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.

Contents 1 The Process 2 Deactivation 3 See also 4 External links

[edit] The Process

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Methanol is made from methane (natural gas) in a series of three reactions:

1. Steam reforming: CH₄ + H₂O → CO + 3 H₂ ΔrH = +206 kJ mol-1
2. Water shift reaction CO + H₂O → CO₂ + H₂ ΔrH = +206 kJ mol-1
3. Synthesis 2 H₂ + CO → CH₃OH ΔrH = -92 kJ mol-1

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% (by weight base on the organics in the product stream) C5+ hydrocarbon products.

[edit] Deactivation

ZSM-5 is deactivated by a carbon build-up ("coking") over time in converting methanol to gasoline. The catalyst can be re-activated by burning off the coke in a stream of hot (500C) air; however, the number of re-activation cycles is limited.

[edit] See also

• Fischer-Tropsch process
• Synthetic Liquid Fuels Program
• Synthetic petrol

[edit] External links

• University of California San Diego webpage
• The production of methanol and gasoline