Every burner on the CAST basis is able to generate soot with either diffusion or premixed flame. In order to operate with a premixed flame the fuel gas is actually mixed with oxidizer such as air or oxygen before it is served to the burner.
In comparison to a diffusion flame, carbon and soot particles formed in a premixed flame also meet the oxidizer within a flame and react with them. As a result, small soot particles and lower mass output are generally expected from a premixed flame. Obviously, the soot particles and the mass output will grow when the oxygen content in the fuel gas reduces and the flame becomes a diffusion flame.