A kinetic model of the synthesis of higher alcohols from CO/H-2 mixtures (HAS) has been developed. The model is grounded on the chemistry of the synthesis, and its structure closely reflects previous mechanistic findings in HAS over modified methanol synthesis catalysts. It provides a detailed description of the product distribution, including CO2, methanol, primary and secondary alcohols up to C-8, the corresponding aldehydes and ketones, methane, and higher hydrocarbons. Isothermal kinetic data over a Cs-promoted Zn/Cr/O catalyst which represent the effects of space velocity, reaction pressure, and feed composition (H-2/CO ratio, CO2 feed content) are successfully fitted using a single set of chemically consistent estimates of the rate parameters. The model is further tested against chemical enrichment experiments in part 2 of the present work.