NOVELTY - Bioreactor is made tubular, is separated by horizontal partition-segments not reaching bottom, in loading, working and unloading sections, upper loading section has loading hatch for biomass loading, top of unlading section has hatch, and working section comprises greater than or equal to 1 module formed by greater than or equal to 1 insert, has mixer and heat exchanger in each module, has hatch in upper part of each module, includes selective devices as connecting pipes to connect pressure U-tubes and selection of biogas, and in processing region between modules has adjustable locking reinforcement situated in module inserts.    USE - As bioreactor for producing biogas (claimed).    DETAILED DESCRIPTION - A bioreactor is made tubular, is separated by partition-segments that are arranged horizontally, but do not reach bottom of container, in three sections including loading section, working section and unloading section, where in loading section of bioreactor in upper part technological loading hatch is provided for biomass loading, in top part of unlading section technological hatch is provided, and working section consists of greater than or equal to 1 module formed by greater than or equal to 1 module insert that is hinge or greater than or equal to 1 segment separator acting as divider of conversion flows, in each module of working section mixer and heat exchanger are installed, in upper part of each module technological hatch is installed, and includes selective devices in form of connecting pipes for connection of pressure U-tubes and selection of biogas; where all sections of bioreactor are heat-insulated, loading section is equipped with heat exchanger or bubble system for air supply, and in processing region between modules adjustable locking reinforcement is installed, which can be situated in module-inserts in form of hinges or module-inserts in form of segment dividers of conversion flows. The bioreactor housing has conical widening of 0.5-2% to unloading side. The bioreactor has elongated shape, or zigzag shape. A mechanical connection of modules of bioreactor is made by flanges, by welding, or by clutches or joints with sealing gaskets. In upper part of working portion module inspection windows are installed. In bioreactor of zigzag form, between modules of working portion, modules of insert in form of hinges are mounted, which establish valves for locking and regulating reinforcement or start of bioreactor by step by step activation of bioreactor during operation. The adjustable valves have screw drive associated with steering wheel or motor. The mixer present inside working section module, is made either vertical or horizontal, and is submerged into biomass together with engine. For vertical submerging mixer, between modules of working portion segment separator of conversion flows is mounted. The segment separator of conversion flows has gap between top and bottom part of segment separator and bioreactor housing, or only between bottom part of segment separator and bioreactor housing. The module-insert comprises reduction motor, connected to horizontal mixer. In unloading section module technological hatch is provided, in which mixing mixer is installed, where mixer is submerged mixer immersed in biomass together with engine. In upper end part of unloading section module branch pipe for unloading biomass is provided. In bottom part of unloading section module branch pipe for unloading biomass in maintenance work operations period, is provided. Inside of bioreactor are installed sensors for pH, methyl-2-butene, temperature, and humidity, which are connected to control microprocessor controller, and as per their signals necessary correction of parameters inside bioreactor is made.