Influence of limestone addition in a 10 kWth Chemical-Looping Combustion unit operated with petcoke
Artikel i vetenskaplig tidskrift, 2011

Ilmenite, a natural mineral composed of FeTiO3, is a low cost material suitable as oxygen-carrier for Chemical-Looping Combustion (CLC) with solid fuels. One option when using the CLC technology with solid fuels is to introduce the fuel directly into the fuel-reactor. There the fuel is gasified and volatiles and gasification products react with the oxygen-carrier. In this study the influence of limestone addition to ilmenite as oxygen-carrier was tested in a continuous 10 kWth CLC pilot for solid fuels. The fuel fed was a petcoke and the gasifying agent was steam. Tests with an ilmenite-limestone mixture as bed material were performed, and also tests using only ilmenite as bed material were carried out for comparison. Global solids circulation was varied as it is an important operational parameter, which determines the solid fuel residence time. The experiments were made at two fuel-reactor temperatures: 950ºC and 1000ºC. Generally, higher residence time of the fuel and higher temperature increased both gasification and combustion efficiencies. This was seen for both with and without limestone addition. The addition of limestone, gave a significant improvement of gas conversion at 950ºC, which could be explained by lime catalyzing the water-gas shift reaction. Moreover, the presence of limestone significantly increased the char conversion both at 950ºC and 1000ºC.

Limestone

Oxygen-carrier

Coal

Ilmenite

Chemical-looping combustion (CLC)

Carbon capture

Författare

Ana Cuadrat

CSIC - Instituto de Carboquimica (ICB)

Carl Johan Linderholm

Chalmers, Energi och miljö, Energiteknik

Alberto Abad

CSIC - Instituto de Carboquimica (ICB)

Anders Lyngfelt

Chalmers, Energi och miljö, Energiteknik

Juan Adánez

CSIC - Instituto de Carboquimica (ICB)

Energy & Fuels

0887-0624 (ISSN) 1520-5029 (eISSN)

Vol. 25 4818-4828

Drivkrafter

Hållbar utveckling

Ämneskategorier

Energiteknik

Styrkeområden

Energi

DOI

10.1021/ef200806q