Abstract: Active carbon catalyst for recovering and removing sulfur oxides contained in flue gas by turning them into sulfuric acid by a catalytic desulfurization reaction. Powdery active carbon and fluororesin are kneaded by shearing force before being molded to a desired profile so that the inter-particulate gaps of powdery active carbon particles are made water-repellent. Flue gas preferably flows downwardly through a tower filled with such an active carbon catalyst, which is made to show a honeycomb structure having surfaces running only in a direction parallel to the flow. The activity of the catalyst maintains an enhanced level if dilute sulfuric acid or water is introduced into the active carbon from the top of the tower to cleanse the surface of the active carbon catalyst so that the catalyst layer is prevented from being clogged and contaminated by ashes and soot contained in flue gas.

Abstract: A process for the wet processing of a dioxin-containing material, wherein the material is contacted with an aqueous solution, acidified with hydrochloric acid and containing a catalyst dissolved therein, at a temperature lower than 100° C. to decompose the dioxins into harmless substances with a decomposition rate of at least 60%.

Abstract: A method for the hydrogenation of coal tar pitch which comprises subjecting said coal tar pitch containing toluene insolubles to slight hydrogenation in the presence of a hydrogenation catalyst having carried on a refractory inorganic oxide carrier at least one member selected from the class consisting of elemental metals, belonging to Groups VI B and VIII in the Periodic Table and oxides and sulfides thereof, under the conditions of 280.degree. to 400.degree. C. of reaction temperature, 20 to 200 kg/cm.sup.2. G of hydrogen pressure, 0.1 to 10 hr.sup.-1 of LHSV, and 500 to 2,000 Nl/liter of hydrogen to liquid ratio, and a catalyst therefor. The "slight" hydrogenation is hydrogenation to a degree such that the difference of hydrogen to carbon atomic ratio between the untreated coal tar pitch and the hydrogenated coal tar pitch falls in the range of 0.03 to 0.5.

Abstract: A catalyst for hydrocracking heavy hydrocarbon oils includes a porous inorganic carrier composed mainly of alumina or titania, and two or more catalytic metal components composited with the carrier. The metals of the catalytic metal components are either (a) V and at least one element selected from Zn, Fe, Co, Ni, Cu, Ag, Sn and Pb or (b) Mo and at least one element selected from Zn, Cu, Ag, Sn, Pb and the lanthanum-series elements. The catalyst has at least 60% of its total pore volume in pores with a diameter of 200 .ANG. or more, at least 40% of its totalpore volume in pores with a diameter of 300 .ANG. or more and not more than 20% of its total pore volume in pores with a diameter of at least 1000 .ANG.. Disclosed also is a process for hydrocracking a heavy hydrocarbon oil in the presence of the above catalyst.

Abstract: Improved .gamma.-alumina suitable for use as a catalyst carrier having high mechanical strength, a large specific surface area, and a substantially uniform pore size distribution in a relatively small portion of the pore size range below 500 A. Said alumina is produced by first establishing a seed aluminum hydroxide hydrogel having a pH of between 6 and 10 and then repetitively and sequentially adding an aluminum compound to adjust the pH to less than 5 or more than 11 to dissolve crystallites of aluminum hydroxide followed by addition of a neutralizing agent to return the hydrogel to the pH range from about 6 to 10 to cause pseudo-boehmite crystallites to grow. After a sufficient number of repetitions of said sequential addition, sparse aggregates of crystallites of the desired structure are formed. These are dried and calcined to produce the said alumina.