Library Subscription: Guest
Home Archives Officers Future meetings Assembly for International Heat Transfer Conferences
International Heat Transfer Conference 15

ISSN: 2377-424X (online)
ISSN: 2377-4371 (flashdrive)

Heat and Mass Transfer Model of a Packed-Bed Reactor for Solar Thermochemical CO2 Capture

DOI: 10.1615/IHTC15.pmd.008893
pages 6541-6553

Leanne Reich
University of Minnesota, Minneapolis, Minnesota 55455, USA

Roman Bader
The Australian National University, Canberra, ACT 2601, Australia

Terrence W. Simon
Department of Mechanical Engineering, University of Minnesota, 111 Church St. S.E., Minneapolis, Minnesota 55455, USA

Wojciech Lipinski
Research School of Engineering, The Australian National University, Craig Bldg. 35A, 35A Science Road Acton ACT 2501, Canberra, Australia


KEY WORDS: Solar energy, carbon emission mitigation, radiation, chemical reactor modeling, carbonation­-calcination cycle

Abstract

A 1 kWth dual-cavity solar thermochemical reactor concept is proposed to capture carbon dioxide via the calcium oxide based calcination?carbonation cycle. The reactor is oriented beam-up wherein concentrated solar energy from a heliostat field enters an aperture located at the bottom of the reactor. In the endothermic calcination step, concentrated solar radiation is captured by the inner cavity and transferred by conduction through a diathermal cavity wall to the particulate CaCO3 medium located in the annular reaction zone. The liberated CO2 is removed from the reactor to external storage. In the exothermic carbonation step, a CO2-containing flows through a bed of CaO particles in the reaction zone, forming CaCO3, while CO2-depleted leaves the system. The reactor design is refined using a numerical heat and fluid flow model for the calcination step. The Monte Carlo ray-tracing method is employed to solve for radiative exchange in the inner cavity, coupled with a computational fluid dynamics analysis to solve the mass, momentum, and energy equations in the concentric reaction zone modeled as a gas-saturated porous medium consisting of optically large semitransparent particles. The cavity diameter and length-to-diameter ratio are varied to study their effects on pressure drop, temperature distribution, and heat transfer in the reactor. Increasing the cavity diameter and length-to-diameter ratio decreases the radial temperature gradients across the cavity wall and within the reaction zone. However, it also results in increased pressure drop and reduced heat transfer to the reaction zone.

Download article Publication Ethics and Malpractice Recommend to my Librarian Bookmark this Page