Nippon Shokubai Kagaku Kogyo Co., Ltd.

Hideo Suzuki

Takahisa Sato

Shigemi Osaka

Shigeru Komatsu

Tatsuo Kubota

Masao Nakano

Takezo Sonoda

Michito Okane

A catalyst for the preparation of maleic anhydride by vapor phase catalytic oxidation of benzene with a molecular oxygen containing gas comprising a porous inert support of an alkali metal content, calculated as oxide, of at most 0.3% by weight and supported thereon a catalytic substance of a constituent composition comprising (a) 1 mole of vanadium pentoxide, (b) 0.3 to 1.2 moles of molybdenum trioxide, (c) 0.005 to 0.05 moles of phosphorus pentoxide, (d) 0.03 to 0.2 moles of sodium oxide and (d) 0 to 0.05 moles of potassium oxide.

Preparation of maleic anhydride

A catalyst for the preparation of maleic anhydride by vapor phase catalytic oxidation of benzene with a molecular oxygen containing gas comprising a porous inert support of an alkali metal content, calculated as oxide, of at most 0.3 % by weight and supported thereon a catalytic substance of a constituent composition comprising (a) 1 mole of vanadium pentoxide, (b) 0.3 to 1.2 moles of molybdenum trioxide, (c) 0.005 to 0.05 moles of phosphorus pentoxide, (d) 0.03 to 0.2 moles of sodium oxide and (d) 0 to 0.05 moles of potassium oxide.

Catalyst for the preparation of maleic anhydride

In a process for desulfurizing hydrogen sulfide-containing gases by contacting a hydrogen sulfide-containing gas with an alkaline aqueous solution containing a naphthoquinonesulfonate to effect absorption of hydrogen sulfide by said aqueous solution and subjecting the effluent to catalytic oxidation by a molecular oxygen-containing gas to separate out sulfur, an improvement which comprises (a) carrying out the absorption of hydrogen sulfide by using a liquid absorbent having a pH value adjusted by means of ammonia to 8 to 10 and containing as catalyst components a naphthoquinonesulfonate and a variable valent metal compound, (b) carrying out the catalytic oxidation of the effluent containing absorbed therein hydrogen sulfide by means of a molecular oxygen-containing gas as to lower the concentration of hydrosulfide ion in the effluent to 70 ppm or less and (c) recirculating the said liquid absorbent or effluent to the contact with the said hydrogen sulfide-containing gas.

Desulfurization process for hydrogen sulfide-containing gases

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Himeji, Japan

Hideo Suzuki