The high yields of methanol can be obtained at
the elevated CO2 pressure of the reactor for the same
reason. As shown in Fig. 13, the methanol yield
clearly increased with the pressure of CO2 up to
125 kPa, but decreased with further increases of pressure.
Mizuno et al. also observed similar phenomena
[20]. Higher molecular-weight hydrocarbons, such as
ethanol, might be converted from methanol at higher
CO2 pressures. A trace of ethanol was detected in
the reaction at the two higher pressures, but was too
small to be quantified.