Hydrocarbon adsorbent and method for adsorbing hydrocarbons
A hydrocarbon adsorbent having a high hydrocarbon desorption start temperature and a method for adsorbing hydrocarbons that uses the hydrocarbon adsorbent are provided. The hydrocarbon adsorbent includes an alkali metal and a zeolite having a ring structure that includes at least 10 members is used. In the hydrocarbon adsorbent, a content of the alkali metal is 1 to 40 mass % based on a total mass of the hydrocarbon adsorbent, a content of the zeolite having a ring structure that includes at least 10 members is 99 to 60 mass % based on the total mass of the hydrocarbon adsorbent, and at least a portion of the alkali metal is in a state of being ion-exchangeable.
1 . A hydrocarbon adsorbent comprising:
an alkali metal; and
a zeolite having a ring structure that includes at least 10 members selected from at least one of a BEA zeolite, an FAU zeolite, or an MOR zeolite, wherein
a content of the alkali metal is 1 to 40 mass % based on a total mass of the hydrocarbon adsorbent,
a content of the zeolite having a ring structure that includes at least 10 members is 99 to 60 mass % based on the total mass of the hydrocarbon adsorbent,
at least a portion of the alkali metal is in a state of being ion-exchangeable,
wherein a content of the alkali metal that is in a state of being ion-exchangeable is 1 mass % or more and 40 mass % or less based on the total mass of the hydrocarbon adsorbent,
the zeolite has a molar ratio of silica to alumina (SiO 2 /Al 2 O 3 ratio) of 5 or more and 20 or less, and the hydrocarbon adsorbent exhibits a desorption start temperature of from 180° C. to less than 200° C.
2 . The hydrocarbon adsorbent according to claim 1 , wherein the content of the alkali metal that is in a state of being ion-exchangeable is 4 mass % or more and 40 mass % or less based on the total mass of the hydrocarbon adsorbent.
3 . The hydrocarbon adsorbent according to claim 1 , wherein the alkali metal is at least one selected from the group consisting of potassium, sodium, rubidium and cesium.
4 . The hydrocarbon adsorbent according to claim 3 , wherein the alkali metal is rubidium and/or cesium.
5 . The hydrocarbon adsorbent according to claim 1 , wherein the zeolite having a ring structure that includes at least 10 members is a zeolite having at least one structure selected from a group of a BEA structure, an MFI structure, an MOR structure and an FAU structure.
6 . A method for adsorbing a hydrocarbon, the method comprising using the hydrocarbon adsorbent according to claim 1 .