Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 9

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  methanol
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Bromine catalyst for the methane to methyl bisulfate reaction

100%
Michalkiewicz B., Balcer S.
Polish Journal of Chemical Technology
|
2012
|
vol. 14
|
issue 4
19-21
EN
A catalytic system KBr - oleum is effective at catalyzing the selective oxidation of methane to methanol via. methyl bisulfate. The influences of methane pressure, sulfur trioxide and temperature on turnover frequency were investigated.
2
Content available remote

Photochemical Conversion of CO₂ into Methyl Alcohol Using SiC Micropowder under UV Light

100%
Azzouz F., Kaci S., Bozetine I., Keffous A., Trari M., Belhousse S., Aissiou-Bouanik S.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 3
479-483
EN
In our study, microparticles SiC powder was investigated as a catalyst for CO₂ photoreduction into methanol under UV light. The photochemical conversion of methanol was studied as function of time of exposition, the concentration and the grain size of the catalyst. The selectivity of the used catalyst to promote methanol formation was noticed. It was noticed also that the grain size and concentration have a great impact on the photochemical conversion of CO₂ to methanol. The best yield of methanol was achieved when a concentration of 0.75 M of SiC powder of 17 μm grain size and an exposure time to UV light of 2 h where assured. Maximum molar concentration of methanol achieved was under UV irradiation of 365 nm. Therefore, the catalytic property of silicon carbide has proved its efficiency in the photochemical conversion of CO₂ into alcohol thus far under UV light.
3
Content available remote

Assessment of the possibility of the methane to methanol transformation

88%
Michalkiewicz B.
Polish Journal of Chemical Technology
|
2008
|
vol. 10
|
issue 2
20-26
EN
The methane to methanol conversion via esterification is an interesting method which makes it possible to eliminate the otherwise necessary phase of obtaining synthesis gas. On the basis of laboratory investigations mass balances for this process were determined. Preliminary assessment of the way of conducting the process and possibilities of practical applications of this technology was also made. It was pointed out that regardless of any possible modifications of methane to methanol conversion via esterification redundant sulfuric acid will always be produced during ester hydrolysis. Production of methanol from methane using this method can only be done when it is combined with producing other substances, which needs using H2SO4.
4
Content available remote

Optimization of rapeseed oil fatty acid esterification with methanol in the presence of sulfuric acid

88%
Brinks J., Malins K., Kampars V., Prilucka J., Apseniece L.
Polish Journal of Chemical Technology
|
2013
|
vol. 15
|
issue 4
54-59
EN
The interest in biodiesel production from low cost feedstocks is still increasing. Such feedstocks usually contain large amounts of free fatty acids, which make the currently employed base catalysts inefficient, thereby promoting the use of acid catalysts. Due to the high activity and low cost, sulfuric acid could become the most widely used acid catalyst for biodiesel production. Research undertaken so far using sulfuric acid for esterifi cation of fatty acids has shown that the products obtained fail to meet the requirements of the standard EN 14214. This paper describes a systematic study of rapeseed oil fatty acids esterification in order to obtain a product complying with the standard EN 14214. The influence of sulfuric acid concentrations (0.1-3.0%), methanol molar ratios (1:1-20:1) and reaction time (0-360 min) was evaluated. Finally, a two-stage esterification process was developed, where in optimal conditions esterification yield of 97.8% and ester content of 99.6% were achieved.
5
Publication available in full text mode
Content available

Photoacoustic Method as a Tool for Analysis of Concentration-Dependent Thermal Effusivity in a Mixture of Methyl Alcohol and Water

88%
Ponikwicki N., Szczepanik Ł., Gondek J., Linde B. B. J., Skrodzka E. B., Molchanov V., Yushkov K. B., Grechishkin R., Ponikwicki N., Szczepanik Ł., Gondek J., Linde B. B. J., Skrodzka E. B., Molchanov V., Yushkov K. B., Grechishkin R.
Archives of Acoustics
|
2019
|
vol. 44
|
issue 1
6
Content available remote

Batch extractive distillation of mixture methanol-acetonitrile using aniline as a asolvent

88%
Li G., Yu Y., Bai P.
Polish Journal of Chemical Technology
|
2012
|
vol. 14
|
issue 3
48-53
EN
Methanol and acetonitrile form a minimum azeotrope at 336.74 K, which contains methanol 76.89 mas%. The simulation and the experiment to separate the mixture by batch extractive distillation using aniline as entrainer is performed. Based on the experimental and simulative VLE data, aniline is chosen to be the suitable solvent. The sensitivity analysis about the number of stages, the refl ux ratio, the solvent feed stage and the solvent fl ow rate is conducted to obtain the optimal parameters and confi guration of the extractive distillation column with minimal energy requirements. The most appropriate confi guration is 30 theoretical stages. The optimal entrainer feeding stage is 8 with a solvent fl ow rate of 20kg/h and the refl ux ratio of 2.0, respectively. The simulation results show the effect of the main variables on the extractive distillation process. The experiment is carried out to corroborate the feasibility of the separation of methanol-acetonitrile by batch extractive distillation.
7
Content available remote

Homogeneous catalytic systems for selective oxidation of methane: state of the art

88%
Balcer S.
|
EN
Homogeneous catalysts for methane oxidation are of a particular interest from scientific and economic points of view. The results show a great potential for activation and functionalization of CH bonds of unreactive methane. There are still gaps in the knowledge of how to rationally design catalysts for this process. In this paper state-of-the-art. in methane oxidation homogenous catalysis is presented.
8
Content available remote

Evaluation of antioxidant, antimutagenic, and lipid peroxidation inhibitory activities of selected fractions of Holarrhena floribunda (G. Don) leaves

75%
Badmus J., Odunola O., Yekeen T., Gbadegesin A., Fatoki J., Godo M., Oyebanjo K., Hiss D.
|
2013
|
vol. 60
|
issue 3
435-442
EN
Exposure to environmental pollutants often leads to an upsurge in the production of reactive oxygen species (ROS). ROS oxidize cellular fatty acids to produce lipid peroxyl radicals, subsequently transformed into lipid peroxides, which decrease membrane fluidity and increase the activity of various enzymes implicated in degenerative diseases and cancer formation. Edible plants that contain exogenous compounds like curcumeroid, β-carotene, turmeric, and so on, protect the aerobic cells from oxidation of free radicals. This study thus evaluates antioxidant and antimutagenic activities of ethyl acetate, aqueous and methanolic fractions of Holarrhena floribunda leaves. Inhibitory activities of the ethyl acetate fraction on Fe2+-induced lipid peroxidation in hen egg yolk; rat liver and brain tissues were also evaluated. The Allium cepa root assay was used to evaluate antimutagenic activity. Results showed that the ethyl acetate scavenged DPPH, OH•, and •O2- much stronger than other fractions, as evidenced by its lowest respective IC50 values. All the fractions displayed antimutagenic activities against cyclophosphamide-induced chromosomal aberrations. Likewise, all the fractions induced a reduction in mitotic index, a hallmark of cytotoxicity in the root meristem of Allium cepa. The decrease in mitotic index was most profound for the ethyl acetate fraction, which also demonstrated a significant lipid peroxidation inhibitory activity in the liver and brain homogenates, but not in egg yolk, compared with the ascorbic acid standard. In general, the results suggest that the ethyl acetate fraction might contain beneficial phytochemicals that should be explored as novel candidates for preclinical drug development.
9
Content available remote

Size-dependent growth kinetics of vitamin C crystals in water solutions of L(+)-ascorbic acid with the addition of methanol and ethanol

75%
Wierzbowska B., Piotrowski K., Koralewska J., Matynia A.
Polish Journal of Chemical Technology
|
2008
|
vol. 10
|
issue 1
60-65
EN
Growth kinetics of vitamin C crystals during the batch mass crystallization process in L(+)-ascorbic acid - methanol - ethanol - water system was determined. The linear growth rate values were estimated on the basis of the product crystal size distributions. The kinetic model of the continuous process in a MSMPR crystallizer was adopted for the batch mode description according to Nyvlt's conception, taking the sizedependent growth (SDG) rate effects into consideration. The kinetic parameter values were determined with a Rojkowski hyperbolic SDG model. A good compatibility between the experimental product crystal population density distributions and the SDG model predictions was observed. The interpretation of the kinetic data was presented and discussed.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.