DYNAMIC SIMULATION OF EVAPORATOR IN ETHANOL BIOREFINERY

Abstract

Biorefineries producing ethanol from sugarcane are, mostly, plants that obtain ethanol from first-generation process. Second-generation ethanol is currently being studied and evaluated technologically and economically. One of the stages of large energy consumption, common to 1st and 2nd generation processes, is the concentration step by evaporator systems. In the present work a phenomenological transient model of Robert type evaporator is implemented using EMSO simulator. The physicochemical properties were calculated by the thermodynamic package VRTherm. The calandria section of the evaporator was modeled as a shell-and-tube heat exchanger, followed by a flash vessel for phase separation using level and pressure controllers. The finitedifferences method was used to discretize the spatial variable in the obtained partial differential equations, and the numerical integrator DASSLC was the code used to solve the resulting system of differential-algebraic equations. The obtained compositions of the liquid and vapor phases and temperatures are in agreement with data obtained from literature. In order to compare the results between a simpler and a more detailed models, flash and Robert type evaporator models were evaluated.