Abstract: An olefin oligomerization catalyst comprises at least one oxide selected from alumina and silica.cndot.alumina having a sulfate ion supported thereon. The amount of the sulfate ion contained in the catalyst is desirably in the range of 0.3 to 60% by weight based on the total weight of the alumina and/or silica.cndot.alumina and the sulfate ion. The olefin oligomerization catalyst can be readily prepared by bringing a sulfuric acid aqueous solution or an ammonium sulfate aqueous solution into contact with at least one compound selected from alumina, silica alumina and their precursors, followed by drying and calcining. Further, an olefin oligomerization catalyst comprises at least one oxide selected from alumina and silica.cndot.alumina on which a transition metal oxide is further supported in addition to the sulfate ion. By the use of the catalyst, a lower olefin produced in, for example, a petroleum refining process can be converted into an oligomer of high value added.

Abstract: An air cell having a single cell or a plurality of cells being aggregated is disclosed, that comprises a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode and composed of a water absorbing material that absorbs and holds an electrolytic solution, an electrolytic solution supply member protrusively disposed at a lower edge of the positive electrode and the negative electrode and adapted for supplying the electrolytic solution to the separator, a spacer for covering an outer surface of the positive electrode and the negative electrode and forming an air layer on the front surface thereof, and a cover member for covering surfaces of the electrolytic solution supply member, the cover member having a blank portion that is at least a minimum opening portion for supplying the electrolytic solution to the electrolytic solution supply member.

Abstract: A process for producing an elastic graphite molded product having light weight and excellent elasticity which comprises the steps of mixing elastic graphite particles as fillers with a binder resin, thereby to adhere the binder resin to the surface of the elastic graphite particles as in the form of a spider web, and thereafter molding the thus obtained mixture.

Abstract: A method for producing an elastic graphite material having a packing density of 1.0 g/cm.sup.3 or lower and a recovery of 50% or higher at a compressibility of 10 to 90% is provided, which comprises: heating a carbonaceous material rapidly while bringing the carbonaceous material into contact with nitric acid for expansion and foaming, and graphitizing the thus expanded and foamed carbonaceous material.

Abstract: A heavy oil such as an atmospheric pressure residue, a reduced pressure residue of petroleum, etc. is heated to 400.degree. to 500.degree. C. to carry out polycondensation and provide a pitch containing mesophase microspheres. This pitch is once cooled to 200.degree. to 400.degree. C. and a turbulent flow is imparted thereto to cause agglomeration of the mesophase microspheres. The resulting agglomerates are separated to obtain a crystallizable material enriched with quinoline insolubles. Production of the crystallizable material is preferably conducted in a separation tank accommodating the lower part of a heating polycondensation reactor (6) and having a stirring device (12).

Abstract: Pitch is produced continuously by heat treating a heavy hydrocarbon oil at a temperature of 350.degree. to 500.degree. C successively in two or more reactors connected in series, outlet to inlet, recirculating, at the same time, one portion of the liquid output substance from at least one reactor into that reactor, and introducing the output substance (molten pitch) of the final reactor into an after-treatment chamber of duct shape with an inactive atmosphere sealed therewithin thereby to cool the output substance.