21st European Symposium on Computer Aided Process Engineering – ESCAPE 21
E.N. Pistikopoulos, M.C. Georgiadis and A.C. Kokossis (Editors)
© 2011 Elsevier B.V. All rights reserved.
Modelling and process integration of carbon
dioxide capture using membrane contactors
Albo, J., Cristóbal, J. and Irabien, A.
Departamento Ingeniería Química y Química Inorgánica. Universidad de Cantabria,
Av de los Castros s/n. 39005 Santander. Spain
Abstract
A zero solvent emission process is proposed using a membrane device and an ionic
liquid as a solvent; integrating a non-dispersive absorption-desorption process, gas
compression, and transport to sequestration area analysis. The study is based on a model
of a hollow fibre module formulated with a system of partial differential equations in
axial and radial directions, depending of the Graetz (Gz), solvent selection (H) and
Sherwood (S
h
) numbers. Numerical absorption results showing carbon dioxide (CO
2
)
recovery costs are presented, comparing them with those obtained in an integrated
conventional process where Monoethanolamine (MEA) is applied as absorbent liquid.
Keywords: CO
2
recovery, zero solvent emission process, process intensification, mass
transfer modelling.
1. Introduction
CO
2
capture and storage (CCS), which involves the processes of capture, transport and
long-term storage of carbon dioxide, is a technology aimed at reducing greenhouse gas
emissions from burning fossil fuels. Previous works [1-4] showed that process
intensification in CO
2
capture can be performed in two steps to develop a zero solvent
emission process: on the one hand the substitution of the equipment for a membrane
device avoiding dragging of solvent drops. On the other hand the substitution of the
absorption liquid for a solvent with lower vapour pressure (e.g. ionic liquids) [1-2]. The
use of this membrane-based technology supposes a relatively new concept in gas
absorption processes and offers many advantages including flexibility, modularity and
controlled interfacial area and flow rates [5-7]. However, the application of membrane
processes is strongly influenced by their economic feasibility as shown in studies
developed in the literature [8].
The model is formulated with a system of partial differential equations in axial and
radial directions, depending on operating conditions and solvent selection [4]. After
capture, the next step in the CCS value chain is compression and transport of CO
2
to
sinks for reuse or permanent storage. Several studies [9-11] have investigated the costs
of undertaking compression and different forms of transportation of CO
2
. In order to
have a better understating of the whole process these costs are also analyzed in this
work.