Abstract: An improved process can be used for depolymerization of polyurethanes under mild conditions. Polyether polyols and polyamines can be recovered in high yields.

Abstract: A new and improved process can be used for depolymerization of polyurethanes with a strong inorganic base. Polyether polyols and polyamines can be recovered in high yields.

Abstract: Granules based on pyrogenically prepared silicon dioxide with the following physico-chemical characteristic data: Average particle diameter: ???10 to 120 ?m BET surface area: ???40 to 400 m2/g Pore volume: ??0.5 to 2.5 ml/g Pore distribution: content of pores of pore diameter <5 nm in the total pore volume of less than 5%, remainder meso- and macropores Tamped density: ?220 to 1,000 g/l Numerical content of particles in the <35% particle size range above the D10 value of the particle size distribution weighted according to volume which have tucks or closed off inner hollow spaces: They are prepared by a procedure in which silicon dioxide is dispersed in a liquid, preferably water, together with one or more auxiliaries, the dispersion is spray dried and the granules are optionally heat-treated and/or silanized. The granules are employed as a catalyst support.

Abstract: A continuous process and apparatus for the production of at least approximately spherical, substantially solid particles, in which the particles are granulated in a circulating fluidized bed. This can be achieved by spraying a suspension or a solution of the solid which forms the particles into a chamber. A drying gas is passed through the chamber at a velocity which is sufficient to effect pneumatic conveying of already partially dried or agglomerated particles. The particles conveyed by the drying gas stream are separated from the exhaust gas stream and returned, at least in part, to the chamber. Particles with a size within the desired particle size range are continuously discharged from the chamber, such that the mass present in the chamber remains constant.