COMBUSTION PROCESS FOR FUEL CONTAINING VANADIUM COMPOUNDS

Oxycombustion process for producing energy wherein low ranking gaseous, liquid, solid, optionally solid melting hydrocarbon fractions are used as fuels, having a vanadium content in amounts by weight from 50 to 5,000 ppm or higher, and alkaline metals Ma in amounts from 20 to 10,000 ppm, wherein magnesium is added as oxide, or as a magnesium compound forming MgO in the combustion process, or mixtures thereof and a silico-aluminate wherein the molar ratio SiO2:Al2O3 ranges from 2:1 to 6:1; the combustor being refractored, isotherm or quasi-isotherm, flameless, working at temperatures in the range 1,250°-1,450° C. and under pressurized conditions, wherein the oxidant being used in admixture with water or steam, the ratio by moles oxidant:(water/steam) being comprised between about 1:0.4 and about 1:3, or the oxidant is used in admixture with flue gases recycled from the flue gases outletting the energy recovery equipments, wherein the water/steam amount is higher than 30% by volume, optionally by adding water to the recycled flue gases, the molar ratio oxidant:(water/steam) in flue gases being comprised from about 1:0.4 to about 1:3; the hydrocarbon fraction being fed in admixture with water or steam, the amount of water/steam being at least 30% by weight with respect to the hydrocarbon fraction.