Abstract: The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a solid base having on their surfaces either a coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, or an inner coat layer of an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium in an amount of from 1 to 20 parts by weight per 100 parts by weight of the solid base and an outer coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, and wherein the solid base is hydrotalcite.

Abstract: The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a solid base having on their surfaces either a coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, or an inner coat layer of an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium in an amount of from 1 to 20 parts by weight per 100 parts by weight of the solid base and an outer coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base.

Abstract: The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a solid base having on their surfaces either a coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, or an inner coat layer of an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium in an amount of from 1 to 20 parts by weight per 100 parts by weight of the solid base and an outer coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, and wherein the solid base is hydrotalcite.

Abstract: The invention provides a catalyst for thermal decomposition of an organic substance having the form of spherical granule having a particle diameter of 0.1 to 1.2 mm, a pore volume of 0.1 to 0.3 mL/g, a tap density of 1.05 to 1.4 g/mL, and a wear rate of 2% by weight or less, the catalyst being obtained by mixing and granulating a pulverized product of an inorganic oxide exemplified by titanium oxide with at least one sol selected from a titania sol, a silica sol, an alumina sol, and a zirconia sol to make spherical granules, calcining the spherical granules at a temperature from 400 to 850° C., and sieving the calcined granules.

Abstract: The invention provides a catalyst for thermal decomposition of an organic substance having the form of spherical granule having a particle diameter of 0.1 to 1.2 mm, a pore volume of 0.1 to 0.3 mL/g, a tap density of 1.05 to 1.4 g/mL, and a wear rate of 2% by weight or less, the catalyst being obtained by mixing and granulating a pulverized product of an inorganic oxide exemplified by titanium oxide with at least one sol selected from a titania sol, a silica sol, an alumina sol, and a zirconia sol to make spherical granules, calcining the spherical granules at a temperature from 400 to 850° C., and sieving the calcined granules.

Abstract: The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction between a dicarboxylic acid or ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a solid base having on their surfaces either a coat layer of titanic acid in an amount of from 0.1 to 50 parts by weight in terms of TiO2 per 100 parts by weight of the solid base, or an inner coat layer of an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium in an amount of from 1 to 20 parts by weight per 100 parts by weight of the solid base and an outer coat layer of titanic acid in an amount of from 0.

Abstract: An ion wind generator is provided at the back of a light source. The ion wind generator negatively ionizes air by corona discharges using negative-side needle electrodes and draws the negatively-ionized air to a ground-side mesh electrode to allow an airflow to be occurred. A photocatalyst filter is provided at the back of the ion wind generator. Even if ozone (O3) is generated and a lower fatty acid is composed by the ozone and alcohol remained in a casing, the lower fatty acid is decomposed into alcohol and oxygen by the photocatalyst filter.

Abstract: An ion wind generator is provided at the back of a light source. The ion wind generator negatively ionizes air by corona discharges using negative-side needle electrodes and draws the negatively-ionized air to a ground-side mesh electrode to allow an airflow to be occurred. A photocatalyst filter is provided at the back of the ion wind generator. Even if ozone (O3) is generated and a lower fatty acid is composed by the ozone and alcohol remained in a casing, the lower fatty acid is decomposed into alcohol and oxygen by the photocatalyst filter.

Abstract: A catalyst for reducing nitrogen oxides into nitrogen and water in the presence of a reducing agent, which comprises:(a) titanium;(b) at least one element selected from the group consisting of tungsten and molybdenum in a total amount of 10-25% by weight in terms of oxides; and(c) niobium in an amount of 0.1-2% by weight in terms of oxides.

Abstract: A catalyst for denitrizing nitrogen oxides contained in waste gases in the presence of arsenic compounds, which comprises: titanium and vanadium therein in weight ratios of oxides of titanium to oxides of vanadium ranging from 99.9:0.1 to 92.0:8.0, the vanadium being concentratedly contained in the surface layer of the catalyst up to 200 .mu.m in depth from the surface of the catalyst in concentrations of at least about 1.5 times as much as the concentrations of vanadium throughout the catalyst.The catalyst may further contain therein at least one of tungsten and zirconium.The catalyst preferably has micropores of about not less than about 50 .ANG. in amounts of 0.25-0.40 ml/g, and micropores of about 50-100 .ANG. in radius in amounts of about 10-40% by volume and micropores of about 1000-60000 .ANG. in radius in amounts of not less than about 10% by volume, respectively, based on the total volume of the micropores of not less than about 50.ANG. in radius.

Abstract: A catalyst for denitrizing nitrogen oxides contained in waste gas which contains a substantial amount of arsenic compounds therein, which comprises:(a) titanium, and(b) at least one element selected from the group consisting of arsenic and manganese. The catalyst is resistant to deactivation by arsenic compounds and retains high denitrizing activity over a long period of time. The catalyst may further contain at least one base metal selected from the group consisting of V, W, Mo, Cu, Fe, Cr, Co, Ni, Zn and Sn.

Abstract: A molded catalyst for fitting into a reactor vessel having an inlet and an outlet for a reactant gas, the catalyst having openings therethrough parallel to the direction of a reactant gas which is introduced into the reactor vessel from the inlet, the catalyst comprising: a wear-resistant front surface facing the inlet of the reactor vessel and a continuation of the front surface extending therefrom, the both being the front portion of the catalyst, and the remaining part of the catalyst made so wear-susceptible as to have either:(a) a wearability of 2-10% in a shaking abrasion test wherein grinding particles having an average particle size of 100 .mu.m and a Mohs scale of 9 are placed in the openings of the catalyst in an amount of 50% by volume based on the total volume of the openings, and the catalyst is shaked for three hours with an amplitude of 77 mm and a frequency of 320 per minute; or(b) a wearability of 7.

Abstract: A catalyst for denitrizing nitrogen oxides contained in waste gases, which comprises:(a) titanium, and(b) at least one base metal selected from the group consisting of V, W, Mo, Mn, Cu, Fe, Cr, Co, Ni, Zn and Sn, the catalyst containing titanium and the base metals in amounts of at least about 50% by weight in terms of oxides based on the catalyst, and titanium in amounts of about 80-99% by weight in terms of oxides and the base metals in amounts of about 20-1% by weight in terms of oxides, respectively, based on the total weight in terms of oxides of titanium and the base metals, and the catalyst having micropores of about 50-75000 .ANG. in radius in amounts of about 0.25-0.45 ml/g, and micropores of about 50-100 .ANG. in radius in amounts of about 10-40% by volume and micropores of about 500-60000 .ANG. in radius in amounts of not less than about 10% by volume, respectively, based on the total volume of the micropores of about 50-75000 .ANG.

Abstract: A molded catalyst for fitting into a reactor vessel having an inlet and an outlet for a reactant gas, the catalyst having openings therethrough parallel to the direction of a reactant gas which is introduced into the reactor vessel from the inlet, the catalyst comprising: a wear-resistant front portion facing the inlet of the reactor vessel, and the remaining portion of the catalyst made so wear-susceptible as to have either:(a) a wearability of 2-10% in a shaking abrasion test wherein grinding particles having an average particle size of 1000 .mu.m and a Mohs scale of 9 are placed in the openings of the catalyst in an amount of 50% by volume based on the total volume of the openings, and the catalyst is shaken for three hours with an amplitude of 77 mm and a frequency of 320 per minute; or(b) a wearability of 7.5-35% in an air abrasion test wherein an air which contains silica particles having an average particle size of 40 .mu.m in amounts of 70 g/m.sup.

Abstract: A method for packing catalysts comprising packing the catalysts having through-holes in the direction of the flow of the gas with plurality of them being arranged in the direction of the flow of the gas through the catalyst-packed layers, characterized by arranging the catalysts in such manner that the sections of the connecting parts in the direction of the flow of the gas do not lie on the same plane as at least one of the above sections of the connecting parts formed by the adjacent catalysts.