Hydrogenation apparatus and method of the CO2 to produce methanol and device and method for cogeneration of methanol and methane to synthesis

The device (100) of CO2 hydrogenation to produce methanol from a syngas comprising: - dihydrogen, H2, released for example by a water electrolysis device, H2O, and - dioxide atoms, CO2, comprising: - a reactor (105) CO2 hydrogenation to produce methanol, called "hydrogenation", comprising: - an input (110) for the syngas and - an outlet (115) for products of the hydrogenation reaction comprising at least methanol, CH3OH or MeOH, - a first conduit (120) for recirculation of at least part of the hot products of the hydrogenation reaction between the reactor outlet to the reactor inlet having a recirculator (125), said "first recirculator" of said part of the reaction products, - means (130) for measuring the syngas flow through the reactor inlet positioned upstream of a junction between the pipe recirculation and the reactor inlet and - means (135) controlling the first recirculator configured to control the recirculation of a quantity of hot products of hydrogenation reaction determined by the flow rate of syngas and a first measured value (140) predetermined setpoint.