JPS5976537A - Adsorbent for mercury vapor - Google Patents

Abstract

PURPOSE:To provide an adsorbent for mercury vapor contained in various gases by depositing an oxide of iodine or oxyacid or its salt corresponding to the oxide on activated carbon. CONSTITUTION:An oxide of I such as I2O5 or IO2, and oxyacids such as HIO2 and HIO3 corresponding to said oxide or an alkali metallic salt of Na, K, etc., an alkaline earth metallic salt of Mg, Ca, Sr, etc. or an ammonium salt such as NH4IO4 or the like as its salt are deposited on activated carbon made from charcoal, coke, and a coconut shell resin. The activated carbon having 200- 2,000m<2>/g is put in the soln. or suspension of the above-mentioned materials with water or other solvent to deposit said materials at 5-500mg amt. of I in each 1g of the activated carbon. Such activated carbon is brought into contact for 1/5-20sec with gas contg. Hg vapor at <=150 deg.C, whereby the Hg vapor is adsorbed off.

Description

[Detailed description of the invention] The present invention relates to mercury vapor adsorbents in gases.

111. Does hydrogen gas, natural gas, incinerator exhaust gas, and exhaust gas from factories that handle mercury often contain mercury vapor? i Hydrogen is used in the process of manufacturing pharmaceuticals, 9 foods, and other products, and #'jk11. Mercury vapor can become a catalyst poison and contaminate products, causing problems. Mercury vapor in natural gas corrodes aluminum heat exchangers during the gas liquefaction process, causing major accidents. Furthermore, mercury vapor in incinerator exhaust gas and exhaust gas from factories that handle mercury vapor poses problems in terms of air pollution and the working environment.

Therefore, mercury vapor in these gases must be removed by some kind of treatment. Until now, methods for removing mercury from gas have been known, such as the chemical cleaning method and the dry adsorption method using adsorbents such as activated carbon and ion exchange resin. The disadvantages are that the removal efficiency of mercury vapor is insufficient and that no waste liquid is produced. The latter dry adsorption method has a small adsorption capacity for mercury vapor and is not fully satisfactory.

In view of these circumstances, the present inventors have conducted extensive research and found that activated carbon supporting iodine oxide or its corresponding oxygen acid or its salt efficiently adsorbs mercury vapor in gas. It was found that the adsorption capacity was extremely large.

That is, the present invention is a mercury vapor adsorbent in which activated carbon supports an oxide of iodine, an oxygen acid corresponding thereto, or a salt thereof (hereinafter also referred to as F-iodine-containing component).

Activated carbon used in the present invention includes charcoal, coke,
It is manufactured by a known method using coconut husk resin as a raw material, and its specific surface area is 200 to 2000 nfl.
Any item may be used as long as it is y.

Examples of iodine oxides used in the oxidation process include li1205, 102, etc., and oxygen acids corresponding to the 42r oxidation of iodine include, for example, HIO2.
゜D I 03, etc., and the salts of the oxygen acids include, for example) salts with alkali metals such as aluminum and potassium;
Salts with alkaline earth metals such as magnesium, calcium, and strontium, salts with ammonium, specifically Na I 02 , K I 02 + Na 103
! K 1035N114103. Mg(IO3)z
, Ca(1(1+)z ,5r(IO3)2゜NFl
, IO4, Kio4. NI]4104 etc. can be opened.

In the present invention, the loading of the iodine-containing component onto activated carbon is from 5 to 500 my, preferably from 10 to 400, as iodine per 1f of activated carbon.

The mercury vapor adsorbent of the present invention contains activated carbon, in addition to the above-mentioned iodine-containing component, thiocyanate, thiosulfate, sulfamate or sulfide of NH, Na, i<, Mg, ca or Sr, or elemental sulfur. (hereinafter also referred to as sulfur components), ■ Sulfuric acid, nitric acid, phosphoric acid.

Acids such as oxalic acid and citric acid (hereinafter also referred to as acid components), ■AI, V, Fe, Co, Ni, Cu, Zn or ammonium sulfates or nitrates (hereinafter referred to as acid components)
It may be one in which one or more of the following components are supported: (also referred to as a salt component) and (ii) a compound or iodide of K, Na4, or NH4 (hereinafter also referred to as a halide component). The above-mentioned sulfur component includes, for example, elemental sulfur, such as old 4SCN, Na5C
N, KSCN, Mg(SCN)2, Ca(SCN)2
Thiocyanates such as ゜5r(SCN)2, e.g. (NH4) 2520g, Na2S203t K
2SzO+, Mg5203. Ca 52031Sr
Thiosulfates such as S203, e.g. NH40S02N
H2゜Na05OzNHz, KO302NH2,
Mp: (O802NH2)2.

Ca (O502NII2)2, S r (050
2NII2)2, such as (NH4)2S, Na2S, K2S, i
N4gS.

Examples include sulfides such as CaS and SrS. Examples of the acid components include sulfuric acid, nitric acid, phosphoric acid, oxalic acid, and citric acid. As for the above inorganic salt, (NH4)2504, A12(504)3
, VO3O4.

FeSO4, Fe2 (804)3. CoSO4, NiS
For sulfuric acid such as O4, CuSO4゜7nSO+, NH4N
O3, Al(NO3)3.

VOO103)2. Fe(N□+)2. Fe(NO
3)3. Co(NO3)21-(NO3)2, Cu(
NO3)2. Examples include nitric acid J islands such as Zn (NO3)2.

, when supporting these components, the supporting h1 is less than 500, preferably 10 to 40 per 11 activated carbons.
There are 0 towns.

Water ρ1 according to the present invention! When preparing steam II and Acid-containing agents, the activated carbon contains 3 iodine components, and also contains no sulfur components, no acid components, and 1! In order to support the r-fuchi component and the halide component, for example, these components to be supported are both dissolved or suspended in water or a solvent,
Examples include a method of impregnating or scattering activated carbon with this and drying or firing it as required.

In addition, each component may be supported individually, and in this case, the order in which they are supported may be arbitrary.

The mercury vapor adsorbent of the present invention exhibits good adsorption effects such as high mercury vapor adsorption efficiency and adsorption capacity even when activated carbon supports only iodine-containing components, but in addition to this, the sulfur component.

Those that support one or more of acid components, inorganic salt components, and halide components are even more effective;
Among the ingredients in (2), those containing a greater variety of ingredients are more effective.

In order to remove mercury vapor from a gas using the mercury vapor adsorbent of the present invention, it is sufficient to bring the gas containing mercury vapor into contact with the adsorbent of the present invention. The contact temperature is 150°C or less, preferably -10 to 120°C, and the contact pressure is 50 to 120°C.
Preferably 01-85% I, contact time 25'C1
V10 to 30 seconds at % exchange valve', preferably ]/'15 to 2
It is 0 seconds. Also, trees! it) The contact fφ1 (of the young agent and the mercury group gas-containing gas) can be carried out using, for example, 1. a fixed Jffi, a moving bed, a fluidized bed, etc.

Example 1゜BET surface area 1280 rrl/f O) 16~
24 mesh of activated carbon Ao with a predetermined amount of iodine oxide (first component).

A specified amount of sulfate or nitrate (second component) and a specified amount of sulfur, thiocyanate, thiosulfate.

1+'1f115, sulfamine rr;>, t= (
Spread the amount of fat evenly on a cloth and dry at 120°C for 5'81. (IB to S to adsorption).

In addition, as a control, the second component 1. Li alone.

hj (positive, component 11.1.

In this way f! #Radar adsorbent A, 0-A, 6,
Each 6 from I3 to S +++i! G cm'! Packed into a glass column with zlc≦1Viyo (1: (air gmP/I included 'j'jcl) 25u of nitrogen gas was flowed at a linear flow rate of 40tc, ij + i L, water j?: 4AI
';Iσ, 7;l;f,lIノ,kei test line 7
The result is ji + 1 in the table below.

From this result, it can be seen that) the charcoal carrying fH', 45-component is an excellent water ii1:I! Junki intake t:ff17i
! It turns out that it is l.

2F two components alone or the third component alone on Ida activated carbon
It can be seen that even in river 5, the ability to absorb mercury vapor is extremely poor, and when a composite component of these components and the first component is added, it exhibits an extremely excellent ability to absorb mercury vapor. .

Example 2゜Example 1. Adsorbent A2+ A6 A6+ A91 A
I, +A14+ 13 +C,F,,I,J,84.
Fill a 1.6σφ glass column with 6 mg of P and 1, and add 11 of 2 mg containing 1φl of water.
Flow hydrogen gas in the anus at a linear flow rate of 40 mj/kick to 3 mj1. ．． A mercury vapor breakthrough adsorption test was conducted and the results are shown in Table 2.

Real IJiii, Example 3゜ Real 77i1i, Example 1. to adsorbent, 2* A41 A6
1 A91 A, +21 Al418 +C, I”,
I, J, M, l) and R each 6 rnf to 1.
A glass column of 6 (up to) φ was filled with 25'CO gas (N2B4Bvo196°02-1) containing mercury vapor.
4. ．． 5v01%, H2O-0.7v01%) was passed through the tube at a linear flow rate of 41) I'-nV/'src, and a breakthrough absorption test for mercury vapor was conducted. The results are shown in Table 8.

(hereinafter referred to as “Kinpaku”) □I Table 8

Claims (1)

[Claims] Activated carbon with iodine oxide or its corresponding i”i:
:? , +', a mercury vapor adsorbent on which an acid or its salt is supported.