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Acid catalysis is recognised as the most reliable industrial ì way to convert hydrocarbons into various products (methanol to olefins and aromatics, glycerol to olefins, methane dehydroaromatization, isomerization, etc.). In this concern, ZSM-5 is extensively used, also because of peculiar type of active sites of such zeolite. In this paper, a fine tuning of the acidity content and strength of ZSM-5 was investigated through a combination of post- synthesis treatments: desilication via alkaline solution and wet impregnation with Mg2+ions followed by calcination. Results show that the insertion of Mg2+has a large influence on the distribution and strength of Brønsted and Lewis acid sites of the hierarchical ZSM-5, as well as an improved crystallinity with respect to the desilicated-one. The hierarchical ZSM-5 zeolite incorporating Mg-species was tested in Methanol- to-olefins reaction and the reduction of acid strength of catalyst increased the selectivity toward light olefins (mainly propylene) as well as it suppressed oligomerisation reactions delaying the coke formation.

Hydrogen is considered one of the energy carriers of the future due to its high mass-based calorific value. Hydrogen combustion generates only water, and it can be used directly as a fuel for electricity/heat generation. Nowadays, about 95% of the hydrogen is produced via conversion of fossil fuels. One of the future challenges is to find processes based on a renewable source to produce hydrogen in a sustainable way. Bioethanol is a promising candidate, since it can be obtained from the fermentation of biomasses, and easily converted into hydrogen via steam catalytic reforming. The correct design of catalysts and catalytic supports plays a crucial role in the optimization of this reaction. The best results have to date been achieved by noble metals, but their high costs make them unsuitable for industrial application. Very satisfactory results have also been achieved by using nickel and cobalt as active metals. Furthermore, it has been found that the support physical and chemical properties strongly affect the catalytic performance. In this review, zeolitic materials used for the ethanol steam reforming reaction are overviewed. We discuss thermodynamics, reaction mechanisms and the role of active metal, as well as the main noble and non-noble active compounds involved in ethanol steam reforming reaction. Finally, an overview of the zeolitic supports reported in the literature that can be profitably used to produce hydrogen through ethanol steam reforming is presented.

© Copyright © 2020 Somer, Abu-Rayya, Schimmenti, Metin, Brenner, Ferrante, Göçmen and Marino. The COVID-19 pandemic has been spreading globally since December 2019, bringing with it anxieties, mortal risk, and agonizing psychological suffering. This study aimed to explore the relationship between maladaptive daydreaming (MD)—an addictive mental behavior to vivid fantasy associated with distress and functional impairment—and forced COVID-19 pandemic-related self-isolation and quarantine. Previous literature indicated that individuals employ MD for the regulation of distress and boredom, wish fulfillment, and entertainment experiences. The literature on the impact of the COVID-19 pandemic on mental health identifies a flareup in psychological difficulties in the general population. In this study we explored the associations between the pandemic threat and mental health indices among individuals with MD. We surveyed 1,565 adults from over 70 countries who responded to calls for participants posted in online MD communities and other general social media sites. Probable MD was determined based on an empirically derived cut-off score on a pertinent measure. After controlling for sociodemographic variables, a series of MANCOVAs, followed by post-hoc ANCOVAs, revealed that individuals with probable MD who were observing lockdown restrictions reported having spent more time in fantasy, experienced more intense and vivid daydreaming, and had a stronger urge to daydream than other participants. Similar statistical procedures indicated that, individuals with probable MD who reported pre-existing anxiety and depression disorders described a greater urge to daydream due to the pandemic and greater difficulty to control this addictive behavior. Compared to individuals with likely normal daydreaming, individuals with suspected MD reported more pandemic-attributed deterioration on a wide array of psychological distress indices. Our data show that the current worldwide pandemic threat is connected with an elevated intensity of this addictive form of mental activity, and that MD is associated with the exacerbation of psychological distress and dysfunction rather than with beneficial regulation of the experienced stressor.

The modification of the physicochemical properties of synthetic zeolites is an important element when these materials are applied as heterogeneous catalysts in the view of more sustainable and effective processes. In this work, desilicated ZSM5 samples were tested on the methanol to dimethyl ether dehydration. Desilication time strongly affects the textural and acidic properties of the samples, and those characteristics determined a different catalytic behaviour. Contact time of 60 min with NaOH solution (alkaline desilication) favourably impact on the activity of the catalysts and its stability against deactivation in terms of methanol conversion and yield to DME, in comparison with parent zeolite and sample prepared after 30 min of desilication. This effect is due to a combination of changes in the properties of acidic sites and mesoporous volume, as confirmed by stability test over 80 h of reaction. The analysis of formed coke confirmed this evidence since the most performing catalyst showed the lowest tendency to form coke as the main consequence of the improved accessibility to the acid sites determined by the induced mesoporosity.

In the last century, a series of problems related to the environment, mainly due to polluting emissions such as CO2, CH4, and N2O, led to revaluation of a series of factors, including that of emissions from motor vehicles. To overcome the problem, new types of less polluting biofuels based on ethanol blends with fossil fuels, have been developed. United States, with the production of ethanol from corn, and Brazil, with the production of ethanol from sugarcane, currently drive the market for the world production of bioethanol, thanks mainly to government subsidies. Despite this, some problems related to energy loss during industrial processes and to the linkage of the first-generation feedstock with both biofuel and food for human consumption, are leading to the development of new-generation feedstocks which exploit lignocellulosic or algal biomasses. This chapter is a brief review of the methods of production of ethanol in the United States and Brazil, giving the generic economical and statistical data of the processes.

Methanol, or methyl alcohol, is the simplest alcohol, appearing as a colorless liquid with a distinctive smell. Nowadays, it is considered one of the most useful chemical compounds. In fact, it is one of the most promising building blocks for obtaining more complex chemical structures, such as acetic acid, methyl tertiary butyl ether, dimethyl ether, methylamine, etc. Furthermore, methanol is also considered a promising clean-burning fuel with a high octane number. Knowing that CO2 and H2 are among the precursors in methanol synthesis, it is noteworthy that the conversion of CO2 to methanol can be considered a promising method for significantly reducing CO2 emissions, and that methanol production can also be used as a convenient energy carrier for hydrogen storage and conservation. In fact, methanol synthesis is the second source, after ammonia production, of hydrogen consumption (which has the highest energy content per weight) via several reactions, such as partial oxidation, steam reforming, autothermal reforming, methanol decomposition, or methanol-water solution electrolysis. Finally, among the recent attractive applications of methanol, the most promising for the future are the production of DME, the production of hydrogen, and the direct methanol fuel cell (DMFC). This chapter is an overview of not only common feedstocks used in the production processes for obtaining methanol (natural gases, CO2, or char/biomass), but also of the historical production processes (such as the BASF process, also known as the “high-pressure method,” and the ICI process, also known as the “low-pressure method”) and the most innovative trends for industrial applications.

The long-term evolution to intractable epilepsy in children treated with cyclosporine administered for graft-versus-host-disease after hematopoietic stem cell transplantation was evaluated. In a group of 185 children treated with cyclosporine after bone marrow transplantation, 15 (8%) presented with acute seizures that were generalized in 7 and focal in 7 and had absence status in 1. Electroencephalography (EEG) and neuroimaging showed predominant abnormalities in the occipital regions. One patient died shortly after the seizure; in seven cases, seizures remitted, whereas relapses were observed in seven others. After the first year, seizures persisted chronically in four cases and evolved to intractable epilepsy. Focal temporal epilepsy was diagnosed in three cases, whereas in the fourth case, a multifocal epilepsy was observed. Magnetic resonance imaging (MRI) detected mesial temporal sclerosis in all of these cases. The risk factors associated with evolution to epilepsy included lower age at transplantation (3—5 years), more than one relapsing seizure in the first year after transplantation, and longer treatment with cyclosporine. Not only can cyclosporine cause acute central nervous system toxicity, it can also determine intractable epilepsy associated with mesial temporal sclerosis. (J Child Neurol 2006;21:861—866; DOI 10.2310/7010.2006.00196).