A Computational Method For Thermo-Exergetic Analysis Of The Sugar Mill Process.

Abstract

This publication presents a computational method for thermo-exergetic analysis of
the process of production in sugar mills. This study is motivated by the deficiency of thermoexergy
studies on that process and environmental impacts. The Brazilian thermo-exergetics
matrix is based in fossil fuels and economical analysis led us to the solutions in cogeneration
from agricultural residues surpluses. This sector can provide solutions that complement the
energy matrix by reduction industrial demand, leading to energy independence or even the
generation of electricity surpluses (rational energy use and optimizations). This methodology
applies the conservation and thermodynamics laws to effectiveness and available work losses
in flows and each chemical component (water and sucrose). The thermodynamic results
determined economically viable alternatives for investments decisions. The computational
routine maps the inlet and outlet variables for each control volume: enthalpies and entropies,
availabilities, mass flows, specific consumptions, irreversibilities and effectiveness. From the
results was possibility to identify that in subsystem 1 the pre-evaporator is the least effective
equipment with effectiveness ≈ 47% and 97,4MW of irreversibility. In subsystem 2 the group
air heater and sugar drier has effectiveness ≈ 25% and 1,37MW of irreversibility while the
second centrifuge has effectiveness ≈ 23% and 115,6MW of irreversibility.