Molar Ratio Of Reactants Research Articles

Ruminant-Waste Protein Hydrolysates and Their Derivatives as a Bio-Flocculant for Oil Sands Tailing Management.

Reclamation of tailings ponds is a critical issue for the oil industry. After years of consolidation, the slurry in tailings ponds, also known as fluid fine tailings, is mainly comprised of residual bitumen, water, and fine clay particles. To reclaim the lands that these ponds occupy, separation of the solid particles from the liquid phase is necessary to facilitate water removal and recycling. Traditionally, synthetic polymers have been used as flocculants to facilitate this process, but they can have negative environmental consequences. The use of biological polymers may provide a more environmentally friendly approach to flocculation, and eventual soil remediation, due to their natural biodegradability. Peptides derived from specified risk materials (SRM), a proteinaceous waste stream derived from the rendering industry, were investigated to assess their viability for this application. While these peptides could achieve >50% settling within 3 h in bench-scale settling tests using kaolinite tailings, crosslinking peptides with glutaraldehyde greatly improved their flocculation performance, leading to a >50% settling in only 10 min. Settling experiments using materials obtained through different reactant ratios during crosslinking identified a local optimum molar reactant ratio of 1:32 (peptide amino groups to glutaraldehyde aldehyde groups), resulting in 81.6% settling after 48 h. Taken together, these data highlight the novelty of crosslinking waste-derived peptides with glutaraldehyde to generate a value-added bioflocculant with potential for tailings ponds consolidation.

New Hyperbranched Polysiloxanes Made by Thiol‐yne Click Reaction: Lanthanide Complexation and Applications in Bioimaging

AbstractHyperbranched polymers, as a unique highly branched polymers with low viscosity, simple synthesis, mixability and high reactivity, have received intensive attention and applied to many fields of resin modification, catalysts, and film materials. In this paper, hyperbranched polymers (P1 and P2) are designed and developed by the thiol‐yne “click” reaction with controlled molar ratio of reactant. After that, lanthanide ions are coordinated with P1 and P2 to prepare new hyperbranched polymer fluorescent products (P1‐Ln3+ and P2‐Ln3+). P1‐Ln3+ and P2‐Ln3+ exhibit excellent fluorescent properties, superb stability, and economic feasibility. Moreover, bioimaging experiments clearly exhibit that P1‐Ln3+ and P2‐Ln3+ has great potential in further biological applications.

Interactions of (η5-CpRu)-[12]cycloparaphenylene full-sandwich complexes with 9-methylguanine

The synthesis and the characterization of (RuCp)-[12]CycloParaPhenylene complexes of the general formula [([12]CPP)(RuCp)n](PF6)n (n = 1–3, 4–6 and 9–12) was achieved by the reaction of [(η5-Cp)Ru(CH3CN)3](PF6) with [12]CPP in dry acetone. The number n of the (RuCp) substitutions on [12]CPP varied depending on the reaction molar ratio, producing mixtures with average (RuCp) moieties, ω1:1 = 2.9, ω1:6 = 4.9, ω1:12 = 10, which were analyzed by 1H NMR spectroscopy and high-resolution ESI mass spectrometry. The [([12]CPP)(RuCp)n]Cln (n = 4–6) was transformed to its corresponding [Cl]− salt which was stable in aqueous solution in the dark, but released (RuCp) solvolyzed species upon UV (365 nm) irradiation. The addition of 9-MeG in an aqueous solution containing [([12]CPP)(RuCp)n]Cln (n = 4–6) which was subsequently irradiated with UV (365 nm) formed adducts between the released (RuCp) and the 9-MeG, where 9-MeG was coordinated through N7. This may be useful in the application of full-sandwich ruthenium-arene complexes in cancer photodynamic therapy.

In situ reaction mechanism of Cu–Ti–CuO system in pure copper melts

In situ reaction was carried out using Cu–Ti–CuO as reaction system and pure copper melt as reaction medium. When the melt temperature is close to the melting point of pure copper, the sample was obtained by casting near the melting point. The effects of reaction parameters, such as the molar ratio of reactants and melt preheating temperature, on the in situ reaction mechanism, as well as the effects of the size, shape and distribution of the reaction products on the near melting point casting structure of the matrix copper were studied, so as to prepare Cu-TiO2 composites with good electrical and mechanical properties. The results show that Cu–Ti–CuO reaction system can produce rutile titanium dioxide particles smaller than 2 μm of pure copper melt, without TiXCuY intermetallic compound, with the molar ratio of Ti to CuO of 1:2, the content of diluent of 50%, the forming pressure of 10 MPa, and the preheating temperature of pure copper melt of 1250 °C. The morphology of TiO2 particles is nearly spherical and dispersed in the copper matrix. The reasons for the formation of TiO2 particles in Cu–Ti–CuO reaction system were analyzed from the perspectives of thermodynamics, kinetics and Redox reaction. When the mass fraction of TiO2 is 3%, the solidification structure of the sample is more uniform than that of pure copper, the grains are refined, and the average grain size is 103.29 μm.

INVESTIGATION OF SYNTHESIS PARAMETERS OF ANTIMONY FLUOROBORATE AND ITS USABILITY AS A FLAME RETARDANT FOR CELLULOSIC FABRICS

In this study, the synthesis parameters of antimony fluoroborate, one of the metal fluoroborates, from antimony trioxide and fluoroboric acid by the wet method, and its usability as flame retardant for cellulosic fabrics have been investigated. The maximum reaction yield was determined depending on the mole ratio of reactants, temperature and stirring speed. The characterization of the product was performed by XRD and FTIR analyses. Antimony fluoroborate was produced with 94% yield at a mole ratio of reactants (nHBF4/nSb2O3) of 6:1, at 70 °C and 300 rpm. The thermal behaviors of untreated fabric and fabric impregnated with antimony fluoroborate solution were analyzed by TGA. The flame retardancy performance of antimony fluoroborate for cellulosic fabrics was determined by the vertical flame test and the limiting oxygen index (LOI) test methods. The results show that impregnating cellulosic fabrics with antimony fluoroborate enhances their thermal stability and flame retardancy.

DIC/Oxyma-based accelerated synthesis and oxidative folding studies of centipede toxin RhTx.

Coupling reagents play crucial roles in the iterative construction of amide bonds for the synthesis of peptides and peptide-based derivatives. The novel DIC/Oxyma condensation system featured with the low risk of explosion displayed remarkable abilities to inhibit racemization, along with efficient coupling efficiency in both manual and automated syntheses. Nevertheless, an ideal reaction molar ratio in DIC/Oxyma condensation system and the moderate reaction temperature by manual synthesis remain to be further investigated. Herein, the synthetic efficiencies of different reaction ratios between DIC and Oxyma under moderate reaction temperature were systematically evaluated. The robustness and efficiency of DIC/Oxyma condensation system are validated by the rapid synthesis of linear centipede toxin RhTx. Different folding strategies were applied for the construction of disulfide bridges in RhTx, which was further confirmed in assays of circular dichroism and patch-clamp electrophysiology evaluation. This work establishes the DIC/Oxyma-based accelerated synthesis of peptides under moderate condensation conditions, which is especially useful for the manual synthesis of peptides. Besides, the strategy presented here provides robust technical supports for the large-scale synthesis and oxidative folding of RhTx.

Biodiesel (methyl oleate) synthesis in the presence of pyridinium and aminotriazolium acidic ionic liquids: Kinetic, thermodynamic studies

Kinetics and thermodynamics of biodiesel (methyl oleate) synthesis using the protic ionic liquids pyridinium hydrogen sulfate (PHS), pyridinium nitrate (PN) and 4-amino-1H-1,2,4-triazolium nitrate (ATN) as catalysts are studied in the current work for the first time. Rate of the biodiesel production is directly related to acidity of the ionic liquids used and their internal hydrogen bonding extent. A detailed thermodynamic analysis on the title reaction is conducted as well. To optimize the reaction conditions, influence of the reaction temperature (25–55 °C), initial alcohol-to-acid molar ratio (1.0–15.0) and catalyst loading (5–15 wt% with respect to the substrate mass) is investigated in details. Catalyst reusability is evaluated for five cycles. Based on the experimental data, a plausible mechanism of biodiesel synthesis is offered. Catalytic performance of the PHS sample in the biodiesel synthesis is remarkably higher than that of the nitrate anion-based ionic liquids. Reaction temperature of 55 °C, an initial reactants molar ratio of 7.0 and a catalyst loading of 10 wt% are established as optimal conditions for the process of biodiesel production. Values of 43.09 kJ/mol and 91.29 × 105 l/mol × min are calculated as activation energy and pre-exponential factor, respectively. ΔSr° and ΔHr° for the process of biodiesel synthesis are found to be 42.32 J/mol × K and 9.64 kJ/mol, respectively. Moreover, ΔH≠ (40.49 kJ/mol) and ΔS≠ (−162.31 J/mol × K) are established as well. The respective ΔGr° (−4.241 kJ/mol) and ΔG≠ (93.727 kJ/mol) at reaction temperature of 55 °C are obtained.

The formation of phycocyanin-EGCG complex for improving the color protection stability exposing to light

Phycocyanin (PC) is a natural pigment-protein complex in food dye applications. In this study, a phycocyanin-epigallocatechin gallate (EGCG) complex (PE) was prepared and the effects of EGCG on the structure and color stability of PC were evaluated. The fluorescence results showed that the binding number n was 62.1 ± 3.41 (EGCG/PC) and the binding constant K was 4.39 (±0.2) × 105 M−1, indicating a weak-binding interaction. Fourier transform-infrared analysis showed that EGCG caused structural changes in PC by partially uncoiling α-helix and increasing β-sheet content. The EGCG induced a PC association at a reaction molar ratio above 40:1 (EGCG/PC). Moreover, EGCG protected phycocyanobilin against color fading, making PE more stable relative to PC under 8-days storage in light. This study provides a novel scheme to stabilize PC by forming a complex with polyphenols, which will facilitate the PC application as a natural blue pigment in food.

Study on the Intensification of Reaction Kinetics and Reactive Distillation for the Esterification of N-Butyl Acetate Using [HSO3-BMIM][HSO4] as a High-Efficiency Ionic Liquid Catalyst

An ionic liquid (IL) catalyst 1-sulfobutyl-3-methylimidazolium hydrogen sulfate, [HSO3-BMIM][HSO4], was used to produce n-butyl acetate (BuAc) via esterification. A novel modified nonideal homogeneous kinetic model was developed by self-catalysis theory. A new reactive distillation (RD) process using [HSO3-BMIM][HSO4] to produce BuAc was intensified using Aspen simulation taking advantage of phase splitting to increase the ester purity. Various design parameters like reactant feed location, reflux ratio, reactant feed molar ratio, flow ratio of products to materials, and condenser pressure were optimized. Fitting results indicated that modified models presented exact prediction results for the [HSO3-BMIM][HSO4]-catalyzed esterification compared with the unmodified model because the former introduced a revisional term for the self-catalysis of HAc, which revealed the mechanism of self-catalysis and interaction between ILs and reactants. The BuAc purity was increased from 91.05 to 95.02 wt % by the RD process intensification. [HSO3-BMIM][HSO4] showed a higher acid conversion (75%) than commercial ILs and resins. The ester yield was higher when using [HSO3-BMIM][HSO4] as the catalyst than resin A (80.89 wt %) in the intensified RD process. This research provides a novel modified method for the kinetic model in the IL-catalyzed reaction where the modified model exhibited a high accuracy and is useful for improving the production efficiency and controlling the catalyst dosage in the chemical engineering process design. The intensified RD process shows a flexible design for IL application, which is helpful for designing industrial scale-up.

Biotic shortcut deselenization coupled to abiotic sulfide oxidation enabled pollutants co-removal and products recovery

Selenate and sulfide are both contaminants which severely pollute water bodies. Respective bioremediation of selenate- and sulfide-contaminated wastewaters requires abundant electron donors and acceptors. Here, we present a novel concept coupling biological selenate to selenite (shortcut deselenization) and chemical sulfide-driven selenite reduction, to remove multiple pollutants simultaneously. Vial tests showed that shortcut deselenization could save at least two thirds of operation time and one third of carbon source, compared to the complete deselenization to elemental selenium. Subsequent co-removal of sulfide and selenite was optimized at reaction pH of ∼10 and reactant molar ratio of ∼4. Using a newly-designed continuous flow system, >95% removal of both selenate and sulfide was achieved by coupling shortcut deselenization to sulfide oxidation. A series of characterization tools revealed that the final collected precipitates were comprised of high-purity hexagonal selenium (97.4%, wt) and inconsiderable sulfur (2.6%, wt). Superior over selenate-reducing solutions generally producing selenium mixed with reagents or microorganisms, the selenium products generated here were highly purified thus very favorable for further recovery and reuse. Overall, this proof-of-concept study provided a promising technology not only for co-removal of multiple pollutants, but also for substantial costs saving, as well as for valuable products recovery.

Cellulose-zeolitic imidazolate frameworks (CelloZIFs) for multifunctional environmental remediation: Adsorption and catalytic degradation

The crystal growth of zeolitic imidazolate frameworks (ZIFs) on biopolymers such as cellulose is a promising method for obtaining hybrid materials that combinenatural and synthetic materials. Cellulose derivative viz. 2,2,6,6‐tetramethylpiperidine‐1‐oxylradical (TEMPO)-mediated oxidized nanocellulose (TOCNF) was used to modulate the crystal growth of ZIF-8 (denoted as CelloZIF-8) and ZIF-L (CelloZIF-L). The synthesis procedure occurred in water at room temperature with and without NaOH. The reaction parameters such as the sequence of the chemical's addition and reactant molar ratio were investigated. The phases formed during the crystal growth were monitored. The data analysis ensured the presence of zinc hydroxide nitrate nanosheets modified TOCNF during the crystallization of CelloZIFs. These phases were converted to pure phases ofCelloZIF-8 and CelloZIF-L. The resultant CelloZIFs materials were used for the adsorption ofcarbon dioxide (CO2), metal ions, and dyes. The materials exhibited high selectivity with reasonable efficiency (100%) toward the adsorption of anionic dyes such as methyl blue (MeB). They can also be used as a catalyst for dye degradation via hydrogenation with an efficiency of 100%. CelloZIF crystals can be loaded into a filter paper for simple, fast, and selective adsorption of MeB from a dye mixture. The materials are recyclable for five cycles without significant loss of their performance. The mechanisms of adsorption and catalysis were also investigated.

Microwave-assisted lipase-catalyzed synthesis of polyethylene glycol stearate in a solvent-free system

Polyethylene glycol stearate, a condensation esterification product of stearic acid and polyethylene glycol 600, was widely applied in the biomedical and healthcare industries. The current work focuses on the enzymatic synthesis of PEG stearate using CALBex10000, a commercial Lipase enzyme in solvent-free conditions using microwave irradiation. The influence of various reaction parameters such as temperature, molar ratio of reactants, and enzyme loading was studied to obtain the highest conversion. Maximum conversion of 85% was attained under molar ratio 1:1 (PEG 600 to stearic acid using 0.7% (w/w) enzyme loading at 60 ​°C of temperature in 70 ​min of reaction time. Further, the thermodynamic parameters were analyzed and compared with the conventional and ultrasound-assisted synthesis of PEG stearate. The enzyme was recycled up to 5th cycle giving more than 35% of the initial activity.

Thermodynamic calculations for the chemical vapor deposition of hexagonal boron nitride using triethylboron, ammonia, and hydrogen

The presence of C in B(C2H5)3 makes possible its incorporation into hexagonal boron nitride (h-BN) thin films grown during chemical vapor deposition (CVD) under select process conditions. A series of CVD phase diagrams that indicate the regions of stability of the phases of h-BN, C and B4C as a function of temperature and input mole ratio of reactants (N/B) under set pressures and H2 diluent-to-reactant mole ratios (H2/(B + N)) have been calculated and analyzed for the TEB/NH3/H2 system. The equilibrium calculations showed that within the total pressure range of 0.01-100 Torr, increasing the H2 content in the TEB/NH3/H2 gas mixture tends to suppress the stability of C throughout a 400–1600 °C temperature range, but it also suppresses the stability of h-BN at higher temperatures. Further, it was determined that increasing the total system pressure suppresses the occurrence of C as a second phase while expanding the stability of h-BN. The thermodynamic equilibrium results were compared to the results of experimental investigations involving the CVD synthesis of sp2-BN as a means to evaluate their usefulness as a guide for avoiding the co-deposition of C and B4C with h-BN.

Mesoporous nickel-alumina catalysts derived from MIL-53(Al) metal-organic framework: A new promising path for synthesizing CO2 methanation catalysts

A new synthesis route for the preparation of highly efficient and stable porous Ni-based alumina catalysts for CO2 methanation is presented. It is based on the use of MIL-53(Al), an Al-containing metal-organic framework (MOF) with high surface area, as sacrificial support. A series of Ni-Al2O3 powder samples with Ni loadings ranging from 5 to 20 wt% was thus obtained. Their properties were thoroughly characterized by a set of complementary techniques including N2-sorption, X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), CO2 adsorption, temperature programmed reduction (H2-TPR) and transmission electron microscopy (TEM). After nickel impregnation and thermal assisted organic ligands elimination, the resulting Ni-Al2O3 materials appear as interwoven alumina nanosheets in which Ni cations are intimately mixed forming NiAl2O4 spinel nanophases dispersed within amorphous alumina. This nanosheet morphology is preserved after the reduction of the Ni cations that leads to Ni0-Al2O3 catalysts composed of homogeneously and highly dispersed Ni0 nanoparticles, even at the highest 20 wt% Ni content. As a result, the activity in CO2 methanation, evaluated between 250–450 °C under atmospheric pressure, using a constant gas hourly space velocity of 68,900 h−1 and a molar reactant ratio H2/CO2 of 4, increased proportionally with respect to the Ni loading. On the most active catalyst, the selectivity to CH4 was always excellent (between 96 % and 100 %) and the obtained CH4 yield (∼70 % at 300 °C) was about two times higher than on a commercial Ni-based Al2O3 catalyst containing 25 wt% of Ni. The catalytic performances were also better than those of the already reported porous catalysts Ni/USY, Ni/SBA-15 as well as a Ni-Al2O3 synthesized by a EISA one-pot procedure, tested under the same reaction conditions for comparison. In this work the utilization of MIL-53(Al) as starting material for the synthesis of Ni-Al2O3 catalysts was responsible for a peculiar improvement of the metallic dispersion due to the high surface area of this MOF and of the metal-support interaction likely due to the existence of remaining NiAl2O4 at the metal-support interface after reduction. Sintering and agglomeration (the main cause of deactivation) were therefore limited, thus boosting the catalytic performance (activity, selectivity and stability).

Production of biodiesel from oleaginous fungal lipid using highly catalytic bimetallic gold-silver core-shell nanoparticle.

This study aims to synthesize, characterize and apply gold-silver core-shell nanoparticles (Au@Ag NPs), a nanocatalyst, to maximize biodiesel production from fungal isolate Fusarium solani (FS12) via a transesterification one-step reaction. The Au@Ag NPs structure was examined by UV-vis spectrophotometer, transmission electron microscopy, X-ray diffraction and Fourier transform infrared (FTIR). All devices were used to characterize Au@Ag NPs and confirmed successful synthesis of nanoparticles. Fungal lipid was quantitatively determined by sulfo-phospho-vanillin colorimetric method. Among 15 F. solani isolates obtained from rhizospheric soils of the date palm, F. solani (AF12) was chosen as the highly significant producer that accumulates above 20% lipid. The maximum biodiesel yield was 91.28±0.19%, obtained under the optimum reaction conditions of 3% Au@Ag NPs as nanocatalyst concentration, and 1:20 oil to methanol molar ratio at 70℃ for 30min. HPLC method was applied for monitoring in situ transesterification reaction. FTIR spectroscopy was used in qualitative analysis of biodiesel by verifying the presence of unique characteristic peaks of diagnostic significance. The quality of the biodiesel produced was confirmed by the high purity of fatty acid methyl esters analysis content up to >99%. These findings propose the applicability of F. solani (FS12) as a promising isolate to accumulate lipids and biodiesel production as a feedstock. The link between nanotechnology and fungi. Au@Ag NPs were synthesized at room temperature, which displayed high catalytic activity for in situ transesterification reaction. Catalytic activity appeared at low temperature, mole ratio and short reaction time. Oleaginous fungi are described as easily grown, have short life cycle, are cost-effective, and they utilized various sources of carbon up to waste and a simplified process to develop scale-up production as well, economic value, opposite the usage of vegetable oils which need for large agricultural areas.

Sonication pre-treatment for the intensified synthesis of tricaproin using acid-resin catalyst

In this study synthesis of triglyceride of hexanoic acid is investigated with the application of amberlyst-15 as a catalyst in a solvent free reaction mixture with pre-treatment of ultrasonic cavitation. In present research outcome of various reaction parameters like reaction temperature, loading of catalyst and molar ratio of reactant on rate of conversion of reactant is studied. Further ultrasonic pre-treatment parameters like pre-treatment time and duty cycle are studied. During study it is established that the ideal reaction conditions for the maximum conversion of reactant were molar ratio of reactant i.e., glycerol: fatty acid as 5:3, reaction temperature of 140 °C, amberlyst-15 loading of 5%. It is also established that the pre-treatment time of 25 min and 80% duty cycle gave good results. Recyclability of amberlyst-15 is established for 15 cycles of esterification reaction. The study showed that the use of ultrasonic pre-treatment and amberlyst-15 as a catalyst have beneficial effect on rate of conversion of reactant and also have an effect on reduction in reaction time to 07 h as compared to conventional synthesis of triglycerides of hexanoic acid. Maximum conversion of 96% was obtained in 07 h with ultrasonic pre-treatment and amberlyst-15.

Systematic Studies of Sodium γ-Octyl Aspartate to evaluate its Biodegradation, Surface Parameters, Micellization Aspects and Thermodynamic Properties of its Binary Mixture using Electrolytes

γ-octyl aspartate has been synthesized with 46.2% yield. The optimized conditions for esterification of aspartic acid and n-octanol are 24 hours duration and 1:1 molar ratio of reactants (aspartic acid: n-octanol). FT-IR, 1H NMR and CHNS element analysis techniques are used for structure elucidation of γ -octyl aspartate. Surface/ interfacial studies, micellization aspects, thermodynamic parameters, biodegradability and binary salt behaviour of sodium γ-octyl aspartate have been studied. The CMC of synthesized surfactants was 0.0078 mol/L, whereas minimum surface area per surfactant molecule was calculated as 29.49 Å2m2; calculated aggregation number was 34 and micelle radius (r) found to be 1.40 nm. The degree of counter-ion dissociation (α) was determined to be 0.86. Thermodynamic parameter - standard free energy of adsorption (ΔG0ads) was calculated as -18.70 kJ/mol. The shape of micelle of synthesized surfactant was noticed to be spherical but during binary studies in some cases, it was found to be cylindrical. OECD and Winkler’s method were used to determine biodegradation of sodium γ-octyl aspartate found to be 95.1 %.

Oxidative degradation of p-chlorophenol by ferrate(VI): Kinetics, intermediates and pathways

The ability of ferrate(VI) (Fe(VI)) to remove p-chlorophenol (4-CP) during water treatment was evaluated by determining the degradation efficiency, kinetics, stoichiometry, and mechanism. pH and reactants molar ratio significantly affect 4-CP degradation efficiency. The optimal degradation was found to occur at pH 9.20, which coincides closely with pKa value for 4-CP (pKa = 9.38). 4-CP was completely degraded by Fe(VI) at a 5:1 or higher mole ratio. The kinetics of the oxidation of 4-CP by Fe(VI) were studied as a function of pH (7.59–10.96) and temperature (20.0–33.5 °C) using the ABTS method. The reaction of Fe(VI) with 4-CP was found to be first-order with respect to each reactant and second-order overall. The apparent rate constants of the reaction decreased non-linearly from 353.98 ± 10.93 to 5.91 ± 0.94 M−1 s−1 with an increase in pH (7.59–10.96). The pH dependence of the rate constants of the reaction between Fe(VI) and 4-CP was explained by using acid-base equilibrium of Fe(VI) and 4-CP. Four parallel reactions could be considered as plausible reactions between Fe(VI) and 4-CP species, but the reaction between deprotonated Fe(VI) and deprotonated 4-CP was the rate-determining step. Organic chlorine intermediates and chloride ion were identified using HPLC-MS and IC, and the pathways for degradation of 4-CP by Fe(VI) were proposed. The results suggest that Fe(VI) is a promising oxidant for mineralizing hazardous 4-CP to form nontoxic products in water and wastewater treatment.

Continuous production of monoacylglycerol via glycerolysis of babassu oil by immobilized Burkholderia cepacia lipase in a packed bed reactor.

This study investigated the glycerolysis of babassu oil by Burkholderia cepacia lipase immobilized on SiO2-PVA particles in a continuous packed bed reactor. Experiments were conducted in a solvent-free system at 273.15K either in an inert atmosphere or in the presence of cocoa butter to prevent lipid oxidation. The reactor (15 × 55mm) was run at a fixed space time of 9.8h using different molar ratios of babassu oil to glycerol (1:3, 1:6, 1:9, 1:12, and 1:15) to assess the effects of reactant molar ratio on monoacylglycerol productivity and selectivity. Nitrogen atmosphere and cocoa butter were equally effective in inhibiting lipid oxidation, indicating that addition of cocoa butter to glycerolysis reactions may be an interesting cost-reduction strategy. An oil/glycerol molar ratio of 1:9 resulted in the highest productivity (52.3 ± 2.9mgg-1h-1) and selectivity (31.5 ± 1.8%). Residence time distribution data were fitted to an axial dispersion model for closed-vessel boundary conditions, giving a mass transfer coefficient (kc) of 3.4229 × 10-6ms-1. A kinetic model based on elementary steps of the studied reaction was written in Scilab and compared with experimental data, providing standard deviations in the range of 5.5-7.5%.

Microwave irradiation assisted methoxylation of α-pinene using potassium alum [KAl(SO4)2] catalyst

Methoxylation is a reaction to produce of ether compounds using methoxy ions. The α-pinene methoxylation using potassium alum catalyst was carried out using a microwave with power variations of 320, 480 and 640 W, mass of the catalyst 0.3; 0.6 and 0; 9 g, and mole ratio of reactants 1:15, 1:30 and 1:45 mole. Identification of the reaction results was performed using GC, GC-MS and FT-IR. The product obtained in α-pinene methoxylation is mirtenyl methyl ether (MME) and terpinyl methyl ether (TME). The conversion of α-pinene with the variation of 480 W microwave power, mass of catalyst 0.3 g and mole ratio of reactants 1:15 at 120 seconds was 99.82% with the selectivity of MME and TME were obtained 32.0 % and 1.4%, respectively.