INGAR   05399
INSTITUTO DE DESARROLLO Y DISEÑO
Unidad Ejecutora - UE
capítulos de libros
Título:
Design of a Hybrid Distillation-Pervaporation Bio-Ethanol Purification Process Using Conceptual Design and Rigorous Simulation Tools
Autor/es:
HOCH, PATRICIA M.; ESPINOSA, JOSÉ
Libro:
2008 AIChE Annual Meeting
Editorial:
AIChE
Referencias:
Lugar: Philadelphia, PA - USA; Año: 2008; p. 1 - 10
Resumen:
Optimization of both design and operation variables of a bio-ethanol purification plant intended to
produce fuel grade ethanol is a challenge to make the bio-fuel a realistic alternative in the energy market.
In this work, we propose an evolutionary optimization procedure which intensively uses both conceptual
and rigorous models for the design and simulation of unit operations involved in a bio-ethanol
purification process. While conceptual models are used to determine initial values for design and
operating variables of a given operation unit, rigorous simulation departing from initial estimates
generated at conceptual design level enables to remove simplifying assumptions, interconnect
equipments and calculate operating and investment costs.
Once an initial design of the purification plant is obtained, opportunities of improvement are easily
recognized and then tested by performing the design and simulation steps until a cost-effective bioethanol
purification plant is achieved.
Finding initial values for the column design is made easier within the conceptual design environment,
which is used to obtain an initial estimation of the total number of trays of the main distillation column,
placement of feed and side streams, and steam flow rate in the simulation environment. In addition,
convergence of the rigorous model is enhanced by using initial estimates of internal profiles generated at
the conceptual design level despite of the highly non-ideal behavior of the multicomponent azeotropic
mixture.
The advantage of the method is that the systematic use of conceptual models allows the designer to
capture the main characteristics of each operation involved in the process.
The main results obtained show a minimum in the operation costs corresponding to a minimum in the
steam flow rate of the hybrid column. This minimum in steam flow rate can be only explained by the
presence of the fusel component, which influences both the energy demand and feasible products of the
hybrid column. Therefore, designs based on the binary system ethanol-water do not represent the system
behavior in an accurate way. From this consideration emerges the importance of properly determining the
amount of trace components that enter the purification process.
From the analysis of the results obtained it is also clear that the investment cost corresponding to the
membrane sector is high enough to promote future research efforts in testing both selectivity and flux
behavior of other commercial pervaporation membranes.
Keywords: Bio-ethanol Purification, Evolutionary Optimization, Conceptual Design, Rigorous Simulation.: Bio-ethanol Purification, Evolutionary Optimization, Conceptual Design, Rigorous Simulation.: Bio-ethanol Purification, Evolutionary Optimization, Conceptual Design, Rigorous Simulation.