Anti-fouling coatings for combustion system components exposed to slag, ash and/or char

1. An anti-fouling coating for combustion system components exposed to any one or more of slag, ash, and char, comprising: any one or more of nano-sized pure refractory metal particles and alloyed refractory metal particles, wherein the nano-sized particles are essentially spheres; a plurality of any one or more of micron-sized pure refractory metal particles and micron-sized alloyed refractory metal particles, wherein the micron-sized particles are essentially spheres; and a matrix comprising a glass or ceramic, wherein anyone or more of the nano-sized and micron-sized pure refractory metal particles and the nano-sized and micron sized alloyed refractory metal particles are disposed within the matrix.

2. The anti-fouling coating of claim 1 , wherein the refractory metal is selected from the group consisting of molybdenum, tantalum, tungsten, vanadium, rhenium, osmium, iridium, niobium, ruthenium, hafnium, zirconium, and combinations thereof and alloys of the refractory metals with base metal elements selected from the group consisting of nickel, iron, chromium, cobalt, silicon, aluminum, and titanium.

3. The anti-fouling coating of claim 1 , wherein the refractory metal particles comprise essentially spherical shapes.

4. A combustion system, comprising at least one component for combusting fuel material wherein the component is exposed to combusted fuel material that produces any of slag, ash or char during operation of the combustion system,

the component having a coating disposed on a surface of the component wherein the coating comprises any one or more of pure refractory metal particles and base-metal alloyed refractory metal particles in a ceramic matrix or glass matrix and

wherein the coating is effective to prevent formation or buildup of any one or more of slag, ash, or char thereon.

5. The combustion system of claim 4 , wherein the refractory metal particles comprise essentially spherical shapes.

6. The combustion system of claim 4 , wherein the refractory metal is selected from the group consisting of molybdenum, tantalum, tungsten, vanadium, rhenium, osmium, iridium, niobium, ruthenium, hafnium, zirconium, and combinations thereof and alloys of the refractory metals with base metal elements are selected from the group consisting of nickel, iron, chromium, cobalt, silicon, aluminum, and titanium.

7. The combustion system of claim 4 , wherein the refractory metal particles comprise nano sized particles and micron sized particles.

8. The combustion system of claim 4 , wherein the component is a gasification chamber and the surface defines at least a portion of the gasification chamber.

9. The combustion system of claim 4 , wherein the component is an injection nozzle and the surface defines at least a portion of the injection nozzle wherein the injection nozzle is configured for injecting fuel into the gasification chamber.

10. The combustion system of claim 4 , wherein the component is 1) a heat exchanger or 2) a component wherein the surface is in a flow path of combustion products.