THE RECOVERY OF ALKALI METAL CATALYST CONSTITUENTS BY THE USE OF SULPHUROUS ACID IN A COAL CONVERSION PROCESS

摘要

In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkaii metal residues are produced, alkali metal constituents are recovered from the particles primarily in the form of water-soluble alkali metal sulphites and bisulphites by treating the particles with a solution of sulphurous acid. The aqueous solution containing water-soluble alkali metal sulphites and bisulphites is then separated from the treated particles, treated to remove soluble aluminium compounds, and then recycled to the gasification process where the alkali metal sulphites and bisulphites serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.