JP2008195872A - Production method of heavy metal-eliminated oil or fat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of heavy metal-eliminated oil or fat by easily removing heavy metal from oil or fat dissolving a heavy metal. <P>SOLUTION: The heavy metal is eliminated by directly contacting heavy metal-dissolving oil or fat with a chelate resin generally used in water. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing oil or fat from which heavy metal is removed from oil or fat in which heavy metal is dissolved.

  Lubricating oils are widely used in driving devices for internal combustion engines, vehicles, machine tools, industrial machines, etc., especially engine oils for the spread of automobiles due to recent motorization and mechanization of work to eliminate labor shortages. Consumption of cylinder oil, hydraulic oil, extreme pressure lubricant, etc. is increasing rapidly. These lubricating oils are currently disposed of as waste oil (hereinafter referred to as waste lubricating oil) when their properties deteriorate after a considerable period of use. As a method for recycling such waste lubricating oil, it is considered to use it as a fuel.

  Various additives are blended in the lubricating oil. Some of these additives contain heavy metals. When waste lubricating oil containing heavy metals is reused as boiler fuel, heavy metals are contained in ash and cause environmental pollution. For this reason, removal of heavy metals from waste lubricating oil has been attempted (for example, see Patent Document 1). In the method described in this document, waste lubricating oil is brought into contact with an aqueous solution of a chelating agent such as ethylenediaminetetraacetic acid, and heavy metals are complexed and transferred to the aqueous solution side for removal.

In addition, it is known that the viscera of marine products such as scallop midgut (uro) and squid viscera (goro) have a large amount of useful substances such as oils that can be used as functional lipids. On the other hand, it is also known that the viscera of these marine products contain high concentrations of heavy metals such as cadmium. For this reason, attempts have been made to remove heavy metals contained in foods or food processing byproducts containing harmful heavy metals such as marine wastes (see, for example, Patent Document 2). In the method described in this document, heavy metals transferred to an aqueous acid solution are removed from a food or food processing by-product with a chelate resin.
JP-A-5-9492 JP 2006-42613 A

  In any of the methods described in these documents, heavy metals are transferred to an aqueous phase and then removed. For this reason, a complicated procedure is required.

  On the other hand, oil-soluble chelating agents are known for recovering heavy metals contained in oil. However, even if heavy metals are trapped by the chelating agent in the oil, a complicated liquid-liquid separation is required to remove them from the oil.

  That is, the present invention has been made in view of the above problems, and an object thereof is to provide a method for producing oil or fat from which heavy metals are removed by easily removing heavy metals from oils or fats in which heavy metals are dissolved. There is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that heavy metals are removed by directly contacting oils or fats in which heavy metals are dissolved with a chelate resin usually used in water. Completed the invention. That is, the present invention is as follows.

  The present invention is a method for producing oil or fat from which heavy metal is removed by bringing oil or fat in which heavy metal is dissolved into contact with a chelating resin.

  The oil or fat may be liquid.

  The recovered heavy metal may be one selected from copper, zinc, lead, and cadmium.

  The present invention includes a step of treating a treated product containing heavy metal with water in a subcritical state or a supercritical state, and a step of bringing oil or fat in which the heavy metal obtained by the treatment is dissolved into contact with a chelate resin. It may be a method for producing oil or fat from which heavy metals have been removed.

  According to the method of the present invention, heavy metal can be almost completely removed from oil or fat in which heavy metal is dissolved by a simple method of contacting the chelate resin. As a result, the treated oil or fat can be used as it is.

  The present invention is described in detail below.

[Oil or fat in which heavy metals are dissolved]
The oil or fat in which heavy metal used in the present invention is dissolved is not particularly limited as long as it is an oil or fat containing heavy metal. For example, waste lubricating oil, hydrocarbon oil having heavy metal (crude oil, petroleum products, etc.), Or the oil or fat obtained from at least 1 sort (s) selected from marine products, such as seafood, an animal, or a plant is mentioned. According to the method of the present invention, the waste lubricating oil can be easily recycled. In addition, functional lipids from which heavy metals have been removed can be obtained from previously discarded portions such as visceral fisheries such as scallop midgut (uro) and squid internal organs (goro).

  Examples of the heavy metal removed by the method of the present invention include cadmium, chromium, copper, tin, mercury, manganese, molybdenum, nickel, lead, and zinc. In particular, copper, zinc, lead and cadmium can be effectively removed. These heavy metals include simple heavy metals and compounds thereof.

[Preprocessing]
In the present invention, when the treatment target is oil or fat obtained from at least one selected from marine products such as seafood, animals or plants, extraction of these oils or fats can be performed using a known technique. However, it is preferable to extract at least one selected from marine products such as fish and shellfish, animals or plants in contact with subcritical or supercritical water. When extraction is performed using water in a subcritical or supercritical state, heavy metals contained in the treatment target move to the oil layer or fat layer. As a result, if heavy metals are removed from oil or fat, it is not necessary to remove heavy metals from the aqueous layer. Moreover, an active ingredient can be obtained from a water-soluble component by appropriately selecting the contact conditions (temperature, pressure, time, mixing ratio, etc.) of water in a subcritical or supercritical state.

  Here, the supercritical state of water means that the temperature and pressure are in a state of a critical point (374 ° C., 22 MPa) or higher, and the subcritical state of water is, for example, 374 ° C. or higher, 2.5 MPa or higher and 22 MPa. Or a state of 374 ° C. or lower and 22 MPa or higher, or a temperature of 374 ° C. or lower and lower than 22 MPa, a high temperature and high pressure state close to the critical point. Preferably, it is the subcritical state of 270 degreeC or more and 320 degrees C or less of water.

  After the contact, the liquid is cooled to separate into a water layer, a fat layer, and an oil layer. The fat layer and the oil layer may coexist depending on the processed product, or may exist independently. A fat layer or oil layer is used in the method of the present invention.

[Metal removal treatment]
In the present invention, a heavy metal is treated by directly treating a fat or oil containing the heavy metal with a chelate resin. In the case of fat, it is heated and brought into contact with the chelate resin in a liquid state.

  The chelate resin that can be used in the present invention is not particularly limited as long as it is a resin having an iminodiacetic acid group or an iminodipropionic acid group and can chelate-bond with a heavy metal ion at a carboxyl group. For example, a chelating resin such as a resin obtained by binding an iminodiacetic acid group or an iminodipropionic acid group to a porous crosslinked polystyrene substrate, a styrene / divinylbenzene copolymer, a carbamic acid resin, or the like is preferable. Specific examples of chelating resins having an iminodiacetic acid group include “Diaion CR11” manufactured by Mitsubishi Chemical Corporation, “Amberlite IRC748” manufactured by Rohm & Haas, “Eporus MX-10” manufactured by Miyoshi Oil & Fats Co., Ltd., and Iminodipropion. Specific examples of chelate resins having acid groups include "Epolas MX-8, 8C" manufactured by Moritex Co., Ltd., "Sumichel" manufactured by Sumika Chemtex Co., Ltd., "Aclean Z" manufactured by Asahi Glass Engineering Co., Ltd. Examples include “Uniselec UR-10S” manufactured by the company and “Purolite, Levacit” manufactured by Urano Co., Ltd.

  The contact method is by directly feeding the chelate resin into fat or oil, or by passing it through a chelate resin column. When the chelate resin is directly put into fat or oil, fat or oil from which heavy metals have been removed can be obtained by simple separation such as filtration. The recovered fat or oil does not contain a component harmful to the human body and can be used as a functional lipid as it is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this Example.

[Removal rate of copper ions in chelate resin, superporous PEI chelate chitosan beads, and chitosan fiber]
(Example 1)
A reaction tube (SUS316) was filled with 3.5 ml of oil obtained from the internal organs of scallops, an aqueous solution of cupric nitrate (II) (concentration 0.01 mol / L), and sealed. The aqueous solution of cupric nitrate (II) was such that the total amount of copper ions contained in the aqueous solution was transferred to the oil layer, so that the copper ion in the resulting oil layer was 0.05 to 1.4 g. This reaction tube was immersed in a constant temperature bath at 250 ° C. and rapidly heated and held for 10 minutes to transfer the copper ions in the cupric nitrate aqueous solution to the oil layer. Thereafter, the reaction tube was taken out of the thermostatic bath, immersed in a cooling bath, rapidly cooled, and returned to room temperature.

  The obtained oil was quantified for copper ions contained in the oil layer with an inductively coupled plasma (Inductively Coupled Plasma). A copper-containing sample (samples 1 to 8) containing 0.05 to 1.4 g of copper ions in the oil layer was obtained.

A chelate resin having an iminodiacetic acid group (manufactured by Mitsubishi Chemical Corporation, product name: Diaion CR-11) neutralized by adding an aqueous sodium hydroxide solution to these oils is added to chelate copper ions. Bonded to resin. The chelate resin was filtered off. The remaining oil was treated with nitric acid, the nitric acid layer was analyzed by ICP, and the amount of copper ions removed by the chelate resin was measured. Table 1 shows the amount of copper ions contained in the oil layer, the amount of copper ions contained in the oil layer (C ₀ ) (mol / l), and the amount of copper ions contained in the oil layer after being removed by the chelate resin (C). (Mol / l), removal rate ((C ₀ -C) / C ₀ ) × 100 (%).

  From Table 1, it can be seen that when the chelate resin is used, the copper ions are almost completely removed.

(Comparative Example 1)
The test was performed in the same manner as in Example 1 except that chitosan beads were used instead of the chelating resin. The results are shown in Table 2. In addition, the superporous PEI chitosan beads used in the present specification were obtained by forming chitosan into beads and then cross-linking and further introducing polyethyleneimine (PEI).

(Comparative Example 2)
The test was performed in the same manner as in Example 1 except that chitosan fiber was used instead of the chelate resin. In the present specification, chitosan fibers are those obtained by forming chitosan into a fibrous form and then crosslinking. The results are shown in Table 2.

  From the results of Example 1 and Comparative Examples 1 and 2, when a chelate resin is used as in Example 1, the copper ion removal rate is 75% or higher, which is higher than that of Comparative Examples 1 and 2. I understood it.

[Release rate of lead ions in chelate resin, superporous PEI chelate chitosan beads and chitosan fiber]
(Example 2)
The test was performed in the same manner as in Example 1 except that lead ion (lead nitrate) was used instead of copper ion. The results are shown in Table 4.

(Comparative Example 3)
The test was performed in the same manner as in Comparative Example 1 except that lead ion (lead nitrate) was used instead of copper ion. The results are shown in Table 5.

(Comparative Example 4)
A test was performed in the same manner as in Comparative Example 2 except that lead ion (lead nitrate) was used instead of copper ion. The results are shown in Table 6.

  From the results of Example 2 and Comparative Examples 3 and 4, when a chelate resin is used as in Example 2, the lead ion removal rate is 27.8% or more, compared to Comparative Examples 3 and 4, and the removal rate of lead ions. Was found to be expensive.

[Removal rate of zinc ion in chelate resin, superporous PEI chelate chitosan beads, superporous PEI chelate chitosan fiber]
(Example 3)
The test was performed in the same manner as in Example 1 except that zinc ions (zinc nitrate) were used instead of copper ions. The results are shown in Table 7.

(Comparative Example 5) A test was performed in the same manner as in Comparative Example 1 except that zinc ions (zinc nitrate) were used instead of copper ions. The results are shown in Table 8.

(Comparative Example 6)
The test was performed in the same manner as in Comparative Example 2 except that zinc ions (zinc nitrate) were used instead of copper ions. The results are shown in Table 9.

  From the results of Example 3 and Comparative Examples 5 and 6, when a chelate resin was used as in Example 3, the zinc ion removal rate was 94.8% or more, compared with Comparative Examples 5 and 6, and the zinc ion removal rate. Was found to be extremely high.

[Change in removal rate of heavy metal ions in chelate resin with subcritical processing temperature change]
[Subcritical processing temperature: 225 ° C]
Example 4
(Removal of copper ions)
The test was performed in the same manner as in Example 1 except that the subcritical treatment was performed at 225 ° C. The results are shown in Table 10.


(Example 5)
(Zinc ion removal)
The test was conducted in the same manner as in Example 1 except that the subcritical treatment was performed at 225 ° C. and zinc ions were used instead of copper ions. The results are shown in Table 11.

(Example 6)
(Removal of cadmium ions)
The test was performed in the same manner as in Example 1 except that the subcritical treatment was performed at 225 ° C. and cadmium ions (cadmium nitrate 0.01 mol / l) were used instead of copper ions. The results are shown in Table 12.

(Example 7)
(Removal of lead ions)
The test was performed in the same manner as in Example 1 except that the subcritical treatment was performed at 225 ° C. and lead ions were used instead of copper ions. The results are shown in Table 13.

[Change in removal rate of heavy metal ions in chelate resin with subcritical processing temperature change]
[Subcritical processing temperature: 275 ° C]
(Example 8)
(Removal of copper ions)
The test was performed in the same manner as in Example 1 except that the subcritical treatment was performed at 275 ° C. The results are shown in Table 14.

Example 9
(Removal of cadmium ions)
The test was performed in the same manner as in Example 1 except that the subcritical treatment was performed at 275 ° C. and cadmium ions were used instead of copper ions. The results are shown in Table 15.

(Example 10)
(Removal of lead ions)
The test was conducted in the same manner as in Example 1 except that the subcritical treatment was performed at 275 ° C. and lead ions were used instead of copper ions. The results are shown in Table 16.

[Change in removal rate of heavy metal ions in chelate resin with subcritical processing temperature change]
[Subcritical processing temperature: 300 ° C]
(Example 11)
(Removal of copper ions)
The test was performed in the same manner as in Example 1 except that the subcritical treatment was performed at 300 ° C. The results are shown in Table 17.

(Example 12)
(Removal of cadmium ions)
The test was conducted in the same manner as in Example 1 except that the subcritical treatment was performed at 300 ° C. and cadmium ions were used instead of copper ions. The results are shown in Table 18.

(Example 13)
(Removal of lead ions)
The test was conducted in the same manner as in Example 1 except that the subcritical treatment was performed at 300 ° C. and lead ions were used instead of copper ions. The results are shown in Table 19.

(Conclusion)
From Examples 4 to 13, it was found that the amount of copper ions, cadmium ions, zinc ions, and lead ions captured by the chelate resin was changed depending on the subcritical treatment conditions of the pretreatment. Specifically, it can be seen that at a low temperature of 225 ° C., the proportion of copper ions removed by the chelate resin is higher than that of cadmium ions, zinc ions, and lead ions. It can be seen that at 275 ° C. and 300 ° C., the proportion of zinc ions removed by the chelate resin is higher than copper ions, cadmium ions, and lead ions.

[Change in removal rate of heavy metal ions dissolved in fat in chelate resin]
(Example 11)
(Removal of copper ions)
The test was performed in the same manner as in Example 1 except that fat was used instead of oil and subcritical treatment was performed at 300 ° C. The treatment with the chelate resin was performed in a state where fat was dissolved. The results are shown in Table 20.

(Example 12)
(Zinc ion removal)
A test was conducted in the same manner as in Example 1 except that fat was used instead of oil, subcritical treatment was performed at 300 ° C., and zinc ions were used instead of copper ions. The results are shown in Table 21.

(Example 13)
(Removal of cadmium ions)
A test was conducted in the same manner as in Example 1 except that fat was used instead of oil, subcritical treatment was performed at 300 ° C., and cadmium ions were used instead of copper ions. The results are shown in Table 22.

(Example 14)
(Removal of lead ions)
A test was conducted in the same manner as in Example 1 except that fat was used instead of oil, subcritical treatment was performed at 300 ° C., and lead ions were used instead of copper ions. The results are shown in Table 23.

(Conclusion)
From Examples 11 to 14, it was found that heavy metals dissolve in fat even when subcritical treatment is performed. It was also found that heavy metal ions dissolved in fat can be removed by a chelate resin.

From the above, it was found that heavy metal ions dissolved in oil or fat can be effectively removed by using a chelate resin.

Claims (4)

  A method for producing oil or fat from which heavy metals have been removed by bringing oil or fat in which heavy metals are dissolved into contact with a chelating resin.   The method for producing oil or fat from which heavy metals have been removed according to claim 1, wherein the heavy metal is recovered by bringing liquid oil or fat into contact with a chelating resin.   The method for producing oil or fat from which heavy metals have been removed according to claim 1 or 2, wherein the heavy metal to be recovered is one selected from copper, zinc, lead, and cadmium. Treating a treated product containing heavy metal with subcritical or supercritical water;
A method for producing oil or fat from which heavy metals have been removed, comprising the step of bringing oil or fat in which heavy metals obtained by the treatment are dissolved into contact with a chelate resin.