Abstract: An electrochemical reactor designed to increase the efficiency of hydrogen production from faeces and urine (excrement) is disclosed. Said reactor comprises two half-cells separated in a selective manner, a membrane systems separating the half-cells (comprising a proton-exchange and an anion-exchange membranes) and a system of electrical bridges that allow two mutually perpendicular electrical fields to be formed, with the electrical field in the horizontal direction between the two half-cells being greater than the vertical electrical field generated within the anode. The half-cells have a configuration of two resistances in series, which allows the potential of each compartment to be controlled in an independent and complementary manner by adjusting the conductivity of the solutions in the half-cells.