NOVELTY - Empowering a methane fermentation plant, comprises, e.g., suspending raw materials, hydrolyzing, performing methane fermentation, performing post-fermentation of digestate, performing phase separation of digestate, inserting the digestate as organic nitrogen-phosphorus- potassium (NPK) fertilizers, drying, performing desulfurization and compacting the resulting biogases, and performing energetic recycling of the resulting biogas as biomethane. The silage storage are used for warehousing and stockpiling of dry lignocellulosic crop residues, e.g., cereal straw and oilseed straw.    USE - The method is useful for material- and energy utilization of lignocellulosic biogenic feedstock (claimed).    ADVANTAGE - The method ensures minimized required use of additional procedural measures and plant engineering components for completion of existing methane fermentation plants. The existing feedstocks can be replaced in the form of animal feed by lignocellulosic biomass waste, preferably from the location near to agricultural production.    DETAILED DESCRIPTION - Empowering a methane fermentation plant for material and energy utilization of lignocellulosic biogenic feedstock, comprises stockpiling raw materials, suspending the raw materials, hydrolyzing the generated bio-suspension, performing methane fermentation of produced hydrolysates, performing post-fermentation of the digestate from the methane fermentation, performing intermediate storage of digestate from the fermentation area, performing phase separation of the digestate, inserting the digestate as organic nitrogen-phosphorus- potassium (NPK) fertilizers, drying, performing desulfurization and compacting the resulting biogases, and energetic recycling of the resulting biogas as biomethane or as fuel for the operation of cogeneration plants. the silage storage are used for warehousing and stockpiling of dry lignocellulosic crop residues such as cereal straw, oilseed straw, corn stover, wheat, corn and oilseed cleaning residues. The lignocellulosic crop residues are crushed to medium batch sizes of less than 10 mm. Dry matter content in the produced bio-suspension, is adjusted to 12-18%. The shredded crop residues are thermomechanically decomposed. The crushed and optionally thermomechanically digested crop residues are suspended using bio-filtration. The hydrolytic treatment of bio-suspension is made in hydrolysis station upstream of methane fermentation, hydrolytic treatment of bio-suspension is performed aerobically. At least for the first stage of the methane fermentation, hydraulically and only partially mixed methane fermenter is used. At least the fermenter of the first stage of the methane fermentation is inoculated with mesophilic methane bacteria-mixed cultures during the first filling for recycling lignocellulosic feedstocks. At least the biogases produced in the main fermenter station are supplied to a biological desulfurization to obtain an organic acid. An INDEPENDENT CLAIM is also included for an arrangement for carrying out the above method, comprising at least one warehouse (4) for the biogenic raw materials, at least one device for suspending or directly introducing the raw materials, at least two serially connected methane fermenters, at least one gas storage for cover the methane fermenter and/or fermentation residue storage, at least one fermentation residue storage and at least one loading station for liquid digestate. An additional plant complex is upstream to the plant component which is previously used for the methane fermentation of renewable raw materials, and the additional plant complex comprises a feedstock crushing device, a phase-separation station, a bio-filtrate tank, an inhibitor elimination station, a suspending station, a hydrolysis station, a main fermenter station, a gas desulfurization station and a bio-acid tank.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block representation of an existing biogas plant supplied with corn silage(drawing includes non-English language text).    Warehouse for whole crop silage (4)    Collection tank for percolating juices (5)    Preliminary tank (6)    Solid dosage complex (7)    Dosing pump (8)