Energy and eMergy evaluation of bioethanol production from wheat in Henan Province, China

摘要

Ethanol production from wheat has become an emerging economic activity in Henan Province due to the establishment in 2001 of the National Program for Alcohol Production. The program aimed at facing the unfolding world energy crisis in the near future and increasing China's energy security. Instead, in spite of claims for "green energy", such an activity is likely to generate great environmental damage and social problems. Moreover, the international market prices for raw materials (especially cereals) and fossil oil are putting this activity under siege. This research presents an energy and eMergy analysis of a typical wheat plantation/alcohol distillery system, in the Henan Province. Comparison is drawn with bioethanol production in Italy, based on corn from intensive, industrialized agriculture. Energy and eMergy indices of ethanol production from wheat and corn in the two agro-industrial systems are respectively as follows: output/input energy ratio, 1.09 (wheat) and 1.19 (corn); transformity of bioethanol, 2.77 × 105 and 1.89 × 105 seJ/J; renewability, 20% and 11%; eMergy yield ratio, 1.24 and 1.14; environmental loading ratio, 4.05 and 7.84; and finally eMergy sustainability index, 0.31 and 0.15. Results show that bioethanol from food crops is not a sustainable source of fuel.