Synthesis Of Acetaldehyde Research Articles

A method to synthesize specific active Cu sites of single-atom catalysts with high stability for acetylene hydration

Single-atom catalysts (SACs) have received much attention in the realm of energy and catalytic conversion due to their maximum atomic efficiency. Herein, we report a cascade anchoring strategy for the preparation of a Cu-S1O2 species of single-atom catalyst attached to a carbon carrier containing P and S (Cu-S1O2 SA/CPS) with a content of 12.4 wt%. Over the Cu-S1O2 SA/CPS catalyst, the conversion of 95.8% and selectivity of 87.2% for acetylene hydration could still be achieved at 70 h (T = 200°C, GHSV(C2H2) = 90 h−1 and VH2O/VC2H2 = 4). X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) tests reveal that the Cu atoms of Cu-S1O2 SA/CPS are predominantly coordinated in a trinary manner (Cu-S1O2). Based on high-resolution aberration-corrected high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM), it is demonstrated that the Cu single-atom sites are highly dispersed in Cu-S1O2 SA/CPS. It is evident from the scanning electron microscopy (SEM) that Cu-S1O2 SA/CPS has a two-dimensional layered structure. The specific structure of the active site Cu is primarily attributed to the coordination of S and O atoms, resulting in its superior stability for acetylene hydration towards the synthesis of acetaldehyde. Density functional theory (DFT) calculations confirm that the formation of the Cu-S1O2 site facilitates the activation of acetylene, which is a pivotal step in the acetylene hydration process and considered as the rate-determining step. This article not only introduces an innovative strategy in the synthesis of Cu SACs but also represents a significant breakthrough in the stability of Cu SACs in acetylene hydration.

Receipt of new catalysts used in the synthesis of acetaldehyde by separating the catalyst CCP into component parts

Receipt of new catalysts used in the synthesis of acetaldehyde by separating the catalyst CCP into component parts

THE IMPACT OF STILLAGE FILTRATE ON THE SYNTHESIS OF VOLATILE IMPURITIES OF ALCOHOL AND THE OPTIMIZATION OF THE RECTIFICATION PROCESS

The aim of this research is to determine the influence stillage filtrate on the synthesis of volatile impurities in alcohol, with subsequent removal through the rectification process in a rectification unit operating in an energy-saving mode at pressures lower than atmospheric. The study was conducted at the state enterprise (hereinafter - SE) "Kozlivsky Distillery" located at: Ternopil region, Kozlivsky district, urban-type settlement Kozliv, using gas chromatographic method for determining the content of microcomponents (acetaldehyde, methanol, fusel oil components, esters) using capillary columns. The rectification unit includes various components such as the mash column, hydroselection column, rectification column, methanol column, impurity concentration column and "zero" column. During the research, technological parameters of operation of each unit component were studied, and the concentration of organic impurities in alcohol at different stages was determined. The results of this study allow improving the efficiency of the rectification unit, which is of great importance in alcohol production. Research was conducted on the impact stillage filtrate on the synthesis of volatile impurities in alcohol during fermentation. The research was carried out with the full use iltrate of stillage at the stage of preparing the fermenting substrate. The mash had different concentrations of dry substances. The stillage filtrate was obtained by centrifugation of native stillage and its suspended matter concentration did not exceed 1%. The influence of the amount stillage filtrate and the number of cycles of its recirculation on the biosynthesis of volatile organic compounds during fermentation was studied. The research results showed that the use stillage filtrate at the stage of preparing the fermenting substrate contributes to reducing water consumption and slows down the synthesis of acetaldehyde and higher alcohols during fermentation. With repeated use stillage filtrate, the synthesis process changes, which affects the concentration of volatile organic compounds in the fermentation mash. This impact should be taken into account when selecting operating modes of the rectification unit. Therefore, to obtain high-quality rectified alcohol, it is necessary to adjust the appropriate operating mode of the rectification unit and consider the influence stillage filtrate on the fermentation process.

Analysis of the whole process for the photocatalytic conversion of ethylene: A possible synthesis strategy and route

It is worth investigating the reduction of ethylene emission and the conversion of ethylene into two- or multi-carbon organic compounds by photocatalysis. In this work, a Z-scheme photocatalytic film of TaON/Ta3N5/WO3/Ni foam was successfully prepared. The photocatalytic activity of TaON/Ta3N5/WO3/Ni foam was evaluated by catalyzing the conversion of ethylene under simulated sunlight irradiation. The TaON/Ta3N5 and WO3 with a mass ratio of 2:8 loaded on Ni foam (TWN-2/8) demonstrated excellent photocatalytic performance. The conversion efficiency and reaction rate for ethylene over TWN-2/8 were 8.9 and 15.3 times higher than those of pure WO3/Ni foam, respectively. Compared to TaON/Ta3N5/Ni foam and WO3/Ni foam, the significantly improved photocatalytic activity of TWN-2/8 was attributed to higher carrier separation efficiency and lower charge transfer resistance, as well as stronger redox ability. A highly selective potential conversion pathway was proposed for the synthesis of ethanol, acetaldehyde and acetic acid from ethylene at different reaction times.

SO2-резистентность как критерий отбора штаммов Saccharomyces cerevisiae для органического виноделия

Sulfur dioxide is a popular conserving agent and antioxidant in winemaking. Unfortunately, it is bad for human health. Some yeast strains can reduce the dose of sulfur dioxide. Such yeasts should have good fermentation activity and dominate when inoculated into grape must. In addition, it should not synthesize sulfur dioxide and SO2-binding substances. The synthesis of sulfur dioxide and carbonyl compounds by yeast is related to the mechanisms of sulfur dioxide detoxification. The research objective was to study the relationship between the resistance of yeast to sulfur dioxide and its ability to synthesize sulfur dioxide and acetaldehyde during growth. 
 The study featured 17 yeast strains of the genus Saccharomyces. The yeasts were cultivated on grape must in a CGQ device until the stationary growth phase. The concentration of free and bound forms of sulfur dioxide was determined by titration, while that of aldehydes was determined by bisulfite method. The sulfite resistance of strains was measured ¬¬by the growth response of yeast cells to sulfur dioxide using CGQ technology. 
 Yeast strains differed in the degree of sulfur dioxide resistance. The samples were divided according to the increase in the lag phase time: by ≥ 8 h (sensitive), by 2–6 h, without changes (resistant). At Wilks L = 0.228 and α = 0.05, the sensitive cultures in a SO2-free medium had the highest value of minimal generation time in the exponential growth phase (5.3 ± 2.1 h). The resistant samples demonstrated the highest synthesis of acetaldehyde (54.7 ± 11.1 mg/L) and sulfur dioxide (21.0 ± 10.3 mg/L). The second group cultures had the lowest content of SO2-bound forms in the medium (10.9 ± 4.2 mg/L) and were in an interposition in terms of other indicators. 
 The time it takes a yeast strain to adapt to sulfur dioxide can be used as a parameter for the primary culture selection in eco-winemaking. According to the physiological and biochemical profile, the resistant strains can be recommended for the production of SO2-low wines, while the samples from the second test group proved optimal for organic wines. Further research will expand the range of yeast strains and their indicators.

DEVELOPMENT AND INVESTIGATION OF PROPERTIES OF MIXED CATALYSTS FOR VAPOR-PHASE HYDRATION OF ACETYLENE

In order to develop new catalysts for the synthesis of acetaldehyde by vapor-phase hydration of acetylene, new mono- and bifunctional catalysts based on cadmium, zinc, chromium, and iron compounds on supports were developed and their most important textural characteristics were studied. It was shown that zinc oxide and cadmium fluoride are bifunctional catalysts, in the presence of which acetaldehyde was synthesized with a yield of 69.0 — 70.0%. It has been established that the stability of their operation before regeneration exceeds more than 100 hours, i.e. 1.3 times more than industrial cadmium-calcium phosphate catalyst.

The aromatic profile of wine distillates from Ugni blanc grape musts is influenced by the nitrogen nutrition (organic vs. inorganic) of Saccharomyces cerevisiae

Although the impact of nitrogen nutrition on the production of fermentative aromas in oenological fermentation is well known today, one may wonder whether the effects studied are the same when winemaking takes place at high turbidities, specifically for the production of wines intended for cognac distillation. To that effect, a fermentation robot was used to analyze 30 different fermentation conditions at two turbidity levels with several factors tested: (i) initial addition of nitrogen either organic (with a mixture of amino acids - MixAA) or inorganic with di-ammonium phosphate (DAP) at different concentrations, (ii) variation of the ratio of inorganic/organic nitrogen (MixAA and DAP) and (iii) addition of different single amino acids (alanine, arginine, aspartic acid and glutamic acid). A metabolomic analysis was carried out on all resulting wines to have a global vision of the impact of nitrogen on more than sixty aromatic molecules of various families. Then, at the end of the alcoholic fermentation, the wines were micro-distilled. A first interesting observation was that the aroma profiles of both wines and distillates were close, indicating that the concentration factor is rather similar for the different aromas studied. Secondly, the fermentation kinetics and aroma results have shown that the nitrogen concentration effect prevailed over the nature of nitrogen. Although the lipid concentration was in excess, an interaction between the assimilable nitrogen and lipid contents was still observed in wines or in micro-distillates. Alanine is involved in the synthesis of acetaldehyde, isobutanol, isoamyl alcohol and isoamyl acetate. Finally, it was demonstrated that modifying the ratio of assimilable nitrogen in musts is not an interesting technological response to improve the aromatic profile of wines and brandies. Indeed, unbalance the physiological ratio of the must by adding a single source of assimilable nitrogen (organic or inorganic) has been shown to deregulate the synthesis of most of the fermentation aromas produced by the yeast. Wine metabolomic analysis confirmed the results that had been observed in micro-distillates but also in the other aromatic families, especially on terpenes. The contribution of solid particles, but also yeast biosynthesis (via sterol management in must) to wine terpenes is discussed. Indeed, the synthesis of terpenes in this oenological context seems to be favored, especially since the concentration of assimilable nitrogen (in addition to the lipid content) favor their accumulation in the medium. A non-negligible vintage effect on the terpene profile was also demonstrated with variations in their distribution depending on the years.Thus, the present study focuses on the metabolism of wine yeasts under different environmental conditions (nitrogen and lipid content) and on the impact of distillation on the fate of flavor compounds. The results highlight once again the complexity of metabolic fluxes and of the impact of nitrogen source (nature and amount) and of lipids. Furthermore, this study demonstrates that beyond the varietal origin of terpenes, the part resulting from the de novo synthesis by the yeast during the fermentation cannot be neglected in the context of cognac winemaking with high levels of turbidity.

Sustainable Wacker‐Type Oxidations

AbstractThe Wacker reaction is the oxidation of olefins to ketones and typically requires expensive and scarce palladium catalysts in the presence of an additional copper co‐catalyst under harsh conditions (acidic media, high pressure of air/dioxygen, elevated temperatures). Such a transformation is relevant for industry, as shown by the synthesis of acetaldehyde from ethylene as well as for fine‐chemicals, because of the versatility of a carbonyl group placed at specific positions. In this regard, many contributions have focused on controlling the chemo‐ and regioselectivity of the olefin oxidation by means of well‐defined palladium catalysts under different sets of reaction conditions. However, the development of Wacker‐type processes that avoid the use of palladium catalysts has just emerged in the last few years, thereby paving the way for the generation of more sustainable procedures, including milder reaction conditions and green chemistry technologies. In this Minireview, we discuss the development of new catalytic processes that utilize more benign catalysts and sustainable reaction conditions.

Sustainable Wacker-Type Oxidations.

The Wacker reaction is the oxidation of olefins to ketones and typically requires expensive and scarce palladium catalysts in the presence of an additional copper co-catalyst under harsh conditions (acidic media, high pressure of air/dioxygen, elevated temperatures). Such a transformation is relevant for industry, as shown by the synthesis of acetaldehyde from ethylene as well as for fine-chemicals, because of the versatility of a carbonyl group placed at specific positions. In this regard, many contributions have focused on controlling the chemo- and regioselectivity of the olefin oxidation by means of well-defined palladium catalysts under different sets of reaction conditions. However, the development of Wacker-type processes that avoid the use of palladium catalysts has just emerged in the last few years, thereby paving the way for the generation of more sustainable procedures, including milder reaction conditions and green chemistry technologies. In this Minireview, we discuss the development of new catalytic processes that utilize more benign catalysts and sustainable reaction conditions.

Transcriptomics and metabolomics of engineered Synechococcus elongatus during photomixotrophic growth

BackgroundConverting carbon dioxide (CO2) into value-added chemicals using engineered cyanobacteria is a promising strategy to tackle the global warming and energy shortage issues. However, most cyanobacteria are autotrophic and use CO2 as a sole carbon source, which makes it hard to compete with heterotrophic hosts in either growth or productivity. One strategy to overcome this bottleneck is to introduce sugar utilization pathways to enable photomixotrophic growth with CO2 and sugar (e.g., glucose and xylose). Advances in engineering mixotrophic cyanobacteria have been obtained, while a systematic interrogation of these engineered strains is missing. This work aimed to fill the gap at omics level.ResultsWe first constructed two engineered Synechococcus elongatus YQ2-gal and YQ3-xyl capable of utilizing glucose and xylose, respectively. To investigate the metabolic mechanism, transcriptomic and metabolomic analysis were then performed in the engineered photomixotrophic strains YQ2-gal and YQ3-xyl. Transcriptome and metabolome of wild-type S. elongatus were set as baselines. Increased abundance of metabolites in glycolysis or pentose phosphate pathway indicated that efficient sugar utilization significantly enhanced carbon flux in S. elongatus as expected. However, carbon flux was redirected in strain YQ2-gal as more flowed into fatty acids biosynthesis but less into amino acids. In strain YQ3-xyl, more carbon flux was directed into synthesis of sucrose, glucosamine and acetaldehyde, while less into fatty acids and amino acids. Moreover, photosynthesis and bicarbonate transport could be affected by upregulated genes, while nitrogen transport and assimilation were regulated by less transcript abundance of related genes in strain YQ3-xyl with utilization of xylose.ConclusionsOur work identified metabolic mechanism in engineered S. elongatus during photomixotrophic growth, where regulations of fatty acids metabolism, photosynthesis, bicarbonate transport, nitrogen assimilation and transport are dependent on different sugar utilization. Since photomixotrophic cyanobacteria is regarded as a promising cell factory for bioproduction, this comprehensive understanding of metabolic mechanism of engineered S. elongatus during photomixotrophic growth would shed light on the engineering of more efficient and controllable bioproduction systems based on this potential chassis.

Impact of Alcohol Consumption on Male Fertility Potential: A Narrative Review.

Alcohol abuse disorder is a serious condition, implicating more than 15 million people aged 12 years and older in 2019 in the United States. Ethanol (or ethyl alcohol) is mainly oxidized in the liver, resulting in the synthesis of acetaldehyde and acetate, which are toxic and carcinogenic metabolites, as well as in the generation of a reductive cellular environment. Moreover, ethanol can interact with lipids, generating fatty acid ethyl esters and phosphatidylethanol, which interfere with physiological cellular pathways. This narrative review summarizes the impact of excessive alcohol consumption on male fertility by describing its metabolism and how ethanol consumption may induce cellular damage. Furthermore, the impact of alcohol consumption on hormonal regulation, semen quality, and genetic and epigenetic regulations is discussed based on evidence from animal and human studies, focusing on the consequences on the offspring. Finally, the limitations of the current evidence are discussed. Our review highlights the association between chronic alcohol consumption and poor semen quality, mainly due to the development of oxidative stress, as well as its genotoxic impact on hormonal regulation and DNA integrity, affecting the offspring’s health. New landscapes of investigation are proposed for the identification of molecular markers for alcohol-associated infertility, with a focus on advanced OMICS-based approaches applied to the analysis of semen samples.

Joint synthesis of acetone and acetaldehyde from acetylene

Joint synthesis of acetone and acetaldehyde from acetylene

Gene and cell therapy on the acquisition and relapse-like binge drinking in a model of alcoholism: translational options.

Studies reviewed show that lentiviral gene therapy directed either at inhibiting the synthesis of brain acetaldehyde generated from ethanol or at degrading brain acetaldehyde fully prevent ethanol intake by rats bred for their high alcohol preference. However, after animals have chronically consumed alcohol, the above gene therapy did not inhibit alcohol intake, indicating that in the chronic ethanol intake condition brain acetaldehyde is no longer the compound that generates the continued alcohol reinforcement. Oxidative stress and neuroinflammation generated by chronic ethanol intake are strongly associated with the perpetuation of alcohol consumption and alcohol relapse "binge drinking". Mesenchymal stem cells, referred to as guardians of inflammation, release anti-inflammatory cytokines and antioxidant products. The intravenous delivery of human mesenchymal stem cells or the intranasal administration of mesenchymal stem cell-generated exosomes reverses both (i) alcohol-induced neuro-inflammation and (ii) oxidative stress, and greatly (iii) inhibits (80-90%) chronic alcohol intake and relapse binge-drinking. The therapeutic effect of mesenchymal stem cells is mediated by increased levels of the brain GLT-1 glutamate transporter, indicating that glutamate signaling is pivotal for alcohol relapse. Human mesenchymal stem cells and the products released by these cells may have translational value in the treatment of alcohol-use disorders.

Evaluation of the use of multiflora bee pollen on the volatile compounds and sensorial profile of Palomino fino and Riesling white young wines

This study investigates the impact of bee pollen on volatile compounds, odour activity values and sensory profiles in Palomino fino and Riesling young white wines. Commercial bee pollen was added to grape must using six different doses (0 (control), 0.1, 0.25, 1, 5, 10 and 20g/L) and fermented under controlled conditions. Volatile compounds were determined with GC and GC–MS chromatography and sensorial analysis using a qualified panel of tasters. Bee pollen produces an increase in volatile compounds depending on the grape variety and the dose applied. It also increases the synthesis of higher alcohols, methanol, esters, acetaldehyde and terpenes, reducing alcohols and fatty acids. Wines with low doses (0.1 and 0.25g/L) showed the higher OAV values (fruity and floral) and scores in overall judgment for the sensory evaluation. High pollen doses decrease fruity character and could result in deviations affecting the sensorial quality.

Self-Assembled Zinc/Cystine-Based Chloroplast Mimics Capable of Photoenzymatic Reactions for Sustainable Fuel Synthesis.

Prototypes of biosystems provide good blueprints for the design and creation of biomimetic systems. However, mimicking both the sophisticated natural structures and their complex biological functions still remains a great challenge. Herein, chloroplast mimics have been fabricated by one-step bioinspired amino acid mineralization and simultaneous integration of catalytically active units. Hierarchically structured crystals were obtained by the metal-ion-directed self-assembly of cystine (the oxidized dimer of the amino acid cysteine), with a porous structure and stacks of nanorods, which show similar architectural principles to chloroplasts. Porphyrins and enzymes can both be encapsulated inside the crystal during mineralization, rendering the crystal photocatalytically and enzymatically active for an efficient and sustainable synthesis of hydrogen and acetaldehyde in a coupled photoenzymatic reaction.

Self‐Assembled Zinc/Cystine‐Based Chloroplast Mimics Capable of Photoenzymatic Reactions for Sustainable Fuel Synthesis

AbstractPrototypes of biosystems provide good blueprints for the design and creation of biomimetic systems. However, mimicking both the sophisticated natural structures and their complex biological functions still remains a great challenge. Herein, chloroplast mimics have been fabricated by one‐step bioinspired amino acid mineralization and simultaneous integration of catalytically active units. Hierarchically structured crystals were obtained by the metal‐ion‐directed self‐assembly of cystine (the oxidized dimer of the amino acid cysteine), with a porous structure and stacks of nanorods, which show similar architectural principles to chloroplasts. Porphyrins and enzymes can both be encapsulated inside the crystal during mineralization, rendering the crystal photocatalytically and enzymatically active for an efficient and sustainable synthesis of hydrogen and acetaldehyde in a coupled photoenzymatic reaction.

Selective synthesis of acetaldehyde from lactic acid on acid zeolites

The gas-phase lactic acid conversion to acetaldehyde was studied on zeolites HMCM22, HZSM5 and NaZSM5 in a plug-flow fixed-bed reactor at 583K. HMCM22 was a strong Brønsted acid zeolite that yielded 39.7% of lactic acid decarbonylation products (acetaldehyde+CO), but formed significant amounts of coke because of lactic acid oligomerization in the narrow sinusoidal channels of the zeolite. HZSM5 exhibited a high density of Brønsted acid sites (Brønsted/Lewis acid sites ratio of 3.1) and promoted at high rates the lactic acid conversion, mainly to decarbonylation products (acetaldehyde+CO yield=57.0%) and lactic acid oligomers. NaZSM5 contained mainly Lewis acid sites of intermediate strength (Brønsted/Lewis acid sites ratio of 0.4) that promoted the high-selectivity synthesis of acetaldehyde from lactic acid (acetaldehyde+CO yield=96.0%) by suppressing the competitive lactic acid oligomerization and coke precursor formation.

Sustainable production of acetaldehyde from lactic acid over the carbon catalysts

The synthesis of acetaldehyde from lactic acid over the carbon material catalysts was investigated. The carbon materials were characterized by scanning electron microscopy for morphologic features, by X-ray diffraction for crystal phases, by Fourier transform infrared spectroscopy for functional group structures, by N2 sorption for specific surface area and by ammonia temperature-programed desorption for acidity, respectively. Among the tested carbon catalysts, mesoporous carbon displayed the most excellent catalytic performance. By acidity analysis, the medium acidity is a crucial factor for catalytic performance: more medium acidity favored the formation of acetaldehyde from lactic acid. To verify, we compared the catalytic performance of fresh activated carbon with that of the activated carbon treated by nitric acid. Similarly, the modified activated carbon also displayed better activity due to a drastic increase of medium acidity amount. However, in contrast to fresh carbon nanotube, the treated sample displayed worse activity due to decrease of medium acidity amount. The effect of reaction temperature and time on stream on the catalytic performance was also investigated. Under the optimal reaction conditions, 100% lactic acid conversion and 91.6% acetaldehyde selectivity were achieved over the mesoporous carbon catalyst.

Strain-dependent production of selected bioactive compounds by Cyanobacteria belonging to the Arthrospira genus.

To investigate the synthesis of selected bioactive compounds in various strains belonging to the Arthrospira genus. The synthesis of vitamin C, polyphenols, vitamin B12, fatty acids and selected volatile compounds (acetone and acetaldehyde) was investigated in six strains belonging to the Arthrospira genus. Among all studies strains, Arthrospira maxima 84·79 was found to be a good producer of fatty acids, whereas strains of Arthrospira platensis demonstrated greater biomass yield and vitamins content. The synthesis of acetaldehyde and acetone may suggest that all the micro-organisms have the ability to carry out dark fermentation, with A. platensis 85·79 producing the greatest quantities of volatile compounds. In our study principal component analysis (PCA) did not indicate any strain-dependent correlations in the synthesis of fatty acids. A significant correlation between strains and synthesized bioactive compounds, except for fatty acids, was observed. There are very little data on the production of described bioactive compounds in Arthrospira genus. This study aims to fill this gap by investigating differences in the synthesis of bioactive compounds which occur in smaller quantities in Cyanobacteria biomass but are also important due to their health-promoting properties.

Mesoporous TiO<sub>2 </sub>Prepared by Using Lac Red as Template：Synthesis, Characterization, and Adsorption of Gaseous Acetaldehyde

Mesoporous TiO2 with anatase crystalline structure (MTiO2) has been synthesized by using Lac Red as template. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), N2 adsorption/desorption. It was found that without any external doping MTiO2 exhibited significant high adsorption abilities for adsorbing the gaseous acetaldehyde by the adsorption ratio of 39.15%.