Dra. Narvaez-Dinamarca, Ana

This study evaluated the stability and reusability of amino-functionalized nanocellulose aerogels as CO2-adsorbent materials. The modified aerogels, synthesized via a controlled silylation using N-[3-(trimethoxysilyl) propyl] ethylenediamine (DAMO), demonstrated excellent thermal stability up to 250 °C (TGA) and efficient CO2 adsorption through chemisorption, which was the main adsorption mechanism. The performance of the aerogels was assessed using both adsorption isotherms and the decay pressure technique, revealing that CO2 adsorption capacity increased with higher amino group loading (4.62, 9.24, and 13.87 mmol of DAMO). At 298 K and 4 bar, CO2 adsorption capacity increased proportionally with the amino group concentration, reaching values of 3.17, 5.98, and 7.86 mmol of CO2 g−1 polymer, respectively. Furthermore, over 20 adsorption/desorption cycles, the aerogels maintained 95% CO2 desorption at ambient temperature, indicating their potential for industrial use. These findings highlight the aerogels suitability as stable, reusable materials for large scale CO2 capture and storage technologies.

Polygeneration systems have been shown to be a flexible arrangement which can meet seasonal product demands for electric power, fuels and chemicals. This is especially relevant for small markets such as isolated small-medium size communities demanding electricity, and fuels. This work is focused on the feasibility of a polygeneration system based on a single-step DME plant to produce 200,000 tonnes/year of DME and 200 MW of electricity. An economic analysis is carried out to assess different configurations and feedstocks for syngas production. The DME-production was simulated at different possible recycle ratios and under the condition of potentially reduced catalyst performance. In all cases, the once-through polygeneration system showed significant improvement over all other configurations e up to 11.6% reduction in the amount of synthesis gas required to produce DME and power e with a corresponding reduction in “wasted” feed leaving as effluent CO2. The flexibility of an integrated system meant that, in cases of decreased catalyst activity or selectivity, the advantages of the integrated system over standalone configurations are even greater e up to 18.6%. Moreover, polygeneration systems show further economic advantages depending upon the selling price of electricity for both fossil fuel and biomass sources of the syngas feedstock.

This paper demonstrates the key role of the property–structure relationship of the support on iron/ceria catalysts on the hydrocarbon selectivity and olefin-to-paraffin ratio for the direct hydrogenation of carbon dioxide into hydrocarbons. The effect is directly related to the reducibility of the different nanostructured ceria supports and their interaction with the iron particles. Herein, we demonstrate that the iron-based catalysts can be modified not only by the addition of promoters, commonly reported in the literature, but also by careful control of the morphology of the ceria support.