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FAO/UNEP/UN-Energy Bioenergy Decision Support Tool -
MODULE 7: Deployment and Good Practices
Box 10: Sweet sorghum IFES in China
In this Integrated Food and Energy System (IFES) black mushrooms or other crops may be inter-planted in the furrow between sweet
sorghum rows. The sweet sorghum seed can be used as food or forage; the leaves can be used to feed cows or fsh. The chopped
stem can be used for making wine or ethanol fuel, fodder and silage. The residue after brewing wine or extracting juice for alcohol
can be used as fodder for cows. The cow manure and crop residues can be used for making biogas. The biogas can be used for
cooking or burnt in greenhouses or plastic sheds to increase illumination and heat, and at the same time the CO2 released can
enhance the growth and development of vegetables or ornamentals in greenhouses. The biogas generator residues can be used as
fertilizer. Thus, a sustainable sweet sorghum IFES is formed for encouraging the development of energy, agriculture, stock breeding
and fsheries in the countryside. The system has high economic benefts, and in arid and saline alkali areas it allows enables the
production of animals and food where other crops have failed. (Li Guiying et al, 2000)
Source: Li Guiying et al, 2000
Soil
Stem
Sweet Sorghum
Residue
Fungus
Leaf
Fish
Grain
Food
Solid compound forrage
Cow
Milk
Electricity,
cooking
Dung
Methane
Burning in greenhouse
Drinkable alcohol, ethanol
CO2 heat and Light
Vegetables
Manure of fertiliser for plant
Closed loop systems are characterised by some operational
principles (Jamieson, 2008):
1. High Productivity, i.e. begin with high-yielding biomass crops;
2. Optimal Use of Biomass, based on the idea that nothing
is considered ‘waste.’ By-products or leftovers from one
process become the starting point for another in cycles that
mimic nature.
3. Crop and Livestock Integration, whereby biofuel production
can reduce the livestock environmental footprint, generally
by two means. The frst is by allowing for fewer extensive
cattle ranches. If high-yielding biofuel crops are grown,
substantial volumes of residues and by-products will also
be produced, often high in protein and suitable for livestock
feeds. The second method is through multiple uses of animal
feed crops; with 1/3 of existing arable land used for growing
animal feeds, there is potential for this to also co-produce
biofuels without signifcantly reducing the amount of livestock
supported.
4. Closing the Loop, using waste treatment by anaerobic
digestion
5. Microalgae / Fish Ponds, the nutrient rich slurry from anaero-
bic digesters can be released into ponds containing microal-
gae and other aquatic plants that become feed for fsh.
In addition to the savings on energy consumption, the use of
by-products as bioenergy feedstock minimises land use require-
ments and reduces GHG emissions from land conversion;
systematic use of by products can reduce the land needed to
produce liquid biofuels by 10-25% (Croezen and Brouwer, 2008).
A large Argentine company implemented a system whereby the
residues from corn used to produce ethanol were used to feed
the livestock, whose dung in turn was used to produce biogas
that generated electricity used in the ethanol plant and also for
milk production
(El Clarin, 2007).