DIQ - Artículos
https://hdl.handle.net/10481/14087
2024-03-28T19:14:05ZImpact of Metal Impregnation of Commercial Zeolites in the Catalytic Pyrolysis of Real Mixture of Post-Consumer Plastic Waste202
https://hdl.handle.net/10481/89614
Impact of Metal Impregnation of Commercial Zeolites in the Catalytic Pyrolysis of Real Mixture of Post-Consumer Plastic Waste202
Paucar Sánchez, Marco Favio; Calero, Mónica; Blázquez García, Gabriel; Rodríguez Solís, Rafael; Muñoz Batista, Mario Jesús; Martín Lara, María Ángeles
This work reports the study of the catalytic pyrolysis of rejected plastic fractions collected from municipal solid waste whose mechanical recovery is not plausible due to technical or poor conservation issues. The chemical recycling using catalytic pyrolysis was carried out over commercial zeolites formulas, i.e., HY and HZSM-5, in which Ni or Co metals were deposited at two different loadings (1 and 5%, wt.). The presence of these transition metals on the zeolitic supports impacted the total production of compounds existing in the liquid oil. The samples were characterized in terms of structural, chemical, and morphologic properties, and the production of different fuel fractions (gasoline, light cycle oil, and heavy cycle oil) was correlated with a combined parameter defined as a ratio of Acidity/BET area.
On the cutting-edge of non-recyclable plastic waste valorization: From pyrolysis char to nitrogen-enriched activated carbon for landfill biogas upgrading
https://hdl.handle.net/10481/89612
On the cutting-edge of non-recyclable plastic waste valorization: From pyrolysis char to nitrogen-enriched activated carbon for landfill biogas upgrading
Ligero, Ana; Rodríguez Solís, Rafael; Blázquez, Gabriel; Muñoz Batista, Mario Jesús; Pérez, Antonio; Calero, Mónica
The rejected fraction of post-consumer plastics collected by mechanical sorting is a source of chemical recycling by processes such as pyrolysis, promoting the circular economy. The char residue produced in this process has been valorized, reinforcing the introduction in the consumption chain, as an adsorbent aimed at the upgrading of a biogas stream. The char was activated with KOH (496 m2 g−1) and the surface of the material was enriched with nitrogen groups (6% wt. by XPS) to raise the CO2 uptake. KOH and urea were used following different strategies, demonstrating that sequential activation and modification is the most efficient approach. Although the surface area was decreased after N insertion, i.e. from 497 to 389 m2 g−1, the CO2 uptake was raised. Specifically, comparing the CO2 uptake per micropore surface was considerably improved after urea functionalization (0.351 vs 0.235 mg m−2). The selectivity was not considerably modified, but the isosteric adsorption heat of the urea-modified sample was higher than the bare one. The behavior in the dynamic tests was studied in fixed-bed column, assessing the effect of temperature, and inlet CO2/CH4 concentration, individually and in mixtures. There was no appreciated loss of performance in the adsorption-desorption cycles. The urea-modification in a two-pot synthesis process proved a better performance in dynamic tests if compared to the non-modified activated char. This work sheds insights into the feasibility of the recycling of plastic residues giving to new added-value materials such as functionalized carbonaceous adsorbents, promoting a circular economy basis.Pla
Sulfonic grafted graphitic-like carbon nitride for the improved photocatalytic production of benzaldehyde in water
https://hdl.handle.net/10481/89375
Sulfonic grafted graphitic-like carbon nitride for the improved photocatalytic production of benzaldehyde in water
Quintana, María Alejandra; Rodríguez Solís, Rafael; Blázquez García, Gabriel; Calero De Hoces, Francisca Mónica; Muñoz Batista, Mario Jesús
This work reports the modification of graphitic carbon nitride (CN) through sulfonation (SCN) as an enhanced strategy for photocatalytic activity during the oxidation of benzyl alcohol to benzaldehyde. CN was prepared from melamine and functionalized with -SO3H groups using different doses of chlorosulfonic acid. The textural, structural, morphological, chemical, and optical properties of the prepared samples were characterized by diverse techniques. The increase in the doping dose produced, a decrease in surface area, a blue-shifted absorption edge under irradiation, and a decrease in the recombination charges. The -SO3H improved the kinetics of benzyl alcohol oxidation (BA) in aqueous solution and raised the selectivity to benzaldehyde (BD). An optimum dosage of precursor led to an SCN sample with the highest removal rate and selectivity. This optimized sample was selected for the study of the reactive oxidant species involved during the photocatalytic process, suggesting that the species with the highest contribution during BA oxidation was the superoxide radical, especially in terms of selectivity for the aldehyde formation. This work examples the modification of carbon nitride to enhance the production of an aldehyde with interest in the industry under a sustainable scheme that involves the transformation of light into chemical energy in aqueous solution.
Multi‑length Scale Approach to Investigate Cleaning of Food‑Derived Deposits Adhered to Hard Surfaces: Mixtures of Starch, Whey Protein, and Lard
https://hdl.handle.net/10481/89193
Multi‑length Scale Approach to Investigate Cleaning of Food‑Derived Deposits Adhered to Hard Surfaces: Mixtures of Starch, Whey Protein, and Lard
Sáenz-Espinar, María José; Arroyo-Camarena, Marina; Vicaria Rivillas, José María; Luzón González, Germán; Ávila Sierra, Alejandro
Fouling, the accumulation of undesirable material on manufacturing equipment surfaces, poses a pervasive challenge in
industrial processes. In the food industry, the complex interactions among these compounds can give rise to stubborn deposits
that deviate from conventional cleaning protocols. In this work, the forces and removal mechanisms of model fouling
agents composed of mixtures of starch, whey protein, and lard deposited on solid surfaces of relevant industrial interest (i.e.
stainless steel, aluminium, and PTFE) are investigated using a multi-length scale approach, involving milli-manipulation
and a lab-simulated Clean-In-Place (CIP) system. The forces involved in the removal process, the types of failure observed
when the deposits are subjected to shear stress (adhesive, mixed, or cohesive), and the performance of the CIP system are
systematically analysed as a function of the cleaning treatments applied. For stainless steel surfaces, alkaline treatment
seems to facilitate the cleaning of lard and starch deposits, while the whey foulant removal tends to be more effective using
hot water under the conditions tested. Hot water is effective for stainless steel and PTFE surfaces, reducing the mechanical
shear stress required, while the alkaline treatment demonstrated superior efficacy for aluminium surfaces. These findings
emphasise the importance of customising cleaning protocols for CIP optimisation.
Towards the photocatalytic production of cinnamaldehyde with phosphorous-tailored graphitic-like carbon nitride
https://hdl.handle.net/10481/89167
Towards the photocatalytic production of cinnamaldehyde with phosphorous-tailored graphitic-like carbon nitride
Quintana, María Alejandra; Picón, Alba; Martín Lara, María Ángeles; Calero De Hoces, Francisca Mónica; Muñoz Batista, Mario Jesús; Rodríguez Solís, Rafael
Photocatalysis has emerged as an environmentally friendly technology to develop selective reactions such as the
oxidation of alcohol to aldehydes. Graphitic carbon nitride (CN) is a metal-free polymeric structure easily
photoactivated under radiation. This work focuses on the enhancement of the photocatalytic activity of bare CN
by doping it with phosphorous (P-CN). Different doping levels of P (2–12 wt.) have been explored and the
samples were fully characterized by XRD, FTIR, N2 physisorption, elemental analysis, XPS, DRS-UV–visible, and
photoluminescence. A better activity and enhanced selectivity were observed in the P-CN samples if compared to
the undoped CN in the oxidation of cinnamyl alcohol to cinnamaldehyde in aqueous solution. The presence of P
was demonstrated to contribute to a better delocalization of photo-generated charges. Moreover, the reactivity
and selectivity of the CN and P-CN samples were analyzed in water-acetonitrile mixtures, appreciating a better
selectivity in the presence of acetonitrile to the detriment of the conversion of the cinnamyl alcohol. The photocatalytic oxidation mechanism over P-CN in aqueous media has been tentatively proposed based on the influence of the reactive oxidative species generated in the process by chemical scavenger tests. They suggested the
contribution of superoxide radicals with more selectivity than the photo-generated holes, the second reactive
species of importance in the overall oxidation scheme. The contribution of hydroxyl radicals was discharged
since its presence was negligible in a probe test based on the formation of 2-hydroxy-terephthalic acid.