B.L.A. Prabhavathi Devi

A green recyclable SO3H-carbon catalyst derived from glycerol for the production of biodiesel from FFA-containing karanja (Pongamia glabra) oil in a single step.

Simultaneous esterification and transesterification method is employed for the preparation of biodiesel from 7.5% free fatty acid (FFA) containing karanja (Pongamia glabra) oil using water resistant and reusable carbon-based solid acid catalyst derived from glycerol in a single step. The optimum reaction parameters for obtaining biodiesel in >99% yield by simultaneous esterification and transesterification are: methanol (1:45 mole ratio of oil), catalyst 20wt.% of oil, temperature 160°C and reaction time of 4h. After the reaction, the catalyst was easily recovered by filtration and reused for five times with out any deactivation under optimized conditions. This single-step process could be a potential route for biodiesel production from high FFA containing oils by simplifying the procedure and reducing costs and effluent generation.

Biodiesel production from used cooking oil by two-step heterogeneous catalyzed process.

The present study demonstrates the production of biodiesel from used cooking oil containing high free fatty acid by a two-step heterogeneously catalyzed process. The free fatty acids were first esterified with methanol using a 25 wt.% TPA/Nb(2)O(5) catalyst followed by transesterification of the oil with methanol over ZnO/Na-Y zeolite catalyst. The catalysts were characterized by XRD, FT-IR, BET surface area and CO(2)-TPD. In the case of transesterification the effect of reaction parameters, such as catalyst concentration, methanol to oil molar ratio and reaction temperature, on the yield of ester were investigated. The catalyst with 20 wt.% ZnO loading on Na-Y exhibited the highest activity among the others. Both the solid acid and base catalysts were found to be reusable for several times indicating their efficacy in the two-step process.

Preparation of biodiesel from rice bran fatty acids catalyzed by heterogeneous cesium-exchanged 12-tungstophosphoric acids.

Biodiesel synthesis from rice bran fatty acids (RBFA) was carried out using cesium exchanged 12-tungstophosphoric acid (TPA) catalysts. The physico-chemical properties of the catalysts were derived from X-ray diffraction (XRD), Fourier transform infrared (FTIR), temperature programmed desorption (TPD) of NH(3) and scanning electron microscopy (SEM). The characterization techniques revealed that the Keggin structure of TPA remained intact as Cs replaced protons. The partial exchange of Cs for protons resulted in an increase in acidity and the catalysts with one Cs(+) (Cs(1)H(2)PW(12)O(40)) showed highest acidity. Under optimized conditions about 92% conversion of RBFA was obtained. The catalyst was reused for five times and retained of its original activity. Pseudo-first order model was applied to correlate the experimental kinetic data. Modified tungstophosphoric acids are efficient solid acid catalysts for the synthesis of biodiesel from the oils containing high FFA.

Efficient solid acid catalysts for esterification of free fatty acids with methanol for the production of biodiesel

12-Tungstophosphoric acid (TPA) with varying contents supported on SnO2 catalysts was prepared and their efficacy as solid acid catalysts for the esterification of palmitic acid with methanol was investigated. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), temperature programmed desorption (TPD) of NH3, Laser Raman, Brunner–Emmett–Teller (BET) surface area and scanning electron microscopy (SEM) techniques. The esterification activity depends on the amount and dispersion of TPA on SnO2 which in turn relates to the amount of acidity. Among the catalysts, 15 wt% TPA/SnO2 was the most promising one with the highest fatty acid conversion. Further, reaction parameters such as catalyst concentration, methanol to palmitic acid mole ratio and reaction temperature were also optimized. The catalyst was recycled and reused with consistent activity. A pseudo first order model was applied to correlate the experimental kinetic data and kinetic parameters were evaluated. The activation energy of the catalysts is comparable to that of mineral acids and lower than usual solid acid catalysts.

Hydrolysis of biomass using a reusable solid carbon acid catalyst and fermentation of the catalytic hydrolysate to ethanol

Solid acid catalysts can hydrolyze cellulose with lower reaction times and are easy to recover and reuse. A glycerol based carbon acid catalyst developed at CSIR-IICT performed well in acid catalysis reactions and hence this study was undertaken to evaluate the catalyst for hydrolysis of biomass (alkali pretreated or native rice straw). The catalyst could release 262 mg/g total reducing sugars (TRS) in 4h at 140 °C from alkali pretreated rice straw, and more importantly it released 147 mg/g TRS from native biomass. Reusability of the catalyst was also demonstrated. Catalytic hydrolysate was used as sugar source for fermentation to produce ethanol. Results indicate the solid acid catalyst as an interesting option for biomass hydrolysis.

Rice bran lysolecithin as a source of energy in broiler chicken diet

1. Rice bran lysolecithin (RBL) was evaluated in broiler chicken diets. In the first experiment, RBL was included in diet at 0, 0·5, 2, 8 and 32 g/kg and fed to 250 broiler chickens from 0 to 42 d of age. In the second experiment, RBL was fed at 0, 25 and 50 g/kg diet to 405 day-old broiler chickens until 21 d of age, while during the finisher phase (22–35 d of age) chickens receiving each concentration of RBL were given all three concentrations of RBL in a 3 × 3 factorial manner. The diets were isocaloric. 2. Body weight, food consumption and food conversion efficiency were unaffected by feeding RBL, while the weight of pancreas increased at ≥2 g/kg of RBL in diet (experiment 1). In experiment 2, body weight was greater in the chickens receiving RBL at either 25 or 50 g/kg (21 d) and 50 g/kg (35 d of age). At 21 d of age, food consumption was greater at 25 or 50 g RBL/kg diet, while food conversion efficiency improved with 50 g RBL/kg diet. 3. Fat digestibility increased with RBL at 32 g/kg (experiment 1) and ≤25 g/kg (experiment 2). Rice bran lysolecithin increased ready to cook weight at 50 g/kg during starter phase and decreased abdominal fat at 25 and 50 g/kg during finisher phase (experiment 2). Liver and meat fat content were not affected. 4. It is concluded that lysolecithin from rice bran oil could be used as energy supplement in broiler chicken diet.

Selective esterification of aliphatic carboxylic acids in the presence of aromatic carboxylic acids over monoammonium salt of 12-tungstophosphoric acid

Abstract Monoammonium salt of 12‐tungstophosphoric acid [(NH4)H2PW12O40] was found to be a practical and useful heterogeneous catalyst for an efficient and selective esterification of aliphatic carboxylic acids with alcohols in the presence of aromatic carboxylic acids. The heteropoly acid–based heterogeneous catalyst has the advantages of a simple workup procedure, water insolubility, and good activity. IICT Communication No. 040417.

Assessment and comparison of the properties of biodiesel synthesized from three different types of wet microalgal biomass

In recent years, microalgae-based carbon-neutral biofuels (i.e., biodiesel) have gained considerable interest due to high growth rate and higher lipid productivity of microalgae during the whole year, delivering continuous biomass production as compared to vegetable-based feedstocks. Therefore, biodiesel was synthesized from three different microalgal species, namely Tetraselmis sp. (Chlorophyta) and Nannochloropsis oculata and Phaeodactylum tricornutum (Heterokontophyta), and the fuel properties of the biodiesel were analytically determined, unlike most studies which rely on estimates based on the lipid profile of the microalgae. These include density, kinematic viscosity, total and free glycerol, and high heating value (HHV), while cetane number (CN) and cold filter plugging point (CFPP) were estimated based on the fatty acid methyl ester profile of the biodiesel samples instead of the lipid profile of the microalgae. Most biodiesel properties abide by the ASTM D6751 and the EN 14214 specifications, although none of the biodiesel samples met the minimum CN or the maximum content of polyunsaturated fatty acids with ≥4 double bonds as required by the EN 14214 reference value. On the other hand, bomb calorimetric experiments revealed that the heat of combustion of all samples was on the upper limit expected for biodiesel fuels, actually being close to that of petrodiesel. Post-production processing may overcome the aforementioned limitations, enabling the production of biodiesel with high HHV obtained from lipids present in these microalgae.

Green recyclable SO3H-carbon catalyst for the selective synthesis of isomannide-based fatty acid monoesters as non-ionic bio-surfactants

A series of novel isomannide-based fatty acid monoesters 3(a–f) were synthesized by employing a highly active, water resistant and easily recoverable carbon-based solid acid catalyst derived from glycerol. The mannitol was reacted with decanoic, lauric, myristic, palmitic, stearic and oleic acids in the presence of a carbon acid catalyst under solvent free conditions to obtain corresponding isomannide fatty acid monoesters involving in situ dehydration of mannitol to isomannide followed by acylation. The optimized reaction conditions for obtaining isomannide monoesters are: fatty acid to mannitol mole ratio (1 : 1.5), catalyst 20 wt% of mannitol, temperature 180 °C and reaction time of 12 h. The carbon acid catalyst was recovered by filtration and reused for five cycles without losing its catalytic activity. The use of a recyclable solid acid catalyst makes this method more convenient, simple, and cost effective in addition to having a high selectivity with good yields. All the synthesized compounds were further evaluated for their surface active properties such as, critical micelle concentration (CMC), surface tension at the CMC (γCMC), surfactant concentration required to reduce the surface tension of the solvent by 20 mN m−1 (pC20), maximum surface excess (τmax), and the interfacial area occupied by the surfactant molecules (Amin) using surface tension measurements. The micellization (ΔG°mic) and adsorption free energies (ΔG°ads) were calculated. Isomannide monomyristate (3c) and isomannide monolaurate (3b) exhibited superior surface active properties followed by isomannide monopalmitate (3d) compared to other isomannide monoesters.

Total synthesis and antifungal activity of (2S,3R)-2-aminododecan-3-ol.

We report the total synthesis of (2S,3R)-2-aminododecan-3-ol has been achieved starting from commercially available 10-undecenoic acid. The key steps involved are Sharpless asymmetric epoxidation, Miyashitas boron-directed C-2 regioselective azidolysis, generated the asymmetric centers and in situ detosylation and reduction of azido tosylate. The antifungal activity of the synthesized (2S,3R)-2-aminododecan-3-ol was evaluated on several Candida strains and was comparable to miconazole, a standard drug.