Federico J Franck Colombres1,2, Enrique A Feijoó1, L Patricia Garolera de Nucci1, Gisela F Díaz1 and Marta C Cruz1
1Sección Ingeniería y Proyectos Agroindustriales – Estación Experimental Agroindustrial Obispo Colombres, Tucumán, Argentina
2Departamento de Mecánica – Universidad Nacional de Tucumán, Av. Independencia 1800, S. M. de Tucumán, Tucumán, Argentina; federicofranck@gmail.com
In Tucumán, bioethanol is produced mainly from distilleries annexed to sugarcane plants that consume thermal and electrical energy supplied largely from the bagasse generated, which contributes to the sustainability of their process. However, additional fossil fuels are also used in the process to supply their energy requirements. The objective of this work was to study the use of agricultural residues from sugarcane harvests, using gasification process with air, to reduce fossil-fuel consumption. A utilization scheme and an appropriate gasification technology were proposed, the flows were determined for the material and energy balance, and a mathematical model proposed. The performance that the gasification gas shows in a natural gas boiler was estimated through a comparative analysis based on a test with natural gas. The efficiency of the boiler using gasification gas, its consumption to replace natural gas and the amount of harvest residues necessary to feed the gasifier were determined. Given the biogenic carbon of the harvest residues, avoided greenhouse gas emissions were estimated as the difference of the emissions from natural gas combustion with those from the combustion of diesel consumed in the logistics of the harvest residues. The result shows that to eliminate natural gas 14 kg of gasification gas/kg of natural gas would be needed and 2.763 kg of gasification gas/kg of harvest residue would be obtained, that is, 5.07 kg of harvest residue/kg of natural gas. Through gasification technology, part of the harvest residues could be used to replace natural gas entirely and reduce CO2 emissions by 94%.