Fuel vapor storage canister, fuel vapor adsorbent for canister, and method of producing fuel vapor adsorbent

Fuel vapor adsorbents used for a fuel vapor storage canister of an automotive vehicle, comprising:

• small granular fuel vapor adsorbent having a microporous structure;
• large granular fuel vapor adsorbent which is larger in size than the small granular fuel vapor adsorbent, the large granular fuel vapor adsorbent having the microporous structure and a macroporous structure which has pores larger in diameter than pores of the microporous structure, the large granular fuel vapor adsorbent being produced by a process including mixing powdery activated carbon, a material which is solid at ordinary temperature and able to evaporate, sublime or decompose at temperatures made during baking, and a binder to form a mixture;
• forming the mixture into a shape;
• and baking the formed mixture.

A method of producing granular fuel vapor adsorbent to be used for a fuel vapor storage canister, the granular fuel vapor adsorbent having a microporous structure and a macroporous structure, the method comprising:

• mixing powdery activated carbon, at least one selected from the group consisting of bentonite, silica sol and alumina sol, serving as a binder, a powdery material which is solid at ordinary temperature and able to evaporate, sublime or decompose at temperatures made during baking, and water to form a mixture;
• forming the mixture into a cylindrical shape;
• and
• baking the formed mixture after drying.

A method of producing large granular fuel vapor adsorbent to be used together with small granular fuel vapor adsorbent for a fuel vapor storage canister, the large granular fuel vapor adsorbent being disposed together with the small granular fuel vapor adsorbent in a casing of the fuel vapor storage canister, the large granular fuel vapor adsorbent being larger in size than the small granular fuel vapor adsorbent, the large granular fuel vapor having a microporous structure and a macroporous structure, the method comprising:

• mixing powdery activated carbon, at least one selected from the group consisting of bentonite, silica sol and alumina sol, serving as a binder, a powdery material which is solid at ordinary temperature and able to evaporate, sublime or decompose at temperatures made during baking, and water to form a mixture;
• forming the mixture into a cylindrical shape;
• and
• baking the formed mixture after drying.