Editing Methanol (section)

===From synthesis gas===
Carbon monoxide and hydrogen react over a catalyst to produce methanol. Today, the most widely used catalyst is a mixture of copper and [[zinc oxide]]s, [[catalyst support|supported]] on [[alumina]], as first used by [[Imperial Chemical Industries|ICI]] in 1966. At 5–10 MPa (50–100&nbsp;atm) and {{convert|250|C}}, the reaction

:{{chem2 | CO + 2 H2 -> CH3OH }}

is characterized by high selectivity (>99.8%). The production of [[syngas|synthesis gas]] from methane produces three [[Mole (unit)|mole]]s of hydrogen for every mole of carbon monoxide, whereas the synthesis consumes only two moles of hydrogen gas per mole of carbon monoxide. One way of dealing with the excess hydrogen is to inject [[carbon dioxide]] into the methanol synthesis reactor, where it, too, reacts to form methanol according to the equation

:{{chem2 | CO2 + 3 H2 -> CH3OH + H2O }}

In terms of mechanism, the process occurs via initial conversion of CO into {{chem2|CO2}}, which is then [[hydrogenation|hydrogenated]]:<ref>Deutschmann, Olaf; Knözinger, Helmut; Kochloefl, Karl and Turek, Thomas (2012) "Heterogeneous Catalysis and Solid Catalysts, 3. Industrial Applications" in ''Ullmann's Encyclopedia of Industrial Chemistry''. Wiley-VCH, Weinheim. {{doi|10.1002/14356007.o05_o03}}</ref>

:{{chem2 | CO2 + 3 H2 -> CH3OH + H2O }}

where the {{chem2|H2O}} byproduct is recycled via the [[water gas shift reaction|water-gas shift reaction]]

:{{chem2 | CO + H2O -> CO2 + H2 }}

This gives an overall reaction

:{{chem2 | CO + 2 H2 -> CH3OH }}

which is the same as listed above. In a process closely related to methanol production from synthesis gas, a feed of hydrogen and {{chem2|CO2}} can be used directly.<ref>{{Cite journal|last1=Bozzano|first1=Giulia|last2=Manenti|first2=Flavio|date=2016|title=Efficient methanol synthesis: Perspectives, technologies and optimization strategies|url=https://www.sciencedirect.com/science/article/pii/S0360128515300484|journal=Progress in Energy and Combustion Science|language=en|volume=56|page=76|doi=10.1016/j.pecs.2016.06.001|bibcode=2016PECS...56...71B |issn=0360-1285}}</ref> The main advantage of this process is that [[Carbon capture and storage|captured {{chem2|CO2}}]] and hydrogen sourced from [[Electrolysis of water|electrolysis]] could be used, removing the dependence on fossil fuels.