Carbon capture, utilization, and storage (CCUS) is one of the key promising technologies that can reduce GHG emissions from those industries that generate CO2 as part of their production processes. Compared to other effective CO2 capture methods, the adsorption technique offers the possibility of reducing the costs of the process by setting solid sorbent with a high capacity of adsorption and easy regeneration and, also, controlling the performance of gas-solid contactor. In this work, an amine-functionalized mesoporous sorbent was used to capture CO2 emissions in a confined-fluidized bed. The adoption of a confined environment allows the establishment of a homogeneous expansion regime for the sorbent and allows to improve the exchange of matter and heat between gas and solid phase. The results illustrate how the different concentration of the solution adopted during the functionalization affects the adsorption capacity. That, measured as mg of CO2 per g of sorbent, was determined by breakthrough curves from continuous adsorption tests using different concentrations of CO2 in air. Mesoporous silica functionalized with a concentration of 20% of APTES proves to be the best viable option in terms of cost and ease of preparation, low temperature of regeneration, and effective use for CO2 capture.
To reduce the anthropogenic CO2 emissions produced from fossil fuel burning plants, the application of carbon capture and storage (CCS) is necessary and development of a more efficient and economically feasible CO2 capture process is essential as an alternative to the conventional amine scrubbing process which uses aqueous amine solutions. CO2 capture can be enhanced by improving both the gas–solid contact efficiency and by tuning a specific high-performance sorbent. The aim of this research is to investigate the adsorption of CO2 using impregnated mesoporous silica in a “confined-fluidized bed”. This non-conventional fluidized bed (sometimes also termed the “packed-fluidized bed”) seems suitable for improving the efficiency of gas–solid processes for which the bypass effect of the gas–solid contact caused by bubbling represents a major drawback. Results, expressed as grams of CO2 adsorbed per kilogram of material, are discussed in terms of amine load in the sorbent, breakthrough time and fraction of bed utilized. The stability of the materials after regeneration cycles is also discussed. The results obtained confirm that the confinement of the bed allows exploiting fluidization technology in adsorption operations. The operating velocity can be fixed at a value at which the thermal effects also connected to the operation are kept under control.
This work is part of a research project aimed at studying potential sorbents for CO2 capture. The main parameters characterising the adsorption process of zeolite 13X were derived with the aim of overcoming the limits of experimental analysis and thus predicting the performances of the materials of interest. In particular, the main parameters that control the adsorption process of CO2 in zeolite 13X were evaluated through parametric optimisation. This systematic procedure allows for the prediction of the performances of the materials at different operating conditions, identifying the most suitable ones for the case under consideration. Another important application lies in the possibility of a preliminary study of a potential process scale-up for future industrial use. The captured carbon dioxide can be stored or used as a reagent in the production of products with higher economic values, such as methanol, DME and others.
Mesoporous silica nanoparticles (MSNs) are promising drug carriers for cancer therapy. Their functionalization with ligands for specific tissue/cell targeting and stimuli-responsive cap materials for sealing drugs within the pores of MSNs is extensively studied for biomedical and pharmaceutical applications. The objective of the present work was to establish MSNs as ideal nanocarriers of anticancer drugs such as 5-FU and silymarin by exploiting characteristics such as their large surface area, pore size, and biocompatibility. Furthermore, coating with various biopolymeric materials such as carboxymethyl chitosan–dopamine and hyaluronic acid–folic acid on their surface would allow them to play the role of ligands in the process of active targeting to tumor cells in which there is an overexpression of specific receptors for them. From the results obtained, it emerged, in fact, that these hybrid nanoparticles not only inhibit the growth of glioblastoma and breast cancer cells, but also act as pH-responsive release systems potentially useful as release vectors in tumor environments.
1 February 2001 in Microporous and Mesoporous Materials