Influence of Mineral Composition of Chars Derived by Hydrothermal Carbonization on Sorption Behavior of CO 2 , CH 4 , and O 2

• Published in: ACS omega 2020-05, Vol.5 (19), p.10704-10714
• Main Authors: Wedler, Carsten, Lotz, Katrin, Arami-Niya, Arash, Xiao, Gongkui, Span, Roland, Muhler, Martin, May, Eric F, Richter, Markus
• Format: Article
• Language: English
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.9b04370

The doping of SiO and Fe O into hydrochars that were produced by the hydrothermal carbonization of cellulose was studied with respect to its impact on the resulting surface characteristics and sorption behavior of CO , CH , and O . During pyrolysis, the structural order of the Fe-doped char changed, as the fraction of highly ordered domains increased, which was not observed for the undoped and Si-doped chars. The Si doping had no apparent influence on the oxidation temperature of the hydrochar in contrast to the Fe-doped char where the oxidation temperature was reduced because of the catalytic effect of Fe. Both dopants reduced the micro-, meso- and macroporous surface areas of the chars, although the Fe-doped chars had larger meso- and macroporosity than the Si-doped char. However, the increased degree in the structural order of the carbon matrix of the Fe-doped char reduced its microporosity relative to the Si-doped char. The adsorption of CO and CH on the chars at temperatures between 273.15 and 423.15 K and at pressures up to 115 kPa was slightly inhibited by the Si doping but strongly suppressed by the Fe doping. For O , however, the Si doping promoted the observed adsorption capacity, while Fe doping also showed an inhibiting effect.