Reference:
D.C. Dumitrache,
B. De Schutter,
A. Huesman, and
E. Dulf,
"Modeling, analysis, and simulation of a cryogenic distillation
process for 13C isotope separation," Journal of Process
Control, vol. 22, no. 4, pp. 798-808, Apr. 2012.
Abstract:
This paper presents a structured and insightful approach to modeling
and simulation of an isotopic enrichment plant that uses distillation
principles for 13C isotope separation. First, after a brief
review of distillation and mass transfer-related topics, a full
nonlinear model for the cryogenic distillation process for
13C isotope separation is derived from first-principles
knowledge. In order to derive the mathematical description of the
concerned isotope separation process, based on the two-film theory, we
will derive the rate of transfer of the 13C isotope from
the vapor phase to the liquid phase. Since the isotope separation by
cryogenic distillation is usually carried out in a very long column
with a small diameter, a good approximation arises by neglecting the
radial diffusion. We continue with the determination of the system of
the partial differential equations that governs the evolution of
desired isotope during the separation process. Next, we solve the
system of partial differential equations, resulting in the full
nonlinear model. Due to the complexity of the full nonlinear model, we
consider two additional alternative modeling approaches resulting in a
quasi-linear model and, when the isotope concentration achieved is
low, a linear approximation model. In the second part of the paper we
use the finite-differences method for the numerical analysis and
numerical simulation of the three models, followed by the assessment
of the linear model for future tasks in modeling, optimization, and
process control.