| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a HC (hydrocarbon) adsorbent composed ofβ-type zeolite, which has <80 SiO<SB>2</SB>/Al<SB>2</SB>O<SB>3</SB>ratio, high HC adsorption retentivity up to high temperature and high heat resistance. <P>SOLUTION: The HC adsorbent consists ofβ-type zeolite having <80 SiO<SB>2</SB>/Al<SB>2</SB>O<SB>3</SB>ratio and is characterized in that the desorption temperature of HC is≥185°C. Theβ-type zeolite which is heat-treated at the temperature of≥700°C and particularly≤800°C, has <80 SiO<SB>2</SB>/Al<SB>2</SB>O<SB>3</SB>ratio and is an H (proton) type is used as the HC adsorbent. The SiO<SB>2</SB>/Al<SB>2</SB>O<SB>3</SB>ratio is preferably <48. The HC adsorbent has high cracking performance, high HC desorption temperature and high heat resistance. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
