A method is provided for producing at least one energy product by catalytically cracking, at a low temperature, a fragmented solid material, without the formation of coke, dioxins and/or furans. A gas atmosphere is maintained at the cracking pressure through gas-exchange communication between the gas atmosphere of the cracking reactor and the gas atmosphere of a device, referred to as a thermochemical vacuum pump, that generates a vacuum pressure formed, by way of a change of state, from an expanded gas state to a condensed liquid state. A second inert oil, referred to as a condensation oil is refluxed at a temperature higher than the evaporating temperature of the condensation oil at the cracking pressure in the thermochemical vacuum pump. The change of state of the condensation oil from the expanded gas state to the condensed liquid state is brought about in the thermochemical vacuum pump in a gas-exchange communication with the gas atmosphere of the cracking reactor and the condensation oil is chosen so that its state-change temperature is at the level of the cracking temperature at the cracking pressure.