Water Content In Methanol Research Articles

Towards Zero-Waste Biodiesel Production: Purification of Methanol Recovery

Abstract The depletion of crude oil sources, along with a rising awareness of the adverse environmental impacts of utilizing fossil fuels, prompted the growth of alternate strategies for converting waste biomass into biofuels. Wakud is a biodiesel production plant in Oman using waste cooking oil to turn it into biodiesel. The process generates excessive amount of methanol, the purpose of this study is to enhance methanol recovery purity. The experimental study was conducted using 3A molecular sieves for methanol dewatering process. In addition to a simulation study that was conducted using ASPEN PLUS software, one distillation column is used to obtain high purity methanol. The results of the experimental study showed 98% pure methanol is achieved. However, the distillation column purified methanol recovery by 99% and the biodiesel obtained by 96%. Both studies proved that these methods would effectively reduce water content in methanol.

Visualization study on combustion characteristics of direct-injected hydrous methanol ignited by diesel in a constant volume combustion chamber

Aiming to regulate the combustion and emission of diesel/methanol dual-fuel engine more effectively, the using of hydrous methanol was proposed in the current study. The ignition and combustion characteristics of direct-injected hydrous methanol ignited by diesel were investigated by optical diagnostics. Visualization experiments were conducted on a constant volume combustion chamber (CVCC) test bench with a dual-direct injection system. Diesel was injected into CVCC prior to methanol. The results show that adjusting water content in methanol and injection interval between diesel and methanol injection are two of the most important strategies that can control the ignition and combustion process. Higher water content in methanol results in much more heat absorption during water evaporation, which should be corresponding to longer ignition delay, longer flame lift-off length (FLOL) and lower spatial integrated natural luminosity (SINL). However, the decomposition of water under high temperature as well as high pressure condition can produce OH groups, which accelerates the combustion process. Moreover, the injection interval can alter the collision timing and position of spray plumes, which are very significant for diesel ignition and methanol combustion. There are almost no monotonic effect laws when water is introduced under different injection interval conditions. Suitable design and calibration of injection strategy is crucial for effective and clean combustion in diesel/hydrous methanol dual-direct injection mode.

Fluoranthene dyes for the detection of water content in methanol.

Three novel fluoranthene dyes were obtained by cycloaddition reactions using acrylonitrile and dialkyl acetylenedicarboxylates. Their fluorescence properties in different polar–organic solvents were investigated systematically. Meanwhile, spectral changes induced by the addition of water in methanol were observed, indicating that these fluoranthenes dyes can be efficiently used to detect the water content in methanol as probes. Significantly, the practical test measurements for the water contents in methanol illustrated the measured results with the three fluorescent probes were basically consistent with the water content added artificially. This demonstrated the potential of these fluoranthene dyes as probes in measuring the water content in methanol.

Characterisation of the effect of water content on the methanol spray combustion

The methanol spray combustion in a laboratory-scale combustor was experimentally studied in the present study, especially for the effect of the water content in methanol on the flame phenomena. The results showed that as the water content in the fuel mixture was less than 10%, and the flames can be sustained stably. The appearance of the flames was not significantly different for various water contents in the fuel mixture. However, the flame length was reduced by increasing water contents, but there was no apparent change in the flame lift-off height. The exergy efficiency was in the range of 18%-21%. In addition, near flame extinction, the increase of specific exergy destruction can be found. As the water content in the fuel mixtures was increased by 10%, the exergy efficiency reasonably decreased by 9.98%, but the thermal efficiency reduced by 26.61%.

Water in Organic Solvents: Rapid Detection by a Terbium‐based turn‐off Luminescent Sensor

AbstractReactions carried out both in protic and aprotic water‐miscible solvents can be affected by the presence of water. We have recently discovered that the luminescence intensity of a methanolic solution of Tb(III) containing salicylic acid [Tb−SA] is highly sensitive to the water content. The water‐induced quenching of Tb(III) luminescence was utilized for the accurate measurement of water content in methanol, ethanol, acetonitrile, and tetrahydrofuran in the 0.1%–4% (v/v) range by a simple and rapid method.

Detecting Cu2+ and H2O in methanol based on aggregation-induced emission fluorescent enhancement

A tridentate Schiff base probe L (2-NC5H4)C(H)=N(C6H4OH-2) was synthesized via a facile reaction. Probe L showed weak fluorescence emission that originated from intermolecular proton transfer in solution. With addition of Cu2+, the emission of L was quenched by the paramagnetic nature of Cu2+. However, after the solution of L and Cu2+ was refluxed, the emission presented a completely opposite result changing from fluorescent quenching to fluorescent enhancement. The fluorescent enhancement was attributed to a planar cis-structure of Cu2+ complex. Hence, a strategy for change of emission behavior of fluorescent probe L to Cu2+ was developed; a “turn on” mode of detection Cu2+ was realized in methanol solution. A simple refluxing made probe L work as a light-up fluorescent sensor for Cu2+ in methanol solution and gave improvement of sensitivity and selectivity in detection of Cu2+. When H2O was added into the solution of the Cu2+ complex, fluorescent enhancement increased and it can be used to detect water content in methanol.

Design of the box type evaporator in the solar adsorption refrigerator

The evaporator is a device used to separate two phases between liquid-gas and liquid-liquid by using heating media. The model uses aluminum material with dimensions 170 mm x 170 mm x 240 mm and uses 3 mm aluminum thickness and three pieces of aluminum pipe with dimensions of 100 mm. The choice of material used it aims to obtain optimal results from the work of the evaporator. The effect of temperature is significant in the process that occurs in the evaporator will determine the effectiveness of the evaporator so that it can separate the water content in methanol. By heating, until one component evaporates on its boiling route, it can separate it from other parts by using methanol with 90% purity. The results of the design that is made produce an evaporator with a volume of 5 liters. The minimum evaporator temperature obtained during testing occurs in the second cycle of 0.5°C. Several factors affect the performance of an evaporator. The total heat needed in the process of reducing the maximum water temperature to the minimum water temperature and the latent heat required by methanol to evaporate.

Catalytic alcohothermal liquefaction of wet microalgae with supercritical methanol

Microalgae are promising feedstock for the production of biofuel due to their high productivity and low interference with food production for their cultivation and usage. Owing to their aquatic production environment, however, energy-intensive dewatering and drying processes may be required before their conversion to biofuel. In order to avoid these processes, their liquefaction through hydrothermal means has attracted attention, with extensive research works. The present research proposes and examines alcohothermal liquefaction of wet microalgae, in an attempt to modify and improve microalgae liquefaction characteristics. Thus supercritical methanol was employed as a reaction media for liquefaction of wet Chlorella vulgaris, and the effects of water presence as well as the effects of heterogeneous oxide catalysts were examined. This methanothermal liquefaction gave high bio-oil yield of 54.5 C% (feed microalgae basis) compared to 30.5 C% by hydrothermal for non-catalytic reaction at 385 °C. With Zr(WO4)2 catalyst methanothermal bio-oil yield increased further to 65.6 C%. The presence of water in the methanol medium somewhat decreased the bio-oil yield, while some of the catalysts mitigated the decrease: at 50 wt% water content in methanol, MnO2, ZnO2 and ZrO2 gave bio-oil yield of 55.5 C%, 59.5 C% and 57.6 C%, respectively. Possible mechanism of catalytic methanothermal liquefaction of wet microalgae is discussed.

Effect of Water Content in Methanol on The Performance and Exhaust Emissions of Direct Injection Diesel Engines Fueled by Diesel Fuel and Jatropha Oil Blends with EGR System

Diesel engines are usually used because of their durability and high efficiency. Therefore the number of diesel engine uses is increasing. This results in an increase in the amount of diesel fuel consumption and air pollution from diesel engine exhaust gases, especially soot emissions. To reduce this soot emission, methanol which is rich in oxygen is added to diesel. The substitution of alcohol into diesel has an impact on the performance of the diesel engine. Therefore, this study is focused on investigating the effect of water content in methanol on diesel engine performance and soot emissions. The study was conducted using an Isuzu 4JB1 diesel engine equipped with a cold EGR system. The ratio of the diesel-jatropha-methanol mixture used is 55/30/15% on a volume basis. While the water content in methanol used is 0 to 25% at a 5% interval. The test is carried out at a stationary 2500 rpm and given a load of 25% to 100% at a 25% interval. A dynamite Land & Sea dynamometer and stages 898 smoke meter were used to measure performance and soot emissions. The experimental data shows that the higher water content in methanol in the mixture of diesel-jatropha-methanol fuel causes a reduction in performance and an increase in soot emissions of diesel engines.

STUDI OPTIMASI EKSTRAKSI KANDUNGAN SENYAWA FENOLIK TOTAL DAN UJI AKTIVITAS ANTIOKSIDAN DARI DAUN MANGGIS (Garcinia mangostana Linn.)

This study aims to determine antioxidant activity and total phenolic content of mangosteen leaves in several different solvents. The antioxidant activity test of the extract was determined by the DPPH method and the total phenolic content was determined by the Folin-Ciocalteu method. The phytochemical test of mangosteen leaves showed the presence of phenolic compounds, saponins, triterpenoids and alkaloids. The extraction results increase with increasing water content in methanol, ethanol and acetone. The highest amount of extract was obtained using 50% acetone solvent (34.98 ± 0.17%). Extraction using 100% ethanol showed the highest total phenolic content (614.25 ± 5.58 mg GAE / g extract) and the lowest IC50 value (5.81 mg / L). The results of this study indicate that the use of 50% acetone solvent can optimize the amount of extract and 100% ethanol can optimize the content of total phenolic compounds and antioxidant activity of mangosteen leaves.

Valorization of harmful algae E. compressa for biodiesel production in presence of chicken waste derived catalyst

Abstract The main objective of this investigation is to compare catalytic activity of three different catalysts derived from chicken waste. The prepared catalysts were characterized by DTG, SEM, BET, XRD, and FT-IR. The effect of catalysts (chicken manure, chicken bone, and egg shell) on biodiesel yield (from E. compressa algal oil) were evaluated by varying calcination temperature, reaction temperature, molar ratio, catalyst amount, mixing speed, reaction time, and water content in methanol. The maximum biodiesel yield was obtained for egg shell catalyst-95% while for chicken bone catalyst −94% and chicken manure catalyst −85% at 9:1 M, 5% (w/w) of catalyst amount, 65 °C, 2% water content, and 400 rpm for 3 h. The chicken bone catalyst is highly active in reaction but in presence of water content (max. 2%) in methanol egg shell shows higher biodiesel yield performance. The recovered catalyst can be used maximum three times with a slight deviation. The quality of biodiesel merged with standards value. The conversion of waste raw materials into valuable resources make this method a cost-effective and reveals a recyclable procedure for the production of biodiesel.

Role Transformation of Poly( N-isopropylacrylamide) Microgels from Stabilizer to Seed in Dispersion Polymerization by Controlling the Water Content in Methanol-Water Mixture.

Poly( N-isopropylacrylamide) (PNIPAM)-based ionic microgels with different diameters were first prepared and then used as particulate stabilizer or seed in dispersion polymerization of styrene. The role of PNIPAM-based ionic microgels could be transformed from particulate stabilizer to seed by controlling the water content in methanol-water mixture. Generally, PNIPAM-based ionic microgels served as particulate stabilizer in methanol in the absence of water, leading to the formation of spherical polystyrene nanoparticles. However, they turned into seeds when water was added into the methanol solution, with the formation of octopus-like nanoparticles. Further study demonstrated that the mechanism for this role transition was related to the special thermosensitivity of PNIPAM microgels in methanol-water mixture. They lost their thermosensitivity in pure methanol solution but restored their thermosensitivity when increasing the water content in methanol-water mixture.

Effect of Water Content in Extraction Mixture on the Pressurized Liquid Extraction Efficiency-Stability of Quercetin 4'-Glucoside During Extraction from Onions.

Pressurized liquid extraction (PLE) is considered as an effective and quick sample preparation method, especially in plant analysis. This quick extraction process favors the isolation of compounds for which long exposure time in high temperatures is undesirable. However, despite this advantage, the application of PLE for plant compounds extraction involves certain problems, such as instability of the compounds. The obtained data proved that even in short-lasting PLE, quercetin 4'-glucoside undergoing the hydrolytical degradation process produces the corresponding aglycon quercetin when water is a component of the applied extractant. The increase of water content in methanol-water extractant mixture heightens the transformation degree of quercetin 4'-glucoside into quercetin and increases its concentration in the PLE extracts. The degradation is accelerated by increased extraction temperature and time. In plant samples, the degradation of quercetin 4'-glucoside is much higher because of the plant matrix effects. The presented results explain why extraction of quercetin from plants by pure methanol is less efficient than by water containing alcohol solutions. More importantly, they prove that the application of water-alcohol extractant during sample preparation leads to the hydrolytical degradation of glycosides to aglycones, and, as a consequence, to false conclusions in plant analysis.

Synthesis and characterization of hydrophilic chitosan-polyvinyl acetate blends and their sorption performance in binary methanol–water mixture

Chitosan-polyvinyl acetate (CHI-PVA) blends were prepared throughout copolymerization reaction. Chitosan (CHI) as a hydrophilic molecule was added to modify the blend surface of polyvinyl acetate (PVA). The sorption effects of CHI-PVA blends were studied in the presence of binary feed mixture of methanol–water (MW). The obtained blends were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), microscopic analysis and conductivity measurements to investigate the chemical structure, crystallinity, surface morphology and electric property, respectively. Effect of water content on the swelling performance of CHI-PVA blends based on (methanol/water) ratio was discussed. CHI-PVA complexes show high swelling performance with 20% CHI based blends from 50% water content in methanol–water mixture.

Influence of the solvent on the complexation of Cm(iii) and Eu(iii) with nPr–BTP studied by time-resolved laser fluorescence spectroscopy

The systematic investigation of the influence of the water content in methanol–water mixtures on the complexation of Cm(iii) and Eu(iii) with nPr–BTP revealed an immense influence of the solvent.

Microwave irradiation-assisted transesterification of soybean oil to biodiesel catalyzed by nanopowder calcium oxide

This study examined the effect of a heterogeneous base catalyst on the transesterification of soybean oil assisted by microwave irradiation. The results showed that nanopowder calcium oxide (nano CaO) was very efficient in converting soybean oil to biodiesel, and microwave irradiation is more efficient than the conventional bath for biodiesel production. However, the water content of methanol can not improve the conversion rate catalyzed by nano CaO. The suitable reaction conditions that can reach a 96.6% of conversion rate were methanol/oil molar ratio, 7:1; amount of catalyst used, 3.0 wt.%; reaction temperature, 338 K; and reaction time, 60 min. The biodiesel produced is within the limits prescribed by the standard of EN-14214.

Epimerization of Cypermethrin Stereoisomers in Alcohols

Isomerization induced by light, heat, and organic solvents has been shown to occur for some pyrethroid insecticides. Alcohols are popular solvents that are used in sample extraction, storage, and analysis. Thus, alcohol-induced epimerization may contribute to the incorrect interpretation of results from enantioselective chemical analysis and bioassay of pyrethroids like cypermethrin. In this study, we investigated the relationship between the rate of epimerization of cypermethrin stereoisomers: 1R-cis-alphaR and 1R-trans-alphaR and short-chain alkyl alcohol properties. In this study, complete epimerization of 1R-cis-alphaR produced an almost equal fraction of 1R-cis-alphaS, and that of 1R-trans-alphaR yielded 1R-trans-alphaS. For both stereoisomers, epimerization was most rapid in ethanol. The same stereoisomers underwent relatively rapid epimerization in methanol, n-propanol, 2-methyl-1-propanol, and n-butanol but were stable in 2-butanol, suggesting that secondary alcohols have reduced reactivity, likely due to steric hindrance. We further evaluated epimerization of 1R-cis-alphaR and 1R-trans-alphaR stereoisomers of cypermethrin as a function of water content in methanol. The presence of water in methanol generally increased the epimerization rate. For 1R-cis-alphaR, epimerization was most rapid with a water content of < or =2%, while for 1R-trans-alphaR, epimerization was most rapid with a water content of 10%. Results from this study clearly show that contact with commonly used primary alcohols may result in rapid abiotic epimerization, underscoring the importance of considering configurational stability in ensuring the analytical integrity and correct interpretation of bioassay data for stereoisomers of cypermethrin and similar pyrethroids.

Transesterification of soybean oil to biodiesel using CaO as a solid base catalyst

In this study, transesterification of soybean oil to biodiesel using CaO as a solid base catalyst was studied. The reaction mechanism was proposed and the separate effects of the molar ratio of methanol to oil, reaction temperature, mass ratio of catalyst to oil and water content were investigated. The experimental results showed that a 12:1 molar ratio of methanol to oil, addition of 8% CaO catalyst, 65 °C reaction temperature and 2.03% water content in methanol gave the best results, and the biodiesel yield exceeded 95% at 3 h. The catalyst lifetime was longer than that of calcined K 2CO 3/γ-Al 2O 3 and KF/γ-Al 2O 3 catalysts. CaO maintained sustained activity even after being repeatedly used for 20 cycles and the biodiesel yield at 1.5 h was not affected much in the repeated experiments.

The hydrophobic effect as a driving force for solute uptake by dealuminated zeolite Y

The hydrophobic nature of a commercial sample of dealuminated zeolite Y (DAY), heretofore referred to as Y901 and available as CBV901 from Zeolyst International, has been examined. Studies were focused on Y901 and related zeolites that were interfaced with bathing polar solvents. Binding isotherms for uptake of non-polar arene test solutes by various zeolites were evaluated from measurements of solute depletion in test solutions that were stirred with zeolite powders. The affinity of naphthalene (NP) for Y901 was found to increase with increasing water content in methanol–water (M/W) mixtures. Up to 2 NP per supercage could be loaded into Y901 from 50/50M/W (v/v). No affinity of NP for Y901 could be detected in neat MeOH. A similar response to water content was observed for uptake of anthracene (AN) and pyrene (PY) by Y901, although studies with these probes were more limited compared to NP due to their inherently lower solubility in polar solvents. In 50/50M/W, the NP-Y901 binding isotherm was sigmoidal in shape. The sigmoidal shape was explained by dimer formation, or preference of NP for NP-occupied supercages, and is supported from observations of static excimer fluorescence at low NP loadings not expected to produce double-occupation of NP in supercages. No affinity of NP for either NaX or NaY could be detected in any polar solvent, regardless of water content. Pyrene excimer formation was also examined in solvated Y901 and was found to be essentially uninhibited in a variety of solvents. In contrast, excimer formation was strongly inhibited in solvated NaX and NaY. This finding lends support to the conclusion from a previous study that the polar-solvated interior of Y901 is less rigid or more fluid than that of NaX and NaY. Such fluidity is likely to be an important factor in the kinetics of solute uptake by Y901. The thermodynamic driving force for uptake of non-polar solutes by Y901 can be explained by the hydrophobic effect and is similar to that found in reversed-phase liquid chromatography. The interior of Y901 is viewed by the solute as an essentially non-polar medium, regardless of the water content of the bathing solvent. The current study reinforces previous assertions from photophysical studies carried out in this laboratory concerning the polarity and fluidity of the environment encountered by solutes in polar-solvated Y901. It also comments uniquely on the hydrophobicity of Y901 from studies of adsorption from solution. Previous descriptions of the hydrophobicity of Y901, and DAY in general, have been based mainly on studies of adsorption from the gas phase.

Wet spinning of silk polymerI. Effect of coagulation conditions on the morphological feature of filament

Regenerated silk fibroin (SF) filaments were prepared by the wet spinning technique. The effect of coagulation conditions, such as coagulant type and coagulation temperature, was investigated on the morphological feature of SF filaments and a theoretical approach was also performed to understand the coagulation phenomena. SEM observation revealed that as the R group size of alcoholic coagulant (ROH) increased, the cross-sectional shape deviated more from a circular form. This is attributed to the fact that as the R group size increased, the mass transfer rate difference increased, but the coagulation rate decreased due to a reduced diffusion rate. Most non-alcoholic coagulants exhibited this circular cross-sectional shape, except dioxane, which showed a clover shape. As the coagulation bath temperature increased, the cross-section deviated less from a circular form, with the reduction of fiber diameter. When methanol/water mixture was used as a coagulant, an ellipse or a dog-bone shape was obtained with higher water content in methanol, which was attributed to the decrease of coagulation rate. Although methanol exhibited a positive value of mass transfer rate difference, a circular shape of cross-section was obtained due to the density difference of the coagulated and uncoagulated parts in the coagulating SF filament.