JPH11137997A - Catalyst for hydrogenation and its production - Google Patents
Catalyst for hydrogenation and its productionInfo
- Publication number
- JPH11137997A JPH11137997A JP9305297A JP30529797A JPH11137997A JP H11137997 A JPH11137997 A JP H11137997A JP 9305297 A JP9305297 A JP 9305297A JP 30529797 A JP30529797 A JP 30529797A JP H11137997 A JPH11137997 A JP H11137997A
- Authority
- JP
- Japan
- Prior art keywords
- palladium
- catalyst
- carbon
- activated carbon
- hydrogenation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 135
- 238000005984 hydrogenation reaction Methods 0.000 title claims abstract description 43
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 167
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 139
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 62
- 239000011148 porous material Substances 0.000 claims abstract description 62
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 40
- 239000002245 particle Substances 0.000 claims abstract description 39
- 150000002940 palladium Chemical class 0.000 claims abstract description 38
- 239000002344 surface layer Substances 0.000 claims abstract description 13
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims description 70
- GOUHYARYYWKXHS-UHFFFAOYSA-N 4-formylbenzoic acid Chemical compound OC(=O)C1=CC=C(C=O)C=C1 GOUHYARYYWKXHS-UHFFFAOYSA-N 0.000 claims description 51
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical group OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 24
- 239000007864 aqueous solution Substances 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 21
- 230000001186 cumulative effect Effects 0.000 claims description 19
- 239000003638 chemical reducing agent Substances 0.000 claims description 17
- 239000000243 solution Substances 0.000 claims description 16
- 239000011734 sodium Substances 0.000 claims description 13
- 239000004480 active ingredient Substances 0.000 claims description 12
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 claims description 12
- 229910052708 sodium Inorganic materials 0.000 claims description 11
- 238000000746 purification Methods 0.000 claims description 10
- 229910052700 potassium Inorganic materials 0.000 claims description 9
- LPNBBFKOUUSUDB-UHFFFAOYSA-N p-toluic acid Chemical compound CC1=CC=C(C(O)=O)C=C1 LPNBBFKOUUSUDB-UHFFFAOYSA-N 0.000 claims description 8
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 7
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 4
- 239000011591 potassium Substances 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 150000001298 alcohols Chemical group 0.000 claims description 3
- 238000009835 boiling Methods 0.000 claims description 3
- 125000004432 carbon atom Chemical group C* 0.000 claims description 3
- 238000002425 crystallisation Methods 0.000 claims description 3
- YJVFFLUZDVXJQI-UHFFFAOYSA-L palladium(ii) acetate Chemical compound [Pd+2].CC([O-])=O.CC([O-])=O YJVFFLUZDVXJQI-UHFFFAOYSA-L 0.000 claims description 3
- 238000007670 refining Methods 0.000 claims 5
- 230000008025 crystallization Effects 0.000 claims 2
- 238000000926 separation method Methods 0.000 claims 2
- 230000000694 effects Effects 0.000 abstract description 23
- 125000000524 functional group Chemical group 0.000 abstract description 3
- 150000003934 aromatic aldehydes Chemical group 0.000 abstract 1
- 125000003118 aryl group Chemical group 0.000 abstract 1
- 230000000977 initiatory effect Effects 0.000 abstract 1
- 238000012360 testing method Methods 0.000 description 33
- 238000006243 chemical reaction Methods 0.000 description 22
- 230000003197 catalytic effect Effects 0.000 description 19
- 239000012535 impurity Substances 0.000 description 10
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 8
- 239000001257 hydrogen Substances 0.000 description 8
- 229910052739 hydrogen Inorganic materials 0.000 description 8
- 238000001179 sorption measurement Methods 0.000 description 8
- 238000006555 catalytic reaction Methods 0.000 description 7
- 238000006722 reduction reaction Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 238000009826 distribution Methods 0.000 description 6
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 5
- 229910017604 nitric acid Inorganic materials 0.000 description 5
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 230000004913 activation Effects 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000002923 metal particle Substances 0.000 description 3
- 239000002861 polymer material Substances 0.000 description 3
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 2
- 238000004811 liquid chromatography Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 238000010517 secondary reaction Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- DYNFCHNNOHNJFG-UHFFFAOYSA-N 2-formylbenzoic acid Chemical compound OC(=O)C1=CC=CC=C1C=O DYNFCHNNOHNJFG-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- 235000013162 Cocos nucifera Nutrition 0.000 description 1
- 244000060011 Cocos nucifera Species 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- FGDQGIKMWOAFIK-UHFFFAOYSA-N acetonitrile;phosphoric acid Chemical compound CC#N.OP(O)(O)=O FGDQGIKMWOAFIK-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- OKTJSMMVPCPJKN-YPZZEJLDSA-N carbon-10 atom Chemical class [10C] OKTJSMMVPCPJKN-YPZZEJLDSA-N 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- -1 polyethylene terephthalate Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000012279 sodium borohydride Substances 0.000 description 1
- 229910000033 sodium borohydride Inorganic materials 0.000 description 1
- 239000011973 solid acid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は有機物の水素添加反
応に用いる触媒、特に粗テレフタル酸の精製工程に用い
る触媒及びその製造法さらには触媒を用いた精製プロセ
スに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst used in a hydrogenation reaction of an organic substance, particularly to a catalyst used in a purification step of crude terephthalic acid, a method for producing the same, and a purification process using the catalyst.
【０００２】[0002]
【従来の技術】テレフタル酸は高分子材料の重要な原料
物質の一つであり、ポリエステル系繊維・フィルムやポ
リエチレンテレフタレート樹脂の原料として広く用いら
れる。2. Description of the Related Art Terephthalic acid is one of the important raw materials for polymer materials, and is widely used as a raw material for polyester fibers / films and polyethylene terephthalate resins.
【０００３】テレフタル酸の工業的製造には数種の方法
があるが、ほとんどがｐ−キシレンを代表とする１，４
−ジアルキルベンゼンの酸化によって行われる。この方
法では、酸化の際の副次的な反応により生成物中に多数
の不純物が含まれており、そのままでは高分子材料の原
料として不適当であるため、通常、精製が行われる。不
純物が存在するテレフタル酸を用いて製造した高分子材
料は黄色ないし褐色に着色し、繊維や樹脂として商品価
値が極めて低くなるが、この着色はテレフタル酸中の不
純物、特にｐ−ホルミル安息香酸（別名４−カルボキシ
ベンズアルデヒド、４−ＣＢＡと略すこともある）の存
在が最も大きな原因となっている。このため精製工程に
おいては、このｐ−ホルミル安息香酸を除去することが
主な目的となっている。There are several methods for the industrial production of terephthalic acid, most of which are 1,4 represented by p-xylene.
Carried out by oxidation of dialkylbenzene. In this method, a large number of impurities are contained in a product due to a secondary reaction at the time of oxidation, and it is unsuitable as a raw material of a polymer material as it is, so that purification is usually performed. A polymer material produced using terephthalic acid containing impurities is colored yellow or brown and has a very low commercial value as a fiber or a resin. This coloring is due to impurities in terephthalic acid, especially p-formylbenzoic acid ( (Also known as 4-carboxybenzaldehyde, sometimes abbreviated as 4-CBA). Therefore, the main purpose of the purification step is to remove the p-formylbenzoic acid.
【０００４】テレフタル酸精製にも幾つかの方法がある
が、その中でも粗テレフタル酸を高温、高圧下で水に溶
解し、ｐ−ホルミル安息香酸を触媒の存在下で水素添加
することによって、再結晶法で容易に分離可能なｐ−ト
ルイル酸にして除去する方法が多く用いられている。こ
れは図１に示す化学反応によって表される。There are several methods for terephthalic acid purification. Among them, crude terephthalic acid is dissolved in water at high temperature and high pressure, and hydrogenated in the presence of a catalyst to re-form p-formylbenzoic acid. A method of removing p-toluic acid, which can be easily separated by a crystallization method, and removing it is often used. This is represented by the chemical reaction shown in FIG.
【０００５】[0005]
【発明が解決しようとする課題】このような触媒を用い
て工業的使用を行うには、触媒の活性および寿命が重要
となる。In order to use such a catalyst for industrial use, the activity and life of the catalyst are important.
【０００６】本発明の目的は、上記の課題を解決し、活
性が良好な触媒およびその製造方法を提供するにある。An object of the present invention is to solve the above problems and provide a catalyst having good activity and a method for producing the same.
【０００７】本発明の他の目的は活性が良好で、かつ長
寿命の触媒およびその製造方法を提供するにある。Another object of the present invention is to provide a catalyst having good activity and a long life, and a method for producing the same.
【０００８】本発明のさらに他の目的はテレフタル酸の
生成プロセスに用いて好適な触媒およびその製造方法を
提供するにある。It is still another object of the present invention to provide a catalyst suitable for use in a process for producing terephthalic acid and a method for producing the same.
【０００９】本発明のさらに他の目的はより改良された
テレフタル酸の生成プロセスを提供するにある。It is yet another object of the present invention to provide a more improved process for producing terephthalic acid.
【００１０】[0010]
【課題を解決するための手段】本発明の一つの特徴によ
れば、パラジウム／炭素触媒は、パラジウム塩の水溶液
に炭素担体を入れて、還元剤でパラジウム塩を還元し、
炭素担体上に金属パラジウムを担持することにより調製
する。炭素担体としては、石炭，石油，椰子殻，木材等
を原料にし、破砕，成型，球状等の形状を有する活性
炭，活性炭以外の同様の炭素材料を使用する。パラジウ
ム塩としては塩化パラジウム，硝酸パラジウムが、還元
剤としては、ホルマリン，メタノール，ギ酸，ヒドラジ
ン，水素化ホウ素ナトリウム，水素ガス等が使用でき
る。また、パラジウム塩以外の金属塩が共存している場
合にも、本発明の目的を達成できる。According to one aspect of the present invention, a palladium / carbon catalyst is provided by placing a carbon carrier in an aqueous solution of a palladium salt, reducing the palladium salt with a reducing agent,
It is prepared by supporting metal palladium on a carbon support. As the carbon carrier, coal, petroleum, coconut shell, wood, or the like is used as a raw material, and activated carbon having a shape such as crushing, molding, and spherical shape, and similar carbon materials other than activated carbon are used. As the palladium salt, palladium chloride and palladium nitrate can be used, and as the reducing agent, formalin, methanol, formic acid, hydrazine, sodium borohydride, hydrogen gas and the like can be used. The object of the present invention can also be achieved when a metal salt other than a palladium salt is present.
【００１１】パラジウム粒子の粒径分布、並びにパラジ
ウム粒子が担持される炭素担体上の位置を制御するため
には、パラジウム塩の水溶液のｐＨを変えることにより
制御した。ｐＨ制御には、塩酸，硝酸等の酸を使用でき
る。パラジウム塩の水溶液に炭素担体を添加すると、パ
ラジウム塩が炭素担体上に吸着するが、パラジウム塩の
水溶液のｐＨによって、吸着の程度が著しく変化する。
吸着の程度が異なるこれらのｐＨを変えた触媒について
活性を評価した。その結果、触媒活性にｐＨ依存性があ
ることがわかり、炭素担体に吸着するパラジウム塩の量
に最適値が存在することが明らかになった。In order to control the particle size distribution of the palladium particles and the position of the palladium particles on the carbon support, they were controlled by changing the pH of the aqueous solution of the palladium salt. Acids such as hydrochloric acid and nitric acid can be used for pH control. When a carbon carrier is added to an aqueous solution of a palladium salt, the palladium salt is adsorbed on the carbon carrier, but the degree of the adsorption varies significantly depending on the pH of the aqueous solution of the palladium salt.
The activity was evaluated for those pH-changed catalysts having different degrees of adsorption. As a result, it was found that the catalytic activity had a pH dependence, and it became clear that there was an optimum value for the amount of palladium salt adsorbed on the carbon support.
【００１２】種々ｐＨを変えて調製した触媒について、
触媒活性とともに、走査型電子顕微鏡によりパラジウム
粒子の直径及び分布を分析した。また、炭素担体の表層
部を削り出し、炭素担体の表面から０．２ｍｍ以上の内
部と、表面から０．２ｍｍ以下の表層部におけるパラジ
ウム濃度を分析した。その結果、いずれの触媒において
も、炭素担体の内部及び表層部の両方にパラジウムが担
持されているが、触媒活性の高い触媒では、炭素担体表
層部にパラジウムが多く担持されており、かつ粒子径も
炭素担体内部に担持されているパラジウムよりも大きい
ことがわかった。活性の高い触媒の構造を模式的に示す
と図２のようになる。Regarding the catalyst prepared by changing various pH,
Along with the catalytic activity, the diameter and distribution of the palladium particles were analyzed using a scanning electron microscope. Further, the surface layer portion of the carbon support was cut out, and the palladium concentration in the interior 0.2 mm or more from the surface of the carbon support and the surface layer portion 0.2 mm or less from the surface was analyzed. As a result, in each of the catalysts, palladium is supported on both the inside and the surface layer of the carbon carrier.However, in a catalyst having high catalytic activity, a large amount of palladium is supported on the surface layer of the carbon carrier, and the particle diameter is large. Was also larger than the palladium supported inside the carbon support. FIG. 2 schematically shows the structure of a highly active catalyst.
【００１３】以上のことから、炭素担体上のパラジウム
粒子の粒子径を制御するためには、パラジウム塩水溶液
のｐＨを制御することで可能であることを見出した。さ
らに、触媒寿命について調べたところ、活性の高い触媒
において、触媒活性の経時的な低下が小さく、長寿命で
あることがわかった。From the above, it has been found that it is possible to control the particle size of the palladium particles on the carbon carrier by controlling the pH of the palladium salt aqueous solution. Further, when the catalyst life was examined, it was found that a catalyst having a high activity had a small decrease in the catalyst activity with time and had a long life.
【００１４】パラジウム／炭素触媒の調製において、パ
ラジウム塩水溶液のｐＨにより、炭素担体へのパラジウ
ム塩の吸着が変化する理由としては、次のように考えら
れる。炭素担体の表面（細孔の表面も含む）にはカルボ
キシル基やヒドロキシル基等の表面官能基が存在してお
り、特に破断面に多く存在すると考えられる。パラジウ
ム塩水溶液のｐＨが十分に低い場合には、溶液中の水素
イオン濃度が高く、カルボキシル基やヒドロキシル基の
水素のイオン化は抑制される。このときパラジウム塩が
添加されると、カルボキシル基やヒドロキシル基の水素
がイオン交換され、パラジウムと置換する。In the preparation of the palladium / carbon catalyst, the reason why the adsorption of the palladium salt on the carbon carrier changes depending on the pH of the aqueous solution of the palladium salt is considered as follows. Surface functional groups such as a carboxyl group and a hydroxyl group are present on the surface of the carbon carrier (including the surface of the pores), and it is considered that the surface functional groups are particularly present in large numbers on the fracture surface. When the pH of the aqueous solution of palladium salt is sufficiently low, the hydrogen ion concentration in the solution is high, and the ionization of hydrogen of the carboxyl group or the hydroxyl group is suppressed. At this time, when a palladium salt is added, hydrogen of a carboxyl group or a hydroxyl group is ion-exchanged and replaced with palladium.
【００１５】一方、パラジウム塩水溶液が酸性領域でｐ
Ｈが十分に高い場合には、溶液中の水素イオン濃度が低
く、カルボキシル基やヒドロキシル基の水素はイオン化
した状態となり、パラジウム塩を添加してもイオン交換
しないと考えられる。On the other hand, palladium salt aqueous solution is p
When H is sufficiently high, the hydrogen ion concentration in the solution is low, the hydrogen of the carboxyl group or the hydroxyl group is in an ionized state, and it is considered that ion exchange does not occur even when a palladium salt is added.
【００１６】これらのことから、パラジウムの炭素担体
上への吸着量は水溶液のｐＨによって変化するものと考
えられる。From these facts, it is considered that the amount of palladium adsorbed on the carbon carrier changes depending on the pH of the aqueous solution.
【００１７】炭素担体、パラジウム塩を含む水溶液に還
元剤を添加すると、炭素担体に吸着したパラジウムは担
体上で還元され、炭素担体に担持されたパラジウム粒子
となる。一般的に吸着パラジウムは原子オーダーで吸着
されているため、還元後のパラジウム金属の粒子経は小
さくなるものと考えられる。一方、炭素担体に吸着せず
に水溶液中に存在するパラジウム塩は、溶液中で還元さ
れてパラジウム金属の粒子となり、これが溶液中を拡散
して炭素担体上に沈着、担時される。When a reducing agent is added to an aqueous solution containing a carbon carrier and a palladium salt, the palladium adsorbed on the carbon carrier is reduced on the carrier to form palladium particles carried on the carbon carrier. Generally, it is considered that the adsorbed palladium is adsorbed in the atomic order, so that the particle diameter of the reduced palladium metal is reduced. On the other hand, the palladium salt present in the aqueous solution without being adsorbed on the carbon carrier is reduced in the solution to form palladium metal particles, which are diffused in the solution, deposited on the carbon carrier, and carried.
【００１８】炭素担体上で還元されて析出したパラジウ
ム粒子表面に液中のパラジウム塩が析出して粒径が大き
くなることも考えられる。また、溶液中で還元されて生
成したパラジウム金属粒子上でも、液中のパラジウム塩
の析出が生じると推測される。いずれの場合において
も、炭素担体の細孔内で析出した場合には、溶液の供給
が不足するため、粒径は大きくなるとしてもその程度は
小さいものと推測される。It is also conceivable that the palladium salt in the liquid precipitates on the surface of the palladium particles reduced and precipitated on the carbon support, and the particle diameter increases. It is also assumed that the palladium salt in the liquid is precipitated on the palladium metal particles generated by reduction in the solution. In any case, when the particles are precipitated in the pores of the carbon support, the supply of the solution is insufficient, so that even if the particle size increases, it is assumed that the degree is small.
【００１９】溶液中で還元・析出した粒子の場合には、
パラジウム塩の拡散は阻害されないためパラジウム粒子
径は大きくなる。大きい粒子は炭素担体の細孔内部には
侵入することができず、担体の表面にのみ沈着する。In the case of particles reduced and precipitated in a solution,
Since the diffusion of the palladium salt is not hindered, the palladium particle diameter increases. Large particles cannot penetrate into the pores of the carbon support, but only deposit on the surface of the support.
【００２０】以上のことから、パラジウム塩水溶液のｐ
Ｈを制御することにより、パラジウム塩の炭素担体への
吸着量を制御することは、結果として還元後のパラジウ
ム粒子径の分布，パラジウム粒子の担持位置を制御する
ことになる。From the above, it can be seen that p
Controlling the amount of palladium salt adsorbed on the carbon carrier by controlling H results in controlling the distribution of the reduced palladium particle diameter and the position where the palladium particles are supported.
【００２１】炭素担体の表層部のパラジウム濃度が高
く、かつ粒子径が炭素担体内部のパラジウム粒子径より
も大きい場合に高活性であり、かつ長寿命である理由は
次のように考えることができる。触媒反応の場を考える
と、微細な細孔には反応物質が拡散して行けず、反応に
あまり寄与できないが、表面では拡散が十分であり、表
面のパラジウム濃度を増加させて活性点を増やすことで
高活性化が図れる。また、使用時の触媒活性の低下原因
と考えられる、パラジウム粒子のシンタリングは、微小
粒子ほど生じやすいため、あらかじめ粒子径を大きくし
ておけばシンタリングが抑制でき、経時的な活性低下を
小さくできる。従って、パラジウム粒子を炭素担体表面
近傍に多く担持させ、かつ表面近傍のパラジウム粒子径
を大きくすることで、高活性で、かつ長寿命の触媒が得
られたものと考えられる。The reason for the high activity and long life when the palladium concentration in the surface layer of the carbon support is high and the particle size is larger than the palladium particle size inside the carbon support can be considered as follows. . Considering the catalytic reaction field, the reactants can not diffuse into the fine pores and can not contribute much to the reaction, but the diffusion is sufficient at the surface, increasing the palladium concentration on the surface to increase the active sites Thus, high activation can be achieved. In addition, sintering of palladium particles, which is considered to be a cause of reduction in catalytic activity during use, is more likely to occur as fine particles, so if the particle diameter is increased in advance, sintering can be suppressed, and the decrease in activity over time is reduced. it can. Therefore, it is considered that a catalyst with high activity and a long life was obtained by supporting a large amount of palladium particles near the surface of the carbon carrier and increasing the diameter of the palladium particles near the surface.
【００２２】なお、本発明が適用される触媒は、主とな
る活性成分がパラジウムからなるものであり、パラジウ
ム単独のみならず、元素周期律表第ＶＩＩＩ族のルテニ
ウム，ロジウム，白金，イリジウム，オスミウムを含む
ものでもよい。The catalyst to which the present invention is applied is one in which the main active ingredient is palladium. Not only palladium alone but also ruthenium, rhodium, platinum, iridium, osmium of Group VIII of the Periodic Table of the Elements. May be included.
【００２３】更に本発明の他の特徴によれば、ｐ−ホル
ミル安息香酸を高い割合で除去するために比較的長時間
を要する課題は、活性炭を担体としパラジウムを主たる
活性成分とする水素添加用触媒において、細孔径２ｎｍ
までの累積細孔容積が０．４０立方ｃｍ／ｇ以上０．５
５立方ｃｍ／ｇ以下の活性炭、さらに限定すれば細孔径
２ｎｍまでの累積細孔容積が０．４０立方ｃｍ／ｇ以上
０．５５立方ｃｍ／ｇ以下で、かつ細孔径２０ｎｍまで
の累積細孔容積が０．４５立方ｃｍ／ｇ以上０．６５立
方ｃｍ／ｇ以下である活性炭を担体に用いることで解決
可能である。この場合の活性炭は粒径が４ないし３２メ
ッシュ、さらに好ましくは４ないし８メッシュの間に含
まれる破砕炭とし、パラジウムを主成分とする活性成分
量は０．１〜５重量％とすることが望ましい。According to a further feature of the present invention, the problem of requiring a relatively long time to remove p-formylbenzoic acid at a high rate is the problem of hydrogenation using activated carbon as a carrier and palladium as a main active ingredient. In the catalyst, the pore size is 2 nm
Cumulative pore volume up to 0.40 cubic cm / g and 0.5
Activated carbon of 5 cubic cm / g or less, and more specifically, cumulative pore volume of 0.40 cubic cm / g or more and 0.55 cubic cm / g or less and a pore diameter of up to 20 nm, more specifically, a pore volume of up to 2 nm. The problem can be solved by using activated carbon having a volume of 0.45 cubic cm / g or more and 0.65 cubic cm / g or less as a carrier. In this case, the activated carbon is a crushed carbon having a particle size of 4 to 32 mesh, more preferably 4 to 8 mesh, and the amount of the active component mainly containing palladium is 0.1 to 5% by weight. desirable.
【００２４】この触媒は湿式による還元、すなわち溶液
中でパラジウム塩を活性炭に吸着させ、還元剤を加えて
還元することが好ましい。還元剤にはに炭素数１ないし
３個の飽和アルコール、特にメタノールを用いることが
望ましい。パラジウム塩には塩化パラジウム、硝酸パラ
ジウム、酢酸パラジウムの中から選んだ１種類以上の物
質、混合物が使用可能である。また還元の条件は、５０
度Ｃ以上、還元剤を加えた溶液の沸点未満の温度で、
０．５ないし１０時間加熱することが望ましい。This catalyst is preferably reduced by a wet method, that is, a palladium salt is adsorbed on activated carbon in a solution and reduced by adding a reducing agent. It is preferable to use a saturated alcohol having 1 to 3 carbon atoms, particularly methanol, as the reducing agent. As the palladium salt, one or more substances and mixtures selected from palladium chloride, palladium nitrate and palladium acetate can be used. The conditions for reduction are 50
At a temperature equal to or higher than C and lower than the boiling point of the solution containing the reducing agent,
It is desirable to heat for 0.5 to 10 hours.
【００２５】図２は本発明による触媒の累積細孔容積１
の一例と従来の触媒の累積細孔容積２の一例とを細孔径
との関係で表したグラフである。FIG. 2 shows the cumulative pore volume 1 of the catalyst according to the invention.
7 is a graph showing an example of the cumulative pore volume 2 of the conventional catalyst and an example of the cumulative pore volume 2 of the conventional catalyst in relation to the pore diameter.
【００２６】またこの触媒反応を長期間にわたって安定
に持続させるためには、触媒の担体となる活性炭に含ま
れるナトリウム、カリウム量を規定することが必要であ
り、具体的には活性炭中に含まれるナトリウムとカリウ
ムの総量が５０μｍｏｌ／ｇ未満、またはナトリウムが
６００ｐｐｍ未満、またはカリウムが９００ｐｐｍ未満
であることが必要である。In order to stably maintain this catalytic reaction over a long period of time, it is necessary to regulate the amounts of sodium and potassium contained in the activated carbon serving as a catalyst carrier. It is necessary that the total amount of sodium and potassium is less than 50 μmol / g, or that sodium is less than 600 ppm, or potassium is less than 900 ppm.
【００２７】テレフタル酸精製における触媒反応の速度
は種々の要因で決定されるが、その中でも反応点の数の
多少が大きな影響を及ぼす。一般に活性炭のように非常
に多数の細孔を有する担体では、活性成分の吸着により
多くの反応点が細孔表面に形成され反応速度も大きい。
活性炭は賦活条件を変えることにより、細孔容積を変え
ることが可能で、単位重量あたりの細孔容積が大きな活
性炭ほど、担体として用いた場合テレフタル酸精製の触
媒反応速度は大きくなる。The speed of the catalytic reaction in the purification of terephthalic acid is determined by various factors. Among them, the number of reaction points has a great influence. In general, in the case of a carrier having a very large number of pores, such as activated carbon, many reaction points are formed on the surface of the pores due to adsorption of active components, and the reaction rate is high.
The activated carbon can change the pore volume by changing the activation conditions. The activated carbon having a larger pore volume per unit weight has a higher catalytic reaction rate for terephthalic acid purification when used as a carrier.
【００２８】細孔容積が小さい場合、触媒製造の際に限
られた表面に活性成分が吸着するために、活性成分の分
散性が悪く金属粒子径が比較的大きくなることで活性が
低くなった。したがって細孔容積が大きい担体を用いる
ことが望ましい。When the pore volume is small, the active component is adsorbed on a limited surface during the production of the catalyst, so that the activity is low due to poor dispersibility of the active component and a relatively large metal particle diameter. . Therefore, it is desirable to use a carrier having a large pore volume.
【００２９】ただし、反応にはそれに適した細孔径が存
在し、反応に関わる不純物分子、例えばｐ−ホルミル安
息香酸が幾何学的に侵入不可能な細孔中に反応点が多数
あっても、その反応点は触媒反応に活かされず反応点が
少ないのと同じことになる。ｐ−ホルミル安息香酸の分
子の大きさは０．８ｎｍ程度であり、これらの分子が反
応点に到達し、また離脱してゆくには少なくともこれ以
上の細孔径が必要である。一方、大きな細孔径の孔だけ
で細孔容積を大きくしようとした場合、必然的に迷宮度
が上がり、反応物質の反応点への到達、生成物の離脱が
遅くなって反応速度は小さくなる。そこで特定範囲の細
孔径の細孔を多くするよう賦活した活性炭を担体として
用いた場合、テレフタル酸精製の触媒反応速度を大きく
することが可能である。However, the reaction has a pore size suitable for it, and even if there are many reaction sites in pores into which impurity molecules involved in the reaction, for example, p-formylbenzoic acid, cannot geometrically enter, The reaction point is not utilized in the catalytic reaction, which is the same as having few reaction points. The size of the molecules of p-formylbenzoic acid is about 0.8 nm, and these molecules need at least a larger pore diameter in order to reach and depart from the reaction site. On the other hand, if an attempt is made to increase the pore volume only by pores having a large pore diameter, the degree of labyrinth will inevitably increase, the reaction material will reach the reaction point and the release of the product will be slowed, and the reaction rate will be reduced. Therefore, when activated carbon activated to increase the number of pores having a specific range of pore diameters is used as a carrier, it is possible to increase the catalytic reaction rate of terephthalic acid purification.
【００３０】しかし、実際に触媒を用いる場合、細孔が
多すぎると担体の強度が低下し粉化が生じやすく、触媒
寿命を短くしたり、装置の配管詰まりを起こしたりして
悪影響をおよぼす。したがって担体の細孔量には適切な
範囲が存在する。However, when a catalyst is actually used, if the number of pores is too large, the strength of the carrier is reduced and powdering is apt to occur, which shortens the life of the catalyst and causes clogging of the piping of the apparatus, which has an adverse effect. Therefore, there is an appropriate range for the pore amount of the carrier.
【００３１】なお、細孔容積と類似の概念として比表面
積があり、一般に比表面積が大きいほど細かな細孔が多
いと言われるが、上記のように反応には特定範囲の径の
細孔が重要であり、マクロな物性値である比表面積の大
小と触媒活性の良否とは必ずしも関連性があるわけでは
ない。実際に発明者らは、同等の比表面積を有する担体
で、活性成分の粒径や分散度が同等であっても触媒活性
が高いものもあれば、非常に低いものもあることを経験
してきた。その場合、分析の結果それらの担体では互い
に異なる細孔径分布を有していることが明らかになっ
た。The specific surface area is a concept similar to the pore volume, and it is generally said that the larger the specific surface area, the more fine pores. It is important that the magnitude of the specific surface area, which is a macro physical property value, is not always related to the quality of the catalytic activity. In fact, the inventors have experienced that some carriers having the same specific surface area, even if the particle diameter and the degree of dispersion of the active ingredients are the same, have high catalytic activity, while others have very low catalytic activity. . In that case, the analysis revealed that those carriers had different pore size distributions.
【００３２】発明者らが種々の活性炭について検討した
結果、細孔径２ｎｍまでの累積細孔容積が０．４０立方
ｃｍ／ｇ以上０．５５立方ｃｍ／ｇ以下の破砕活性炭、
さらに限定するならば細孔径２ｎｍまでの累積細孔容積
が０．４０立方ｃｍ／ｇ以上０．５５立方ｃｍ／ｇ以下
で、かつ細孔径２０ｎｍまでの累積細孔容積が０．４５
立方ｃｍ／ｇ以上０．６５立方ｃｍ／ｇ以下である破砕
活性炭を触媒担体とすることにより、ｐ−ホルミル安息
香酸水素添加速度が非常に大きく、また充分な強度を有
する触媒を得られることが明らかになった。As a result of investigations on various types of activated carbon, the inventors have found that a crushed activated carbon having a cumulative pore volume of 0.40 cubic cm / g or more and 0.55 cubic cm / g or less up to a pore diameter of 2 nm,
More specifically, the cumulative pore volume up to a pore diameter of 2 nm is 0.40 cubic cm / g or more and 0.55 cubic cm / g or less, and the cumulative pore volume up to a pore diameter of 20 nm is 0.45 cubic cm / g.
By using a crushed activated carbon having a cubic cm / g or more and 0.65 cubic cm / g or less as a catalyst carrier, it is possible to obtain a catalyst having a very high p-formyl hydrogen benzoate addition rate and a sufficient strength. It was revealed.
【００３３】この場合、空間速度を大きくとるために
は、担体粒径を４ないし３２メッシュの範囲、より好ま
しくは４ないし８メッシュの範囲にすることが必要であ
る。これより細かい担体の場合には空間速度を大きくと
るのに大きな差圧が必要であり、余分な運転ユーティリ
ティが必要になる他、触媒床に力がかかって触媒の機械
的劣化を促進する。またこれより粗い破砕炭は製造自体
が困難であり、現在のところ実際的ではない。In this case, in order to increase the space velocity, it is necessary to set the carrier particle size in the range of 4 to 32 mesh, more preferably in the range of 4 to 8 mesh. In the case of a finer support, a large differential pressure is required to increase the space velocity, which requires extra operating utilities and also applies a force to the catalyst bed to promote mechanical deterioration of the catalyst. Also, coarser crushed coal is difficult to manufacture itself and is not practical at present.
【００３４】こうした触媒の活性成分にはパラジウムま
たはパラジウムを主とする８族貴金属元素が有効であ
り、これ以外の元素では活性が不足であったり、副反応
が生じて使用が困難である。活性成分量を０．１〜５重
量％とする理由は、これより少ない場合には触媒活性が
ほとんどないためで、これより多い場合は製造に要する
コストが多大となり工業的に用いることが困難になるた
めである。As an active component of such a catalyst, palladium or a Group 8 noble metal element mainly composed of palladium is effective, and other elements are insufficient in activity or cause a side reaction to be difficult to use. The reason for setting the amount of the active ingredient to 0.1 to 5% by weight is that if the amount is less than this, there is almost no catalytic activity, and if it is more than this, the cost required for production becomes large and it becomes difficult to use industrially. It is because it becomes.
【００３５】さらにこの触媒を製造する場合には、活性
成分の粒成長を防止するため還元に際して穏和な条件を
用いることが必須である。それには活性成分前駆体の塩
の溶液中で担体にそれを吸着させた後、液相において比
較的低温で還元を行うことが望ましい。活性成分前駆体
の塩には、塩化パラジウム、硝酸パラジウム、酢酸パラ
ジウム、それらの混合物が使用可能である。それ以外の
物質は高価で工業用途に不適であったり、反応を阻害す
る元素が残留するためである。還元剤としては炭素数が
１ないし３個の飽和アルコール、すなわちメタノール、
エタノール、１−プロパノール、２−プロパノールが好
ましいが、その中でも特にメタノールが有効である。ま
た還元条件は５０度Ｃ以上、還元剤を加えた溶液の沸点
未満が望ましく、それより低い時は還元反応が遅すぎ、
それ以上では活性成分の粒成長が生じる。Further, when producing this catalyst, it is essential to use mild conditions for reduction in order to prevent the growth of the active ingredient particles. For this purpose, it is desirable to adsorb it on the carrier in a solution of the salt of the active ingredient precursor and then carry out the reduction at a relatively low temperature in the liquid phase. As the salt of the active ingredient precursor, palladium chloride, palladium nitrate, palladium acetate, and a mixture thereof can be used. Other substances are expensive and unsuitable for industrial use, or elements that inhibit the reaction remain. As the reducing agent, a saturated alcohol having 1 to 3 carbon atoms, that is, methanol,
Ethanol, 1-propanol and 2-propanol are preferred, and among them, methanol is particularly effective. The reduction conditions are preferably 50 ° C. or higher and lower than the boiling point of the solution to which the reducing agent has been added. When the temperature is lower than 50 ° C., the reduction reaction is too slow,
Above that, grain growth of the active ingredient occurs.
【００３６】長寿命触媒を得るために担体とする活性炭
に含まれるアルカリ量の規定が必要な理由は、活性炭に
含まれるアルカリは水溶液中で容易に脱離しやすく、触
媒成分の吸着時に活性炭にアルカリが多く含まれている
場合には、活性成分とアルカリの間での交換により活性
成分が活性炭に吸着し、こうして得られた触媒では触媒
成分が担体から脱離しやすくなるためである。The reason why it is necessary to specify the amount of alkali contained in the activated carbon as a carrier in order to obtain a long-life catalyst is that the alkali contained in the activated carbon is easily desorbed in an aqueous solution, and the activated carbon is adsorbed upon adsorption of the catalyst component. When a large amount of is contained, the active component is adsorbed on the activated carbon by exchange between the active component and the alkali, and in the catalyst thus obtained, the catalyst component is easily desorbed from the carrier.
【００３７】[0037]
【発明の実施の形態】以下、本発明の一実施例を説明す
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.
【００３８】（実施例１）０．２ｇのパラジウムを含
む、硝酸パラジウムの水溶液５００ｍｌに活性炭（破砕
品、４〜８メッシュ、比表面積約１０００平方ｍ／ｇ）
３９．８ｇを入れ、硝酸パラジウムを活性炭担体に吸着
させた。その後、還元剤としてメタノールを５００ｍｌ
添加し、約７０度Ｃで加熱することでパラジウム塩を還
元し、担体上に担持した。これをろ過・水洗・乾燥して
パラジウム／炭素触媒を得た。パラジウム担持量は０．
５重量％とした。硝酸パラジウム水溶液に添加する塩酸
量を変えることで、ｐＨを変えた。硝酸パラジウム水溶
液のｐＨが０．０〜２．０の範囲で触媒を調製し、触媒
活性を評価した。(Example 1) Activated carbon (crushed product, 4 to 8 mesh, specific surface area: about 1000 m2 / g) was added to 500 ml of an aqueous solution of palladium nitrate containing 0.2 g of palladium.
39.8 g was charged, and palladium nitrate was adsorbed on the activated carbon carrier. Then, 500 ml of methanol as a reducing agent
The palladium salt was reduced by adding and heating at about 70 ° C., and was supported on a carrier. This was filtered, washed with water and dried to obtain a palladium / carbon catalyst. The amount of palladium supported is 0.
It was 5% by weight. The pH was changed by changing the amount of hydrochloric acid added to the aqueous solution of palladium nitrate. A catalyst was prepared at a pH of the aqueous solution of palladium nitrate of 0.0 to 2.0, and the catalytic activity was evaluated.
【００３９】触媒活性は、内容積５００ｍｌのオートク
レーブ中に、４−ＣＢＡを３０００ｐｐｍ含むテレフタ
ル酸４０ｇ，水１５０ｍｌ、及び触媒０．５ｇを入れ、
水素を５ｋｇ／平方ｃｍ封入した後、撹拌しながら２８
５度Ｃまで昇温した。その時の圧力は約７０ｋｇ／平方
ｃｍであった。２８５度Ｃで１５分間保持した後に冷却
し、９５度Ｃでろ過して固体と液体を分離し、固体を乾
燥した。得られた固体はテレフタル酸と触媒の混合物で
あり、この中からテレフタル酸を抜き取り、含有されて
いる４−ＣＢＡ濃度を液体クロマトグラフィで分析し、
その値から触媒活性を評価した。なお、触媒を添加せず
に実験しても、一部が液中に溶解して取り込まれるた
め、仕込み時の濃度３０００ｐｐｍよりも低くなり、テ
レフタル酸中の４−ＣＢＡ濃度は約１０００ｐｐｍであ
った。The catalytic activity was determined by placing 40 g of terephthalic acid containing 3000 ppm of 4-CBA, 150 ml of water, and 0.5 g of the catalyst in an autoclave having an internal volume of 500 ml.
After sealing 5 kg / square cm of hydrogen, 28
The temperature was raised to 5 ° C. The pressure at that time was about 70 kg / cm 2. After holding at 285 ° C. for 15 minutes, the mixture was cooled, filtered at 95 ° C. to separate a solid and a liquid, and the solid was dried. The obtained solid is a mixture of terephthalic acid and a catalyst, from which terephthalic acid is extracted, and the concentration of 4-CBA contained is analyzed by liquid chromatography.
The catalyst activity was evaluated from the value. In addition, even if it experimented without adding a catalyst, since the part was melt | dissolved in liquid and taken in, the concentration at the time of preparation became lower than 3000 ppm, and the 4-CBA concentration in terephthalic acid was about 1000 ppm. .
【００４０】担体上のパラジウム粒子の分散状態を見る
ため、触媒の断面を走査型電子顕微鏡で観察した。ま
た、触媒表層部と内部におけるパラジウム粒子の量的分
布を調べるため、触媒全体としてのパラジウム濃度を求
めると同時に、表面から０．２ｍｍの表層部を削り取っ
た部分の重量とパラジウム濃度を求め、表層部及び内部
のパラジウム濃度を求めた。In order to check the dispersion state of the palladium particles on the carrier, the cross section of the catalyst was observed with a scanning electron microscope. Further, in order to examine the quantitative distribution of palladium particles in the catalyst surface layer portion and inside, the palladium concentration of the entire catalyst was determined at the same time as the weight and palladium concentration of the portion obtained by shaving the surface layer portion of 0.2 mm from the surface were determined. The palladium concentration in parts and inside was determined.
【００４１】以上の結果を表１にまとめた。触媒調製時
のパラジウム塩水溶液のｐＨが０．７から２．０の場合
に、試験後の４−ＣＢＡ濃度が低く、高活性であること
がわかる。また、高活性を示した触媒では、表層部のパ
ラジウム粒子径が大きく、かつ表層部にパラジウムが多
く担持されていることがわかる。Table 1 summarizes the above results. It can be seen that when the pH of the aqueous solution of palladium salt during preparation of the catalyst is 0.7 to 2.0, the 4-CBA concentration after the test is low and the activity is high. In addition, it can be seen that in the catalyst exhibiting high activity, the palladium particle diameter in the surface layer is large, and a large amount of palladium is supported on the surface layer.
【００４２】[0042]
【表１】 [Table 1]
【００４３】（実施例２）実施例１の方法で調製した触
媒について、寿命試験を実施した。内容積２００ｍｌの
オートクレーブに、４−ＣＢＡを３０００ｐｐｍ含むテ
レフタル酸１６ｇ，水６０ｍｌ、及び触媒６．０ｇを入
れ、水素を５ｋｇ／ｃｍ封入した後、３００度Ｃで２０
時間保持した。(Example 2) The catalyst prepared by the method of Example 1 was subjected to a life test. In an autoclave having an inner volume of 200 ml, 16 g of terephthalic acid containing 3000 ppm of 4-CBA, 60 ml of water, and 6.0 g of a catalyst were charged, and hydrogen was sealed at 5 kg / cm.
Hold for hours.
【００４４】終了後に、触媒活性を実施例１と同様の方
法で評価した。その結果を表２に示す。触媒調製時のｐ
Ｈが０．７から２．０の場合に、試験後４−ＣＢＡ濃度
が低いことがわかる。すなわち、試験時間が２００時間
と短いけれども、本実験では高活性を示した触媒が同時
に長寿命であるという結果が得られた。After completion, the catalytic activity was evaluated in the same manner as in Example 1. Table 2 shows the results. P at the time of catalyst preparation
When H is 0.7 to 2.0, the 4-CBA concentration after the test is low. That is, although the test time was as short as 200 hours, the result obtained in this experiment was that the catalyst showing high activity had a long life at the same time.
【００４５】[0045]
【表２】 [Table 2]
【００４６】（実施例３）実施例１の方法において、パ
ラジウム塩として硝酸パラジウムの代わりに塩化パラジ
ウムを用いて触媒を調製し、実施例１と同様の方法で触
媒活性を評価した。その結果、実施例１と同様の、触媒
活性のｐＨ依存性が得られた。Example 3 A catalyst was prepared in the same manner as in Example 1 except that palladium chloride was used instead of palladium nitrate as the palladium salt, and the catalytic activity was evaluated in the same manner as in Example 1. As a result, the same pH dependence of the catalytic activity as in Example 1 was obtained.
【００４７】（実施例４）実施例１の方法において、還
元剤としてメタノールを硝酸パラジウムの水溶液との体
積比が１／４となる量だけ添加して触媒を調製し、実施
例１と同様の方法で触媒活性を評価した。その結果、実
施例１と同様の、触媒活性のｐＨ依存性が得られた。Example 4 In the method of Example 1, a catalyst was prepared by adding methanol as a reducing agent in an amount such that the volume ratio with respect to an aqueous solution of palladium nitrate was reduced to 1/4. The catalytic activity was evaluated by the method. As a result, the same pH dependence of the catalytic activity as in Example 1 was obtained.
【００４８】（実施例５）実施例１の方法において、硝
酸パラジウム水溶液のｐＨ制御のために添加する塩酸の
代わりに、硝酸を用いて触媒を調製し、実施例１と同様
の方法で触媒活性を評価した。その結果、実施例１と同
様の、触媒活性のｐＨ依存性が得られた。Example 5 A catalyst was prepared in the same manner as in Example 1 except that nitric acid was used instead of hydrochloric acid added to control the pH of the aqueous solution of palladium nitrate. Was evaluated. As a result, the same pH dependence of the catalytic activity as in Example 1 was obtained.
【００４９】（実施例６）賦活度が異なる活性炭６種に
つき、窒素吸着法により細孔容積を求めた。２ｎｍま
で、および２０ｎｍまでの累積細孔容積の値を表３に示
す。これらの活性炭に塩化パラジウム溶液をパラジウム
量に換算して０．５重量％加えて、充分吸着させた後メ
タノールを２．５リットル／ｇ−Ｐｄの割合で加え、恒
温槽中７０度Ｃで３時間加熱して還元し、触媒を得た。
触媒５．０ｇを、それぞれｐ−ホルミル安息香酸３００
０ｐｐｍを含有する粗テレフタル酸５０ｇおよび水５０
０ｍｌと混合し、内容量１リットルの撹拌機付きオート
クレーブに入れてバッチ試験を行った。気相を７．５気
圧の水素で置換し、２６０度Ｃで１５分加熱保持した
後、溶液を冷却してテレフタル酸を析出させた。得られ
たテレフタル酸中のｐ−ホルミル安息香酸の濃度は、カ
ラムにシリカＯＤＳ、溶離液にリン酸−アセトニトリル
を用いた液体クロマトグラフィによって測定した。結果
を表３に示す。Example 6 The pore volume of six types of activated carbons having different degrees of activation was determined by a nitrogen adsorption method. Table 3 shows the values of the cumulative pore volume up to 2 nm and up to 20 nm. To these activated carbons, a palladium chloride solution was added in an amount of 0.5% by weight in terms of the amount of palladium, and after sufficient adsorption, methanol was added at a rate of 2.5 L / g-Pd. After heating for a period of time to reduce, a catalyst was obtained.
5.0 g of the catalyst were each added to p-formylbenzoic acid 300
50 g of crude terephthalic acid containing 0 ppm and 50
The mixture was mixed with 0 ml and placed in a 1-liter autoclave with a stirrer to conduct a batch test. After replacing the gas phase with 7.5 atm of hydrogen and heating and holding at 260 ° C. for 15 minutes, the solution was cooled to precipitate terephthalic acid. The concentration of p-formylbenzoic acid in the obtained terephthalic acid was measured by liquid chromatography using silica ODS as a column and phosphoric acid-acetonitrile as an eluent. Table 3 shows the results.
【００５０】[0050]
【表３】 [Table 3]
【００５１】Ｎｏ．１は担体活性炭の累積細孔容積が小
さいために触媒上における反応速度が十分ではなく、ｐ
−ホルミル安息香酸の残存量が多い。また、Ｎｏ．６は
細孔容積が充分大きく、反応速度は速いが、担体の強度
が弱いために試験中の撹拌によって触媒が粉々に粉砕さ
れており、いずれも触媒に用いることは不適当である。No. No. 1 shows that the reaction rate on the catalyst is not sufficient due to the small cumulative pore volume of the activated carbon support, and p
-The residual amount of formylbenzoic acid is large. In addition, No. No. 6 has a sufficiently large pore volume and a high reaction rate, but the strength of the carrier is weak, so that the catalyst is pulverized into pieces by stirring during the test, and any of them is unsuitable for use as a catalyst.
【００５２】一方、本発明の請求範囲に入るＮｏ．２〜
５の活性炭を担体として用いた場合には、触媒反応が良
好でｐ−ホルミル安息香酸の残存量が比較的少なく、か
つ、強度も高く触媒として用いるのに適している。On the other hand, No. 1 falling within the claims of the present invention. Two
When the activated carbon of No. 5 is used as a carrier, the catalytic reaction is good, the residual amount of p-formylbenzoic acid is relatively small, and the strength is high, which is suitable for use as a catalyst.
【００５３】（実施例７）実施例６の触媒Ｎｏ．３の活
性炭を用い、ただし塩化パラジウム添加量をパラジウム
量に換算して０．００５重量％、０．２重量％、１．０
重量％、３．０重量％の触媒を製造し、実施例６と同様
にバッチ試験および試料分析を行った。結果を表４に示
す。(Example 7) The catalyst No. Activated carbon of No. 3 was used, except that the amount of palladium chloride added was converted to the amount of palladium to 0.005 wt%, 0.2 wt%,
By weight, 3.0% by weight of the catalyst was prepared and subjected to the batch test and the sample analysis as in Example 6. Table 4 shows the results.
【００５４】[0054]
【表４】 [Table 4]
【００５５】細孔容積が充分であっても、活性成分の少
ない触媒Ｎｏ．７では試験後の不純物濃度が高すぎ触媒
として用いられない。また、活性成分量が多いＮｏ．
９、１０では、活性成分量を多くしても不純物除去量が
頭打ちであり、製造コストが増すだけで得策ではない。
工業的には５ｗｔ％程度が上限である。Even if the pore volume is sufficient, the catalyst No. In No. 7, the impurity concentration after the test was too high to be used as a catalyst. In addition, No. 1 having a large amount of active ingredient
In Nos. 9 and 10, even if the amount of the active ingredient is increased, the amount of impurities removed reaches a plateau, and the production cost is increased, which is not a good idea.
Industrially, about 5 wt% is the upper limit.
【００５６】（比較例１）実施例６の触媒Ｎｏ．３同様
に、ただし還元剤を水素５体積％含有窒素気流中として
３２０度Ｃ３時間加熱還元して製造した触媒を、実施例
６と同様にバッチ試験を行って評価した。分析の結果、
試験後のテレフタル酸中のｐ−ホルミル安息香酸濃度は
６５３ｐｐｍであった。Ｘ線回折および透過型電子顕微
鏡観察によって解析したところ、この試料のパラジウム
平均粒径は約１９ｎｍであった。この位のパラジウム径
では活性が不足であり、触媒として不適である。Comparative Example 1 The catalyst of Example 6 3. Similarly, a catalyst produced by heating and reducing the reducing agent in a nitrogen gas stream containing 5% by volume of hydrogen at 320 ° C. for 3 hours was evaluated by performing a batch test in the same manner as in Example 6. As a result of the analysis,
The concentration of p-formylbenzoic acid in terephthalic acid after the test was 653 ppm. When analyzed by X-ray diffraction and transmission electron microscope observation, the average particle size of palladium of this sample was about 19 nm. At a palladium diameter of this order, the activity is insufficient, making it unsuitable as a catalyst.
【００５７】（実施例８）実施例６のＮｏ．１とＮｏ．
５の２つの触媒について、触媒約１００ｇを固定床に設
置し、粗テレフタル酸（ｐ−ホルミル安息香酸３０００
ｐｐｍ含有）２０重量％水溶液を送液しながら反応させ
るフロー試験を行った。反応温度は２７０度Ｃ、反応槽
の水素分圧は１０ｋｇｆ／平方ｃｍとし、それぞれの触
媒につき送液速度を変え、重量空間速度（ＷＨＳＶ）を
変化させることにより、反応速度とｐ−ホルミル安息香
酸残存量との関係を調べた。実験条件と結果を表５に示
す。(Embodiment 8) 1 and No.
About two catalysts of No. 5, about 100 g of the catalyst was placed on a fixed bed, and crude terephthalic acid (p-formylbenzoic acid 3000
A flow test was conducted in which the reaction was carried out while sending a 20 wt% aqueous solution (containing ppm). The reaction temperature was 270 ° C., the hydrogen partial pressure in the reaction tank was 10 kgf / square cm, and the reaction rate and p-formylbenzoic acid were changed by changing the liquid sending rate and the weight hourly space velocity (WHSV) for each catalyst. The relationship with the remaining amount was examined. Table 5 shows the experimental conditions and results.
【００５８】[0058]
【表５】 [Table 5]
【００５９】本発明によらない触媒Ｎｏ．１では、比較
的空間速度の小さな３．２ｈ（−１）であっても試験後
のテレフタル酸中ｐ−ホルミル安息香酸濃度が４３４ｐ
ｐｍであり、触媒活性が不足している。これよりも空間
速度の大きい領域ではさらに不純物濃度は高くなり、触
媒として用いるのは不適当である。一方、本発明による
触媒Ｎｏ．５では比較的大きい空間速度１１．１ｈ（−
１）においてもｐ−ホルミル安息香酸濃度は１６ｐｐｍ
と低く抑えられており、これより小さな空間速度におい
ても不純物除去の活性は高い。このように本発明を用い
ることにより、広範囲の空間速度において高い触媒活性
が得られる。Catalyst No. not according to the present invention. In No. 1, the p-formylbenzoic acid concentration in terephthalic acid after the test was 434 p even when the space velocity was relatively small at 3.2 h (−1).
pm, and the catalyst activity is insufficient. In a region where the space velocity is higher than this, the impurity concentration becomes higher, and it is unsuitable to use as a catalyst. On the other hand, the catalyst No. 5, the relatively high space velocity 11.1h (-
The p-formylbenzoic acid concentration in Example 1) was 16 ppm.
The activity of removing impurities is high even at a lower space velocity. Thus, by using the present invention, high catalytic activity can be obtained at a wide range of space velocities.
【００６０】（実施例９）Ｎａを１３００ｐｐｍ、Ｋを
１７５０ｐｐｍ含み、ｐＨが１０．４である活性炭１０
ｇを蒸留水１００ｍｌで１、５、１０回それぞれ洗浄し
た。未処理活性炭、および上記３種の水洗活性炭を用い
て、それぞれＰｄ０．５ｗｔ％を担持した触媒を調製し
た。これらの触媒を用いて実施例１と同様のバッチ試験
をそれぞれ行った。また触媒の寿命試験として、それぞ
れの触媒を上記のテレフタル酸溶液に入れて、オートク
レーブ中２８０度Ｃで１００時間保持した後取り出し、
上記と同じバッチ試験を行った。(Example 9) Activated carbon 10 containing 1300 ppm of Na and 1750 ppm of K and having a pH of 10.4
g was washed 1, 5 and 10 times with 100 ml of distilled water. Using untreated activated carbon and the above-mentioned three types of washed activated carbon, catalysts each supporting 0.5 wt% of Pd were prepared. Using these catalysts, the same batch test as in Example 1 was performed. As a catalyst life test, each catalyst was put into the above terephthalic acid solution, kept at 280 ° C. for 100 hours in an autoclave, and then taken out.
The same batch test was performed as described above.
【００６１】Ｐｄ吸着前の活性炭中の不純物量、活性炭
ｐＨ、寿命試験前後のバッチ試験結果を表６に示す。未
処理の活性炭ではＮａとＫの総量が１０１μｍｏｌ／ｇ
であり、これを用いた触媒の寿命試験前のバッチ試験で
はテレフタル酸中のｐ−ホルミル安息香酸濃度が８ｐｐ
ｍであった。しかし寿命試験後のｐ−ホルミル安息香酸
濃度は７２０ｐｐｍと大幅に増大しており、触媒の劣化
が大きいことがわかる。水洗１回の活性炭では、Ｎａと
Ｋの総量が７９μｍｏｌ／ｇで、これを用いた触媒では
寿命試験前後のバッチ試験におけるｐ−ホルミル安息香
酸濃度はそれぞれ２２ｐｐｍおよび７１７ｐｐｍであ
り、これも劣化が顕著である。一方、水洗５回、水洗１
０回の活性炭では、ＮａとＫの総量がそれぞれ４４μｍ
ｏｌ／ｇ、３４μｍｏｌ／ｇであり、これらの触媒の寿
命試験後のバッチ試験においてｐ−ホルミル酸濃度はそ
れぞれ５４９ｐｐｍ、４１５ｐｐｍであった。どちらも
寿命試験前に比べて触媒活性は劣化しているものの、そ
の度合は未処理、水洗１回の活性炭を用いた場合に比べ
て小さくなっており、長寿命の触媒である。Table 6 shows the amounts of impurities in the activated carbon before the adsorption of Pd, the pH of the activated carbon, and the results of batch tests before and after the life test. In untreated activated carbon, the total amount of Na and K is 101 μmol / g
In a batch test before the life test of the catalyst using this, the concentration of p-formylbenzoic acid in terephthalic acid was 8 pp.
m. However, the concentration of p-formylbenzoic acid after the life test was remarkably increased to 720 ppm, indicating that the deterioration of the catalyst was large. In the activated carbon once washed with water, the total amount of Na and K was 79 μmol / g, and in the catalyst using this, the p-formylbenzoic acid concentrations in the batch test before and after the life test were 22 ppm and 717 ppm, respectively. It is. On the other hand, washing 5 times, washing 1
In zero activated carbon, the total amount of Na and K was 44 μm each.
ol / g and 34 μmol / g, and the p-formyl acid concentration was 549 ppm and 415 ppm in a batch test after the life test of these catalysts. In both cases, the catalyst activity was deteriorated as compared to before the life test, but the degree was smaller than that in the case of using untreated, activated carbon once activated carbon, and a long life catalyst.
【００６２】[0062]
【表６】 [Table 6]
【００６３】（実施例１０）実施例９と同じＮａを約１
３００ｐｐｍ、Ｋを約１７５０ｐｐｍ含み、ｐＨが１
０．４である活性炭を０．０１、０．０３、０．０５Ｎ
の硝酸水溶液で洗浄した後、水洗を３回実施した。これ
らの活性炭を用いて実施例９と同じく、Ｐｄ０．５ｗｔ
％を担持した触媒を調製した。実施例９と同様、寿命試
験の前後にバッチ試験を行い、触媒活性の変化を調べ
た。Example 10 The same Na as in Example 9 was added to about 1
300 ppm, about 1750 ppm of K, pH 1
0.4, activated carbon 0.01, 0.03, 0.05N
After washing with an aqueous solution of nitric acid, water washing was performed three times. Using these activated carbons, Pd 0.5 wt.
% Was prepared. As in Example 9, a batch test was performed before and after the life test, and a change in catalytic activity was examined.
【００６４】活性炭中の不純物量と寿命試験前後のバッ
チ試験結果を表７に示す。０．０１Ｎ硝酸酸洗した活性
炭を用いた触媒では、ＮａとＫの総量が６１μｍｏｌ／
ｇであり、寿命試験前のバッチ試験ではｐ−ホルミル安
息香酸濃度が２９ｐｐｍであったが、寿命試験後は未処
理の活性炭を用いた触媒と同様、劣化が顕著であった。
一方、０．０３Ｎ、０．０５Ｎ硝酸酸洗の活性炭を用い
た触媒は、ＮａとＫの総量がそれぞれ１５μｍｏｌ／
ｇ、５μｍｏｌ／ｇであり、いずれも寿命試験後の触媒
活性が高く長寿命の触媒である。Table 7 shows the amounts of impurities in the activated carbon and the results of batch tests before and after the life test. In a catalyst using activated carbon washed with 0.01 N nitric acid, the total amount of Na and K was 61 μmol /
g, and the p-formylbenzoic acid concentration was 29 ppm in the batch test before the life test, but after the life test, the deterioration was remarkable like the catalyst using the untreated activated carbon.
On the other hand, a catalyst using activated carbon washed with nitric acid at 0.03 N and 0.05 N has a total amount of Na and K of 15 μmol /
g and 5 μmol / g, all of which have high catalytic activity after the life test and are long-lived catalysts.
【００６５】[0065]
【表７】 [Table 7]
【００６６】[0066]
【発明の効果】以上述べたように、本発明により、比較
的大きい空間速度でも長期間にわたって高い活性を有す
る水素添加触媒が得られる。また工業プロセスの上から
は、運転条件に多少のばらつきが生じても安定した品質
の製品を得ることが可能となる。As described above, according to the present invention, a hydrogenation catalyst having high activity over a long period of time even at a relatively high space velocity can be obtained. In addition, from the industrial process, it is possible to obtain a product of stable quality even if the operating conditions slightly vary.
【００６７】なお本発明では担体として活性炭のみを挙
げているが、将来的に活性炭と同じ性質、すなわち固体
酸点がなく、担体表面において副次的反応が生じないも
ので、かつ、本発明と同程度の細孔分布を有する材料が
得られた場合、本発明と同様の効果が期待できる。In the present invention, only activated carbon is mentioned as a carrier. However, in the future, activated carbon has the same properties as activated carbon, ie, it has no solid acid sites, does not cause any secondary reaction on the surface of the carrier, and has the same properties as the present invention. When a material having the same pore distribution is obtained, the same effect as that of the present invention can be expected.
【図面の簡単な説明】[Brief description of the drawings]
【図１】テレフタル酸精製プロセスにおける、ｐ−ホル
ミル安息香酸を水素添加してｐ−トルイル酸に転化させ
る反応を示した図である。FIG. 1 is a diagram showing a reaction for converting p-formylbenzoic acid to p-toluic acid by hydrogenation in a terephthalic acid purification process.
【図２】本発明による水素添加触媒担体の細孔径と累積
細孔容積の関係の一例である。FIG. 2 is an example of the relationship between the pore diameter and the cumulative pore volume of the hydrogenation catalyst carrier according to the present invention.
【図３】本発明による触媒の構造を模式的に示した図で
ある。FIG. 3 is a diagram schematically showing the structure of a catalyst according to the present invention.
１：本発明による累積細孔容積 ２：従来技術による累
積細孔容積 ３：パラジウム粒子 ４：活性炭1: Cumulative pore volume according to the invention 2: Cumulative pore volume according to the prior art 3: Palladium particles 4: Activated carbon
───────────────────────────────────────────────────── フロントページの続き (72)発明者 山下 寿生 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Toshio Yamashita 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd.
Claims (21)
た水素添加用パラジウム／炭素触媒において、（１）パ
ラジウム粒子が炭素担体の内部及び表面に担持されてお
り、（２）炭素担体の表面から０．２ｍｍ以上の内部に
比べて、表面から０．２ｍｍ以下の表層部の方に多くの
パラジウムが担持されており、（３）炭素担体の上記表
層部のパラジウム粒子の直径が、内部のパラジウム粒子
の直径よりも大きい、ことを特徴とする水素添加用パラ
ジウム／炭素触媒。1. A palladium / carbon catalyst for hydrogenation in which palladium is supported on a porous carbon support, wherein (1) palladium particles are supported on the inside and surface of the carbon support, and (2) the surface of the carbon support A larger amount of palladium is carried on the surface layer portion of not more than 0.2 mm from the surface as compared with the inside of not more than 0.2 mm from the surface, and (3) the diameter of the palladium particles in the surface layer portion of the carbon carrier is A palladium / carbon catalyst for hydrogenation, which is larger than the diameter of the palladium particles.
素触媒において、前記多孔質炭素担体が活性炭であるこ
とを特徴とする水素添加用パラジウム／炭素触媒。2. The palladium / carbon catalyst for hydrogenation according to claim 1, wherein the porous carbon carrier is activated carbon.
た水素添加用パラジウム／炭素触媒において、パラジウ
ム塩の水溶液中に炭素担体を添加し、パラジウム塩の一
部を炭素担体上に吸着させた後、還元剤を添加すること
により、吸着しているパラジウム塩を還元すると同時
に、水溶液中のパラジウム塩を還元して炭素担体表面に
沈着させることを特徴とする水素添加用パラジウム／炭
素触媒の製造方法。3. A palladium / carbon catalyst for hydrogenation in which palladium is supported on a porous carbon carrier, the carbon carrier is added to an aqueous solution of a palladium salt, and a part of the palladium salt is adsorbed on the carbon carrier. Thereafter, a palladium salt adsorbed is reduced by adding a reducing agent, and at the same time, the palladium salt in the aqueous solution is reduced and deposited on the surface of the carbon carrier, thereby producing a palladium / carbon catalyst for hydrogenation. Method.
素触媒において、前記パラジウム塩の水溶液のｐＨが
０．７〜２．０であることを特徴とする水素添加用パラ
ジウム／炭素触媒の製造方法。4. The palladium / carbon catalyst for hydrogenation according to claim 3, wherein the pH of the aqueous solution of the palladium salt is 0.7 to 2.0. Method.
素触媒において、前記パラジウム塩が硝酸パラジウムと
塩化パラジウムから選ばれた少なくとも１つよりなるこ
とを特徴とする水素添加用パラジウム／炭素触媒の製造
方法。5. The palladium / carbon catalyst for hydrogenation according to claim 4, wherein the palladium salt comprises at least one selected from palladium nitrate and palladium chloride. Production method.
性成分とする水素添加用触媒において、前記活性炭の細
孔径２ｎｍまでの累積細孔容積が０．４０立方ｃｍ／ｇ
以上０．５５立方ｃｍ／ｇ以下であることを特徴とする
水素添加触媒。6. A hydrogenation catalyst comprising activated carbon as a carrier and palladium as a main active component, wherein said activated carbon has a cumulative pore volume up to a pore diameter of 2 nm of 0.40 cubic cm / g.
A hydrogenation catalyst having a molecular weight of 0.55 cubic cm / g or less.
性成分とする水素添加用触媒において、前記活性炭の細
孔径２ｎｍまでの累積細孔容積が０．４０立方ｃｍ／ｇ
以上０．５５立方ｃｍ／ｇ以下であり、かつ前記活性炭
の細孔径２０ｎｍまでの累積細孔容積が０．４５立方ｃ
ｍ／ｇ以上０．６５立方ｃｍ／ｇ以下であることを特徴
とする水素添加触媒。7. A hydrogenation catalyst comprising activated carbon as a carrier and palladium as a main active component, wherein said activated carbon has a cumulative pore volume up to a pore diameter of 2 nm of 0.40 cubic cm / g.
0.55 cubic cm / g or less and the cumulative pore volume of the activated carbon up to a pore diameter of 20 nm is 0.45 cubic c.
A hydrogenation catalyst having a m / g of 0.65 cubic cm / g or less.
おいて、前記活性炭が４ないし３２メッシュ、より好ま
しくは４ないし８メッシュの粒径を有する破砕炭である
ことを特徴とする水素添加触媒。8. The hydrogenation catalyst according to claim 6, wherein the activated carbon is crushed carbon having a particle size of 4 to 32 mesh, more preferably 4 to 8 mesh. .
おいて、前記パラジウムの担持量が０．１〜５重量％で
あることを特徴とする水素添加触媒。9. The hydrogenation catalyst according to claim 6, wherein the carried amount of palladium is 0.1 to 5% by weight.
水素添加触媒において、その製造方法としてパラジウム
塩の溶液中に前記活性炭を含浸し、パラジウム塩を活性
炭に吸着させた後、還元剤を添加してパラジウム塩を還
元することによりパラジウムを活性炭に担持することを
特徴とする水素添加触媒の製造方法。10. The hydrogenation catalyst according to claim 6, wherein the activated carbon is impregnated in a solution of a palladium salt, the palladium salt is adsorbed on the activated carbon, and then a reducing agent is used. A method for producing a hydrogenation catalyst, characterized in that palladium is supported on activated carbon by reducing palladium salt by adding a catalyst.
方法において、前記還元剤が炭素数が１ないし３の飽和
アルコールであることを特徴とする水素添加触媒の製造
方法。11. The method for producing a hydrogenation catalyst according to claim 10, wherein the reducing agent is a saturated alcohol having 1 to 3 carbon atoms.
方法において、前記還元剤がメタノールであることを特
徴とする水素添加触媒の製造方法。12. The method for producing a hydrogenation catalyst according to claim 10, wherein the reducing agent is methanol.
方法において、前記パラジウム塩が塩化パラジウム、硝
酸パラジウム、酢酸パラジウムの中から選ばれる１種類
以上の物質または混合物であることを特徴とする水素添
加触媒の製造方法。13. The method for producing a hydrogenation catalyst according to claim 10, wherein the palladium salt is at least one substance or a mixture selected from palladium chloride, palladium nitrate, and palladium acetate. A method for producing a hydrogenation catalyst.
方法において、前記還元剤を添加後、５０度Ｃ以上、還
元剤を加えた前記溶液の沸点未満の温度で０．５ないし
１０時間加熱することを特徴とする水素添加触媒の還元
方法。14. The method for producing a hydrogenation catalyst according to claim 10, wherein after the addition of the reducing agent, the temperature is at least 50 ° C. and lower than the boiling point of the solution to which the reducing agent has been added for 0.5 to 10 hours. A method for reducing a hydrogenation catalyst, comprising heating.
安息香酸を、活性炭を担体とし、パラジウムを主たる活
性成分とする水素添加触媒存在下でｐ−トルイル酸に変
換した後、晶析、固液分離によって高純度テレフタル酸
を得るテレフタル酸精製プロセスにおいて、前記水素添
加触媒の担体として用いる活性炭の細孔径２ｎｍまでの
累積細孔容積が０．４０立方ｃｍ／ｇ以上０．５５立方
ｃｍ／ｇ以下であることを特徴とするテレフタル酸精製
プロセス。15. After converting p-formylbenzoic acid contained in crude terephthalic acid into p-toluic acid in the presence of a hydrogenation catalyst using activated carbon as a carrier and palladium as a main active ingredient, crystallization, solid-liquid In the terephthalic acid refining process of obtaining high-purity terephthalic acid by separation, the activated carbon used as a carrier for the hydrogenation catalyst has a cumulative pore volume up to 2 nm of pore diameter of 0.40 cubic cm / g to 0.55 cubic cm / g. A terephthalic acid refining process, characterized in that:
安息香酸を、活性炭を担体とし、パラジウムを主たる活
性成分とする水素添加触媒存在下でｐ−トルイル酸に変
換した後、晶析、固液分離によって高純度テレフタル酸
を得るテレフタル酸精製プロセスにおいて、前記水素添
加触媒の担体として用いる活性炭の細孔径２ｎｍまでの
累積細孔容積が０．４０立方ｃｍ／ｇ以上０．５５立方
ｃｍ／ｇ以下で、かつ細孔径２０ｎｍまでの累積細孔容
積が０．４５立方ｃｍ／ｇ以上０．６５立方ｃｍ／ｇ以
下であることを特徴とするテレフタル酸精製プロセス。16. After converting p-formylbenzoic acid contained in crude terephthalic acid into p-toluic acid in the presence of a hydrogenation catalyst using activated carbon as a carrier and palladium as a main active ingredient, crystallization, solid-liquid In the terephthalic acid refining process of obtaining high-purity terephthalic acid by separation, the activated carbon used as a carrier for the hydrogenation catalyst has a cumulative pore volume up to 2 nm of pore diameter of 0.40 cubic cm / g to 0.55 cubic cm / g. And a cumulative pore volume up to a pore diameter of 20 nm is 0.45 cubic cm / g or more and 0.65 cubic cm / g or less.
ル酸精製プロセスにおいて、前記水素添加触媒が請求項
３または請求項４のいずれかに記載の水素添加触媒であ
ることを特徴とするテレフタル酸精製プロセス。17. The terephthalic acid refining process according to claim 15 or 16, wherein the hydrogenation catalyst is the hydrogenation catalyst according to claim 3 or 4. process.
ル酸精製プロセスにおいて、前記水素添加触媒の製造に
請求項５から請求項９までのいずれかに記載の方法を用
いることを特徴とするテレフタル酸精製プロセス。18. A terephthalic acid refining process according to claim 15 or 16, wherein said hydrogenation catalyst is produced by using the method according to any one of claims 5 to 9. Purification process.
添加用触媒において、活性成分を吸着させる時点で活性
炭に含まれるナトリウムとカリウムの総計が５０μｍｏ
ｌ／ｇ未満である活性炭を用いることを特徴とする水素
添加用触媒。19. The hydrogenation catalyst according to claim 6, wherein the total amount of sodium and potassium contained in the activated carbon at the time of adsorbing the active component is 50 μmo.
A catalyst for hydrogenation comprising using activated carbon having an amount of less than 1 / g.
れかに記載の水素添加用触媒において、活性成分を吸着
させる時点で活性炭に含まれるナトリウム濃度が６００
ｐｐｍ未満である活性炭を用いることを特徴とする水素
添加用触媒。20. The hydrogenation catalyst according to claim 6, wherein the concentration of sodium contained in the activated carbon at the time of adsorbing the active component is 600.
A catalyst for hydrogenation comprising using activated carbon having a concentration of less than 1 ppm.
れかに記載の水素添加用触媒において、活性成分を吸着
させる時点で活性炭に含まれるナトリウム濃度が９００
ｐｐｍ未満である活性炭を用いることを特徴とする水素
添加用触媒。21. The catalyst for hydrogenation according to any one of claims 6 to 9, wherein the concentration of sodium contained in the activated carbon at the time of adsorbing the active component is 900.
A catalyst for hydrogenation comprising using activated carbon having a concentration of less than 1 ppm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9305297A JPH11137997A (en) | 1997-11-07 | 1997-11-07 | Catalyst for hydrogenation and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9305297A JPH11137997A (en) | 1997-11-07 | 1997-11-07 | Catalyst for hydrogenation and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11137997A true JPH11137997A (en) | 1999-05-25 |
Family
ID=17943415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9305297A Pending JPH11137997A (en) | 1997-11-07 | 1997-11-07 | Catalyst for hydrogenation and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11137997A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016047504A (en) * | 2014-08-28 | 2016-04-07 | 宇部興産株式会社 | Hydrogenation process, pretreatment method for hydrogenation catalyst, and hydrogenation catalyst using the same |
-
1997
- 1997-11-07 JP JP9305297A patent/JPH11137997A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016047504A (en) * | 2014-08-28 | 2016-04-07 | 宇部興産株式会社 | Hydrogenation process, pretreatment method for hydrogenation catalyst, and hydrogenation catalyst using the same |
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