Experimental evaluation and modeling of steam gasification and hydrogen inhibition in Chemical-Looping Combustion with solid fuel
Artikel i vetenskaplig tidskrift, 2012

A Chemical-Looping Combustion (CLC) system is composed of two fluidized bed reactors, an air reactor and a fuel reactor. Oxygen is transferred from the air to the fuel by solid oxygen carrier particles circulating between these two reactors. By this arrangement, the N2 from the air is kept separated from the fuel gases as a part of the process and an almost pure stream of CO2 is obtained from the fuel reactor. This work investigates and models the influence of the steam and hydrogen concentration in the fuel reactor on the rate of solid fuel conversion in Chemical-Looping Combustion. Two kinds of fuel were examined, Swedish wood char and El Cerrejon bituminous coal (Colombian coal). Four different bed materials have been used in the reactor, ilmenite, nickel and oxide scales as an oxygen carrier and quartz sand for gasification experiments. The temperature was 970 °C for all experiments. Different fractions of steam and hydrogen were added to the fluidizing stream. Additionally, gasification experiments of fuel particles pretreated in mixtures of H2 and N2 were performed in order to determine the reversibility of the observed hydrogen inhibition. The results show that the best models for describing the behavior of steam gasification and fuel conversion in Chemical-Looping Combustion for a Swedish wood char and the El Cerrejon coal is the oxygen exchange model. For both fuels, it can be seen that higher steam concentration increases the rate of char conversion and, higher hydrogen concentration decreases the rate as a result of hydrogen inhibition. No irreversible hydrogen inhibition could be observed.

Gasification

Chemical-Looping Combustion

CO2 capture

Ilmenite

Hydrogen inhibition

Oxygen carrier

Författare

Golnar Azimi

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Martin Keller

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Amin Mehdipoor

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Henrik Leion

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

International Journal of Greenhouse Gas Control

1750-5836 (ISSN)

Vol. 11 1-10

Styrkeområden

Energi

Materialvetenskap

Ämneskategorier

Kemiteknik

DOI

10.1016/j.ijggc.2012.07.018

Mer information

Skapat

2017-10-07