Influence Of Methanol Research Articles

Influence of Methanol on the Dissolution of Lignocellulose Biopolymers with the Ionic Liquid 1-Ethyl-3-methylimidazolium Acetate

Ionic liquids are the basis of a promising technology for the dissolution and fractionation of lignocellulosic materials. The use of a miscible organic cosolvent as additive may improve the physical properties of the dissolving fluid, as compared to those of the ionic liquid alone. Alternatively, this organic substance added in larger amounts can act as antisolvent for the regeneration of the nonvolatile lignocellulose fractions dissolved. In this work, mixtures of methanol and 1-ethyl-3-methylimidazolium acetate (an archetypal ionic liquid for dissolution of lignocelluloses) were characterized from a thermal and physical point of view. Their ability to dissolve representative standards of the lignocellulose biopolymers (cellulose, hemicellulose, lignin) was assessed. Very different solubilities of the three biopolymer standards were observed as a function of composition of the solvent, suggesting the possibility of a selective dissolution procedure to separate mixtures of the disengaged polymers. Precipi...

Optimum conditions determination of methyl methacrylate obtaining over tungsten-containing catalyst

The main common methods of methyl methacrylate producing are acetoncyanohydrin method and oxidation of isobutylene and tert-butanol. Because of the significant drawbacks of these methods, it is important to develop new, alternative ways of methyl methacrylate obtaining, one of which could be aldol condensation of methyl propionate with formaldehyde in the gas phase. The actual task for today is to find out effective catalysts for this process. For this aim, methyl propionate condensation with formaldehyde was studied in the presence of B 2 O 3 -P 2 O 5 -WO 3 /SiO 2 catalyst, which previously has showed high activity in the condensation of propionic acid with formaldehyde to methacrylic acid. The paper also investigates the influence of methanol on the side reaction of methyl propionate hydrolysis; it was found that adding methanol causes a slight increase in MMA selectivity, but the yield of unsaturated products decreases, and therefore adding methanol to the reaction mixture for the MP condensation with FA over B 2 O 3 -P 2 O 5 -WO 3 /SiO 2 catalyst is impractical. The optimum conditions for MP condensation with FA, namely temperature 653 K and contact time 12 s were found. Under these conditions, in the presence of B 2 O 3 -P 2 O 5 -WO 3 /SiO 2 catalyst with an atomic ratio of components B:P:W 3:1:0.6 respectively total yield of MMA and MAA was 31.91% while their total selectivity was 32.3%.

Effect of methanol content in commercial formaldehyde solutions on the porosity of RF carbon xerogels

Methanol is used commercially as a stabilizer in solutions of formaldehyde to prevent its precipitation. However, the methanol content of commercially available formaldehyde solutions differs from one supplier to another. The pH, dilution and R/F ratio have been demonstrated to be interdependent variables that can be manipulated to tailor the porous properties of RF carbon xerogels. This work considers the methanol contained in formaldehyde solutions as a new variable to be studied in conjunction with those just mentioned. For the purpose of this study, the influence of methanol on the final porous properties of RF carbon xerogels has been evaluated. It was found that carbon xerogels synthesized using formaldehyde solutions with lower concentrations of methanol showed a higher total pore volume and pore size, and in turn, a lower density and a greater porosity. The porosity of RF carbon xerogels could therefore be radically modified depending on the commercial formaldehyde solution used for their synthesis.

Process Parameter Optimization in Jatropha Methyl Ester Yield Using Taguchi Technique

Among all alternate fuel sources available, the biodiesel of Jatropha curcas appears to be a potential fuel as it widely exists in Asia. The Jatropha methyl ester (JME) is produced by transesterification process. In the transesterification process, alkyl group of ester exchanges with that of an alcohol. This work focuses on optimizing various parameters like quantities of methanol, KOH, and stirrer speed, which influence high JME yield. Based on L9 orthogonal array, experiments are conducted by using Taguchi technique. All the nine combinations of L9 orthogonal array are experimentally done for extraction of JME, and then it is used for analysis in Taguchi technique. The analysis of maximum yield is done on the basis of “larger is better” signal to noise ratio (S/N ratio). The best combination in the L9 orthogonal array is found to be methanol (110 ml), KOH (1.306 gm), and stirrer speed (1200 rpm). The influence of methanol, KOH, and stirrer speed on the yield is found by analysis of variance (ANOVA). Based on the results of ANOVA, it is found that the influence of methanol, KOH, and stirrer speed on the yield are obtained as 70.10%, 20.35%, and 5.78%, respectively.

Preparation of highly reusable biocatalysts by immobilization of lipases on epoxy-functionalized silica for production of biodiesel from canola oil

In the present work, lipases from Candida antarctica (CALB), Thermomyces lanuginosus (TLL) and Rhizomucor miehei (RML) were covalently immobilized on epoxy-functionalized silica. The immobilized lipases were used to produce biodiesel by transesterification of canola oil with methanol. It was found that lipases immobilized on silica provided biocatalyst derivatives with lower cost compared with the cost of commercially available Novozym 435. Thermal stability of the immobilized derivatives and the influence of methanol on the catalytic activity were also evaluated. Optimum oil to methanol ratio at 1:3 was observed for CALB and RML in biodiesel production; the corresponding fatty acid methyl ester (FAME) yields obtained after 96h were 68% and 45% at 50°C respectively. The lipase from T. lanuginosus immobilized on epoxy-functionalized silica displayed particularly high catalytic ability regarding reaction rate and final yield. TLL also gave high FAME contents in the reaction mixture with up to 6 molar equivalents of methanol to oil (98%). The immobilized TLL was quite stable and can be reused for 16 cycles without significant loss in activity (5%). The immobilized preparations of RML and CALB also presented a good reusability, keeping 85% of their initial activities after 16 cycles of the reaction.

Influence of methanol and water extracts of orange peel on stability of refined palm kernel oil

The antioxidative effect of methanol and water orange peel extracts on Refined Palm Kernel Oil (RPKO) stored for twelve months at room temperature (270C-330C) was determined by monitoring the colour, refractive index, free fatty acid (FFA), acid value (AV) and peroxide value (PV). The oil was dosed with different concentrations (200 ppm to 1000 ppm) of the extracts and butylatedhydroxytoluene (BHT) (Cone. 200 ppm. The colour and refractive index of RPKO containing the extracts ranged between 11.0-13.0 units and 1.458-1.460 respectively whereas the colour and refractive index of RPKO with no additive (0 ppm) and 200 ppm BHT were 10.0 units and 1.460 accordingly. Free fathy acid (FFA) and acid value (AV) of RPKO containing methanol and water orange peel extracts were lower than RPKO containing 200 ppm BHT and they were significantly different at P<0.05 from RPKO that contained no additive (0 ppm). PV of RPKO containing additives were slightly lower than PV of RPKO that contained no additive but they were not significantly different at P<0.05.The methanol and water orange peel extracts are more effective in combating hydrolytic rancidity than oxidative rancidity of RPKO. The methanol and water orange peel extracts have better antioxidant activity than butylatedhydroxytoluene DOI: http://dx.doi.org/10.3329/bjsir.v49i4.22628 Bangladesh J. Sci. Ind. Res. 49(4), 249-254, 2014

Experimental Study on the Supercritical Water Co-Oxidation of Municiple Sludge with Methanol

The influence of methanol on the sludge removal rate of COD was investigated and the mechanism was obtained. The results show that the adding of methanol solution can improve the sludge COD removal rate, when the mass fraction of methanol is 5%, COD removal rate can be highly 99.98% compared 98.26% of that without methanol. The mechanism of co-oxidation is that methanol oxidation process can produce free radicals HO· and HO2·, they attack intermediate phenol and acetic acid, promote acetic acid to C-C bond fracture and ring-opening of phenol.

The controversial fuel methanol strategy in China and its evaluation

Methanol has already been used widely throughout the whole nation. This paper firstly analyzes the strategic development of the use of methanol as a fuel in China, including standards, organization and the present situation. It points out the different standpoints at home and abroad on the highly controversial issue as to whether China should develop fuel methanol. Then it evaluates current strategies and introduces GHG emission as an evaluation method to be accepted both home and abroad. Recommendations for policies of fuel methanol are given to improve operation mode. It is suggested that only coal-abundant provinces should continue to use M5 as their alternative fuel for gasoline, while all other areas and provinces should gradually abandon the use of methanol. A small scale application of M85 and M100 should still be used for evaluating methanol's influence on the environment.

A concentration-dependent effect of methanol on Candida antarctica lipase B in aqueous phase

Abstract The influence of methanol on enzyme is of great importance in enzymatic synthesis. The influence of methanol on the activity of Candida antarctica lipase B (CALB) upon hydrolysis of tributyrin was investigated by enzyme kinetics analysis. Dynamic light scattering (DLS) and circular dichroism (CD) was used to measure the variation of hydrodynamic diameter and secondary structure change of CALB at different methanol concentration, respectively. A concentration-dependent influence of methanol on CALB was observed. The activity of CALB slightly increased with less than 1.2 mol l −1 of methanol, followed by sustained decrease at higher methanol concentrations. DLS result indicated that the negative effect of methanol on CALB was supposed to follow different mechanisms due to the significant variation of particle size of CALB at different methanol concentrations. Both reversible competitive inhibition based on enzymatic kinetics analysis and inactivation based on CD spectroscopy study were supposed to contribute to the negative effect of methanol on CALB with methanol concentration in the range of 1.2 mol l −1 to 6 mol l −1 . And after arriving at percolation threshold concentration of 6 mol l −1 , methanol was mainly performed as aggregate and precipitate agent for CALB, which resulted in low effective enzyme concentration in the solution.

The Numerical Simulation of Methanol and N-Heptane Dual Fuel Combustion

Several influence for the soot and NOx emission of methanol and n-heptane dual fuel combustion is advised, using homogeneous charge compression ignition model in CHEMKIN-PRO. The calculating results indicate that methanol plays an important role in the course of soot formation, but the effect of methanol is smaller for NOx. With the increase of methanol quantities, the soot formation is reduced and the soot particle diameter is smaller; if the fuel equivalence ratio is small, the influence of methanol is obvious to NOx emission. If the fuel equivalence ratio ≥ 1.0 , the trend of NOx emission changed. With the increase of methanol, NOx emission early increased, and decreased late.

A dinuclear alkynylplatinum(ii) pyridinedicarboxamide: conformational change-induced switching of emission properties

The synthesis and characterisation of a dinuclear pyridinedicarboxamide-platinum(II) complex exhibiting tunable optical properties based on metal-metal interaction are reported. Conformational change-induced switching between metal-to-ligand charge-transfer and metal-metal-to-ligand charge-transfer emission properties by the influence of methanol was demonstrated.

Determination of the Dissociation Constants of Some Macrolide Antibiotics in Methanol–Water Binary Mixtures by UV-Spectroscopy and Correlations with the Kamlet and Taft Solvatochromic Parameters

The dissociation constants of six common human and veterinary antibiotics, namely, erythromycin, roxithromycin, tilmicosin, oleandomycin, josamycin, and spiramycin in 15 %, 25 %, 40 % and 50 % (v/v) methanol–water solvent mixtures were determined by UV/pH titration and correlated with the Kamlet and Taft solvatochromic parameters, π ∗, α and β. Kamlet and Taft’s general equation was reduced to two terms by combined factor analysis and target factor analysis in these mixtures: the independent term and polarity/polarizability π ∗, which are solvatochromic parameters. The influence of methanol on the dissociation constants was investigated. Further, the quasi-lattice quasi-chemical (QLQC) model of preferential solvation has been applied to quantify the preferential solvation by water of electrolytes in methanol–water mixtures.

Experimental and modeling study on the influences of methanol on premixed fuel-rich n-heptane flames

The structures of two laminar premixed n-heptane/O2/Ar flames (F1.60: Ф=1.60, C/O=0.51, and F1.80: Ф=1.80, C/O=0.57) and one laminar premixed n-heptane/methanol/O2/Ar flame (F1.80M: Ф=1.80, C/O=0.51) are studied at low pressure (4000Pa) by using synchrotron photoionization and molecular-beam sampling-mass spectrometry (PI-MBMS) techniques. Calculations are performed with a modified chemical mechanism, which satisfactorily simulates the tested flames. The results show that as equivalence ratio increases, the maximum flame temperature is reduced and the flame front is shifted away from the burner surface. The post-flame CO concentration in F1.80M is lower than that in F1.80, which is attributed not only to the difference in inlet carbon flux but also to the variation in CO formation pathway. As methanol is added, the peak concentrations of C2–C7 hydrocarbon intermediates are reduced substantially, and the extent of the reduction in the case of constant C/O ratio is smaller than that in the case of constant equivalence ratio. The production of formaldehyde is promoted with the addition of methanol. Reaction flux analysis indicates that the self-recombination of propargyl radical (C3H3) and the cross reaction between C3H3 and allyl radical (a-C3H5) are the dominant pathways leading from small aliphatics to benzene for all the flames.

Increased significance of food wastes: Selective recovery of added-value compounds

A single-step selective separation of two food additives was investigated using alcohol-salt aqueous two-phase systems (ATPS). The selective partitioning of two of the most used additives from a processed food waste material, vanillin and l-ascorbic acid, was successfully accomplished. The results obtained prove that alcohol-salt ATPS can be easily applied as cheaper processes for the selective recovery of valuable chemical products from food wastes and other sources.As a first approach, the phase diagrams of ATPS composed of different alcohol+inorganic salt+water were determined at 298 (±1)K and atmospheric pressure. The influence of methanol, ethanol, 1-propanol, and 2-propanol and K3PO4, K2HPO4 or KH2PO4/K2HPO4 in the design of the phase diagrams was addressed. After the evaluation of the phase diagrams behaviour, the influence of the phase forming constituents was assessed towards the partition coefficients and recovery percentages of vanillin and l-ascorbic acid among the coexisting phases. Both model systems and real processed food waste materials were employed. Using these ATPS as partitioning systems it is possible to recover and separate vanillin, which migrates for the alcohol-rich phase, from l-ascorbic acid, which preferentially partitions for the salt-rich phase.

Unique Approach toward ZnO Growth with Tunable Properties: Influence of Methanol in an Electrochemical Process

A unique approach has been developed to deposit ZnO with tunable morphology and physical properties by introducing methanol in an electrochemical process. As the methanol increases in the aqueous e...

Kinetic study of calcium carbonate precipitation in gas field brine containing methanol

Precipitation of calcite in pipelines and process vessels of petroleum industry may jeopardize flow assurance, and give rise to corrosion problems. In the present study growth rate of calcite crystals in gas-field brine under the influence of methanol used for hydrate prevention was experimentally investigated. Experimental results showed that calcite precipitated per unit mass of brine increased as the methanol concentration in the brine increased from 0 to 60 wt%. Different concentrations of methanol in brine are influential in mechanisms of growth, nucleation, and agglomeration of calcite. Kinetic parameters in rate equations of these mechanisms were calculated by model fitting to experimental data. Agreement of the model predictions with experimental results beyond the range at which the model parameters were adjusted indicated the validity of the model parameters. Results of this study may be used in petroleum industry to predict calcite crystallization at different concentrations of methanol in the gas-field brine in pipelines and process vessels.

Epoxidation Processes by Pyridoxal Dioxomolybdenum(VI) (Pre)Catalysts Without Organic Solvent

AbstractMolybdenum(VI) pyridoxal thiosemicarbazonato complexes have proved to be efficient catalysts in the olefinic epoxidation of cyclooctene by aqueous TBHP in the absence of an organic solvent. High activity and selectivity have been obtained with a catalyst loading of just 0.05% molybdenum in the case of one mononuclear (pre)catalyst (TOF 3360 h−1) under solvent‐free conditions. The influence of methanol on the activity and selectivity has been studied.

Rapid HPLC Method for Determination of Parachloroaniline in Chlorhexidine Antiseptic Agent in Mouthrinses, Ophthalmic and Skin Solution

We described a simple and rapid method to quantify simultaneously chlorhexidine (CHD) and its major metabolite, para Chloroaniline (pCA) by HPLC with UV detection without the additional need of mobile-phase amine modifiers or ion-pairing reagents, with good resolution between pCA and CHD, symmetry peak of the compound and short run time. HPLC-UV analyses were performed using a Dionex® Summit liquid chromatograph (Dionex Corp, Sunnyvale, CA, USA). Chromatographic separations were carried out on a Luna® 150 mm×3 mm i.d. column packed with 3 µm CN (cyano) particles (Phenomenex®), guarded by an on-line filter. Mobile phase consist of methanol:water with sodium chloride with 0.02% of formic acid (55:45). Wavelengths for pCA and for CHD are 238 and 255 nm respectively. Influence of methanol and of sodium chloride content in the eluant has been studied. Linearity of CHD is very good, from 0.5 up to 21.2 µg/l while linearity of pCA is in the range of 0.05 to 10 µg/l with correlation coefficients above 0.999. Resolution between the components is above 4, asymmetry is about 1.3 and 1.7 for pCA and CHD respectively and the run time is less than 5 minutes. This method has been applied to CHD solution of different medical devices. No interference has been reported, and the analysis of direct injection of solution, without any treatment is achieved in less than five minutes.In conclusion, we present a validated method for dosage of CHD and its major impurity pCA, known to be carcinogen, available into medical products or medicinal device for in-vitro diagnostic.

Liquid fuel from waste polyolefins: Part II. Thermal and pressure degradation of waste polyolefins in the presence of methyl alcohol

In the paper, the study on co-decomposition of polyolefins and thermally unstable methyl alcohol is presented. The process temperature was maintained above 400 °C. The pressure at the end of process, depending on the feed composition, was 3–25 MPa. In the first variant, the raw material was polyolefin product, in the form of solidifying liquid, previously partially decomposed. Basing on the satisfactory results regarding the methanol influence on the quality of obtained liquid fractions, extended technological concepts were proposed, in which also solid waste polyolefins can be used without the phase of previous thermocatalytic decomposition. Dissolution of raw polymer is facilitated by paraffin oil addition. The only disadvantage is a large fraction of sulphur, purposely introduced in case of methods that use technological oil. In the last case, waste polyolefins were used, but without oil type additions. Although the efficiency of the liquid product is not as high as in oil technologies, the fractions with satisfactory results are obtained. The results show decomposition of polymer bonds with a simultaneous hydroconversion of unsaturated structures.

A study of the influence of methanol and iodine molecule adsorption on the conductivity of Langmuir films of TDOB AM BCC liquid crystals

This paper studies the influence of adsorption of methanol and iodine molecules on the conductivity of para-tetradecyloxybenzyliden-amino-2-methylbutyl-cyanocinnamate that was obtained using the Langmuir-Blodgett method. The growth of conductivity of the studied films at methanol absorption and the reduction of conductivity upon iodine absorption was discovered. An explanation of the observed conductivity variation at adsorption is proposed.