Comparison of Material Activity and Selectivity in the Electrocatalytic Oxidation of Dibenzothiophene

There is an increasing demand for efficient methods to remove sulfur from oil products, such as oxidative desulfurization. In this work, a set of five materials (gold, glassy carbon, nickel, palladium and platinum) were evaluated as electrochemical catalysts for the oxidation of dibenzothiophene (DBT). Bulk electrolysis performed without water present, produced DBT dimer, while the addition of 2 M water, produced dibenzothiophene sulfoxide (DBTO), both more polar than DBT. LC-MS and NMR were used to characterize the oxidation products. Faradaic efficiencies ranged from 18.4–56.5% for DBT consumption without water present, and there was a correlation between higher rate constants, lower activation energies and more efficient DBT oxidation. With water present, selectivity for DBTO formation was highest using gold, with a Faradaic efficiency of 87.9%. Group ten metals demonstrated low Faradaic efficiencies due to competitive water oxidation. Though there were differences in the observed selectivity for DBT oxidation, all catalysts reduced the concentration of DBT in solution by similar amounts. Our findings indicate that the overall percent conversion does not give a complete picture of catalytic activity. Of the materials tested, gold was the most selective for oxidation to DBTO, with the presence of water improving the overall reaction activity.

Catalytic Effects of the New Schiff Base Metal Complexes on the Conversion of Benzyl Alcohol to Benzaldehyde and Benzoic Acid

In this study, two new salicylidene hydroxyl ligands (HL1 and HL2) and their metal complexes (Cu2+, Mn2+, Fe3+, Ru3+, Cr3+, and VO2+) were synthesized and characterized by the spectroscopic and analytical methods. The molecular structure of the ligand HL1 was determined by a single-crystal X-ray diffraction study. Catalytic effects of the Schiff base metal complexes on benzyl alcohol were investigated in the H2O2 medium. In this oxidation reaction, the percent conversion of benzyl alcohol to benzaldehyde and benzoic acid was determined as %benzaldehyde and %benzoic acid by the gas chromatography (GC) method. Finally, the synthesized metal complexes found the highest catalytic effect that Co and Mn metal complexes 97-98% benzyl alcohol conversion. And maximum %benzoic acid formation is seen in MnL1 (39%) and VOL1 (58%) metal complexes.

Synthesis and Characterization of Hyperbranched and Organosilicone Modified Waterborne Polyurethane Acrylates Photosensitive Resin

A new type of waterborne polyurethane acrylate was synthesized for use as a UV curing coating. The N,N-dihydroxy methyl ethyl-3-Methyl aminopropanoate monomer was first prepared via adding reactions of methyl acrylate and diethanol amine with methyl alcohol as the solvent. Then, the hyperbranched prepolymer was obtained by addition of trimethylolpropane with toluenesulfonic acid as catalyst and N,N-dimethyl formamide as solvent. The resulting hyperbranched and organosilicone modified waterborne polyurethane acrylates was synthesized through the mixed reaction of prepolymer and Hydroxy silicone oil, polyethylene glycol-1000, toluene diisocynate, dimethylolpropionic acid, 1,2-propylene glycol, hydroxyethyl acrylate, and triethylamine with dibutyltin dilaurate as the catalyst. The molecular structures were characterized by FT-IR and 1H NMR spectroscopy and GPC analysis and the thermal stability was studied by using TGA. Moreover, the influence of contemodnt of hydroxyl silicone oil, dimethylolpropionic acid, polyethylene glycol-1000, and prepolymer to various of properties such as glossiness, hardness, adhesive force, abrasion resistance, water absorption, elongation at break and tensile strength of films were analyzed. The temperature and catalyst dosage impact on percent conversion of isocyanate group (–NCO) were also studied. It was proven that the best dosage of hydroxyl silicone oil and dimethylolpropionic acid were 4.6%, the dosage of polyethylene glycol-1000 was 50%, and the amount of hyperbranched prepolymer was 0.5%, which could make the film achieve the optimum properties. The percent conversion of isocyanate group (–NCO) was maximum when reacting two hours at 80 °C with 0.2% catalyst.

Concurrently Produce a Novel High-Potency Sweetener (Glycyrrhetic Acid 3-O-Mono-β-D-glucuronide) and Lignocellulolytic Enzymes using Plant Entophytic Chaetomium Globosum DX-THS3 by Solid-State Fermentation

Licorice straw was used for the first time as a medium for glycyrrhetic acid 3-O-mono-β-D-glucuronide (GAMG) and lignocellulosic enzyme production via solid-state fermentation (SSF) of endophytic fungus Chaetomium globosum DX-THS3. Under optimal fermentation conditions, the percent conversion of glycyrrhizin reached 90% in 15 days, whereas the control needed 35 days to achieve the same result. The productivity of optimization (P=2.1 mg•g-1•day-1) was 2.33-fold that of non-optimization (P=0.9 mg•g-1•day-1). Meanwhile, high activities of filter paper enzyme (FPase) (234.6 U/g), carboxymethyl cellulase (CMCase) (29.25 U/g), xylanase (72.52 U/g), and β-glucuronidase activity (264.17 U/g) were obtained faster than those in the control during SSF. Our study provides a novel and efficient strategy for GAMG production and indicates C. globosum DX-THS3 as a potential producer of lignocellulolytic enzymes.

Paper Mill Sludge as a Source of Sugars for Use in the Production of Bioethanol and Isoprene

Paper mill sludge (PMS) solids are predominantly comprised of cellulosic fibers and fillers rejected during the pulping or paper making process. Most sludges are dewatered and discharged into landfills or land spread at a cost to the mill; creating large economic and environmental burdens. This lignocellulosic residual stream can be used as a source of sugars for microbial fermentation to renewable chemicals. The aim of this study was to determine the possibility of converting mill sludge to sugars and then fermentation to either isoprene or ethanol. Chemical analysis indicated that the cellulosic fiber composition between 28 to 68% and hemicellulose content ranged from 8.4 to 10.7%. Calcium carbonate concentration in the sludge ranged from 0.4 to 34%. Sludge samples were enzyme hydrolyzed to convert cellulose fibers to glucose, percent conversion ranged from 10.5 to 98%. Calcium carbonate present with the sludge resulted in low hydrolysis rates; washing of sludge with hydrochloric acid to neutralize the calcium carbonate, increased hydrolysis rates by 50 to 88%. The production of isoprene “very low” (190 to 470 nmol) because the isoprene yields were little. Using an industrial yeast strain for fermentation of the sludge sugars obtained from all sludge samples, the maximum conversion efficiency was achieved with productivity ranging from 0.18 to 1.64 g L−1 h−1. Our data demonstrates that PMS can be converted into sugars that can be fermented to renewable chemicals for industry.

Effect of Urea Fertilizer on the Biochemical Characteristics of Soil

Urea-potash mixture was added to the manured soil at three different concentrations equivalent to 0.8, 1.6 and 2.4g f urea per 10Kg of soil. Nitrate and nitrite N concentration in the soil increased within 24h after addition of urea. The nitrate N content in soil without urea was 17 µg and in urea fertilized soils, it ranged from 39.9-47 µg/g of soil after 19h. . Increase in total mineralizable N was around 67- 160% in urea fertilized soils in comparison to the control. Percent conversion of urea to nitrate and nitrite N decreased at higher concentrations of the fertilizer. Addition of biochar to urea amended soil did not bring about significant change in the available N content. Decrease in total mineralizable N and accumalation of available P was observed over the period of 15 days. Addition of urea resulted in acidification of the soil. Acidification of the soil could be correlated with increase in acid phosphatase concentration. The soil amended with biochar exhibited significant buffering capacity in the region of pH 7.4-9. Int. J. Appl. Sci. Biotechnol. Vol 7(4): 414-420

Oxidative Desulfurization of Dibenzothiophene Using Dawson Type Heteropoly Compounds/Tantalum as Catalyst

Catalyst (NH4)6[b-P2W18O62]/Ta has been synthesized by simple wet impregnation at 30-40 °C under atmospheric conditions using Dawson type polyoxometalate (NH4)6[b-P2W18O62] and tantalum. The catalyst was characterized by FTIR spectrophotometer, XRD, SEM, and N2 adsorption desorption methods. FTIR spectrum of (NH4)6[b-P2W18O62]/Ta showed that Dawson type polyoxometalate (NH4)6[b-P2W18O62] and Ta was successfully impregnated which was indicated by vibration spectrum at wavenumber of 900-1100 cm-1 for polyoxometalate and 550 cm-1 for Ta. The surface area of the (NH4)6[b-P2W18O62]/Ta after impregnation was higher than (NH4)6[b-P2W18O62]•nH2O and its morphology was found to be uniform. The catalytic activity of (NH4)6[b-P2W18O62]/Ta toward desulfurization of dibenzothiophene was three times higher than the original catalyst of (NH4)6[b-P2W18O62]•nH2O without impregnation. The catalytic regeneration test of catalyst (NH4)6[b-P2W18O62]/Ta showed that the catalytic activity for first regeneration of catalyst has similar catalytic activity with the fresh catalyst without loss of catalytic activity indicated by almost similar percent conversion.

OPTIMASI SINTESIS BIOSURFAKTAN LAURIL AMIDA DARI ASAM LAURAT DAN DIETANOLAMINA MENGGUNAKAN PELARUT HEXANE DAN ENZIM LIPASE TERIMOBILISASI

Lauril amide is one of nonionic surfactant and has potency to become an ecofriendly surfactant. The main problem on lauril amide synthesis is the low conversion of lauric acid. Optimation of lauril amide synthesis is done with three variabels which give influence of amidation reaction. One stage amidation was done by reacting lauric acid with diethanolamine using catalyst Novozyme 435® with substrate ratio lauric acid:diethanolamine 1:1; 2:1; 3:1; 4:1; 5:1, amount of catalyst 1,8; 4; 7; 10; 11,8% from lauric acid total amount, solvent ratio 0; 1:1; 2:1; 3:1; 4:1 from lauric acid total amount and reacted for 24 hours with temperature reaction 55oC and 500 rpm. Product is separated from catalyst using filtration method and then purified by washing with acetone and heated at temperature of 90 oC to remove solvent. Product has been analyzed with acid value to obtained percent conversion of lauril amide, determine of Hydrophilic Liphophilic Balance value, spectroscopy Fourier Transform Infrared and determine of critical micelle concentrasion. Percent conversion optimum has obtained 86,16% at condition substrate ratio 1:1, enzyme concentration Novozyme 435® 7% and solvent ratio 2:1. Analysis result of lauril amide surfactant gave the hidrophile liphophile balance value about 11,93, it means that lauril amide surfactant can be used as emultion oil in water.

Effect of Ferocene Concentration on the Percent Conversion and Molecular Weight of Poly(Methyl Methacrylate) Homopolymers

This research is addressing the effect of different ferrocene concentration (0.00, 2.15x10-3, 4.30x10-3, 8.60x10-3, and 12.9x10-3) on the bulk free radical polymerization of methyl methacrylate monomer in benzene using benzoyl peroxide as initiator. The polymerization was conducted at 60º C under free oxygen atmosphere. The resulting polymers were characterized by FTIR. The results were compared with the presence and absence of ferrocene at 10% conversion. The %conversion was 3.04% with no ferrocene present in the polymerization medium and its increase to 9.06 with a first lowest ferrocene concentration added, i.e. 2.15 x10-3mol/l. This was positively reflected on the poly(methyl methacrylate) molecular weight measured by viscosity technique, especially in the presence of ferrocene.