(395ae) Heat Integrated Moving Bed Adsorption Process for Carbon Dioxide Capture

Heat integrated moving bed adsorption process for carbon
dioxide capture

Yongho Son, Kiwoong
Kim, Daewook Kim, and Kwang Soon Lee^*

Sogang
university, South korea

 (kslee@sogang.ac.kr)

A heat
integrated moving bed adsorption (MBA) process is proposed as a potentially
viable CO₂ capture process from large scale CO₂ emitting
plants. The proposed process depicted in Figure 1 consists of an adsorption bed
and two desorption beds through which the adsorbent particles are continuously
circulated. The adsorption bed is run under a low temperature and 1 atm while
the adsorbent and gas flow in opposite directions. The adsorbent particles
discharged from the adsorption bed are carried to a desorption bed under a high
temperature and 1 atm, and transferred to another desorption bed under a high
temperature and a vacuum, and returned to the adsorption bed. Heat integration
is designed to maximally recover the heat of adsorption from the adsorption bed
to supply the heat of desorption required in the desorption beds.

Fig. 1. The schematic diagram of MBA process.

The unsteady-state
numerical model of the MBA process has been developed. The governing partial
differential equation (PDE) model was set up from the mass and energy balances
for the gas and solid phases and the associated constitutive equations. Then,
an ordinary differential equation (ODE) model in time was derived by applying a
collocation technique along the spatial coordinate. The process behavior with
the variation of manipulable variables has been shown.

Afterward, the
economy as a CO2 capture process from a large CO2 source was assessed. Economy
evaluation using a numerical model was carried out in comparison with other
existing techniques. Process optimization and economy evaluation was performed
for the case that zeolite 13X is used as the adsorbent.

The lower bounds of the optimization were set
as 65% recovery and 99.5% purity of CO2. The MBA process at optimum operating
conditions exhibits the cost reduction of about 52% compared to the
conventional MEA-absorption process by Fluor Daniel Co.

The MBA process is proposed only conceptually
but reveals a great potential as a novel process that can replace the existing
CO2 capture processes. In addition, the process idea may be transferred to
solid-phase absorption processes and enhance the economic feasibility greatly.

Table 1. Economy
analysis of the MBA process and the MEA absorption process.

[1] D.G.
Chapel, C.L. Mariz, and J. Ernest. Recovery
of Co2 from flue gases: commercial trends, (1990), Aliso Viejo