Emissions reduction system and method

Abstract

A reformate/buffer system and method for operating an exhaust emissions control device are disclosed herein. In one embodiment, the reformate/buffer system comprises: a hydride storage bed, a hydride cycling bed disposed in fluid communication with the hydride storage bed, a hydrogen separation device, a reformate flow path, coolant flow passages in thermal communication with the hydride cycling bed, and reformer flow passages in thermal communication with the hydride cycling bed. The reformate flow path is formed by the hydride storage bed, the hydride cycling bed, and the hydrogen separation device and is disposed in fluid communication with the hydride storage bed and hydride cycling bed.

What is claimed is:  
     
         1 . A reformate/buffer system, comprising: 
 a hydride storage bed;    a hydride cycling bed disposed in fluid communication with the hydride storage bed;    a hydrogen separation device;    a reformate flow path formed by the hydride storage bed, the hydride cycling bed, and the hydrogen separation device and is disposed in fluid communication with the hydride storage bed and hydride cycling bed;    coolant flow passages in thermal communication with the hydride cycling bed; and    reformer flow passages in thermal communication with the hydride cycling bed.    
     
     
         2 . The system of  claim 1 , wherein the hydride cycling bed is concentrically disposed between hydrogen separation device and the hydride storage bed, with the hydrogen separation device disposed adjacent at least a portion of an interior surface of the hydride cycling bed.  
     
     
         3 . The system of  claim 2 , wherein the hydride cycling bed is disposed around at least a portion of the reformer flow passages and the hydride storage bed is disposed around at least a portion of the coolant flow passages.  
     
     
         4 . The system of  claim 3 , wherein the hydride cycling bed is disposed around at least another portion of the coolant flow passages.  
     
     
         5 . The system of  claim 3 , wherein the at least a portion of the coolant flow passages are disposed in an alternating relationship to the reformer flow passages.  
     
     
         6 . The system of  claim 1 , wherein the hydride storage bed, and hydride cycling bed each have a semicircular or semi-elliptical geometry and are arranged to form a circle or ellipse.  
     
     
         7 . The system of  claim 6 , wherein the hydrogen separation device is disposed between at least a portion of at least one of the hydride storage bed and the hydride cycling bed and the reformate flow path.  
     
     
         8 . The system of  claim 1 , further comprising a reformer catalyst disposed within at least a portion of the reformate flow passage.  
     
     
         9 . A method for operating an exhaust emissions system, comprising: 
 reforming fuel to produce a reformate comprising reformate hydrogen and byproducts;    passing the reformate through a reformate flow path formed by the hydride storage bed, the hydride cycling bed, and the hydrogen separation device and is disposed in fluid communication with the hydride storage bed and hydride cycling bed;    separating the reformate hydrogen from the byproducts;    absorbing the reformate hydrogen in a hydride cycling bed while removing heat from the hydride cycling bed;    heating the hydride cycling bed to desorb hydrogen at least until a partial pressure of hydrogen over the hydride cycling bed attains a selected level;    storing the desorbed hydrogen in a hydride storage bed; and    during cold start, desorbing storage bed hydrogen and burning a first portion of the storage bed hydrogen in an engine.    
     
     
         10 . The method of  claim 9 , further comprising introducing a second portion of the storage bed hydrogen to a reformer and heating the reformer to its light-off temperature.  
     
     
         11 . The method of  claim 10 , further comprising introducing a third portion of the storage bed hydrogen to an exhaust emission control device and heating the exhaust emission control device to its light-off temperature.  
     
     
         12 . The method of  claim 9 , further comprising introducing a third portion of the storage bed hydrogen to an exhaust emission control device and heating the exhaust emission control device to its light-off temperature.  
     
     
         13 . The method of  claim 10 , further comprising recharging the hydrogen storage bed by after the engine attains the light-off temperature, wherein the recharging comprises 
 reforming fuel to produce a reformate comprising reformate hydrogen and byproducts;    separating the reformate hydrogen from the byproducts;    absorbing the reformate hydrogen in a hydride cycling bed while removing heat from the hydride cycling bed;    heating the hydride cycling bed to desorb hydrogen at least until a partial pressure of hydrogen over the hydride cycling bed attains a selected level; and    storing the desorbed hydrogen in a hydride storage bed.