Cyclohexylation of Naphthalene Over USY Zeolites

1999 ◽  
Vol 64 (1) ◽  
pp. 138-148 ◽  
Author(s):  
Miroslav Michvocík ◽  
Dušan Mravec ◽  
Milan Hronec ◽  
Agáta Smiešková ◽  
Pavol Hudec
Keyword(s):  
Liquid Phase ◽  
Hydrochloric Acid ◽  
Thermal Stabilization ◽  
Y Zeolite ◽  
Zeolite Structure ◽  
Positive Effect

The influence of thermal stabilization of NH4-Y zeolite and modification of USY zeolites with solutions of hydrochloric acid on the cyclohexylation of naphthalene in the liquid phase was studied. Removal of the part of extra-framework aluminium from zeolite structure has a positive effect on both conversion of naphthalene and amount of dicyclohexylnaphthalenes formed. Modification of zeolites leads to an increase in conversion and selectivity of β-substitution in the naphthalene cyclohexylation.

Activity and regenerability of dealuminated zeolite Y in liquid phase alkylation of benzene with 1-alkene

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Michal Horňáček ◽  
Pavol Hudec ◽  
Andrej Nociar ◽  
Agáta Smiešková ◽  
Tibor Jakubík
Keyword(s):  
Catalytic Activity ◽  
Liquid Phase ◽  
Hydrochloric Acid ◽  
Zeolite Y ◽  
Batch Reactor ◽  
Selective Extraction ◽  
Y Zeolite ◽  
Hy Zeolite ◽  
Alkylation Of Benzene

AbstractHY-zeolite and its deep-bed dealuminated and EFAL-extracted forms were tested in liquid phase alkylation of benzene with 1-hexadecene in a batch reactor at 120°C. Deep-bed dealumination of the HY-sample at 560 °C followed by careful selective extraction of extra-framework aluminium by hydrochloric acid increased the catalytic activity as well as oxidative regenerability of Y-zeolite.

scholarly journals Liquid–Liquid Phase Separation Enhances TDP-43 LCD Aggregation but Delays Seeded Aggregation

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548
Author(s):  
Donya Pakravan ◽  
Emiel Michiels ◽  
Anna Bratek-Skicki ◽  
Mathias De Decker ◽  
Joris Van Lindt ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Hydrophobic Interactions ◽  
Low Complexity ◽  
Liquid Phase Separation ◽  
End Stage ◽  
Positive Effect ◽  
Self Aggregation ◽  
Lateral Sclerosis ◽  
Liquid Liquid Phase Separation

Aggregates of TAR DNA-binding protein (TDP-43) are a hallmark of several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). Although TDP-43 aggregates are an undisputed pathological species at the end stage of these diseases, the molecular changes underlying the initiation of aggregation are not fully understood. The aim of this study was to investigate how phase separation affects self-aggregation and aggregation seeded by pre-formed aggregates of either the low-complexity domain (LCD) or its short aggregation-promoting regions (APRs). By systematically varying the physicochemical conditions, we observed that liquid–liquid phase separation (LLPS) promotes spontaneous aggregation. However, we noticed less efficient seeded aggregation in phase separating conditions. By analyzing a broad range of conditions using the Hofmeister series of buffers, we confirmed that stabilizing hydrophobic interactions prevail over destabilizing electrostatic forces. RNA affected the cooperativity between LLPS and aggregation in a “reentrant” fashion, having the strongest positive effect at intermediate concentrations. Altogether, we conclude that conditions which favor LLPS enhance the subsequent aggregation of the TDP-43 LCD with complex dependence, but also negatively affect seeding kinetics.

ChemInform Abstract: Dealumination of Sodium Y Zeolite with Hydrochloric Acid

ChemInform ◽  
1987 ◽  
Vol 18 (33) ◽  
Author(s):  
E. F. T. LEE ◽  
L. V. C. REES
Keyword(s):  
Hydrochloric Acid ◽  
Y Zeolite

scholarly journals Solid-liquid systems for the hydrolysis of glycoalkaloids from potato (Solanum tuberosum L) tuber sprouts and solanidine isolation

2003 ◽  
Vol 57 (6) ◽  
pp. 288-292
Author(s):  
Nada Nikolic ◽  
Mihajlo Stankovic ◽  
Milorad Cakic
Keyword(s):  
Solanum Tuberosum ◽  
Liquid Phase ◽  
Hydrochloric Acid ◽  
Solid Phase ◽  
Solanum Tuberosum L ◽  
Volume Ratio ◽  
Liquid Systems ◽  
Pharmacologically Active ◽  
Solid Liquid ◽  
Hydrolysis Of

Solanidine (C17H43O/V) is a steroidal aglycone of glycoalkaloids and an important precursor for the synthesis of hormones and some pharmacologically active compounds. Glycoalkaloids are hydrolysed by mineral acid yielding solanidine and a carbohydrate moiety. In this paper the kinetics of hydrolysis of glycoalkaloids from potato (Solanum tuberosum L) tuber sprouts by using solid-liquid systems were studied as well as solanidine isolation from the liquid phase of the system. The dried and milled tuber sprouts of potato were used as the solid phase and solutions of hydrochloric acid of different concentration in 96 % vol. ethanol, mixed with chloroform in a volume ratio of 2:3, 1:1, 3:2 and 4:1, were used as the liquid phase. The aim of the paper was to choose the optimal concentration of hydrochloric acid in ethanol, the volume ratio of hydrochloric acid in ethanol to chloroform in the liquid phase and the time for solanidine hydrolytic extraction, as well as to isolate solanidine from the liquid phase.

scholarly journals Bioderivatization as a concept for renewable production of chemicals that are toxic or poorly soluble in the liquid phase

2020 ◽  
Vol 117 (3) ◽  
pp. 1404-1413 ◽  
Author(s):  
Pachara Sattayawat ◽  
Ian Sofian Yunus ◽  
Patrik R. Jones
Keyword(s):  
Liquid Phase ◽  
Glucose Consumption ◽  
Product Yield ◽  
Cellular Growth ◽  
Product Titer ◽  
Product Removal ◽  
Enhanced Solubility ◽  
Poorly Soluble ◽  
Reduced Toxicity ◽  
Positive Effect

Bio-based production technologies may complement or replace petroleum-based production of chemicals, but they face a number of technical challenges, including product toxicity and/or water insolubility. Plants and microorganisms naturally biosynthesize chemicals that often are converted into derivatives with reduced toxicity or enhanced solubility. Inspired by this principle, we propose a bioderivatization strategy for biotechnological chemicals production, defined as purposeful biochemical derivatization of intended target molecules. As proof of principle, the effects of hydrophobic (e.g., esterification) and hydrophilic (e.g., glycosylation) bioderivatization strategies on the biosynthesis of a relatively toxic and poorly soluble chemical, 1-octanol, were evaluated in Escherichia coli and Synechocystis sp. PCC 6803. The 1-octanol pathway was first optimized to reach product titers at which the host displayed symptoms of toxicity. Solvent overlay used to capture volatile products partially masked product toxicity. Regardless of whether solvent overlay was used, most strains with bioderivatization had a higher molar product titer and product yield, as well as improved cellular growth and glucose consumption, compared with strains without bioderivatization. The positive effect on bioproduction was observed with both the hydrophobic and hydrophilic strategies. Interestingly, in several combinations of genotype/induction strength, bioderivatization had a positive effect on productivity without any apparent effect on growth. We attribute this to enhanced product solubility in the aqueous or solvent fraction of the bioreactor liquid phase (depending on the derivative and medium used), with consequent enhanced product removal. Overall, under most conditions, a benefit of bioproduction was observed, and the bioderivatization strategy could be considered for other similar chemicals as well.

Liquid-phase Oxidation of Benzene with Molecular Oxygen over Vanadium Complex Catalysts Encapsulated in Y-Zeolite

2014 ◽  
Vol 43 (11) ◽  
pp. 1734-1736 ◽  
Author(s):  
Atsushi Okemoto ◽  
Yoshiki Inoue ◽  
Koichi Ikeda ◽  
Chiaki Tanaka ◽  
Keita Taniya ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Molecular Oxygen ◽  
Liquid Phase Oxidation ◽  
Vanadium Complex ◽  
Y Zeolite ◽  
Phase Oxidation ◽  
Oxidation Of Benzene
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