The increase of the greenhouse effect during the last years led to the development of new technologies in the field of the capture of gases with high environmental impact. CO2 represents the most important, not only for its high GWP value [1], but also for its massive emissions due to its production in several human activities. Among other technologies, the adsorption by solid sorbents are very relevant and interesting for pressure or temperature swing adsorption processes. For this reason, the development of novel materials with good performances in terms of CO2 capacity and selectivity towards other gases is very relevant. Novel geopolymer (amorphous alkali aluminosilicates) based composites have been developed in this work by addition of zeolites, and characterized as solid adsorbents. The presence of different scale of porosity in the geopolymer-zeolite composites can be relevant for improving the performance of the sorbent. In micropores (typical of zeolites), the effective gas diffusivity may assume rather low values, so the contemporary presence of a diffused mesoporosity (typical of geopolymers) contributes to maintain the gas diffusion at level close to that of unconfined system [1]. The experimental characterization of the geopolymers-zeolite composites revealed a good CO2 adsorbent capacity, remarkably higher than those of CH4 and N2, resulting in a quite high selectivity. Therefore, these materials showed a significant ability in the selective capture of CO2, making them interesting and suitable for CCS applications. The geopolymer matrix, with well-known good mechanical behavior as well a remarkable formability, combined with highly adsorbent systems such as a zeolite, allows to fabricate solid adsorbent with improved properties.
Characterization of novel geopolymer - zeolite composites as solid adsorbents for CO2 capture
E Papa;V Medri;F Miccio;E Landi;
2017
Abstract
The increase of the greenhouse effect during the last years led to the development of new technologies in the field of the capture of gases with high environmental impact. CO2 represents the most important, not only for its high GWP value [1], but also for its massive emissions due to its production in several human activities. Among other technologies, the adsorption by solid sorbents are very relevant and interesting for pressure or temperature swing adsorption processes. For this reason, the development of novel materials with good performances in terms of CO2 capacity and selectivity towards other gases is very relevant. Novel geopolymer (amorphous alkali aluminosilicates) based composites have been developed in this work by addition of zeolites, and characterized as solid adsorbents. The presence of different scale of porosity in the geopolymer-zeolite composites can be relevant for improving the performance of the sorbent. In micropores (typical of zeolites), the effective gas diffusivity may assume rather low values, so the contemporary presence of a diffused mesoporosity (typical of geopolymers) contributes to maintain the gas diffusion at level close to that of unconfined system [1]. The experimental characterization of the geopolymers-zeolite composites revealed a good CO2 adsorbent capacity, remarkably higher than those of CH4 and N2, resulting in a quite high selectivity. Therefore, these materials showed a significant ability in the selective capture of CO2, making them interesting and suitable for CCS applications. The geopolymer matrix, with well-known good mechanical behavior as well a remarkable formability, combined with highly adsorbent systems such as a zeolite, allows to fabricate solid adsorbent with improved properties.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
