NOVELTY - Raw materials are gasified or converted to hydrogen and carbon monoxide mixture which is methanated to produce mixture of methane and water steam and working fluid. The mixture is fed into an engine (2) to produce mechanical energy. The un-separated gasification product and primary working fluid are fed into an engine, and heat and kinetic energy of the mixture are transformed into mechanical energy. The spent primary working fluid is split to hydrogen, carbon monoxide and byproducts, and processes are repeated in cycle. Thus, transformation of energy is enabled.    USE - Transformation of energy for vehicles.    ADVANTAGE - The method enables efficient transformation of energy with suppressed consumption of water, oxygen and catalyst for gasification and conversion of gases in the engine.    DETAILED DESCRIPTION - Raw materials are fed into gasification or conversion reaction chamber (1) and subjected to gasification or conversion in an autothermal or thermal mode, to produce hydrogen, carbon monoxide and byproducts. The byproducts are separated, and hydrogen and carbon monoxide mixture is fed into methanation reaction chamber (3) to produce mixture of methane and water steam and working fluid. The mixture is fed into an engine for expansion to produce mechanical energy. The un-separated gasification product and the primary working fluid are fed into an engine for expansion and heat and kinetic energy of the mixture are transformed into mechanical energy. The spent primary working fluid after cooling in the engine is split to hydrogen, carbon monoxide and byproducts. The hydrogen and carbon monoxide are separated and fed into the methanation reaction chamber and subjected to catalytic process to produce methan-steam mixture, and secondary working fluid which are fed into contour (II) of the engine or into other engine and transformed into mechanical energy by expansion. The spent methane-steam mixture and byproducts are fed back into the gasifying or conversion reaction chamber to form the mixture of hydrogen and carbon monoxide, in cyclic process, and cycle is closed. Thus, transformation of energy with energy carrier regeneration in cyclic process is enabled.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic drawing of transformation of energy.    Conversion reaction unit assembly (1)    Engine (2)    Methanation reaction chamber (3)