Presently, energy costs of Virginia Bright tobacco (VBt), especially for curing, are a major expense of this crop. To reduce these costs, an anaerobic digestion plant is under construction at Fattoria Autonoma Tabacchi of Città di Castello (PG), one of the major VBt producers in Central Italy. Digestion is carried out in two digestion tanks where biogas (methane 60% v/v, carbon dioxide 39% v/v, and other gases) and digested phase (7-10% w/w DM) are produced. Biogas (470 Nm3/h), after purification, is burned in a cogeneration plant to produce electricity (1 MWe) and heat (2.6 thermal MWh). Some 4-500 ha of maize and triticale silages are grown as feedstocks for the plant in nearby growers’ soils. Heat is planned to be used in several ways: (i) to warm up waters of tobacco float system nurseries, also to extend their use in cold season to produce turfgrass sods; (ii) to pre-heat air entering into the curing chambers, in order to contain energy costs; (iii) to dishydrate and stabilize the digested phase to 35% w/w DM. Both liquid and “solid” digested phases are delivered to soils where silage crops are grown, as organic fertilizers. Some of the water phase (0.2% N plus K, and trace elements) is reused in the first step of the digestion or delivered to nurseries, but the largest part is applied in fertigation to crops during Summer droughty season.
Bioenergy from Anaerobic Digestion Process for a More Sustainable Tobacco Production
MIELE, SERGIO;
2008-01-01
Abstract
Presently, energy costs of Virginia Bright tobacco (VBt), especially for curing, are a major expense of this crop. To reduce these costs, an anaerobic digestion plant is under construction at Fattoria Autonoma Tabacchi of Città di Castello (PG), one of the major VBt producers in Central Italy. Digestion is carried out in two digestion tanks where biogas (methane 60% v/v, carbon dioxide 39% v/v, and other gases) and digested phase (7-10% w/w DM) are produced. Biogas (470 Nm3/h), after purification, is burned in a cogeneration plant to produce electricity (1 MWe) and heat (2.6 thermal MWh). Some 4-500 ha of maize and triticale silages are grown as feedstocks for the plant in nearby growers’ soils. Heat is planned to be used in several ways: (i) to warm up waters of tobacco float system nurseries, also to extend their use in cold season to produce turfgrass sods; (ii) to pre-heat air entering into the curing chambers, in order to contain energy costs; (iii) to dishydrate and stabilize the digested phase to 35% w/w DM. Both liquid and “solid” digested phases are delivered to soils where silage crops are grown, as organic fertilizers. Some of the water phase (0.2% N plus K, and trace elements) is reused in the first step of the digestion or delivered to nurseries, but the largest part is applied in fertigation to crops during Summer droughty season.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
