Examinando por Autor "Armenise, Sabino"

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Evaluation of two approaches for the synthesis of hierarchical micro-/mesoporous catalysts for HDPE hydrocracking
(Elsevier, 2023) Armenise, Sabino; Costa, Catia S.; Luing, Wong Syie; Ribeiro, M. Rosário; Silva, João M.; Onfroy, Thomas; Valentin, Laetitia; Casale, Sandra; Muñoz, Marta; Launay, Franck
Plastic waste management has become a pressing global issue. A viable and sustainable alternative to incineration is the conversion of polyethylene into chemicals or fuels by through hydrocracking. To improve the catalytic performance during hydrocracking, bifunctional catalysts are required, in which the zeolite imparts the acid function, and the metallic function is provided by a noble or transition metal, such as nickel. In this study, acid supports were synthesized using two strategies, namely zeolitisation and desilication, for comparison. The synthesized materials exhibited Si/Al molar ratios of approximately 10, hierarchical micro-/mesoporosities, and a bifunctional character after incorporation of nickel up to 5 wt%. The materials were extensively characterized by various techniques, including powder X-Ray diffraction, N2 sorption, acidity measurement, and scanning electron microscopy. The characterization results showed that the desilicated HZSM5 zeolite was the most effective support for nickel impregnation, leading to a quantitative conversion of High-Density Polyethylene (HDPE) by hydrocracking and the formation of predominantly hydrocarbons with 5 carbon atoms. A clear disparity in composition, with a prevalence of a gasoline-type fraction, was observable in the liquid phase from HZSM5 to Ni particles supported on hierarchical HZSM-5 (Ni@m-HZSM-5w). The hierarchy factor (HF), the molar ratio between Lewis and Brønsted acid sites, and the accessibility factor (ACI) were combined to form the interplay factor (IF). The investigation resulted in materials with IF values between 0.35 and 7, and a positive correlation between HDPE conversion and IF values is observed. In conclusion, this study suggests that the desilication of HZSM5 zeolite is a promising route for the development of efficient catalysts for the hydrocracking of plastic waste.
Plastic Pyrolysis over HZSM-5 Zeolite and Fluid Catalytic Cracking Catalyst under Ultra-Fast Heating
(Elsevier, 2022) Wong, Syie Luing; Armenise, Sabino; Nyakuma, Bemgba Bevan; Bogush, Anna; Towers, Sam; Lee, Chia Hau; Wong, Keng Yinn; Lee, Ting Hun; Rebrov, Evgeny; Muñoz, Marta
Plastic pollution compromises the environment and human well-being, and a global transition to a circular economy of plastics is vital to address this challenge. Pyrolysis is a key technology for the end-of-life recycling of plastics, although high energy consumption limits the economic feasibility of the process. Various research has shown that the application of induction heating in biomass pyrolysis reduces energy consumption when compared to conventional heating. Nevertheless, the potential of induction heating in plastic pyrolysis is rarely explored. This paper presents an exploratory study on the thermal and catalytic pyrolysis of high-density polyethylene, low-density polyethylene, and polypropylene in a fixed bed reactor through induction heating. An MFI-type HZSM-5 zeolite (SiO2/Al2O3 = 23) and an FAU-type spent fluid catalytic cracking (FCC) catalyst with distinctive Brønsted acidity and textural properties were used. A complete conversion of the plastic feedstocks was achieved within 10 min, even without a catalyst. Thermal pyrolysis produced wax (72.4–73.9 wt%) and gas products, indicating a limited degree of polymer cracking. Catalytic pyrolysis over HZSM-5 and FCC catalyst significantly improved polymer cracking, leading to higher gas (up to 75.2 wt%) and liquid product (up to 35.9 wt%) yields at the expense of wax yield (up to 25.4 wt%). In general, the gas products were rich in C3 and C4 compounds. The liquid product composition was highly dependent on the catalyst properties, for example, the HZSM-5 produced high aromatics, while the FCC catalyst produced high alkenes in the liquid products. The catalyst acidity and textural properties played an essential role in plastic pyrolysis within the short reaction time. This study demonstrated the feasibility of a fast, energy-efficient, and versatile plastic valorization technology based on the application of induction heating, where the plastic feed can be converted into wax, gas, and liquid products depending on the end-use applications.
Plastic waste recycling via pyrolysis: A bibliometric survey and literature review
(Elsevier, 2021) Armenise, Sabino; Syie Luing, Wong; Ramírez-Velásquez, José M.; Launay, Franck; Wuebben, Daniel; Ngadi, Norzita; Rams, Joaquín; Muñoz, Marta
Plastic materials have been crucial to the development of science, technology, and almost all aspects of modern progress since the mid-twentieth century. However, the increasingly unsustainable culture of plastic consumption and the accumulation of plastics in landfills, oceans, and broader ecosystems has also made negative, potentially irreversible environmental impacts. In recent decades, scientists and engineers have spent significant time and resources searching for more effective plastic waste management techniques based on thermochemical routes like pyrolysis. Indeed, plastic to fuel conversion has the potential to severely limit plastic pollution and to contribute to the circular economy, but industrial scale plastic pyrolysis has not been achieved. Therefore, this paper presents a bibliometric analysis and systematic literature review of pyrolysis-related articles in the Web of Science database published between 2001–2020. The resulting articles (n = 670) show that Spain is the most productive country in terms of total output and that there are an increasing number of researchers focused on this topic worldwide. The results also highlight the current landscape and future directions of plastic pyrolysis research based on the following hot topics: i) kinetic triplets as a vital component of plastic pyrolysis and scaling up processes, ii) catalysts syntheses and performance, iii) co-pyrolysis of plastic/biomass mixtures, and iv) reactor design and reaction parameters. In conclusion, the study offers a comprehensive overview of plastic pyrolysis progress, which will remain a major area of research for chemists and engineers in the coming decade and a powerful tool for environmental management.