Abstract: Processes for the removal of hydrogen sulphide from gas streams and for the regeneration of spent scrubbing liquor used in an absorber to remove hydrogen sulphide from a gas stream, are disclosed. In the former process, hydrogen sulphide is removed by five-valent oxovanadium which is simultaneously reduced to its four-valent state, the precipitation of which is prevented by having a sufficiently high concentration of total alkalinity present in the scrubbing solution. In the latter process the four-valent oxovanadium is oxidized to its five-valent state, preferably by an oxygen-containing gas, and a suffficently high concentration of total alkalinity is provided in the scrubbing liquor to yield a desired re-oxidation rate of the four-valent oxovanadium.

Abstract: The invention is directed to improving the quality of fluidization of fluidized solids and comprises the addition of fluidization promoters in particle form that have a smaller density and particle size than the neat solids. In a preferred embodiment of the invention the catalyst is a Fischer-Tropsch catalyst and the fluidization promoter comprises carbon particles.