Kinetic data from the literature were used to predict formation rates and product yields of oil and gas at typical low-temperature conditions of coal maturation. These data indicate that gas formation rates from hydrocarbon thermolysis are several orders of magnitude too low to have generated known coal-seam natural gas reserves, assuming bulk first-order kinetics defined by a single activation energy and preexponential factor. By assuming distributed activation energies, thermal cracking of liquid hydrocarbons and coal kerogen to methane can occur at sufficiently high rates to produce commercial quantities over long periods of geologic time. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and transition-metal-catalyzed CO2 hydrogenation form gas at very high rates at geologic temperatures. Rates of gas production in these reactions are orders of magnitude higher than those predicted from thermolysis; moreover, the gaseous products for metal-catalyzed hydrogenolysis of hydrocarbon liquids and for CO2 hydrogenation are nearly the same as those of typical natural coalbed gases, while gases from thermal and catalytic cracking differ from most coalbed gases. The available data are most consistent with a model involving thermal and catalytic cracking of kerogen to oil followed by iron- and nickel-metal-catalyzed hydrogenolysis of oil to natural gas. In CO2-containing coal gases, natural gas may also be formed by iron-catalyzed CO2 hydrogenation.