Abstract: The present invention relates to a method for obtaining a high yield of sugar alcohols containing five to six carbon atoms from cellulose-containing materials. In a first step the starting materials (for example microcrystalline cellulose, alpha-cellulose, wood and cellulose-containing residues, such as sugar cane bagasse or wood shavings) and an acid are brought into close contact with the substrates by a impregnation carried out in the liquid or gaseous phase. In addition, in a second step the starting materials impregnated with acid and preferably dried are brought into contact by the action of mechanical energy, such that the cellulose-containing materials are degraded into water-soluble products. Subsequently, in a third step, sugar alcohols having five to six carbon atoms are obtained in a high yield and in high selectivity from the water-soluble products in aqueous solution by hydrolytic hydrogenation by means of a metal-containing catalyst under hydrogen pressure.

Abstract: The present invention relates to a method for obtaining a high yield of sugar alcohols containing five to six carbon atoms from cellulose-containing materials. In a first step the starting materials (for example microcrystalline cellulose, alpha-cellulose, wood and cellulose-containing residues, such as sugar cane bagasse or wood shavings) and an acid are brought into close contact with the substrates by a impregnation carried out in the liquid or gaseous phase. In addition, in a second step the starting materials impregnated with acid and preferably dried are brought into contact by the action of mechanical energy, such that the cellulose-containing materials are degraded into water-soluble products. Subsequently, in a third step, sugar alcohols having five to six carbon atoms are obtained in a high yield and in high selectivity from the water-soluble products in aqueous solution by hydrolytic hydrogenation by means of a metal-containing catalyst under hydrogen pressure.

Abstract: An apparatus for friction stir welding includes a rotatably drivable pin having a drive end and a free end; a cylindrical engaging portion provided between the drive end and the free end and including a circumferential surface for engagement with one or more workpieces; and first and second shoulder elements arranged concentrically around the pin and positioned on respective sides of the of the engaging portion adjacent the drive end and the free end, respectively. The first and second shoulder elements include respective first and second bearing surfaces facing the engaging portion and extending perpendicularly to the axis of rotation. The mechanical and thermal loading of the pin and the thermal loading of the workpieces are reduced by merit of the second shoulder element being connected to the pin so as to be freely rotatable about the axis of rotation.

Abstract: Shown and described is an apparatus (1) for friction stir welding with a pin (3) which can be driven in a rotating manner and has a drive end (11) and a free end (13), wherein between the drive end (11) and the free end (13) there is provided a cylindrical engaging portion (15), with a first shoulder element (5), which is arranged on the side of the engaging portion (15) that is facing the drive end (11) concentrically around the pin (3) with respect to the axis of rotation (9) and which has a first bearing surface (19), facing the engaging portion (15) and extending perpendicularly to the axis of rotation (9), and with a second shoulder element (7), which is arranged on the side of the engaging portion (15) that is facing the free end (13) concentrically around the pin (3) with respect to the axis of rotation (9) and which has a second bearing surface (29), facing the engaging portion (15) and extending perpendicularly to the axis of rotation (9).