Low-temperature methanol synthesis in liquid-phase with a Raney Nickel–alkoxide system: effect of Raney Nickel pretreatment and reaction conditions
✍ Scribed by Eun Sook Lee; Ken-ichi Aika
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 356 KB
- Volume
- 141
- Category
- Article
- ISSN
- 1381-1169
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✦ Synopsis
The CO hydrogenation in liquid-phase was carried out using a set catalyst composed of Raney-Ni and CH ONa in an 3 Ž autoclave of 234 ml under the reaction condition of 5 MPa, 423 K and 2 h. A high productivity CO conversion of 92.4%
. with methanol selectivity of 99.8% was achieved by eliminating the water after leaching of the Raney-Ni catalyst and by Ž . using CH ONa rather than CH CH ONa. Ni CO was observed in the liquid-phase after the reaction under the condition of 3 3 2 4 Ž . Ž . high CO content COrH ) 2 . However, the formation of Ni CO was not observed, when stoichiometric gas ratio 2 4 Ž . Ž H rCO s 2 was used with Raney-Ni and CH ONa at 423 K, 5 MPa, and 2 h. Carbonylation of CH OH CH ONa 2 3 3 3 . Ž . catalysis seems to be faster than the carbonylation of Raney-Ni to Ni CO under these conditions. Hydrogenolysis of 4 Ž . methyl formate MeF on the Raney-Ni yielded both methanol and methane at 443 K. However, the by-product methane was Ž . never obtained when using Raney-Ni with CH ONa under the stoichiometric gas ratio H rCO s 2 at 423 K, 5 MPa, and 2 3 2 h. The essential pathway must be the carbonylation of methanol to MeF with the CH ONa catalyst followed by the 3 hydrogenolysis of MeF to methanol with the Raney-Ni; however, the synergy effect between Raney-Ni and CH ONa are 3 suggested in the mechanism.