Process for the preparation of ruthenium catalysts, supported on activated carbon, which are selective in the production of light olefins from the synthesis gas

摘要

In the process for the preparation of ruthenium catalysts, supported on activated carbon, which are selective in the production of light olefins from the synthesis gas, use is made of high surface area activated carbon which is treated with inorganic acids in order to eliminate the inorganic matter and then at 1000 degree C in an inert atmosphere in order to destroy the residual surface groups. The vanadium oxide promoter is then incorporated by impregnation with a solution of ammonium vanadate in ethanol, drying in an inert atmosphere and calcining at 420 degree C. Ruthenium is deposited on this precursor either by adsorption of a solution of the Ru3(CO)12 complex in pentane or by impregnation with an ethanol solution of ruthenium trichloride. The precursors are then activated in a hydrogen flux at temperatures between 300 and 400 degree C. The CO hydrogenation reaction is carried out at atmospheric pressure in a dynamic system on stoichiometric CO:H2=1:2 mixtures. The unpromoted Ru catalyst is a typical methanation catalyst the percentage of CH4 in the reaction products is 99%. The incorporation of the vanadium oxide promoter in the ruthenium catalyst causes a significant increase in selectivity for light olefins, which rises to 75%.