PhD Thesis - Energy Systems Research Unit - University of Strathclyde

That is
CO + 2H2 CH3OH
CO2 + 3H2 CH3OH + H2O
56 kg CO + 8 kg H2 64 kg CH3OH
88 kg CO2 + 12 kgH2 64 kg CH3OH + 36 kg H2O
Further hydrogen, carbon monoxide and carbon dioxide for these reactions may
also be derived from the methane content of the biogas if desired, via steam
reforming as described previously. The production rates by weight (in kg/hr) of
hydrogen, and the other gases, are determined as described previously, and the
extra gases produced via steam reforming of methane are added to these if
desired. The methanol production reactions will not, in practice, go to
completion so a completion percentage must, again, be applied.
Firstly the amount of methanol that can be derived from the carbon monoxide
and hydrogen present is determined. If there is excess carbon monoxide (i.e.
there is more than 7 (56 divided by 8) times the weight of hydrogen), the
amount of methanol produced (in kg/hr) is calculated, using direct proportion,
from the weight of hydrogen present. If there is excess hydrogen, the weight of
methanol produced is calculated, using direct proportion, from the weight of
carbon monoxide present. In either case, the completion percentage is applied,
and the remaining weight of each gas is determined.
The weight of methanol that can be derived from the carbon dioxide and
hydrogen present is then determined, and added to the previous amount, in the
same manner, using the second chemical equation. It is common practice to
introduce extra carbon dioxide into this reaction in order to increase the
hydrogen use. If this is desired, the weight of methanol that can be made from
the hydrogen present is calculated, from the second chemical equation, using
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