Emergy analysis of cassava chips-suitable feedstock for fuel ethanol in China

The theory and indices of Odum's concept of emergy are explained. The environmental and economic inputs and sustainability of cassava chips production system are evaluated by emergy methodology. The emergy indices of cassava chips production system were calculated as follows: Tr (transformity) was 6.85E + 11 sej/kg, EYR (emergy yield ratio) was 1.11, ELR (environmental loading ratio) was 1.75, EIR (emergy investment ratio) was 9.33, and ESI (emergy sustainability indice) was 0.63. The emergy indices of four kinds of feedstock for fuel ethanol—corn, wheat, sugarcane, and cassava chips—were compared. Least solar energy was consumed when taking cassava chips as feedstock for fuel ethanol. According to the emergy indices, using cassava chips as the feedstock of fuel ethanol is helpful for sustainable development in China.