NOVELTY - Apparatus (10) comprises biohydrogenator (12) including a completely mixed bioreactor (14) having an input for receiving organic and a gravity settler (16) located downstream of the completely mixed bioreactor and hydraulically connected with an output of the bioreactor, including a feedback conduit (20) and output conduit; hydrogen producing microorganisms located in the bioreactor; and biomethanator. The organic waste entering the completely stirred bioreactor is broken down microbiologically by the hydrogen producing microorganisms to predominantly hydrogen gas and carbon dioxide.    USE - The apparatus is useful for producing hydrogen and methane gas from organic waste (claimed).    ADVANTAGE - The apparatus avoids contamination of the microbial hydrogen-producing cultures with methane-producing cultures necessitating frequent re-start-up and/or other methanogenic bacteria inactivation techniques, and the low bacterial yield of hydrogen-producers culminating in microbial washout from the system and failure, hence provides sustained biological hydrogen production. Decoupling of the sludge retention time from the hydraulic retention time through solids/liquid separation for the hydrogen-producing bioreactor, and subsequent sludge recirculation to the hydrogen reactor, allows for operation at high biomass concentrations. The apparatus provides: higher hydrogen production rates and long term sustainability of the system for continuous hydrogen and methane production; chemical oxygen demand removal up to 90%, and energy recovery from waste and the ability to handle high organic loadings.    DETAILED DESCRIPTION - Apparatus (10) comprises biohydrogenator (12) including a completely mixed bioreactor (14) having an input for receiving organic waste into the completely mixed bioreactor and a gravity settler (16) located downstream of the completely mixed bioreactor and hydraulically connected with an output of the completely mixed bioreactor for receiving an output from the completely mixed bioreactor, including a feedback conduit (20) connecting a bottom of the gravity settler to the completely mixed bioreactor for recirculating settle biomass from the gravity settler to the completely mixed bioreactor and output conduit from the bottom of the gravity settler for discharging of excess biomass; hydrogen producing microorganisms located in the completely mixed bioreactor; biomethanator located downstream of the gravity settler and hydraulically connected with an output of the gravity settler. The organic waste entering the completely stirred bioreactor is broken down microbiologically by the hydrogen producing microorganisms to predominantly hydrogen gas and carbon dioxide, and a mixture of volatile fatty acids and primary alcohols, and where hydrogen gas and carbon dioxide are emitted from the completely mixed bioreactor, and where a liquid effluent containing the volatile fatty acids, primary alcohols and hydrogen producing microorganisms flow to the gravity settler and when in the gravity settler the hydrogen producing microorganisms settle to the bottom of the gravity settler and are concentrated in the gravity settler while liquid effluent containing predominantly the volatile fatty acids and the primary alcohols flow into the biomethanator, where the volatile fatty acids and the primary alcohols are broken down microbiologically predominantly to methane gas and carbon dioxide, and where settled hydrogen producing microorganisms in the bottom of the gravity settler are recirculated back to the completely mixed bioreactor, and where the methane gas and carbon dioxide produced in the biomethanator are emitted and liquid waste containing residual organics are discharged from biomethanator. An INDEPENDENT CLAIM is also included for producing hydrogen and methane from organic waste, comprising flowing organic waste into the biohydrogenator    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of the system for employing the process of producing hydrogen and methane gas from organic waste.    Apparatus (10)    Biohydrogenator (12)    Mixed bioreactor (14)    Gravity settler (16)    Feedback conduit (20)