Greenhouse gasses emissions and energy balances of a non- vertically integrated sugar and ethanol supply chain: a case study in Argentina

ACRECHE M.M.; VALEIRO A.H.

ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2013 vol. 54 p. 146 - 154

0360-5442

In order to address society?s concerns regarding the sustainability of sugar and ethanol production and use, this paper calculates the energy and greenhouse gasses (GHG) emissions? balances of a nonvertically integrated sugarcane industry in Tucumán-Argentina. The essential operations involved in the sugar/ethanol production cycle were taken into account. Results show that this industry generated an energy balance of 3.4:1. GHG emissions during sugarcane production were 1824 and 2231 kg CO2eq. ha_1 year_1 for low and middle to high farms? technological levels, respectively. The mill process emitted 1187 kg CO2eq. ha_1 year_1. The main factors influencing these balances were gas-oil and nitrogen fertilizers used in the agricultural stage, natural gas consumed by the sugar mill, and sugarcane burning (only for GHG balance). The impact of ethanol use in reducing GHG emissions under the current production scheme (6.8 Mg ha_1 of sugar and 380.9 kg ha_1 of ethanol), in final blends of 95% gasoline and 5% ethanol in vehicles, is negligible. A sensitivity analysis indicates that switching to 100% bagasse used as fuel in mill?s boilers, ethanol being produced directly from sugarcane juice, and a final blend of 90% gasoline and 10% ethanol, an amount of 1746 kg CO2eq. ha_1 year_1 of GHG emissions could be avoided.