| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an environmentally compatible method for methane synthesis that allows utilization of a hydrogen raw material of high purity. <P>SOLUTION: The relation between the H<SB POS="POST">2</SB>/CO<SB POS="POST">2</SB>molar ratio (r) and unreacted CO<SB POS="POST">2</SB>shows that, when r exceeds 4.0, the CO<SB POS="POST">2</SB>value lowers suddenly and is about 1 ppm at r=4.5 and almost 0 at r=5.0. Furthermore, it is shown that an inflexion point exists within the range of 4.1<r<4.2. Examining H<SB POS="POST">2</SB>, on the other hand, when r>4.0, the excess H<SB POS="POST">2</SB>increases as r increases. The same tendency can be seen as the CO<SB POS="POST">2</SB>with respect to the relation between the molar ratio and residual CO. Likewise, the inflexion point exists within the range of 4.1<r<4.2. These facts show that, when a reaction is carried out within a range of a not smaller molar ratio (r≥4.2) than that where the inflexion point appears, CO<SB POS="POST">2</SB>-decreasing effects get smaller while plant capacity and the running cost of PSA and a compressor necessary for recovery and recycling of the excess H<SB POS="POST">2</SB>get larger, resulting in reduced economical merits. <P>COPYRIGHT: (C)2012,JPO&INPIT |
