Reactivity comparison of German lignite and Victorian brown coal chars under oxy-fuel conditions

Luguang Chen, Thomas Reid, Sankar Bhattacharya

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch

Abstract

Oxy-fuel combustion is a promising technology for achieving near-zero CO2 emission from coal combustion. Char combustion is the controlling step in coal combustion. In this study, we compare the combustion behavior of a German lignite char and a Victorian brown coal char under oxyfuel conditions. Chars were prepared from a German lignite (Hambach) and a Victorian (Yallourn) brown coal in a drop-tube furnace (DTF) at 800 °C in pure CO2 atmosphere at an estimated residence time of 2 seconds. Char reactivity was investigated by a Thermogravimetric Analyzer (TGA) in the temperature range of 200°C to 1000°C at heating rate from 5K/min to 20 K/min and O 2 concentration from 2% up to 50% v/v in CO2. Both burnout temperature and the peak temperature were serious to be affected by the heating rate and oxygen concentration. With increase in the heating rate, both burnout temperature and peak temperature was found to increase for the two chars. The activation energies were also determined and compared. Except at 20% carbon conversion, the activation energies of German char were found to be much lower than that of Yallourn char. For the German char, the highest reactivity is observed with 50% O2 in the gas; however, at around 800 °C temperature, the highest reactivity is obtained when the O2 level is at 5%. Moreover, for Yallourn char, the highest reactivity is obtained at 5% O2, which is much higher (more than double) than that of German char.

Original languageEnglish
Title of host publication28th Annual International Pittsburgh Coal Conference 2011, PCC 2011
Subtitle of host publicationPittsburgh, PA, United States; 12-15 September 2011
EditorsBadie I. Morsi
Pages996-1004
Number of pages9
Volume2
Publication statusPublished - 2011
EventInternational Pittsburgh Coal Conference (PCC 2011) - David L. Lawrence Convention Center, Pittsburgh, United States of America
Duration: 12 Sep 201115 Sep 2011
Conference number: 28th
http://fscarbonmanagement.org/events/2011-international-pittsburgh-coal-conference-pcc

Conference

ConferenceInternational Pittsburgh Coal Conference (PCC 2011)
Abbreviated titlePCC 2011
CountryUnited States of America
CityPittsburgh
Period12/09/1115/09/11
Internet address

Keywords

  • Char reactivity
  • Oxyfuel
  • Thermogravimetric

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