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1.
Korean Journal of Chemical Engineering ; 40(4):693-705, 2023.
Article in English | Web of Science | ID: covidwho-2309145

ABSTRACT

Plastic is one of the most widely used materials in industries including packaging, building, and construction due to its lightweight, low cost, durability, and versatility. However, the mass production of plastics has exacerbated plastic pollution. Globally, plastic waste is predominantly incinerated, landfilled, or released into the environment;only 5-6% is recycled in the United States. Although conventional management protocols such as incineration and landfilling are evidently effective for plastic waste disposal, they are associated with significant environmental and societal challenges. In addition, most recycled plastic is downcycled, and thus does not provide sufficient incentive to use recycled materials instead of virgin materials. This review discusses thermo-chemical upcycling processes such as (catalytic) pyrolysis and heterogeneous catalysis. Furthermore, we present the recent progress in the thermo-chemical upgrading of single-type plastic waste, heterogeneous plastic mixtures, and post-consumer plastic waste obtained from different locations and, finally, suggest future research directions.

2.
Catalysts (2073-4344) ; 13(3):620, 2023.
Article in English | Academic Search Complete | ID: covidwho-2250866

ABSTRACT

Coronavirus disease-2019 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is the most difficult recent global outbreak. Semiconducting materials can be used as effective photocatalysts in photoactive technology by generating various reactive oxidative species (ROS), including superoxide (•O2−) and hydroxyl (•OH) radicals, either by degradation of proteins, DNA, and RNA or by inhibition of cell development through terminating the cellular membrane. This review emphasizes the capability of photocatalysis as a reliable, economical, and fast-preferred method with high chemical and thermal stability for the deactivation and degradation of SARS-CoV-2. The light-generated holes present in the valence band (VB) have strong oxidizing properties, which result in the oxidation of surface proteins and their inactivation under light illumination. In addition, this review discusses the most recent photocatalytic systems, including metals, metal oxides, carbonaceous nanomaterials, and 2-dimensional advanced structures, for efficient SARS-CoV-2 inactivation using different photocatalytic experimental parameters. Finally, this review article summarizes the limitations of these photocatalytic approaches and provides recommendations for preserving the antiviral properties of photocatalysts, large-scale treatment, green sustainable treatment, and reducing the overall expenditure for applications. [ FROM AUTHOR] Copyright of Catalysts (2073-4344) is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

3.
ChemCatChem ; : 1, 2023.
Article in English | Academic Search Complete | ID: covidwho-2288287

ABSTRACT

This collection of papers from Latin American catalytic researchers was born from online interaction during the trialing times of the COVID‐19 pandemic. The collection showcases the diversification that the field of catalysis has had in our region and features works from Argentina, Brazil, Chile, Colombia, Mexico, and Venezuela, as well as contributions from Latin American researchers who have developed their careers abroad. [ABSTRACT FROM AUTHOR] Copyright of ChemCatChem is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

4.
Journal of Water Process Engineering ; 50, 2022.
Article in English | Web of Science | ID: covidwho-2211024

ABSTRACT

The outbreak of COVID-19 has led to the increase in face mask waste globally. In this study, face mask-derived carbocatalysts doped with nitrogen (N-Mask) were fabricated through one-step pyrolysis of 1:5 w/w mixture of face mask and urea at different temperatures to activate peroxymonosulfate (PMS) for gatifloxacin (GAT) degradation. The N-Mask prepared at 800 degrees C (N-Mask800) exhibited the highest GAT degradation rate with k(app) = 0.093 min(-1) which could be attributed to its high N doping level (17.1 wt%) and highest specific surface area (237.13 m(2) g(-1)). The relationship between k(app), catalyst loading and PMS dosage at various pHs on GAT degradation were successfully established. It was also found that the GAT degradation rate was inhibited in the sequential operating mode compared to the simultaneous operating mode. It was construed that adsorption and catalysis share the same active sites. Deterioration in catalytic performance was observed over successive cycles due to the surface chemistry change during catalysis, and difficulty in catalyst recovery after treatment. Radical scavenger study revealed that both radical and nonradical pathways were involved during GAT degradation, with nonradical pathway playing a dominant role. XPS analysis revealed that pyrrolic N and graphitic N can facilitate PMS activation via radical and nonradical pathways. Based on the LC-MS/MS analysis, the GAT degradation intermediates were identified, and the possible degradation pathways were tentatively proposed. Overall, this study demonstrated that carbocatalyst derived from face mask could be transformed into costeffective and environmentally friendly PMS activator for environmental wastewater treatment applications.

5.
Catalysts ; 12(2):237, 2022.
Article in English | ProQuest Central | ID: covidwho-1715128

ABSTRACT

The transition from fossil to bio-based fuels is a requisite for reducing CO2 emissions in the aviation sector. Jet biofuels are alternative aviation fuels with similar chemical composition and performance of fossil jet fuels. In this context, the Hydroprocessing of Esters and Fatty Acids (HEFA) presents the most consolidated pathway for producing jet biofuels. The process for converting esters and/or fatty acids into hydrocarbons may involve hydrodeoxygenation, hydrocracking and hydroisomerization, depending on the chemical composition of the selected feedstock and the desired fuel properties. Furthermore, the HEFA process is usually performed under high H2 pressures and temperatures, with reactions mediated by a heterogeneous catalyst. In this framework, supported noble metals have been preferably employed in the HEFA process;however, some efforts were reported to utilize non-noble metals, achieving a similar performance of noble metals. Besides the metallic site, the acidic site of the catalyst is crucial for product selectivity. Bifunctional catalysts have been employed for the complete process of jet biofuel production with standardized properties, with a special remark for using zeolites as support. The proper design of heterogeneous catalysts may also reduce the consumption of hydrogen. Finally, the potential of enzymes as catalysts for intermediate products of the HEFA pathway is highlighted.

6.
Catal Today ; 2020 Oct 17.
Article in English | MEDLINE | ID: covidwho-866477

ABSTRACT

A unified treatment of the renewable portfolio standards is given concerning direct methanol fuel. The current mechanism of electrocatalysis of methanol oxidation on platinum and non-platinum-containing alloys is summarized for the systematic improvement of the rate of electro-oxidation of methanol are discussed. Policy realignment under the five-year plan is discussed in length to demonstrate how policy, markets, and engineering designs contribute towards the development of model direct methanol fuel cells operational enhancement, and factors that affect critical performance parameters for commercial exploitation are summarized for catalytic formulations and cell design within the context of why this investment in technology, education, and finances is required within the global context of sustainable energy and energy independence as exposed by thirteenth the five-year plan. The prolog focuses on the way, whereas the section on methanol fuel cells on the how and the post log on what is expected post-COVID-19 era in science and technology as China pivots to a post-fossil fuel economy. China's industrial growth has been through internal market reforms and supplies side economics from the Chinese markets for fossil fuels except for petroleum. The latest renewable portfolio standards adopted have common elements as adopted from North American and the United Kingdom in terms of adaptation of obligation in terms of renewable portfolio standards as well as a realization that the necessity for renewables standards for the thirteen five year plan (from 2016 to 2020) need to less rigorously implemented due to performance targets that were met during the eleventh (06-10) and twelfth five-year plans (11-15) in terms of utilization of small coal-ire power plants, development of newer standards, led to an improvement of energy efficiency of 15 %, reduction of SOx/NOx by an average of 90 % and PM2.5 by 96 % over the last two five-year plans. The current phase of the plan has a focus on energy generation from coal and a slowing down of renewables or Renewable energy curtailment of approximately 400 T Wh renewables including 300 T Wh of non-hydro power, principally from Guangdong, and Jiangsu for transfer of hydropower and Zhejiang, Tianjin, Henan for non-hydro power transfer with Beijing and Shanghai playing important roles in renewables energy curtailment and realignment using an integrated approach to optimize each provinces energy portfolio. The realignment of the renewable energy portfolio indicates that the newly installed capacity in Sichuan, Yunnan, Inner Mongolia, and Zhejiang will account for less than 20 % of the current renewable energy portfolio but with the NOx SOx and PM2.5 savings already accrued. The catalytic reduction of carbon dioxide to methanol (70 / 110 million metric tons from all sources in 2019 for China/world) is one technological approach to reduce global carbon dioxide emissions and suggests that catalytic methanol synthesis by CO2 hydrogenation may be a plausible approach, even if it is more expensive economically than methanol synthesis by the syngas approach. This is because the CO2 emissions of the synthesis are lower than other synthesis methodologies. The Chinese government has placed a premium on cleaner air and water and may view such an approach as solving the dual issues of fuel substitution and reduction of CO2. Thus, the coupling of hydrogen generation from sustainable energies sources (Solar 175 / 509 GW) or wind (211/591.5 GW in 2019) may be an attractive approach, as this requires slightly less water than coal gasification. Due to the thermodynamic requirement of lower operating pressure and higher operating pressure, currently, there is no single operational approach, although some practice approaches (220 °C at 48 atm using copper) and zinc oxide/alumina are suggested for optimal performance.

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