zHW: Multiple Independent Reactions
Formaldehyde is produced on an industrial scale by the incomplete oxidation of methanol in air. Principle by-products include formic acid, carbon dioxide, and carbon monoxide. Find a set of independent reactions for this reaction system.
Contents
Chemical Species
The first step is to provide a list of all chemical species partcipating in the reaction system. Use molweight to verify correct entry of this list of species.
species = { ... 'CH3OH', ... % Methanol 'O2', ... % Oxygen 'CH2O', ... % Formaldehyde 'CHOOH', ... % Formic Acid 'CO', ... % Carbon Monoxide 'CO2', ... % Carbon Dioxide 'H2O'}; % Water molweight(species);
Species Mol. Wt. ------- -------- CH3OH 32.04 O2 32.00 CH2O 30.03 CHOOH 46.03 CO 28.01 CO2 44.01 H2O 18.02
Independent Reactions
The rank of the stoichiometric matrix indicates the number of independent reactions that are possible.
V = stoich(species); disp(' '); disp('V = '); disp(V); fprintf('\nNumber of Independent Reactions = %g\n',rank(V));
V = -1 0 0 0 0 -1 0 0 0 0 -1 0 0 0 0 -1 3 -2 2 1 -2 2 -1 0 2 0 1 1 Number of Independent Reactions = 4
Displaying the Independent Reactions
disp_reaction(V,species);
CH3OH + 2 CO2 <=> 3 CO + 2 H2O O2 + 2 CO <=> 2 CO2 CH2O + CO2 <=> 2 CO + H2O CHOOH <=> CO + H2O