Honeycomb adsorbent, method of manufacturing the honeycomb adsorbent and canister

Abstract

A cylindrical column-shaped honeycomb adsorbent has a plurality of cell passages extending along an axial direction of the honeycomb adsorbent. The plurality of cell passages are configured so that a pitch of adjacent cell passages is within a range of 1.5 mm˜1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm˜0.60 mm. With this configuration, the honeycomb adsorbent exhibits BWC (Butane Working Capacity) of 6.5 g/dL or greater. By mixing fibrous meltable core melting away during baking, the honeycomb adsorbent has macropores configured to have a volume of 0.15 mL/g˜0.35 mL/g with respect to an overall weight of the honeycomb adsorbent and metal oxide particles having a proportion of weight of 150˜250% with respect to the activated carbon.

What is claimed is: 
     
       1. A honeycomb adsorbent having a cylindrical column shape, the honeycomb adsorbent formed by molding and baking powdery activated carbon together with binder and installed in a closest chamber to a drain port of a canister having a plurality of chambers, the honeycomb adsorbent comprising:
 a plurality of cell passages extending along an axial direction of the honeycomb adsorbent; 
 macropores formed with fibrous meltable core melting away during the baking, the macropores being configured to have a volume of 0.15 mL/g˜0.35 mL/g with respect to an overall weight of the honeycomb adsorbent; and 
 metal oxide particles having a an optimized proportion of weight of 150˜250% with respect to the activated carbon, and 
 the plurality of cell passages being configured so that a pitch of adjacent cell passages is within a range of 1.5 mm˜1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm˜0.60 mm, and 
 the honeycomb adsorbent being configured to exhibit BWC (Butane Working Capacity) of 6.5 g/dL or greater. 
 
     
     
       2. The honeycomb adsorbent as claimed in  claim 1 , wherein:
 an occupation ratio that is determined by outside dimensions of the honeycomb adsorbent and dimensions of the cell passages is at least 50%. 
 
     
     
       3. The honeycomb adsorbent as claimed in  claim 1 , wherein:
 a shape in a cross-section of the cell passage is any one of a hexagon, a quadrangle, a triangle and a circle. 
 
     
     
       4. The honeycomb adsorbent as claimed in  claim 3 , wherein:
 the shape in the cross-section of the cell passage is the hexagon. 
 
     
     
       5. The honeycomb adsorbent as claimed in  claim 1 , wherein:
 the metal oxide particles are iron oxide particles. 
 
     
     
       6. A canister having the honeycomb adsorbent as claimed in  claim 1 . 
     
     
       7. The canister as claimed in  claim 6 , further comprising:
 at least an additional adsorbent. 
 
     
     
       8. A method of manufacturing a honeycomb adsorbent for a canister, comprising:
 making mixture as mold material by adding, to powdery activated carbon, metal oxide particles having a an optimized proportion of weight of 150˜250% with respect to the activated carbon, meltable core made of fiber whose specific gravity is 1.1 g/cm 3 ˜1.3 g/cm 3  and having a proportion of weight of 40˜100% with respect to the activated carbon, the meltable core melting away during baking, and binder; 
 extruding the mold material into a cylindrical column-shaped intermediate mold body having therein a plurality of honeycomb cell passages, the plurality of cell passages being configured so that a pitch of adjacent cell passages is within a range of 1.5 mm˜1.8 mm and so that a thickness of a wall between the cell passages is within a range of 0.45 mm˜0.60 mm after the baking; and 
 baking the intermediate mold body, the baked intermediate mold body of the honeycomb adsorbent exhibiting BWC (Butane Working Capacity) of 6.5 g/dL or greater. 
 
     
     
       9. The method of manufacturing the honeycomb adsorbent for the canister as claimed in  claim 8 , wherein:
 the fiber forming the meltable core is polyamide resin fiber or polyester resin fiber. 
 
     
     
       10. The method of manufacturing the honeycomb adsorbent for the canister as claimed in  claim 8 , wherein:
 the fiber forming the meltable core has a diameter of 10 μm and a length of 0.5 mm. 
 
     
     
       11. The honeycomb adsorbent as claimed in claim 1, wherein the macropores are a pore whose diameter is equal to or greater than 50 nm and less than 1000 nm. 
     
     
       12. The honeycomb adsorbent as claimed in claim 1, wherein the optimized proportion of weight is ˜0 to ˜423% of the metal oxide particles with respect to the activated carbon. 
     
     
       13. The method of manufacturing the honeycomb adsorbent for the canister in claim 8, wherein the optimized proportion of weight is ˜0 to ˜423% of the metal oxide particles with respect to the activated carbon. 
     
     
       14. The method of manufacturing the honeycomb adsorbent for the canister in claim 8, further comprising optimizing an amount of the meltable core with respect to a bleed emission. 
     
     
       15. The method of manufacturing the honeycomb adsorbent for the canister in claim 14, wherein the bleed emission is 20 mg or less. 
     
     
       16. A honeycomb adsorbent for a canister, the honeycomb adsorbent comprising:
 a plurality of cell passages extending along an axial direction of the honeycomb adsorbent;   macropores formed with fibrous meltable core melting away during baking, the macropores being configured to have an optimized volume with respect to an overall weight of the honeycomb adsorbent; and   metal oxide particles having a proportion of weight with respect to the activated carbon to increase the specific heat of the adsorbent;   the honeycomb adsorbent being configured to exhibit BWC (Butane Working Capacity) of 6.5 g/dL or greater with a flow resistance of 10 Pa/cm or lower.   
     
     
       17. The honeycomb adsorbent as claimed in claim 16, wherein the plurality of cell passages is configured so that a pitch of adjacent cell passages is within a range of 1.5 mm to 1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm to 0.6 mm. 
     
     
       18. The honeycomb adsorbent as claimed in claim 16, wherein a shape in a cross-section of the plurality of cell passages is a hexagon. 
     
     
       19. The honeycomb adsorbent as claimed in claim 16, wherein a bleed emission of the canister is 20 mg or less. 
     
     
       20. The honeycomb adsorbent as claimed in claim 16, including a composition amount of nylon fiber between about ˜0 g per 100 g of activated carbon to about ˜170 g per 100 g of activated carbon. 
     
     
       21. A honeycomb adsorbent for a canister, the honeycomb adsorbent comprising:
 a plurality of cell passages extending along an axial direction of the honeycomb adsorbent;   macropores formed with fibrous meltable core melting away during baking, the macropores being configured to have an optimized volume with respect to an overall weight of the honeycomb adsorbent; and   metal oxide particles having a proportion of weight with respect to the activated carbon to increase the specific heat of the adsorbent;   the honeycomb adsorbent being configured to exhibit BWC (Butane Working Capacity) of 6.5 g/dL or greater per testing by ASTM D5228;   wherein the fuel canister has a Diurnal Breathing Loss (DBL) bleed emission of 20 mg or less.   
     
     
       22. The honeycomb adsorbent as claimed in claim 21, wherein the plurality of cell passages is configured so that a pitch of adjacent cell passages is within a range of 1.5 mm to 1.8 mm, and so that a thickness of a wall between the cell passages is within a range of 0.45 mm to 0.6 mm. 
     
     
       23. The honeycomb adsorbent as claimed in claim 21, wherein a shape in a cross-section of the plurality of cell passages is a hexagon. 
     
     
       24. The honeycomb adsorbent as claimed in claim 21, wherein a flow resistance of the honeycomb absorbent is 10 Pa/cm or lower. 
     
     
       25. The honeycomb adsorbent as claimed in claim 21, wherein a composition amount of nylon fiber is between about ˜0 g per 100 g of activated carbon to about ˜170 g per 100 g of activated carbon. 
     
     
       26. A honeycomb adsorbent formed from activated carbon, comprising:
 a plurality of cell passages extending along an axial direction of the honeycomb adsorbent having a pitch of adjacent cell passages in a range of 1.5 mm to 1.8 mm, and a thickness of a wall between the cell passages in a range of 0.45 mm to 0.60 mm;   macropores having a volume of about 0.15 mL/g to about 0.35 mL/g with respect to an overall weight of the honeycomb adsorbent measured by ISO 15901-1;   metal oxide particles having an optimized proportion of weight with respect to the activated carbon; and   wherein the fuel canister has a Diurnal Breathing Loss (DBL) bleed emission of 20 mg or less.   
     
     
       27. The honeycomb adsorbent as claimed in claim 26, wherein a composition amount of nylon fiber is between about ˜0 g per 100 g of activated carbon to about ˜170 g per 100 g of activated carbon.  
     
     
       28. The honeycomb adsorbent as claimed in claim 26, wherein the optimized proportion of weight is ˜0 to ˜423% of the metal oxide particles with respect to the activated carbon. 
     
     
       29. The honeycomb adsorbent as claimed in claim 26, wherein the macropores are a pore whose diameter is equal to or greater than 50 nm and less than 1000 nm.