| Project/Area Number |
12450325
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
触媒・化学プロセス
|
|---|
| Research Institution | Shizuoka University |
|---|
Principal Investigator |
UENO Akifumi Shizuoka Univ., Dept. of Material Science, Prof., 工学部, 教授 (30135420)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
AZUMA Naoto Shizuoka Univ., Dept. of Material Science, Associate Prof., 工学部, 助教授 (50192464)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥14,700,000 (Direct Cost: ¥14,700,000)
Fiscal Year 2001: ¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 2000: ¥8,800,000 (Direct Cost: ¥8,800,000)
|
|---|
| Keywords | Methane / Partial Oxidation / Formaldehyde / Direct Production / Catalysts / Molybdic Acids / Silica Support / Excess Water Vapor / メタン部分酸化 / 水蒸気雰囲気 / シリカ担持 |
|---|
| Research Abstract |
Studies on the evaluation of catalyst life and the mechanism of catalyst deactivation :
At the beginning of this project research, we thought that the catalyst deactivation was likely caused by the deposition and accumulation of carbon over the catalyst surface. But now it is probed that the catalyst deactivation comes from the loss of molybdenum compounds during heating the catalysts to the reaction temperature and during the reaction at 600 ℃. A part of Mo compounds, mainly consisted of α- MoO_3, easily sublimated out of the reactor and deposited on the wall of tubes connected with the reactor. So, the key technique for a long life lies in the design of catalysts against sublimation of Mo compounds during both pretreatments and reaction at high temperature. Since Mo compounds dispersed out side of the silica support were found to remove rapidly, we believe that the most important technique is in the catalyst preparation to entrap the Mo compounds inside the micro-pores of silica supports.
Study on the activation mechanisms of methane into oxygenates :
In the present study, we use SMA (H_4SiMo_<12>O_<40>) dispersed on silica as catalysts for partial oxidation of methane into oxygenates. One of the features of SMA is to possess 4 protons in 1 SMA molecule. In this project research KOH treated silica supports were often used, where H^+ ions in SMA molecules were substituted with K^+ ions. It was found that the K^+-substituted SMA/silica catalysts showed a low activity, and that almost all of the methane in the feed remained at the outlet of the reactor. This means that the protons in SMA have an important role for the activation of methane into oxygenates. Now. we are thinking about the presence of CH_5^+, generated by the reaction of H^+ on SMA and CH_4, as an important reaction intermediate for partial oxidation of methane on SMA/Si0_2 catalysts.
|
