Process and apparatus for oxygen enrichment in fuel conveying gases

A process for improving a combustion system for burning solid fuel particles in a combustion chamber and creating a flue gas, the method comprising:

• creating a fuel gas stream by mixing the solid fuel particles with a conveying gas;
• transporting the fuel gas stream through a fuel duct extending toward the combustion chamber allowing the fuel gas stream to be introduced into the combustion chamber at a fuel exit plane, the fuel exit plane being coincident with a wall of the chamber;
• injecting an oxygen stream through an injection device into said fuel gas at an oxygen injection location selected to create a mixing zone to mix the oxygen stream and the fuel gas stream, the mixing zone extending from a position upstream of the fuel exit plane.