JPH0526541B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for regenerating an adsorbent, and more specifically, an adsorbent containing monovalent and/or zero-valent copper and/or silver supported on a carrier is converted into an acetylene compound. The present invention relates to a method for regenerating the adsorbent by treating it with hydrogen at a temperature higher than room temperature after bringing it into contact with the adsorbent. (Prior art) Contact between an acetylene compound and copper and/or silver has been avoided because the acetylenides of copper and/or silver produced are unstable and sometimes explosive. . (Problems to be Solved by the Invention) The present inventors have discovered a method for purifying and removing trace amounts of acetylene compounds contained in vinyl compounds using an adsorbent in which copper and/or silver compounds are supported on a carrier. , had previously applied for a patent, but at that time, there was no known method for regenerating the used adsorbent, and there was a need for an appropriate regeneration method. (Means for Solving the Problems) As a result of intensive research on such a regeneration method, the present inventors discovered that an adsorbent containing monovalent and/or zero-valent copper and/or silver supported on a carrier is an acetylene compound. It has been discovered that the adsorbent can be reused by contacting the adsorbent with hydrogen and then subjecting it to hydrogen treatment at a temperature higher than room temperature. That is, in the present invention, when an acetylene compound adsorbed on an adsorbent containing monovalent and/or zero-valent copper and/or silver supported on a carrier is removed from the adsorbent and regenerated, the adsorbent is hydrogenated. This is a method for regenerating an adsorbent, which is characterized by treating the adsorbent at a temperature higher than room temperature in the presence of the adsorbent. The acetylene compound in the present invention has the general formula R
-C≡CH, where R is hydrogen or the number of carbon atoms
Refers to hydrocarbons up to 10, for example, CH≡CH,
CH ₃ C≡CH, C ₂ H ₅ C≡CH, C ₃ H ₇ C≡CH,
(CH ₃ ) ₂ CHC≡CH, C ₄ H ₉ C≡CH, C ₅ H ₁₁ C≡
CH, C ₆ H ₁₃ C≡CH, C ₇ H ₁₅ C≡CH, C ₈ H ₁₇ C≡
CH, C ₉ H ₁₉ C≡CH, C ₁₀ H ₂₁ C≡CH, CH ₂ = CH
-C≡CH, C ₆ H ₅ -C≡CH, and the like.
Further, there is no particular problem even if the substituent R contains a nitrogen atom and/or an oxygen atom. For example, H.C.
≡C・COOCH ₃ , HC≡C・CH ₂ OH, HC≡C・
CH ₂ COOH, HC≡C・CH ₂ −N(CH ₃ ) ₂ , HC≡
C・CH(CH ₃ )NHCH(CH ₃ ) ₂ , HC≡C・CH
(OH)CH ₃ , HC≡C・CH(OH)C ₆ H ₅ ,

[Formula] Examples include HC≡C・CONH ₂ and HC≡C・COOH. The adsorbent that can be used in the present invention has at least one of copper and/or silver inorganic acid salts, organic acid salts, or oxides supported on a carrier, and monovalent and/or It is reduced to zero-valent copper and/or silver. As the carrier, various metal oxides, activated carbon, etc. can be used, and alumina, silica, activated carbon, etc. are particularly preferred. In the composition, the ratio of copper and/or silver to carrier can be chosen in the range from 1 to 48% by weight, preferably from 5 to 30% by weight. There are no particular restrictions on the method for preparing the adsorbent, and any commonly used supporting method may be used as appropriate. As an example, it can be prepared by the following method. After impregnating an alumina carrier with a predetermined amount of a solution of an acid or water-soluble salt such as copper chloride, copper nitrate, copper acetate, or copper sulfate, the copper salt is dissolved in air or an inert gas containing oxygen. Heat to high temperature. This copper oxide is then reduced to monovalent or metallic copper by a dry or wet method using a suitable reducing agent such as hydrogen, hydrazine, formaldehyde, or sodium formate. There are no strict restrictions on the regeneration conditions when carrying out the method of the present invention, but it is generally carried out under the following conditions. The regeneration temperature can be selected in the range of 20 to 300°C, preferably 50 to 200°C. Regeneration pressure is 0~30Kg/
cm ² G, preferably in the range of 0 to 10 Kg/cm ² G. The required hydrogen flow rate depends on the supported copper and/or
Alternatively, a molar ratio relative to silver can be selected from 0.001 to 100, preferably from 0.1 to 10. The hydrogen used in the present invention may be pure or diluted with an inert gas, such as nitrogen. Furthermore, it is preferable to clean or purge the inside of the system with an inert gas in advance during regeneration. The preferred reaction type for carrying out the method of the present invention is a fixed bed reaction, and either an external heating type or an internal heating type can be used as the reactor, but the reactor is not limited thereto. (Effects of the Invention) By the method described above, the adsorbent can be easily and safely regenerated and reused. This is probably because the adsorbed acetylene compound was hydrogenated, desorbed, and regenerated. (Example) Hereinafter, typical examples of the method of the present invention will be shown and more specifically explained. However, these are merely examples, and it goes without saying that the present invention is not limited thereto. (Preparation method of adsorbent) Adsorbent A 290 g of copper nitrate trihydrate was dissolved in 318 g of water, and 318 g of γ-alumina was added thereto and evaporated and concentrated in a water bath.
The obtained copper salt-supported material was calcined in air at 600°C for 3 hours, and then subjected to reduction treatment at 200°C for 2 hours under a hydrogen stream to obtain copper-supported alumina adsorbent A. Adsorbent B 12 g of silver nitrate was dissolved in 32 g of water, 32 g of γ-alumina was added thereto, and the mixture was evaporated and concentrated on a water bath. The obtained silver salt support was calcined in air at 600°C for 3 hours, and then subjected to reduction treatment at 200°C for 2 hours under a hydrogen stream.
Silver-supported alumina adsorbent B was obtained. Adsorbent C 30 ml of activated carbon that had been dried at 150° C. for 3 hours was packed into a column with an inner diameter of 8 mm, and 40 ml of ethanol in which 6 g of cuprous chloride was dissolved was flowed. Thereafter, reduction treatment was performed at 200° C. for 2 hours in a hydrogen stream to obtain copper-supported activated carbon adsorbent C. Example 1 30 ml of adsorbent A was taken and packed into a column with an inner diameter of 8 mm, and a 1,3-butadiene mixture containing 1000 ppm of ethyl acetylene was passed through the column at room temperature and under a gauge pressure of 10 Kg/cm ² at LHSV 5 hr ^-1 . After passing the liquid for 1 hour,
The inside of the system was purged with nitrogen, and then hydrogen was passed through at 200 ml/mm at 00°C for 2 hours to carry out regeneration treatment. After cooling to room temperature and passing a 1,3-butadiene mixture containing ethyl acetylene, sampling and composition analysis were performed, and no acetylene compound was detected. Even after repeating the same operation 10 times, the ability of the adsorbent to adsorb ethyl acetylene did not decrease. Example 2 Adsorbents B and C were also tested in the same manner as in Example 1 to examine their ability to adsorb ethyl acetylene, and no decrease in activity was observed. Example 3 A styrene mixture containing 50 ppm of phenylacetylene in styrene was repeatedly subjected to liquid passage/regeneration treatment in the same manner as in Example 1. However, the pressure was normal pressure, and LHSV was performed at 10 Hr ^-1 . Even after regeneration exceeded 10 times, the phenylacetylene adsorption ability did not decrease.

Claims (1)

[Claims] 1. When removing and regenerating an acetylene compound adsorbed on an adsorbent containing monovalent and/or zero-valent copper and/or silver supported on a carrier, the adsorbent is treated in the presence of hydrogen, A method for regenerating an adsorbent characterized by processing at a temperature higher than room temperature.