 Polyetherimide resin compositions with improved ductility |
| OF THE INVENTION In a preferred embodiment, the thermoplastic resin composition of the present ... |
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| Slurry preparation of bis (halophthalimides) and of polyether polymers |
| PREFERRED EMBODIMENTS Any diamino compound may be employed in the method of this invention. E... |
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| Acyl and ester derivatives of 1,3-diazabicyclo[3,3,0]octane |
| What is claimed is: 1. An optically active or racemic compound represented by the general formula (1... |
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| Water purification system |
| OF THE INVENTION It is of paramount importance in various sections of the world at the present ... |
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| High performance solar still |
| What is claimed is: 1. A high performance solar distillation apparatus for vaporization and ... |
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| Process for distilling water and distillation apparatus |
| It is an object of the present invention to provide a process for distilling water in a high heat ... |
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| Solar apparatus and process |
| What is claimed is: 1. Solar apparatus for producing alcohol including a frame portion, a heating ... |
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| Automated solar still |
| I claim: 1. An automated solar still having a temperature sensitive valve incorporated within a ... |
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| Solar distillation device |
| I claim: 1. A distillation plant for distilling liquids, the distillation plant comprising: a ... |
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Catalyst for producing phthalic anhydride and process by using the same
| Details |
Inventors: Ueda, Kenji; Okuno, Masaaki; Kawabata, Tatsuya; Tanaka, Shinya;
Assignee: Nippon Shokubai Co., Ltd. (Osaka, JP)
Primary Examiner: Tsang; Cecilia
Assistant Examiner:
Attorney, Agent or Firm: Lowe, Price, LeBlanc & Becker
The invention relates to a catalyst for producing phthalic anhydride by gas phase catalytic oxidation of o-xylene and/or naphthalene with molecular oxygen or gas containing molecular oxygen and, to a process for producing phthalic anhydride by using said catalyst. The catalyst is made by supporting, on a heat-resistant inorganic carrier, a catalytic active substance which comprises: vanadium oxide; anatase type titanium dioxide having specific surface area of 10 to 60 m.sup.2 /g; niobium; at least one element selected from potassium, cesium, rubidium and thallium; phosphorus; and antimony. The catalytic active substance is prepared by using a five-valent antimony compound as an antimony source. The process for producing phthalic anhydride comprises use of said catalyst. |
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DETAILED DESCRIPTION The present invention provides a catalyst further improved on the catalyst performance compared with hitherto-known conventional catalysts and, therefore, useful for producing phthalic anhydride.
Accordingly, it is an object of this invention to provide a catalyst for producing phthalic anhydride with high selectivity by vapor phase catalytic oxidation of o-xylene and/or naphthalene.
It is a further object of this invention to provide a catalyst for producing phthalic anhydride by vapor phase catalytic oxidation of o-xylene and/or naphthalene, which makes it possible to produce phthalic anhydride with high selectivity even under high load and high temperature conditions and, which is superior in durability and makes it possible to produce phthalic anhydride under stable conditions for a long period of time.
The present inventors have found by extensive research that the above-mentioned object is attained, especially under a high temperature condition, by using a five-valent antimony compound such as represented by Sb.
sub.
2 O.
sub.
5 as a starting material, instead of a conventional trivalent antimony compound such as represented by Sb.
sub.
2 O.
sub.
3, in introducing antimony into a vanadium-titanium-based catalyst as an ingredient of catalytic active substances.
Based on this finding, the present invention was achieved.
Furthermore, it is found that the above-mentioned object is attained, especially under a high temperature condition, by using a five-valent antimony compound such as represented by Sb.
sub.
2 O.
sub.
5 as a starting material to introduce antimony even in a vanadium-titanium-based catalyst into which silver has been already added.
The first invention provides a catalyst for producing phthalic anhydride by vapor phase catalytic oxidation of o-xylene and/or naphthalene with molecular oxygen or gas containing molecular oxygen, having supported on a heat-resistant inorganic carrier a catalytic active substance; which comprises (A) 1 to 20 parts by weight of vanadium oxide as V
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Liquid Purification 
