NOVELTY - Obtaining a biocrude from a gas comprising carbon dioxide (CO2) comprises: (a) feeding gas comprising CO2 to a reactor containing a crop which comprises at least one species of microalgae capable of photosynthesis; (b) realization of photosynthesis by microalgae species from CO2 powered to produce biomass; (c) anaerobic fermentation of biomass; (d) biomass thermochemical decomposition fermented at a pressure between 0 and 20 MPa and a temperature between 200 and 420 degrees C for a biocrude mixed with water and gases; and (e) biocrude separation.    USE - The process is useful for obtaining biocrude from gas comprising CO2, where gas comes from an industry such as cement. The biocrude is useful for combustion of internal combustion engines, turbines or boilers that work with fuel oil (all claimed).    ADVANTAGE - The invention provides procedure for obtainment of biocrude from greenhouse effect gases, where the procedure is advantageously industrial and continuous. Through the procedure, there is achieved the capture, conversion and reevaluation of CO2 among other greenhouse effect gases in an efficient manner, in such a manner that a negative net balance is achieved or, what is the same, by means of the present procedure more CO2 is captured than is generated, rendering it beneficial and sustainable for the environment.    DETAILED DESCRIPTION - Obtaining a biocrude from a gas comprising carbon dioxide (CO2) comprises: (a) feeding gas comprising CO2 to a reactor containing a crop which comprises at least one species of microalgae capable of photosynthesis; (b) realization of photosynthesis by microalgae species from CO2 powered to produce biomass; (c) anaerobic fermentation of biomass; (d) biomass thermochemical decomposition fermented at a pressure between 0 and 20 MPa and a temperature between 200 and 420 degrees C for a biocrude mixed with water and gases; and (e) biocrude separation, where, after the stage of photosynthesis, the reactor is displaced between 5 and 100% of the crop, which is then separated into a solid fraction containing biomass, which will subsequently be subjected to anaerobic fermentation step, and a fraction liquid containing carbonate and/or bicarbonates, which are separated from the liquid fraction, to then return to the reactor at least partially liquid fraction substantially free of carbonates and/or bicarbonates. An INDEPENDENT CLAIM is biocrude obtained by the process comprising from 65 to 95% carbon.