waste liquid.

The oil recovery apparatus of the present invention will be described with reference to a conceptual diagram. In FIG. 1, heated steam of a steam generator () passes through a steam regulating valve (), and a distillation pot () containing waste liquid.
And heated and distilled by steam. The volatile oil evaporates together with the water vapor, is cooled and liquefied in the cooling section (), and reaches the liquid separating section (). In the liquid separation part, the oil layer and the water layer are separated, for example, the oil component that is hardly soluble in water having a large specific gravity is in the lower layer,
The oil having a small specific gravity is separated into an upper layer. The separated oil is appropriately purified and reused as necessary. A liquid feed pump is used to move these liquids, and the oil dissolved in the aqueous layer is removed in the adsorption tank (). The thermometer () is used to check the internal temperature.

In FIG. 2, an aqueous layer containing volatile oil is returned to a steam generator for reuse by using an aqueous layer circulation pump instead of the adsorption tank of FIG. At this time, the water layer can be automatically conveyed by adopting the liquid level sensors in various places.

The apparatus of the present invention has the following advantages over the conventional apparatus or method. 1) No new harmful substances are generated by the treatment (the generation of dioxin by the treatment with organochlorine compounds is a social problem). 2) Extremely low running costs (cooling water, heating steam, labor costs). 3) Recovered oil can be reused. 4) Operation is extremely easy. 5) Extremely high safety. 6) Automation is easy. 7) By circulating the water layer, the water layer containing volatile oil does not go out of the system, and it is possible to prevent environmental pollution by harmful substances.

[0013]

Next, the present invention will be described in more detail by using a waste liquid containing tetrachloroethylene (abbreviated as TCE) in the field of cleaning in which discharge regulations are strict. Example 1 In a 3 l round-bottomed flask, 1.0 kg of a cleaning shop waste liquid (TCE distillation residue) containing tetrachloroethylene was weighed, and an electric steam generator (OSG- manufactured by Osaka Electric Industry Co., Ltd.) was used.
0.8-0.9 kg / cm ² (absolute pressure 0.5-4.5)
kg / cm ² ), and the mixture was subjected to distillation for about 20 minutes (internal temperature: 100 to 103 ° C.). For qualitative determination of TCE, use a gas chromatography / mass spectrometer (GCM manufactured by Shimadzu Corporation).
S-QP2000A). Distillate is collected in a separating funnel, and the upper layer (water layer) and the lower layer (TCE layer)
And TCE in the distillation residue and the space in the distillation vessel were also analyzed according to a conventional method. The upper layer passed through an activated carbon tank was analyzed in the same manner.

Results TCE content in each fraction (average value of 3 times) 313.10 g / kg of raw material waste liquid 158.45 mg / 1.51 kg of liquid separation upper layer Activated carbon passing water Not detected (discharge regulation: 0.1 ppm) Lower) Separation lower layer 297.07 g in 354.9 g Residue Not detected (Emission regulation: 0.1 ppm or less) Container space 4.81 ppm (Working environment evaluation standard 50 ppm or less)

Example 2 In Example 1, the upper part (water layer) flowing out of the liquid separator was introduced into a storage tank attached to a steam generator. A liquid level sensor (upper and lower) is attached to the storage tank and is electrically linked to the water layer circulation pump. The aqueous layer containing volatile oil in the storage tank was successively introduced into the steam generator according to an instruction from a liquid level sensor in the steam generator, and used for steam distillation. As a result of performing several batches continuously, tetrachloroethylene which should be discharged outside the system as an aqueous layer in addition to the oil discharged from the separator from the system outside the system, the aqueous layer portion 1.
An average of 65.0 mg was recovered per 0 kg.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an oil recovery device according to claim 1 of the present invention.

FIG. 2 is a conceptual diagram of an oil recovery apparatus according to a second embodiment of the present invention.

[Explanation of symbols] ・ ・ Steam generator, ・ ・ Steam regulating valve, ・ ・ Distillation pot,
..Cooling part, liquid separation part, adsorption tank, thermometer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 3/00-3/42 C02F 1/04-1/18

Claims (3)

(57) [Claims] 1. A volatile oil component is subjected to steam distillation while heating steam is sent from a heating steam generator to a waste liquid containing a volatile oil component, and a volatile oil layer and an aqueous layer obtained by steam distillation are separated. Is an oil recovery apparatus characterized in that a water layer containing volatile oil is returned to a steam generator and an aqueous layer containing volatile oil is not discharged outside the system except for outside the system. 2. A heating steam generator, a steam regulating valve, a distillation still equipped with a thermometer containing a waste liquid to be treated, a cooler, and a liquid separator equipped with a liquid level sensor, in this order, and an oil layer is separated from the liquid separator. Includes a distillate withdrawal pump to remove from the system and a water layer circulation pump to return the water layer to the heated steam generator,
The device according to claim 1. 3. The steam pressure of the heated steam is 1 to 5 kg in absolute pressure.
The device according to claim 1 or 2, wherein the ratio is / cm2.