Abstract: A process is disclosed for the separation of catalyst-free working solution from working solution containing palladium black of the hydrogenation circuit of the anthraquinone process for the production of hydrogen peroxide. The problem addressed was to improve the separation of a catalyst-free working solution from the hydrogenation circuit containing Pd black, which was previously carried out using filter candles, in order to reduce the process costs. This problem is solved by the use of a microfilter operating on the crossflow principle with a filter membrane of ceramic material, more particularly .alpha.-aluminum oxide, or polyolefin with an average pore diameter of 0.1 to 3.0 .mu.m, preferably 0.1 to 1.5 .mu.m, and more preferably 0.5 to 1.5 .mu.m. The crossflow rate is generally 0.5 to 5 m/sec.

Abstract: Untreated coal is activated with steam at temperatures of 600.degree. to 950.degree. C. in a vibrating fluid bed, which is directly heated. The untreated coal is pre-dried by counter-current passage of the waste gases from the reaction either during feeding of the untreated coal or in the first part of the vibrating fluid bed trough. During the activation, secondary air can be passed in through a sparge pipe which is arranged parallel to the vibrating fluid bed trough. It is possible to carry out the heating exclusively with the supply of secondary air.