Analysis of a Two-Stage Fuel Reactor System for the Chemical-Looping Combustion of Lignite and Bituminous Coal

作者：Haus Johannes^*; Lyu Kai; Hartge Ernst Ulrich; Heinrich Stefan; Werther Joachim

来源：Energy Technology, 2016, 4(10): 1263-1273.

DOI：10.1002/ente.201600102

• coal
• copper oxide
• chemical looping
• solid fuel
• two-stage reactor

To investigate the influence of the fuel characteristics on the conversion behavior in a chemical-looping combustion facility, lignite coal dust (d(90,3)=233m) and two fractions of bituminous coal with different particle sizes (fine fraction d(90,3)=163m, coarse fraction d(50,3)=707m) were used as solid fuel. To improve the conversion performance, a pilot plant with a rated power of 25kW was constructed with a two-stage fuel reactor. The influence of the fuel composition, particle size, and the presence/absence of elemental oxygen on the conversion in the fuel reactor are presented. The used oxygen carrier was produced by the impregnation of -alumina oxide with copper oxide, which is able to release gaseous oxygen, but loses this ability because of deactivation. The lignite dust shows a very good conversion performance and carbon capture efficiencies over 95% as well as oxygen demands below 2%. Both bituminous coal fractions have a good performance with regard to fuel conversion and oxygen demand but they suffer from a high carbon slip. Hence the carbon capture efficiency is around 60% for the fine fraction and 40% for the coarse one. The performance improvement as a result of the second stage was investigated separately, and we proved that it enhances the overall conversion. In addition, the oxygen carrier generated a favorable reaction environment by releasing elemental oxygen in the second stage of the fuel reactor.

• 出版日期2016-10