Methanol to gasoline
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The methanol to gasoline process is a method of producing liquid hydrocarbons for use as synthetic fuel from methanol by heating with ZSM-5 zeolite catalyst. It was developed by Mobil in early 1970s.
[edit] The Process
Methanol is made from methane (natural gas) in a series of three reactions:
- Steam reforming: CH4 + H2O → CO + 3 H2ΔrH = +206 kJ mol-1
- Water shift reaction CO + H2O → CO2 + H2 ΔrH = +206 kJ mol-1
- Synthesis 2 H2 + CO → CH3OH ΔrH = -92 kJ mol-1
Thus overall: CO2 + CO + 5 H2 → 2 CH3OH + H2O + heat
The methanol thus formed may be converted to gasoline by the Mobil process. First methanol is dehydrated to give dimethyl ether:
- 2 CH3OH → CH3OCH3 + H2O
This is then further dehydrated over a zeolite catalyst, ZSM-5, to give a gasoline with 80% C5+ hydrocarbon products.