Development of Hydroprocessing Route to Transportation Fuels from Non-Edible Plant-Oils

Catalysts with tunable porosity, crystallinity and acidity can selectively produce aviation fuels and road transportation fuels via hydroprocessing of non-edible oils. Here we discuss several catalyst supports—mesoporous alumina, silica–alumina and hierarchical mesoporous zeolites, developed and used as support for hydroprocessing catalysts (Ni–Mo, Co–Mo, Ni–W), for the selective production of transportation fuels. These developed catalysts were used for the hydroconversion of waste cooking-oil, jatropha-oil, algal-oil and their mixtures with petroleum refinery oils. The physicochemical properties of the catalyst were tuned for optimal performance on the basis of evaluation results on high pressure fixed bed microreactors and pilot scale reactors. These studies targeted the production of transportation fuels (gasoline, kerosene and diesel) by hydroprocessing (hydrotreating or hydrocracking) renewable feed stocks or co-processing with fossil based oils. Modelling and process optimization studies for prediction of kinetic rate parameters and to know the reaction pathways for the conversion of these feed stocks to various range of hydrocarbon fuels, were also carried out. These studies provided the vital information that the reaction pathways were temperature dependent.     

Asymmetrical flow field-flow fractionation as a novel technique for the analysis of PS-b-PI copolymers

Asymmetrical flow field-flow fractionation (AF4) was used as a fractionation technique to investigate the molecular heterogeneity of poly(styrene-b-isoprene) diblock copolymers synthesized by either sequential living anionic polymerization or coupling of living precursor blocks. AF4 coupled to multi-angle laser light scattering (MALLS), refractive index (RI), and ultraviolet (UV) detectors was used to separate the diblock copolymers from the homopolymers and coupling products, and the molar masses of the different components were analyzed. In order to get more information about the separated block copolymers, homopolymers, and coupling products, fractions were collected directly after the AF4 channel. The collected fractions were analyzed offline by ¹H NMR to provide identification of the different species and additional information on the true chemical composition, and the microstructure of the diblock copolymer was obtained.

A Convenient Route To 1,2-Dibenzoyl-1-Arylethylenes

Short and convenient syntheses of 1,2-cis-dibenzoyl-1-ary 1-ethylenes 5a-e, 6 and 8a-d from the corresponding aryl ethers and dibenzoyl acetylene have been developed using boron trifluoride-etherate or aluminium chloride as catalyst.     

Search of truncation of (N−1) electron basis containing full connected triple excitations in computing main and satellite ionization potentials via Fock‐space coupled cluster approach

A valence‐universal multireference coupled cluster (VUMRCC) theory, realized via the eigenvalue independent partitioning (EIP) route, has been implemented with full inclusion of triples excitations for computing and analyzing the entire main and several satellite peaks in the ionization potential spectra of several molecules. The EIP‐VUMRCC method, unlike the traditional VUMRCC theory, allows divergence‐free homing‐in to satellite roots which would otherwise have been plagued by intruders, and is thus numerically more robust to obtain more efficient and dependable computational schemes allowing more extensive use of the approach. The computed ionization potentials (IPs) as a result of truncation of the (N−1) electron basis manifold involving virtual functions such as 2h‐p and 3h‐2p by different energy thresholds varying from 5 to 15 a.u. with 1 a.u. intervals as well as thresholds such as 20, 25, and 30 a.u. have been carefully looked into. Cutoff at around 25 a.u. turns out to be an optimal threshold. Molecules such as C₂H₄ and C₂H₂ (X = D,T), and N₂ and CO (X = D,T,Q) with Dunning's cc‐pVXZ bases have been investigated to determine all main and 2h‐p shake‐up and 3h‐2p double shake‐up satellite IPs. We believe that the present work will pave the way to a wider application of the method by providing main and satellite IPs for some problematic N‐electron closed shell systems. © 2013 Wiley Periodicals, Inc.     

Speciation of 30 % tri-n-butyl phosphate solvent during extraction of nitric acid

Several solutions of 30 % TBP/n-dodecane were equilibrated with different concentrations of aqueous nitric acid solutions at 298.15 K at a phase ratio of unity. The resultant equilibrated aqueous and organic solutions were analyzed for acidity. A three-solvate model with molecular HNO₃ based mechanism was assumed for nitric acid extraction by TBP. With nonlinear chemometric methods, the coefficients were evaluated. With the set of optimized coefficients, derived on the basis of experiments reported in this work, the estimated solvate species and free-TBP species in the TBP containing organic phase were found to be in good agreement with the reported concentrations in the literature.     

Experimental and Theoretical Studies on Synthesized Compounds as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

Imidazole derivatives, namely, 1-((1-(piperazinomethyl)-1H-benzoimidazol-2-yl)methyl)-2-phenylhydrazine (PBIP), and 1-((1-(morpholinomethyl)-1H-benzoimidazol-2-yl)methyl)-2-phenylhydrazine (MBIP) were synthesized and investigated as inhibitors for mild steel corrosion in 15% HCl solution using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. It was found that the inhibition efficiency of both the inhibitors increases with increase in concentration of inhibitors and decreases with increase in temperature. The inhibitors, PBIP and MBIP, show corrosion inhibition efficiency of 92.6% and 91.4% at 300 ppm concentration, respectively, at 303 K. Polarization studies showed that both the studied inhibitors were of mixed type in nature. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed for surface study of uninhibited and inhibited mild steel samples. The semi-empirical AM1 method was employed for theoretical calculations.     

Ion beam irradiation of ZnS dispersed in PMMA and its photocatalytic application

ZnS nanoparticles implanted with 45 keV O⁵⁺ ion beam exhibited 83.6 % degradation of methyl blue in 2 h. This idea was utilized to fabricate nanocomposite system of ZnS and PMMA where ZnS nanoparticles were immobilized in PMMA film and irradiated with 45 keV O⁵⁺ ion beam at particle fluence of 2.5 × 10¹⁵, 1 × 10¹⁶ and 4 × 10¹⁶ particles/cm². These irradiated batches of ZnS nanoparticle immobilized in PMMA batches revealed formation of porous structure characterized by scanning electron microscopy and these batches exhibited 54 % photocatalytic degradation of methyl blue in 80 min which was higher as compared to the pristine ZnS nanoparticles.     

Effect of hybrid fillers on the mechanical behavior of polypropylene based hybrid composites

The present study investigates the effect of hybrid fillers such as graphene nanoplatelets (GnPs) and Titanium di-oxide (TiO₂) in polypropylene (PP) composites on the mechanical properties. The compatibilizing agent of Maleic anhydride grafted polypropylene (MAPP) are used in the polypropylene based composites to increase the interfacial adhesion between matrix and fillers. The experiments are designed according to L₁₆ orthogonal array (OA) based design of experiments (DOE). The parameters selected for this study are GnPs, TiO₂ and MAPP with four different levels are used.By using Orthogonal array and Taguchi based experimental design, the performance characteristics of tensile modulus, tensile strength, elongation at break and toughness can be analyzed with more objective through a small set of experiments.Taguchi based analysis are used to find out the optimal parameters to maximize the tensile properties for the GnPs and TiO₂ reinforced PP hybrid composites. Further, analysis of variance (ANOVA) is investigated to identify the most significant parameters which influence the mechanical properties.From the analysis it was found that the optimal parameters of 3 ?wt% GnPs, 2 ?wt% TiO₂ and 6 ?wt% MAPP for maximum tensile modulus and tensile strength. The most significant parameter for tensile modulus and tensile strength is GnPs followed by TiO₂ and MAPP according to ANOVA analysis.     

On-Surface Synthesis of Cumulene-Containing Polymers via Two-Step Dehalogenative Homocoupling of Dibromomethylene-Functionalized Tribenzoazulene

Cumulene compounds are notoriously difficult to prepare and study because their reactivity increases dramatically with the increasing number of consecutive double bonds. In this respect, the emerging field of on-surface synthesis provides exceptional opportunities because it relies on reactions on clean metal substrates under well-controlled ultrahigh-vacuum conditions. Here we report the on-surface synthesis of a polymer linked by cumulene-like bonds on a Au(111) surface via sequential thermally activated dehalogenative C−C coupling of a tribenzoazulene precursor equipped with two dibromomethylene groups. The structure and electronic properties of the resulting polymer with cumulene-like pentagon–pentagon and heptagon–heptagon connections have been investigated by means of scanning probe microscopy and spectroscopy methods and X-ray photoelectron spectroscopy, complemented by density functional theory calculations. Our results provide perspectives for the on-surface synthesis of cumulene-containing compounds, as well as protocols relevant to the stepwise fabrication of carbon–carbon bonds on surfaces.