TECHNOLOGY FOCUS - BIOLOGY - Preferred Method: In method (M1), cutting vegetation; fermenting the vegetation to form biogas comprising methane and CO2; and reacting the biogas with water and metal to form synthesis gas and metal oxide; silaging the cut vegetation, and fermenting silaged vegetation comprises obtaining compost; the metal is zinc; and recycling the metal oxide comprises reacting the zinc oxide with carbonaceous material (preferably carbon) in boiling zinc; condensing zinc vapor of boiling zinc to obtain liquid zinc; and reacting methane and CO2 formed in in the biological conversion with the obtained liquid zinc; obtaining carbon in a method involves gasifying biomass to obtain carbon and combustible gases; oxidizing the obtained combustible gases; and heating boiling zinc with heat obtained from oxidizing the combustible gases. In the method, recycling involves electrolyzing, thermally decomposing the metal oxide in the presence of carbonaceous material, thermally decomposing comprises heating with solar thermal energy. The recycling involves utilizing electrical power; combusting portions of the vegetation to produce at least a portion of electrical power. The method (M1) further involves combusting a portion of the biological material to obtain electricity; and where recycling the metal oxide comprises utilizing the electricity; microbiologically converting the bagasse to form biogas comprising methane and CO2; reacting biogas with water and metal to form synthesis gas and metal oxide; combusting sugarcane leaves and/or stems to form electric power; and electrolyzing the metal oxide to regenerate the metal, electrolyzing comprises utilizing electric power. The method (M2) further involves microbiologically converting second vegetation to biogas; reacting biogas with water and metal to obtain syngas and metal oxide; and producing an alcohol from syngas; biologically converting second vegetation to ethanol; vegetation is sugarcane bagasse; and the second vegetation is sugarcane sugar. Preferred Components: The carbonaceous material comprises at least one of vegetation and methane. The carboxylic acid comprises at least one of succinic acid and butyric acid. The vegetation comprises at least one switchgrass (Panicum virgatum), hay, forage, sugarcane or portion of it, and starch forming plant, such as maize, rice, wheat, barley, sorghum, oats, millets, rye, triticale, and buckwheat. The biological material comprises at least one of switchgrass, hay forage, and green starch forming plant is not fully ripe enough to be harvested for ethanol production or suitable as foods for humans, livestock. The biological material comprises sugarcane bagasse or portions of sugarcane that are not fermentable to ethanol. The green starch forming plants comprises at least one of maize, rice, wheat, barley, sorghum, oats, millets, rye, triticale, and buckwheat.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred System: The metal regenerating unit comprises a carbon source; a reactor with liquid zinc, having an inlet for receiving metal oxide from the syngas producing unit, an inlet for receiving carbonaceous material from carbon source, and an outlet for exiting gaseous zinc; and also comprises a heat exchanger, keeping the temperature of reactor above the boiling temperature of zinc. The heat exchanger receives heat from a combustor, which receives combustible gas from reactor. The inlet receives carbon from a pyrolysis chamber, where carbonaceous material is pyrolized. The carbonaceous material is pyrolized in the absence of air. The container with liquid metal has a metal inlet, for introducing metal in solid state into container. The inlet comprises elastic seals. The heat transferring member is a portion of container, portion directly contacting liquid metal in container. The reaction chamber and container are concentric. The metal regenerating unit comprises an electrolytic bath. The reaction chamber is configured for receiving a carbonaceous material and reacting carbonaceous material with a metal oxide produced by a reaction between metal and biogas and water. The first and second metals are the same. The metal regeneration unit comprises: a conduit; a heat exchanger; a first valve and a second valve defining between them along conduit an intermediate zone. An acid inlet for introducing an acid into intermediate zone. The metal reproducing unit comprises an electrolytic bath, a solar heater, capable of heating metal oxide as to decompose it. The reproducing unit comprises an inlet for a carbonaceous material. The system further comprises a bagasse fermentation unit, having an outlet for biogas, the bagasse fermentation unit being configured for producing biogas from at least one of bagasse and other sugarcane portions not fermentable to ethanol, such as vinasse; a syngas producing unit, configured for receiving biogas from the bagasse fermentation unit, and for producing syngas from biogas; a fuel producing unit, configured for producing a carbonaceous fuel from products of the syngas producing unit; a metal regenerating unit, configured for regenerating metal from metal oxide produced in the syngas producing unit. The metal regenerating unit also comprises a heat exchanger, keeping the temperature of reactor above the boiling temperature of zinc. EXAMPLE - No suitable example given.