SILVA, M. C.; http://lattes.cnpq.br/5902558315613643; SILVA, Márcia Camila da.
Resumo:
Distillation is the most important industrial process for separating mixtures. An
azeotropic mixture needs specific distillation methods to separate its components
and one of these methods is pressure-swing distillation (PSD), which uses two
distillation columns operating at different pressures. The azeotropic point can be
shifted due pressure variation and obtain the substances practically pure.
However, pressure-swing distillation in its simplest form can present a high
energy consumption, when compared to other separation methods. Some design
modifications can be made in the process to make it more economically attractive.
Among these changes, we can mention the use of columns with varied diameter
(VDC), which can significantly reduce the capital costs. In addition to design
changes, determining a process control structure is also indispensable. Control
is necessary for a process to operate safely and for the top and bottom products
to remain within the desired specifications after disturbances that normally occur
in the process. Within this context, this work appeared in order to evaluate the
performance of the control of the pressure-swing separation process using
columns with varied diameter (VDC). The performance of the process control
using VDC was compared with that of the process using columns with uniform
diameter (UDC), in face of disturbances in the feeding through PRBS signals
(Binary Sequence Pseudo-Random). The Integral Square Error (ISE) was the
criterion used to compare the performance of both cases. According to the results
obtained, the simulated system with columns with uniform diameter showed lower
ISE values for the composition of the products for most of the tested disturbances.