In this paper, a new methodology was developed for the design and optimization of a low NOx-CO burner. To begin, the working of an experimental 2 MW, natural gas burner, in a superheated steam boiler, was studied. A computational fluid dynamics (CFD) model was built and validated with the data obtained from the above-mentioned experimental burner, which included the input of working conditions, simplifications (if any), geometrical model, mesh-refining process, setting up physical models, contour conditions, handling of algorithms of solution, and the incorporation of improved user-defined functions (UDF). A new burner design evolved as a result of this, and the first model was then modified to obtain a secondary CFD, low NOx-CO emission model, which was called the "prototype burner".