Schematic representation of the FTT processes simulated in this work. Green line: C-O dissociation of acetaldehyde (CH₂O), forming the CH₂ chain initiator and O, and H₂ addition to atomic O to form H₂O. Blue lines: formation of ethanol (CH₃CH₂OH) by (i) reaction of CH₂ with CO, forming ketene (CH₂CO), and (ii) two H₂ additions to ketene to form first acetaldehyde (CH₃CHO) and finally ethanol. Red lines: formation of methane (CH₄) by H₂ addition to CH₂.