(519d) Energetic and Environmental Assessment of Biomass Processing in the Sugar-Cane Industry

Kahwaji Janho, M., Cleveland State University
Shuster, Q. A., Cleveland State University
Gatica, J. E., Cleveland State University
Hernández, M. R., Universidad Nacional de Tucuman
Mele, F. D., Universidad Nacional de Tucuman
Colombo, M., Universidad Nacional de Tucuman

Bio-fuels have come to be recognized as possible, environmentally friendly alternatives to fossil fuels. This work studies a Bio-ethanol production process complementing a sugar mill, through computer simulations, using ASPEN PLUS® as the simulation engine.

The process flowsheet examined includes three major processing stages typical of distillery installations for fuel-grade production in typical sugar-cane processing facilities: (1) the fermentation stage, (2) the separation stage, and (3) the dehydration stage.

Using plant data from a bio-ethanol pilot plant in Northwestern Argentina (NOA) a kinetic model is formulated for a fed-batch molasses fermentation process. The model for this unit, along with a user-defined separation module, is then integrated into a commercial process simulator.  Different schemes meeting equivalent performance standards in terms of purity and recovery are examined in this paper.

Particular attention is given to energetic integration by performing a pinch-analysis to each of the fundamental stages to find a global optimum. Optimization is achieved by minimizing a given objective function that accounts for bio-ethanol recovery, separation efficiency, and minimization of effluents. Life Cycle Analysis is used to complete the assessment of operating parameters/conditions on environmental effects.