JP2004267917A - Sulfur compound adsorbent, its production method, and sulfur compound removal/recovery using it and adsorbent regeneration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient removal/recovery method for a sulfur compound capable of efficiently adsorbing and removing the sulfur compound contained in a gas or a liquid even in a low concentration and using a sulfur compound adsorbent having adsorption capacity and an adsorbent. <P>SOLUTION: The adsorbent comprises a heated treatment substance of a metal-containing hydroxide containing a sulfate ion or a carbonate ion. As the metal-containing hydroxide, the compound represented by the general formula: M<SP>II</SP><SB>1-x-z</SB>M<SP>III</SP><SB>x</SB>M<SP>IV</SP><SB>z</SB>(OH)<SB>y</SB>A<SP>n-</SP><SB>(2+x+2z-y)/n</SB>-mH<SB>2</SB>O is preferable. In the formula, M<SP>II</SP>is a divalent metal including at least one kind of Zn<SP>2+</SP>, Co<SP>2+</SP>and Cu<SP>2+</SP>; M<SP>III</SP>is a trivalent metal including at least one kind of Al<SP>3+</SP>, Fe<SP>3+</SP>and Mn<SP>3+</SP>; M<SP>IV</SP>is a tetravalent metal including at least one kind of Ti<SP>4+</SP>, Zr<SP>4+</SP>, Sn<SP>4+</SP>, Mn<SP>4+</SP>and Ce<SP>4+</SP>; A<SP>n-</SP>is an anion including at least one kind of divalent ion of SO<SB>4</SB><SP>2-</SP>and CO<SB>3</SB><SP>2-</SP>; n is an average valency of anion; and x, y, z and m are the number satisfying 0≤x≤0.8, 0≤y≤0.7, 0≤z≤0.4 and 0<m≤3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a novel adsorbent for a sulfur compound, more specifically, an adsorbent capable of efficiently removing a sulfur compound contained in a gas or a liquid even at a low concentration, and a method for removing a sulfur compound using the same. It is about.
[0002]
[Prior art]
Sulfur compounds have become a serious problem as environmental harmful substances such as odor-causing substances and acid rain-causing substances, and their removal technology is required. For example, hydrogen sulfide and mercaptans, which are odorous air pollutants, and water-based or organic solvent-based substances There is a need for a technique for previously removing harmful sulfur compounds, such as harmful sulfur compounds contained in liquefied natural gas and gasoline, from the viewpoint of preventing their release into the environment.
[0003]
So far, adsorbents capable of selectively removing sulfur compounds include clay mineral composites (see Patent Document 1), titanium oxide / copper oxide / iron oxide composites (see Patent Document 2), and zinc oxide / alkali complexes. (See Patent Document 3), silicate / zinc / activated carbon composite (see Patent Document 4), silicate gel containing metal salt (see Patent Document 5), Raney copper (see Patent Document 6), apatite compound containing transition metal (patent) Literature 7, a manganese oxide-based adsorbent (see Patent Literature 8), phosphate-added activated carbon (see Patent Literature 9), a composite metal oxide (see Patent Literature 10), a copper component-supporting porous material (see Patent Literature 11) ), A metal oxide-supported organic polymer (see Patent Document 12), an iron / copper composite metal hydrated oxide (see Patent Document 13), and the like.
However, although these adsorbents show good adsorption performance for sulfur compounds at a certain concentration, low-concentration sulfur compounds are not necessarily satisfactory in terms of adsorption-removability and adsorption capacity. Absent.
[0004]
[Patent Document 1]
JP-A-50-160816 (Claims and others)
[Patent Document 2]
JP-B-59-32169 (claims and others)
[Patent Document 3]
JP-A-1-203040 (Claims and others)
[Patent Document 4]
JP-A-4-349934 (claims and others)
[Patent Document 5]
JP-A-4-290546 (Claims and others)
[Patent Document 6]
JP-A-6-55065 (claims and others)
[Patent Document 7]
JP-A-7-96175 (Claims and others)
[Patent Document 8]
JP-A-9-85077 (Claims and others)
[Patent Document 9]
JP-A-10-192703 (Claims and others)
[Patent Document 10]
JP-A-11-28352 (Claims and others)
[Patent Document 11]
JP 2001-123188 A (Claims and others)
[Patent Document 12]
JP-A-2002-177767 (Claims and others)
[Patent Document 13]
JP-A-2002-320847 (Claims and others)
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a sulfur compound adsorbent that can efficiently adsorb and remove sulfur compounds contained in a gas or a liquid even at a low concentration, and that has a large adsorption capacity and an efficient sulfur using the adsorbent. An object of the present invention is to provide a method for removing and recovering a compound.
[0006]
[Means for Solving the Problems]
An object of the present invention is to heat-treat a metal hydrate containing a sulfate ion or a carbonate ion, and the carbonate ion is converted into a carbon dioxide gas and the sulfate ion is converted into a sulfur oxide gas, and escapes from the solid. At that time, a sulfur compound is adsorbed. Based on the knowledge that a suitable site is formed and that the solid becomes porous and an adsorbent with a large adsorption capacity can be obtained, the metal hydrate containing a polyanion such as a sulfate ion or a carbonate ion can be obtained. This was achieved by an adsorbent consisting of a heat-treated oxide.
[0007]
That is, the present invention is as follows.
(1) A sulfur compound adsorbent comprising a heat-treated metal hydrate containing a sulfate ion or a carbonate ion.
(2) A metal hydrate containing a sulfate ion or a carbonate ion has a general formula
M^II _1-x-zM^III _xM^IV _z(OH)_yA^n- _{(2 + x + 2z-y) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following: M^IVIs Ti⁴⁺, Zr⁴⁺, Sn⁴⁺, Mn⁴⁺And Ce⁴⁺A tetravalent metal containing at least one of the following, A^n-Is SO₄ ^2-And CO₃ ^2-An anion containing at least one divalent ion of the above, n is the average valence of the anion, x, y, z and m are 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4, 0 <m ≦ 3) The metal compound hydrate represented by (1) above.
(3) Zn²⁺, Co²⁺And Cu²⁺An aqueous solution containing a water-soluble compound of a divalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺Mixed aqueous solution containing a water-soluble compound of a trivalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of²⁺Mixed aqueous solution containing a water-soluble compound of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of⁴⁺, Zr⁴⁺, Sn⁴⁺And Ce⁴⁺An alkali hydroxide or an aqueous solution thereof is added to a mixed aqueous solution containing a water-soluble compound of a tetravalent metal containing at least one of
M^II _1-x-zM^III _xM^IV _z(OH)_yA^n- _{(2 + x + 2z-y) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following: M^IVIs Ti⁴⁺, Zr⁴⁺, Sn⁴⁺, Mn⁴⁺And Ce⁴⁺A tetravalent metal containing at least one of the following, A^n-Is SO₄ ^2-, N is the average valence of the anion, x, y, z and m are 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4, x + z <1 , 0 <m ≦ 3)
Wherein the metal hydrate containing sulfate ions is precipitated, and the precipitate is subjected to heat treatment at 100 to 600 ° C., wherein the adsorbent for a sulfur compound according to the above (1) or (2), Manufacturing method.
(4) Zn²⁺, Co²⁺And Cu²⁺An aqueous solution containing a water-soluble compound of a divalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A mixed aqueous solution containing a water-soluble compound of a trivalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of²⁺Mixed aqueous solution containing a water-soluble compound of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of⁴⁺, Zr⁴⁺, Sn⁴⁺And Ce⁴⁺An alkali carbonate or an aqueous solution thereof is added to a mixed aqueous solution containing a water-soluble compound of a tetravalent metal containing at least one of
M^II _1-x-zM^III _xM^IV _z(OH)_yA^n- _{(2 + x + 2z-y) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following: M^IVIs Ti⁴⁺, Zr⁴⁺, Sn⁴⁺, Mn⁴⁺And Ce⁴⁺A tetravalent metal containing at least one of the following, A^n-Is CO₃ ^2-, N is the average valence of the anion, x, y, z and m are 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4, x + z <1 , 0 <m ≦ 3)
Wherein the metal hydrate containing carbonate ion is precipitated, and the precipitate is further subjected to a heat treatment at 100 to 600 ° C., wherein the sulfur compound adsorbent according to the above (1) or (2), Manufacturing method.
(5) A metal hydrate containing a sulfate ion or a carbonate ion has a general formula
M^II _1-xM^III _x(OH)_yA^n- _{(2 + xy) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following, A^n-Is SO₄ ^2-And CO₃ ^2-An anion containing at least one divalent ion among them, n is the average valence of the anion, x, y and m are 0 ≦ x ≦ 0.67, 0 ≦ y ≦ 0.7, 0 <m ≤3)
The sulfur compound adsorbent according to the above (1), which is a crystalline metal hydrate represented by the formula:
(6) Zn²⁺, Co²⁺And Cu²⁺An aqueous solution containing a water-soluble compound of a divalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of²⁺After adding an alkali hydroxide or an aqueous solution thereof in the presence of sulfate ions to a mixed aqueous solution containing at least one of the water-soluble compounds of
M^II _1-xM^III _x(OH)_yA^n- _{(2 + xy) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following, A^n-Is SO₄ ^2-, N is the average valence of the anion, and x, y, and m are numbers satisfying 0 ≦ x ≦ 0.67, 0 ≦ y ≦ 0.7, and 0 <m ≦ 3.)
Wherein the crystalline metal hydrate containing sulfate ions is precipitated, and the precipitate is heated at 100 to 600 ° C. to produce the sulfur compound adsorbent according to the above (5). Method.
(7) Zn²⁺, Co²⁺And Cu²⁺An aqueous solution containing a water-soluble compound of a divalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of²⁺After adding alkali carbonate or an aqueous solution thereof to a mixed aqueous solution containing at least one of the water-soluble compounds of
M^II _1-xM^III _x(OH)_yA^n- _{(2 + xy) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following: A^n-Is CO₃ ^2-, N is the average valence of the anion, and x, y and m are numbers satisfying 0 ≦ x ≦ 0.67, 0 ≦ y ≦ 0.7, and 0 <m ≦ 3). The method for producing a sulfur compound adsorbent according to (5), wherein the crystalline metal hydrate containing carbonate ions is precipitated, and the precipitate is heated at 100 to 600 ° C. .
(8) Zn²⁺, Co²⁺And Cu²⁺A divalent metal oxide containing at least one of²⁺, Co²⁺And Cu²⁺An aqueous solution containing a water-soluble compound of a divalent metal containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of²⁺To a mixed aqueous solution containing at least one water-soluble compound of the formula
M^II _1-xM^III _x(OH)_yA^n- _{(2 + xy) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following, A^n-Is SO₄ ^2-, N is the average valence of the anion, and x, y, and m are numbers satisfying 0 ≦ x ≦ 0.67, 0 ≦ y ≦ 0.7, and 0 <m ≦ 3.)
Wherein the crystalline metal hydrate containing sulfate ions is precipitated, and the precipitate is heated at 100 to 600 ° C. to produce the sulfur compound adsorbent according to the above (5). Method.
(9) A method for removing and recovering a sulfur compound and regenerating an adsorbent, comprising the following steps (I) and (II).
Step (I)
A step of adding the sulfur compound adsorbent according to (1), (2) or (5) to a gas or liquid containing a sulfur compound to adsorb and remove the sulfur compound.
Step (II)
A step of subjecting the adsorbent obtained in step (I) to which the sulfur compound has been adsorbed to a heat treatment at 500 ° C. or higher to desorb and recover or decompose the sulfur compound and regenerate the adsorbent.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In the adsorbent of the present invention, a metal hydrate containing a sulfate ion or a carbonate ion, which is used as a precursor thereof and is an object to be subjected to a heat treatment, is not particularly limited, but the metal is polyvalent, and especially divalent to tetravalent. Is appropriate in terms of stability. Zn as a divalent metal²⁺, Co²⁺, Cu²⁺However, the trivalent metal is Al³⁺, Fe³⁺, Mn³⁺However, as a tetravalent metal, Ti⁴⁺, Zr⁴⁺, Sn⁴⁺, Mn⁴⁺, Ce⁴⁺Are preferred, and among them, the polyvalent metal is composed of these metals or is mainly composed of these metals, and in the metals of each valence, the equivalent metal of these predetermined metals is a majority in atomic ratio with respect to the total amount. Preferably, it accounts for 70% or more, especially 80% or more.
Further, a composite can be used as the metal hydrated oxide.
[0009]
As such a metal hydrated oxide, general formula (I)
M^II _1-x-zM^III _xM^IV _z(OH)_yA^n- _{(2 + x + 2z-y) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following: M^IVIs Ti⁴⁺, Zr⁴⁺, Sn⁴⁺, Mn⁴⁺And Ce⁴⁺A tetravalent metal containing at least one of the following, A^n-Is SO₄ ^2-And CO₃ ^2-An anion containing at least one divalent ion of the following, n is the average valence of the anion, x, y, z and m are 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4, 0 <m ≦ 3), among which at least M^II(In general formula (I), further satisfying x + z <1), in particular, general formula (II)
M^II _1-xM^III _x(OH)_yA^n- _{(2 + xy) / n}・ MH₂O
(Where M^IIIs Zn²⁺, Co²⁺And Cu²⁺A divalent metal comprising at least one of the following: M^IIIIs Al³⁺, Fe³⁺And Mn³⁺A trivalent metal comprising at least one of the following, A^n-Is SO₄ ^2-And CO₃ ^2-An anion containing at least one divalent ion among them, n is the average valence of the anion, x, y and m are 0 ≦ x ≦ 0.67, 0 ≦ y ≦ 0.7, 0 <m ≤3)
The crystalline metal hydrate represented by the following formula is preferable.
[0010]
The content of divalent, trivalent, and tetravalent metals in such a polyvalent metal hydrate is not particularly limited, but it is preferable to increase the content of the polyvalent anion. Based on the total amount of these polyvalent metals, 33 to 100%, particularly 50 to 100%, divalent metals, 0 to 67%, trivalent metals, 0 to 50%, and tetravalent metals, 0 to 20% for the trivalent metals. Each range is preferred.
For anions, SO₄ ^2-And / or CO₃ ^2-However, in addition to the above, other substances such as a hydroxyl ion, a halogen ion, an oxyhalogen ion, a nitrate ion, and a hydrogen carbonate ion may be present together.
The water content of the hydrated polyvalent metal is mH₂O preferably has a range in which m satisfies 0.5 ≦ m ≦ 2.
[0011]
In order to enhance the structural stability at the time of the heat treatment, the metal hydrate is preferably crystalline, and among them, the crystalline metal hydrate of the general formula (II) is preferable. As such a crystalline metal hydrate, a metal hydrate or a composite metal hydrate having a layered structure containing the above-mentioned polyvalent anion between layers is preferable, but is not limited as long as it is crystalline. This layered structure is obtained by alternately stacking layers composed of metal oxides and layers composed of anions and water. Therefore, when the metal hydrated oxide having a layered structure is subjected to heat treatment, first, the interlayer water mH₂When O is evaporated and the heat treatment is further continued, polyvalent anions between the layers are decomposed and gas is released. At that time, the metal oxide layer is stable, and the polyvalent anion between the layers is decomposed and can maintain the original structure even if it escapes as a gas, and the porous structure is formed and maintained. Become like
[0012]
To prepare the metal hydrate, one or more water-soluble compounds of the above-mentioned divalent metal, trivalent metal and tetravalent metal are used as an aqueous solution or a mixed aqueous solution.
As the water-soluble compound, halides, oxyhalides, nitrates, sulfates, bicarbonates and the like can be used. In addition, hydroxides such as nickel hydroxide, zinc hydroxide, copper hydroxide, iron hydroxide, magnesium hydroxide and aluminum hydroxide can be used if desired.
As a source of sulfate ions, it is convenient to use a sulfate for the water-soluble compound itself, but a sulfate such as sodium sulfate or potassium sulfate may be used. At this time, it is preferable that the sulfate is used as an aqueous solution, since it can take a simple addition form such as dropping.
[0013]
The metal hydrate containing a sulfate ion is preferably an aqueous alkali metal hydroxide or an aqueous solution thereof, preferably an aqueous alkali metal hydroxide solution, in which a raw metal salt aqueous solution containing a sulfate ion in advance, among which the raw metal salt itself is a sulfate, is used. Is added and the mixture is precipitated.
The content of the polyvalent anion can be adjusted by controlling the pH and the solution temperature during precipitation. The higher the concentration of sulfate ions in the raw material solution, the higher the sulfate ion content of the precipitate. Regarding the pH at the time of precipitation, it is generally possible to increase the content of polyvalent anions by precipitating the hydroxide from a low pH. It is preferable to set the range of 7 <pH <11 for a valent metal salt, 3 <pH <10 for a trivalent metal salt, and 1 <pH <9 for a tetravalent metal salt.
In order to increase the content of sulfate, it is advantageous to use a sulfate of a polyvalent metal as a raw material metal salt. However, an alkali hydroxide solution containing a sulfate is added to an aqueous solution of a polyvalent metal salt to precipitate the solution. You may make it do.
[0014]
The metal hydrate containing a carbonate ion is usually obtained by adding an alkali carbonate or an aqueous solution thereof to an aqueous solution of a polyvalent metal salt to cause precipitation. The concentration of the aqueous alkali carbonate solution is not particularly limited, but is preferably 0.1 M or more in consideration of precipitation efficiency and the like. The amount of alkali carbonate to be added is preferably in the range of 0.9 to 2 in equivalent ratio to the amount of polyvalent metal.
[0015]
The metal hydrate having a layered structure containing sulfate ions is Zn²⁺, Co²⁺And Cu²⁺A divalent metal water-soluble compound containing at least one of the following is hydrolyzed with alkali hydroxide in the presence of sulfate ions, preferably further aged, or²⁺, Co²⁺And Cu²⁺A divalent metal oxide containing at least one of²⁺, Co²⁺And Cu²⁺The compound is added to an aqueous solution containing a water-soluble compound of a divalent metal containing at least one of the above, and reacted in the presence of sulfate ions. The composite metal hydrate having a layered structure containing sulfate ions is Zn²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of²⁺Is hydrolyzed with an alkali hydroxide in the presence of sulfate ions, preferably further aged, or Zn²⁺, Co²⁺And Cu²⁺A divalent metal oxide containing at least one of²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of²⁺By adding to a mixed aqueous solution containing at least one of the above water-soluble compounds and reacting in the presence of sulfate ions.
[0016]
The hydrolysis is performed using an alkali metal hydroxide such as sodium hydroxide (also referred to as alkali hydroxide), an alkali metal carbonate such as sodium carbonate, an alkali metal bicarbonate such as sodium hydrogen carbonate, ammonia, or the like. Preferably, an alkali hydroxide is added. Among them, an aqueous solution is preferably added dropwise to an aqueous solution or a mixed aqueous solution of a predetermined water-soluble compound.
[0017]
The metal hydrate having a layered structure containing carbonate ions is Zn²⁺, Co²⁺And Cu²⁺Is obtained by hydrolyzing a water-soluble compound of a divalent metal containing at least one of the above with alkali carbonate, and preferably further aging. The composite metal hydrate having a layered structure containing carbonate ions is Zn²⁺, Co²⁺And Cu²⁺A water-soluble compound of a divalent metal containing at least one of³⁺And Fe³⁺A water-soluble compound of a trivalent metal containing at least one of²⁺The mixture is obtained by hydrolyzing a mixture of water-soluble compounds containing As the water-soluble compound of a divalent metal and the water-soluble compound of a trivalent metal, a halide, a nitrate, a sulfate, a hydrogen carbonate, or the like can be used, but a halide or a nitrate is preferable in consideration of the subsequent treatment. In addition, if desired, hydroxides such as nickel hydroxide, iron hydroxide, magnesium hydroxide, and aluminum hydroxide can be used.
[0018]
In the method for producing the predetermined hydrated oxide having a layered structure, the water-soluble compound as a raw material is preferably used as an aqueous solution or a mixed aqueous solution. In addition, in order to obtain a product having good crystallinity, hydrolysis is performed at a temperature of 40 to 120 ° C., particularly 60 to 100 ° C., in a pH range of 8 to 12, especially 9 to 11, and ripening is performed in a temperature range of 30 to It is preferably carried out at a temperature in the range of 70 ° C.
[0019]
The adsorbent of the present invention can be obtained by heat-treating a metal hydrate or a composite metal hydrate containing a polyanion such as a sulfate ion or a carbonate ion. The temperature of the heat treatment depends on the type of the anion, but is usually selected in the range of 100 to 600C, preferably 200 to 500C.
The heat treatment is particularly performed on a crystalline metal hydrate having a layered structure, so that polyvalent anions between the layers decompose and escape as a gas. It is preferable because it rises.
[0020]
In order to remove a sulfur compound using the sulfur adsorbent of the present invention, the adsorbent may be added to a gas or liquid (for example, a solution) containing the sulfur compound. After a predetermined time after the addition of the adsorbent, if the adsorbent is separated from a gas or a liquid (for example, a solution), the sulfur compound is taken into the adsorbent, and the sulfur compound in the gas or the liquid (for example, a solution) is removed. You. Although the adsorption time depends on the particle size of the adsorbent and the concentration of the sulfur compound, when the adsorbent is a powder, most of the sulfur compound is taken into the adsorbent in usually 30 minutes to 5 hours.
[0021]
The sulfur compound adsorbed by the adsorbent can be removed by heating the adsorbent. This heat treatment temperature is selected in the range of usually 300 to 900 ° C, preferably 500 to 800 ° C. By this heat treatment, the adsorbed sulfur compound is desorbed or decomposed and released as a gas, so that the adsorbent can be regenerated.
[0022]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the adsorbent of this invention, a low-concentration sulfur compound can be efficiently adsorbed and removed, and a bad smell removal and environmental purification are greatly contributed, and also the adsorbent can be easily regenerated. There is an advantage.
[0023]
【Example】
Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
[0024]
Example 1
80 g of zinc oxide was added to 2 liters of a 1M aqueous solution of zinc sulfate, stirred at 30 ° C. for 1 hour, and allowed to stand for 1 day to form a precipitate, which was filtered. As a result of X-ray diffraction, the precipitate thus obtained was hydrous zinc hydroxide having a layered structure and being crystalline and having a sulfate ion content of 0.9 mmol / g. The sulfated hydrous zinc oxide was further heat-treated in air at 300 ° C. for 4 hours to obtain an adsorbent. 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm, and the amount of hydrogen sulfide adsorbed was measured to be as large as 120 mg / g. From this, it is clear that the present adsorbent has good sulfur compound adsorption performance.
[0025]
Comparative Example 1
80 g of zinc oxide was added to 2 liters of a 1 M aqueous solution of zinc nitrate, and the mixture was stirred for 1 hour and allowed to stand for 1 day. Then, the formed precipitate was filtered to obtain hydrous zinc oxide containing nitrate ions. The nitrated ion-containing zinc hydroxide was heat-treated in air at 300 ° C. for 4 hours to obtain an adsorbent. 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm, and the amount of hydrogen sulfide adsorbed was measured to be as low as 15 mg / g.
[0026]
Example 2
A 1M aqueous solution of sodium carbonate was added to 100 ml of a 1M aqueous solution of cobalt nitrate until the pH reached 8, thereby precipitating hydrous cobalt oxide containing carbonate ions. Water was added to the suspension to make the total volume 2 liter, and after stirring for 4 hours, the precipitate was centrifuged. The carbonated hydrous cobalt oxide-containing precipitate was heat-treated at 300 ° C. for 3 hours in the air to release carbonate ions to obtain an adsorbent. 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm, and the amount of hydrogen sulfide adsorbed was measured. As a result, it was as high as 65 mg / g. From this, it is clear that the present adsorbent has good sulfur compound adsorption performance.
[0027]
Comparative Example 2
A 1M aqueous solution of sodium hydroxide was added to 100 ml of a 1M aqueous solution of cobalt nitrate until the pH reached 8, thereby precipitating hydrous cobalt oxide containing nitrate ions. Water was added to the suspension to make the total volume 2 liter, and after stirring for 4 hours, the precipitate was centrifuged. This nitrate ion-containing hydrated cobalt oxide precipitate was heated in air at 300 ° C. for 3 hours to obtain an adsorbent. 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm, and the amount of hydrogen sulfide adsorbed was measured to be as low as 10 mg / g.
[0028]
Example 3
A 1 M aqueous sodium carbonate solution is added to 100 ml of an aqueous solution containing 0.5 M copper sulfate and 0.5 M manganese sulfate until the pH becomes 8, and a mixture of hydrated copper oxide and manganese hydroxide containing carbonate ion and sulfate ion is precipitated. Was. Water was added to the suspension to make the total volume 2 liter, and after stirring for 4 hours, the precipitate was centrifuged. These metal hydrate precipitates containing polyanions were heated in air at 300 ° C. for 3 hours to decompose and release polyvalent anions to obtain an adsorbent. 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm, and the amount of hydrogen sulfide adsorbed was measured. As a result, it was as high as 90 mg / g. From this, it is clear that the present adsorbent has good sulfur compound adsorption performance.
[0029]
Comparative Example 3
A 1M aqueous solution of sodium hydroxide was added to 100 ml of an aqueous solution containing 0.5 M copper nitrate and 0.5 M manganese nitrate until the pH reached 8, thereby precipitating a mixture of copper oxide containing nitrate ions and manganese oxide. Water was added to the suspension to make the total volume 2 liter, and after stirring for 4 hours, the precipitate was centrifuged. The nitrate ion-containing composite metal hydrate precipitate was heated in air at 300 ° C. for 3 hours to release nitrate ions to obtain an adsorbent. When 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm and the amount of adsorption was measured, the amount of hydrogen sulfide adsorbed was as small as 30 mg / g.
[0030]
Example 4
To a 100 ml aqueous solution containing 0.7 M zinc chloride, 0.2 M titanium chloride, and 0.1 M zirconium oxychloride, add a 1 M aqueous sodium carbonate solution until the pH of the solution becomes 8, and add carbonated ion-containing zinc hydroxide and water. A mixture of titanium oxide and hydrous zirconium oxide was precipitated. Water was added to the suspension to make the total volume 2 liter, and after stirring for 4 hours, the precipitate was centrifuged. This carbonate ion-containing composite metal hydrate precipitate was subjected to a heat treatment in air at 300 ° C. for 3 hours to release carbonate ions to obtain an adsorbent. 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm, and the amount of hydrogen sulfide adsorbed was measured to be as high as 140 mg / g. From this, it is clear that the present adsorbent has good sulfur compound adsorption performance.
[0031]
Comparative Example 4
To 100 ml of an aqueous solution containing 0.7 M zinc chloride, 0.2 M titanium chloride, and 0.1 M zirconium oxychloride, add a 1 M aqueous sodium hydroxide solution until the pH of the solution becomes 8, and add chloride-containing hydrous zinc oxide; A mixture of hydrous titanium oxide and hydrous zirconium oxide was precipitated. Water was added to the suspension to make the total volume 2 liter, and after stirring for 4 hours, the precipitate was centrifuged. The chloride-containing composite metal hydrate precipitate was heat-treated in air at 300 ° C. for 3 hours to obtain an adsorbent. When 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm and the amount of adsorption was measured, the amount of hydrogen sulfide adsorbed was as small as 40 mg / g.
[0032]
Example 5
To a 100 ml aqueous solution containing 0.75 M zinc chloride and 0.25 M aluminum chloride, add a 1 M aqueous sodium carbonate solution until the pH of the solution becomes 8, and stir at 80 ° C. for 4 hours. A mixture of aluminum was precipitated. Water was added to the suspension to bring the total volume to 2 liters, and the mixture was stirred for 4 hours and aged, and then the precipitate was centrifuged. X-ray diffraction of the precipitate revealed that the precipitate was a crystalline compound having a layered structure. As a result of elemental analysis, the carbonate ion content was found to be 1.2 mmol / g. The precipitate was heated in air at 300 ° C. for 3 hours to decompose and release carbonate ions, thereby obtaining an adsorbent. When 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm and the amount of adsorption was measured by a batch method, the amount of hydrogen sulfide adsorbed was as large as 130 mg / g. From this, it is clear that the present adsorbent has good sulfur compound adsorption performance.
[0033]
Example 6
80 g of zinc oxide was added to 2 liters of a 1M aqueous solution of copper sulfate, and the mixture was stirred for 1 hour and left standing for 1 day to form a precipitate. The precipitate was filtered, and as a result of X-ray diffraction, a metal hydrate having a layered structure and being crystalline and having a sulfate ion content of 1.5 mmol / g was obtained. Further, the sulfated metal-containing metal hydrate was heated in air at 300 ° C. for 4 hours to obtain an adsorbent. When 1 g of this adsorbent was put into a gas having a hydrogen sulfide concentration of 10 ppm and the amount of adsorption was measured, the amount of hydrogen sulfide adsorbed was as large as 150 mg / g. From this, it is clear that the present adsorbent has good sulfur compound adsorption performance.
[0034]
Example 7
1 g of the adsorbent synthesized in Example 4 was put into 600 liters of a gas having a hydrogen sulfide concentration of 300 ppm, and the amount of hydrogen sulfide adsorbed was measured. As a result, the amount was 150 mg / g. The adsorbent was taken out and heated in air at 700 ° C. for 1 hour. When the sulfur concentration of the adsorbent after the heat treatment was analyzed, it was 0.5% or less, and 95% or more of sulfur could be desorbed. From this, it is clear that the adsorbed sulfur compound can be easily desorbed by the heat treatment.
[0035]
Example 8
0.3 g of the adsorbent from which the sulfur compound was desorbed in Example 7 was directly put into 200 liters of a gas having a hydrogen sulfide concentration of 300 ppm, and the amount of hydrogen sulfide adsorbed was measured. However, high adsorption performance was maintained.
In addition, 0.4 g of the adsorbent from which the sulfur compound was desorbed in Example 7 was added to 10 ml of a 1 M aqueous solution of zinc sulfate, and the mixture was stirred for 1 hour and allowed to stand for 1 day. Heat treatment was performed to obtain an adsorbent. When 0.3 g of this adsorbent was put into 200 liters of a gas having a hydrogen sulfide concentration of 300 ppm, the amount of hydrogen sulfide adsorbed was measured and found to be as high as 150 mg / g. From this, it is clear that the adsorbent after desorption can be regenerated by performing the sulfate treatment again.

Claims (9)

A sulfur compound adsorbent comprising a heat-treated metal hydrate containing a sulfate ion or a carbonate ion. Metal hydrous oxides containing sulfate ion or carbonate ion, the general formula ^{_{M II 1-x-z M}} III x M IV z (OH) y A n- (2 + x + 2z-y) / n · mH 2 O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ^{3+ metal, M IV} is ^{Ti 4+, Zr 4+, Sn 4+} , tetravalent metal containing at least one of ^{Mn 4+} and ^{Ce 4+, a n-} is _SO ^{4 2-and} _CO ^{3 2-} at least one of An anion containing a divalent ion of the formula, n is the average valence of the anion, x, y, z and m are 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4 And a metal hydrate represented by the following formula: 0 <m ≦ 3). Zn ^2+, an aqueous solution containing a water-soluble compound of a divalent metal comprising at least one of ^{Co 2+} and ^{Cu 2+,} or ^Zn 2+, water-soluble divalent metal including at least one of ^{Co 2+} and ^{Cu 2+} Mixed aqueous solution containing a compound and a water-soluble compound of a trivalent metal containing at least one of Al ³⁺ and Fe ³⁺ , or water solubility of a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ A mixed aqueous solution containing a compound and a water-soluble compound of Mn ²⁺ , or a water-soluble compound of a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and at least one of Al ³⁺ and Fe ³⁺ a water-soluble compound of trivalent metal ^including, Ti ^4+, Zr ^4+, water solubilizing tetravalent metal containing at least one of ^{Sn 4+} and ^{Ce 4+} A mixed aqueous solution containing an object, an alkali or an aqueous solution thereof hydroxide was added in the presence of sulfate ions, formula ^{_{M II 1-x-z M}} III x M IV z (OH) y A n- (2 + x + 2z-y) / n・ MH ₂ O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ^{3+ metal, M IV} is ^{Ti 4+, Zr 4+, Sn 4+} , tetravalent metal containing at least one of ^{Mn 4+} and ^{Ce 4+, a n-} is an anion containing _SO ^{4 2-,} n is an average of the anion The valences x, y, z and m are numbers satisfying 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4, x + z <1, 0 <m ≦ 3. is there)
3. The method for producing a sulfur compound adsorbent according to claim 1, wherein a metal hydrate containing a sulfate ion is precipitated, and the precipitate is heated at 100 to 600 ° C. . Zn ^2+, an aqueous solution containing a water-soluble compound of a divalent metal comprising at least one of ^{Co 2+} and ^{Cu 2+,} or ^Zn 2+, water-soluble divalent metal including at least one of ^{Co 2+} and ^{Cu 2+} Mixed aqueous solution containing a compound and a water-soluble compound of a trivalent metal containing at least one of Al ³⁺ and Fe ³⁺ , or water solubility of a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ A mixed aqueous solution containing a compound and a water-soluble compound of Mn ²⁺ , or a water-soluble compound of a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and at least one of Al ³⁺ and Fe ³⁺ a water-soluble compound of trivalent metal ^including, Ti ^4+, Zr ^4+, water solubilizing tetravalent metal containing at least one of ^{Sn 4+} and ^{Ce 4+} A mixed aqueous solution containing things, adding alkali carbonate or an aqueous solution thereof, the general formula ^{_{M II 1-x-z M}} III x M IV z (OH) y A n- (2 + x + 2z-y) / n · mH 2 O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ^{3+ metal, M IV} is ^{Ti 4+, Zr 4+, Sn 4+} , tetravalent metal containing at least one of ^{Mn 4+} and ^{Ce 4+, a n-} is an anion containing a _CO ^{3 2-,} n is an average of the anion The valences x, y, z and m are numbers satisfying 0 ≦ x ≦ 0.8, 0 ≦ y ≦ 0.7, 0 ≦ z ≦ 0.4, x + z <1, 0 <m ≦ 3. is there)
3. The method for producing a sulfur compound adsorbent according to claim 1, wherein a metal hydrate containing carbonate ions represented by the formula: is precipitated, and the precipitate is heated at 100 to 600 ° C. . Metal hydrous oxides containing sulfate ion or carbonate ion, the general formula ^{_{M II 1-x M III x}} (OH) y A n- (2 + x-y) / n · mH 2 O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ³⁺ The metal, ^An- is an anion containing at least one divalent ion of SO ₄ ^2- and CO ₃ ^2- , n is the average valence of the anion, x, y and m are 0 ≦ x ≦ 0.67, 0 ≦ y ≦ 0.7, 0 <m ≦ 3)
The sulfur compound adsorbent according to claim 1, which is a crystalline metal hydrate represented by the formula: Zn ^2+, an aqueous solution containing a water-soluble compound of a divalent metal comprising at least one of ^{Co 2+} and ^{Cu 2+,} or ^Zn 2+, water-soluble divalent metal including at least one of ^{Co 2+} and ^{Cu 2+} the compound, in a mixed aqueous solution containing at least one water-soluble compounds and water-soluble compounds of Mn ²⁺ trivalent metal including at least one of Al ³⁺ and Fe ^3+, alkali hydroxide in the presence of sulfate ions or after addition of the aqueous solution, and reacted at 40 to 120 ° C., the general formula ^{_{M II 1-x M III x}} (OH) y a n- (2 + x-y) / n · mH 2 O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ^{3+ metal, a n-anion} containing _SO ^{4 2-,} n is the average valence of anion, x, y and m are, 0 ≦ x ≦ 0.67,0 ≦ y ≦ 0.7,0 <m ≤3)
The method for producing a sulfur compound adsorbent according to claim 5, wherein a crystalline metal hydrate containing a sulfate ion represented by the formula: is precipitated, and the precipitate is heated at 100 to 600 ° C. . Zn ^2+, an aqueous solution containing a water-soluble compound of a divalent metal comprising at least one of ^{Co 2+} and ^{Cu 2+,} or ^Zn 2+, water-soluble divalent metal including at least one of ^{Co 2+} and ^{Cu 2+} the compound, in a mixed aqueous solution containing at least one trivalent water-soluble compound of a metal and a water-soluble compound of Mn ²⁺ containing at least one of Al ³⁺ and Fe ^3+, it was added alkali carbonate or an aqueous solution thereof Thereafter, the reaction was carried out at 40 to 120 ° C., and the general formula M ^II _1-x M ^III _x (OH) _y ^An- _{(2 + xy) / n} · mH ₂ O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ^{3+ metal, a n-anion} containing _CO ^{3 2-,} n is the average valence of anion, x, y and m are, 0 ≦ x ≦ 0.67,0 ≦ y ≦ 0.7,0 <m ≤3)
The method for producing a sulfur compound adsorbent according to claim 5, wherein a crystalline metal hydrate containing carbonate ions represented by the formula: is precipitated, and the precipitate is heated at 100 to 600 ° C. . Zn ^2+, an oxide of a divalent metal comprising at least one of ^{Co 2+} and ^{Cu 2+,} Zn 2+, an aqueous solution containing a water-soluble compound of a divalent metal comprising at least one of ^{Co 2+} and ^{Cu 2+} Or a water-soluble compound of a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , a water-soluble compound of a trivalent metal containing at least one of Al ³⁺ and Fe ³⁺ , and Mn ²⁺ was added to a mixed aqueous solution containing at least one of the water-soluble compounds, are reacted in the presence of sulfate ions, formula ^{_{M II 1-x M III x}} (OH) y a n- (2 + x-y) / _n · mH ₂ O
Wherein M ^II is a divalent metal containing at least one of Zn ²⁺ , Co ²⁺ and Cu ²⁺ , and M ^III is a trivalent metal containing at least one of Al ³⁺ , Fe ³⁺ and Mn ^{3+ metal, a n-anion} containing _SO ^{4 2-,} n is the average valence of anion, x, y and m are, 0 ≦ x ≦ 0.67,0 ≦ y ≦ 0.7,0 <m ≤3)
The method for producing a sulfur compound adsorbent according to claim 5, wherein a crystalline metal hydrate containing a sulfate ion represented by the formula: is precipitated, and the precipitate is heated at 100 to 600 ° C. . A method for removing and recovering a sulfur compound and regenerating an adsorbent, comprising the following steps (I) and (II).
Step (I)
A step of adding the sulfur compound adsorbent according to claim 1, 2 or 5 to a gas or liquid containing a sulfur compound, and adsorbing and removing the sulfur compound.
Step (II)
A step of subjecting the adsorbent obtained in step (I) to which the sulfur compound has been adsorbed to a heat treatment at 500 ° C. or higher to desorb and recover or decompose the sulfur compound and regenerate the adsorbent.