a solid state fermentation method was developed for the production of citric acid from date pulp (obtained of date syrup production from the process) by aspergillus niger ptcc 5010. poor yield was obtained when potassium ferrocyanide treated date pulp were used as substrate, but methanol at a 3-4% concentration markedly increased the forma-tion of citric acid from the waste. the optimum range o...

the silica boron sulfuric acid nanoparticles (sbsans) as an efficient heterogeneous solid acid catalyst with both brønsted and lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. this new and efficient methodology has advantages in comparison with currently ...

margarine contains a higher level of unsaturated and trans-fatty acids (tfa) than butter. the aim of this study was to investigate the physicochemical properties of these products in iranian market during storage. physicochemical analyses included fatty acid composition, peroxide and anisidine values, slip melting point (smp), color, chlorophyll content, solid fat content (sfc) and texture anal...

The methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing ofpolyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability ofthe solid acid was investigated for the facile conversion of benzylic alcohols to the unsymmetricalethers with aliphatic alcohols in the presence of the solid acid. Results show that the solid acid isan ap...

Effective conversion of lignocellulosic material as renewable energy source has significant reflection on economic and environmental impact. Diluted acid hydrolysis at optimal condition was used to liberate fermentable sugar. The sorghum stalks, the alkali pretreatment of biomass and hydrolysis in diluted hydrochloric acid were investigated. The hydrolysis reaction was carried out in a 5L react...

quinolines, an important class of potentially bioactive compounds, have been synthesized by treatment of o-aminoarylketones and carbonyl compounds utilizing niobium (v) chloride / polyethylenglycole(nbcl5.peg) and niobium(v)chloride (nbcl5) as available and inexpensive catalysts. the quinoline derivatives were prepared in glycerol, an excellent solvent in terms of environmental impact, with hig...

Palm oil solid wastes consist of cellulose, hemicellulose and lignin. In this study, a single stage of acid hydrolysis process of palm oil empty fruit bunch (EFB) for production of fermentable sugar was carried out under moderate temperature (45°C) and ambient pressure. The effect of four different process variables such as solid size, HCl concentration, solid percentage and temperature were in...

an efficient and simple procedure for the synthesis of 1,8-dioxo-octahydroxanthenes from the aromatic aldehydes and 5,5-dimethylcyclohexane-1,3-dione (dimedone) in the presence of boric acid [bo3h3 or b(oh)3] as an inexpensive and reusable catalyst is described. the salient features of this methodology are: the elimination of corrosive liquid acids, high yields, simple methodology, short reacti...

silica-bonded n-propyldiethylenetriamine sulfamic acid (sbpdsa) was found as an efficient solid acid for the synthesis of coumarins. coumarin derivatives were obtained via the pechmann condensation reaction of phenols and β-keto-esters at 80 oc under solvent-free conditions. also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. t...

sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl]ester (saspspe) is employed as a recyclable catalyst for the silylation of hydroxyl groups. a good range of primary, secondary alcohols and phenolic hydroxyl groups were effectively converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of saspspe at room temperature with short rea...