JPS6161618A - Harmful gas adsorbent - Google Patents

Abstract

PURPOSE:To adsorb and remove efficiently by bringing halogen and hydrogen halide in a gas into contact with a specified adsorbent. CONSTITUTION:(1) A zinc compd. and (2) >=1 kind selected from a group consisting of (a)>=1 kind of alkali metal compd., (b)>=1 kind of an alkaline earth metal compd., and (c)>=1 kind among the compds. of Al, Ti, U, Cr, Mn, Fe, Co, Ni, Cd, and Pb are incorporated into activated carbon to obtain an adsorbent. A gas contg. halogen and/or hydrogen halide is brought into contact with the adsorbent to remove the halogen and/or hydrogen halide from the gas. Consequently, halogen and/or hydrogen halide from the gas. Consequently, halogen and hydrogen halide in the gas can be efficiently removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adsorbent for removing halogens and/or hydrogen halides and a method for treating gases containing said hydrogen compounds.

Process gases from petrochemical plants and chemical plants, by-product gases from 1pJ steel plants, electrolyzed hydrogen, reforming steam, and various other exhaust gases contain halogens and hydrogen halides. Hydrogen chloride is extremely harmful to the human body, even in large amounts, and has a corrosive effect on metal surfaces of equipment and equipment.Hydrogen is also toxic to the touch, so it often becomes a problem in processes such as chemical conversion. .

As a method for removing halogens and hydrogen halides from gases, chemical cleaning methods using K such as alkaline solutions or adsorption methods using activity etc. have been proposed, but the removal effects are poor and efficient adsorbents are desired. It was rare.

In view of these circumstances, the inventors of the present invention have conducted intensive studies and found that activated carbon contains a zinc compound, an alkali metal compound, an alkaline earth metal compound, Al, Ti, and v.

Cr, Mn, Fe, Co, Ni, Cd, P
The present invention was completed based on the discovery that halogens and hydrogen halides in the gas can be removed very efficiently by containing the metal compound b.

That is, the present invention L(1) Zinc compound and (2) (a) One or more alkali metal compounds.

(b) one or more alkaline earth metal compounds and (c) Al, Ti, V, Or, IJn, F'
e, Co, Ni.

An adsorbent for removing halogen and/or hydrogen halide, comprising activated carbon containing one or more of (a), (bl, and (c)) selected from the group consisting of one or more of Cd and Pb compounds. Z halogen and/or
Or a gas containing hydrogen halide: (1) Zinc compound (hereinafter sometimes referred to as the first component).

(2) (a) One or more alkali metal compounds.

(b) one or more alkaline earth metal compounds; and (c) An, Ti, 'i, Cr, 1ion,
Fe, Co, Ni.

An adsorbent comprising activated carbon containing one or more of (a), (b), and (c) (hereinafter also referred to as the second component) selected from the group consisting of one or more of Cd and Pb compounds. This is a method for removing halogen and/or hydrogen halide from the gas, which is characterized by contacting the gas.

The adsorbent of the present invention can be manufactured by incorporating the first component and the second component into activated carbon.

The activated carbons used in this case are coal, coke, charcoal, and Kingara. Manufactured by a known method using resin or the like as a raw material, and has a specific surface area of 200 to 2000 m
Any material with a diameter of 2/9 may be used, and its shape may be, for example, spherical, 9 cylindrical, crushed, powdered, or R-shaped, depending on the gas processing method.

Examples of the zinc compound used as the first component in the present invention include inorganic acid salts such as carbonates, basic carbonates, nitrates, sulfates, phosphates, silicates, halides, oxides, and hydroxides. Or inorganic compounds, Gitf! l lump,
Examples include organic acid salts such as ap acid salts and oxalate salts.

As an alkali metal compound which is one of the second components, L
Inorganic compounds such as bicarbonates, carbonates, nitrates, borates, silicates, sulfates, halides, and hydroxides of i, Na, K, Rh, and Cs.

Formate, acetate, oxalate, benzoate, pheno-μ
and organic acid salts such as sulfonic acid salts.

Examples of alkaline earth metal compounds that are another second component include carbonates, nitrates, sulfates, phosphates, halides, oxides, and hydroxides of Bθ, Mg, Ca, 'Sr, and Ba. Examples include inorganic acid salts or inorganic compounds such as, and organic acid salts such as formates, acetates, and oxalates.

The second parabola of the pond is Al, Ti, V, Cr, I
n.

Compounds of F'θ, Co, Ni, Cd, and Pb include carbonates, hydrogen carbonates, nitrates, borates, silicates, sulfates, phosphates, and halides of these metals.

Inorganic acid salts or inorganic compounds such as hydroxides, ammonium salts, oxides, organic acid salts such as formates, acetates, V oxalates, benzoates, salts of pheno-μ, salts of sulfonic acids, etc. Examples include.

The adsorbent of the present invention is one in which activated carbon contains both a first component and a second component. In this case, the second component is an alkali metal compound (hereinafter also referred to as component (a)) alone, Alkaline earth metal compound [component (b)
)] alone or Al, Cr, Ti
, 'Y, Mn, Te, Co, Ni, Cd.

Pb compounds [hereinafter also referred to as component (C)] may be contained alone, but among these, component (a) and component (b), component (b) and component (c), Alternatively, it may contain two types of components such as component (c) and component (a), or it may contain three types of components such as component (a), component (b), and component (c) at the same time. good.

Furthermore, the first component may contain two or more kinds of compounds, and the second component may contain two or more kinds of the same component, such as containing two different kinds of components in component (a). It may also contain different components.

The content of the first component in the metal compound-containing activated carbon is active I#1
The content of the second component is 0.1q to 3.0 atoms, preferably 0.2 to 20 key atoms, based on the metal per gram of activated carbon, and the content of the second component is 0.1 q-atoms to 3.0 atoms per gram of activated carbon. Atom ~ 5.01'/one atom, preferably α2η one atom ~ 4.
0! It is one atom.

The adsorbent of the present invention may be one in which each component is supported or impregnated to a certain degree of activity, or it may be obtained by adding each component to an activated carbon raw material and then activating this. Alternatively, a part of the first component and the second component may be added to the activated carbon raw material to activate it, and the remaining components may be impregnated therewith. When each component is impregnated onto activated carbon, it is preferable to dry or bake it after impregnation.

A possible method for impregnating each component onto activated carbon is to impregnate or spray activated carbon with a solution in which each component is dissolved or suspended in water (including an aqueous acid or alkali solution), various solvents, or the like. In addition, in the above preparation method, drying refers to a step of evaporating water or solvent in the impregnated activated carbon at a temperature of about 130°C or less, and calcination refers to a step of evaporating water or solvent in the impregnated activated carbon at a temperature of about 130°C or less.
This is a process in which the m-adhered activated carbon dried at the above temperature is heated in an atmosphere of inert gas, carbon dioxide, waterfish 9C2 combustion exhaust gas, etc., to thermally decompose some of the metal compounds and social parts.

In the above method, when substances other than oxides are impregnated onto activated carbon as the first component and second component (excluding alkali metal compounds), it is preferable to heat-treat the activated carbon by drying or firing after impregnation. When the second component (excluding the alkali metal compound) is not heat-treated with high activity, it is preferable to use an oxide as the first component and the second component (excluding the alkali metal compound). When an alkali metal compound other than an alkali metal hydroxide, carbonate, or Ti subacid is impregnated onto activated carbon as a second component, it is recommended to perform heat treatment such as drying or calcination after impregnation. ! At/? If no heat treatment is performed after that, the primary acid salt of hydroxide is used as an alkali metal compound,! ! It is better to use carbonate.

In the present invention, halogen refers to F2. C1□, Br2
and 2, hydrogen halides are HF', HC
I, HBr and ■Eng.

In order to remove halogen and hydrogen halide from a gas using the present invention, it is sufficient to bring the gas containing halogen and hydrogen halide into contact with an adsorbent.

Examples of contact methods include fixed layer, transfer*[.

Known means such as a fluidized bed can be used. In this case, the contact temperature is 600°C or less, preferably 0 to 300°C, and the pressure is 3001177cm2 or less, preferably 0.1
~250 kO/ctx2. Also, the contact time is 2
5° C., 1710 to 100 seconds, preferably 175 to 80 seconds, based on 1:97.

EXAMPLES The present invention will be explained in more detail below with reference to Examples.

Example I BET specific surface area 1150 m2/9016~24mes
A predetermined amount of the first component (zinc nitrate) and second component (alkali metal nitrate, alkaline earth metal nitrate, and A, Ti, V, and Cr) are added to the activated carbon AQ of h.

An aqueous solution containing In, Fa, Co, Hl, Cd, and Pb nitrates (v is a sulfate) was uniformly sprayed.

50 ytl of the obtained impregnated material was packed into a 4cxφ quartz glass column, and heated at a temperature increase rate of 5°C 7'win while flowing nitrogen gas at a linear flow rate of 10em/sec.
It was baked at 00° C. for 30 minutes.

The content of each metal compound in the nine adsorbents obtained is as shown in Table 1. l: AW1g each as metal 0
．． It was 2 to 2.01 N-atoms.

As a control, activated carbon AQ was impregnated with nitrate of each metal alone in the same manner as described above, and further impregnated with nitrate of each metal in nitrogen gas for 30 minutes.
An adsorbent was prepared which was calcined at 00°C for 30 minutes.

Each 15 pieces of the adsorbent thus obtained was divided into 1.6aφ
A gas (N2-9
7.5vo1%, H2O-Z, 5vo1%) was passed at a linear flow rate of 40w/sec (30℃ conversion) and a temperature of 200℃, and the change in removal rate of HCl-Cl2 (total C1 conversion are shown in Table 1.

Example 2 Adsorbents A□, AI, A3. of Example 1. Ag, B
2゜B3・B4・C19C6・C9・Dl, B2・B3
・Fill 15d each of B6, DB and Dlo into a L61Jφ glass cuff, and add 20pp of HHCl and CC.
30°C gas containing 12-1Qpp (B2-8 vol.
%.

N292VO1%) was passed through the tube at a linear flow rate of 40 em/sea, and the change over time in the removal rate of HCl-Cl2 (in terms of total C1) was investigated. The results are shown in Table 2.

Table 2 Example 3 Absorption agent A□ of Example 1, Al, A3. B2. C
6゜B3 and Dlo each 15gttl-1.6c shoulder φ
Filled a glass column with HHCl-20pp, 0O
Gas containing 12-10pp (N2-97.5vo1%,
H2O-15vo1%), HHBr-20pp, BB
r2-1Opp-containing gas ([2-97,5vo1%,
Tl2O-Z5vo1%)1. and HI-20
ppm, HI2-10pp containing gas (B2-97.
5vo1%.

B20-Z5vo1%) respectively at a flow rate of 4Qem/s
ea (30℃ conversion), distributed at a temperature of 250℃, HCl
-Cl2 (total C1 conversion) HBr Br2 (total Br conversion) and )II-Cl2 (total Ia calculation) to find the time until it leaks from the column (time until each removal rate reaches 95%), The results are summarized in Table 3.

Table 3

Claims (1)

[Claims] 1. (1) a zinc compound and (2) (a) one or more alkali metal compounds, (b) one or more alkaline earth metal compounds, and (c) Al, Ti, V, Cr, Mn, Fe, Co, Ni
Adsorption for removing halogen and/or hydrogen halide, comprising activated carbon containing one or more of (a), (b), and (c) selected from the group consisting of one or more of Cd and Pb compounds. Agent 2, a gas containing halogen and/or hydrogen halide, (1) a zinc compound, (2) (a) one or more alkali metal compounds, (b) one or more alkaline earth metal compounds, and (c) Al, Ti, V, Cr, Mn, Fe, Co, Ni
The gas is brought into contact with an adsorbent made of activated carbon containing one or more of (a), (b), and (c) selected from the group consisting of one or more of the following compounds: , Cd, and Pb. Method for removing halogen and/or hydrogen halide from