Combined manganese/iron oxides as oxygen carrier for chemical looping combustion with oxygen uncoupling (CLOU) in a circulating fluidized bed reactor system
Paper in proceedings, 2011

Two kinds of particles consisting of mainly manganese and iron oxides have been examined as oxygen carrier for chemicallooping combustion with O2 uncoupling in a circulating fluidized-bed reactor. The first was produced by spray drying and consisted of 66.8 wt% iron oxide and 33.2 wt% manganese oxide. The second was a manganese ore which also contained iron oxide and silica oxide. During O2 uncoupling experiments, both materials were found to release O2 in gas phase at temperatures above 850°C, when fluidized with CO2. 7-8 h of continuously operating experiments were recorded for each oxygen carrier, and it was found that the O2 release increased with increased reactor temperature. At 1000°C, the O2 concentration in the outlet from the fuel reactor was in the order of 7.5 vol% for the synthetic particles. For the ore, the O2 concentration was roughly 0.7 vol% at 990°C. Further, chemical-looping combustion experiments with natural gas as fuel were carried out. While the conversion of fuel to CO2 and H2O initially was very high (96%) for the synthetic particle and decent (75%) for the ore, both oxygen carriers were found to erode into dust during combustion experiments. Some of the ore particles also swelled greatly. The solids circulation stopped abruptly after 4 h of combustion experiments for the synthetic particle, and after 2 h for the ore. In both cases, the stoppage was likely associated with the physical breakdown of the particles. It is concluded that combined oxides of manganese and iron have very interesting thermodynamical properties and could potentially be suitable for chemical-looping applications. The physical and chemical stability of such materials will have to be further studied and improved though.

Combined oxides

Manganese oxide

Iron oxide

Chemical-looping with oxygen uncoupling

Chemical-looping combustion

Author

Magnus Rydén

Chalmers, Energy and Environment, Energy Technology

Anders Lyngfelt

Chalmers, Energy and Environment, Energy Technology

Tobias Mattisson

Chalmers, Energy and Environment, Energy Technology

Energy Procedia. 10th International Conference on Greenhouse Gas Control Technologies; Amsterdam; 19-23 September 2010

1876-6102 (ISSN)

Vol. 4 341-348

Driving Forces

Sustainable development

Subject Categories

Energy Engineering

Other Chemistry Topics

Areas of Advance

Energy

DOI

10.1016/j.egypro.2011.01.060

More information

Created

10/7/2017