Methods and system for removing impurities from heavy fuel

1. A method of removing impurities from heavy fuel, said method comprising:

providing a first stationary adsorption column;

packing adsorbent particles that have a particle size distribution in a graduated particle orientation such that the smallest particles are positioned closest to an outlet end of the first column and such that the largest particles are positioned closest to a feed end of the first column, wherein at least about 50% of said particles have a diameter greater than about 18 microns into the first column;

diluting heavy fuel with a solvent to form a solvent-fuel mixture; and

supplying the solvent-fuel mixture through the first column to facilitate removing impurities from the mixture, wherein the impurities comprise a metal.

2. A method in accordance with claim 1 wherein packing the particles in the first column further comprises orienting the particles in at least three discrete layers by packing a first discrete layer of particles with particles having an average particle size of less than about 38 micrometers, packing a second discrete layer with particles having an average particle size of about 53 micrometers to about 75 micrometers on top of the first discrete layer, and packing a third discrete layer of particles having an average particle size of about 106 micrometers to about 425 micrometers on top of the second discrete layer.

3. A method in accordance with claim 1 further comprising:

slurrying the particles with the solvent prior to packing the particles in the first column;

circulating the solvent through the particles;

removing any excess air trapped within the first column; and

removing a product from the first column at one or more intermediate stages of the first column.

4. A method in accordance with claim 1 , wherein providing a first stationary adsorption column further comprises providing a second adsorption column in a parallel or series-parallel relationship with the first stationary adsorption column.

5. A method in accordance with claim 1 further comprising inserting at least two baffles within the column.

6. A method in accordance with claim 1 further comprising directing the solvent-fuel mixture through the column such that the residence time of the mixture is between about 10 and 20 minutes.

7. A method in accordance with claim 1 further comprising removing a product from the first column from at least one intermediate stage.

8. A method for removing impurities from heavy fuel comprising:

providing a first stationary adsorption column;

packing a plurality of adsorbent particles in the first column in a graduated particle orientation such that the smallest particles are positioned at an outlet end of the first column and the largest particles are positioned at a feed end of the first column;

diluting heavy fuel with a solvent to form a solvent-fuel mixture; and

directing the solvent-fuel mixture through the first column to facilitate removing impurities from the mixture, wherein the impurities comprise a metal.

9. A method in accordance with claim 8 , wherein packing a plurality of adsorbent particles in the first column further comprises layering the particles in at least two discrete sections.

10. A method in accordance with claim 8 , wherein packing a plurality of adsorbent particles in the first column further comprises layering said particles in at least three discrete sections by packing a first discrete layer of particles with particles having an average particle size of less than about 38 micrometers, packing a second discrete layer with particles having an average particle size of about 53 micrometers to about 75 micrometers on top of the first discrete layer, and packing a third discrete layer of particles having an average particle size of about 106 micrometers to about 425 micrometers on top of the second discrete layer.

11. A method in accordance with claim 8 further comprising slurrying the particles with the solvent prior to packing the particles in the first column and directing the solvent-fuel mixture through the first column such that the residence time of the solvent-fuel mixture is between about 10 and 20 minutes.

12. A method in accordance with claim 8 further comprising inserting at least two baffles within the first column.

13. A method in accordance with claim 8 , wherein providing a first stationary adsorption column further comprises providing a second adsorption column in a parallel or series-parallel relationship with the first stationary adsorption column.

14. A method in accordance with claim 8 further comprising removing a product from the first column from at least one intermediate stage.