Mahesh Varma - Academia.edu (original) (raw)

Papers by Mahesh Varma

Journal of Industrial and Engineering Chemistry, 2015

ABSTRACT Extraction of α-toluic acid from aqueous solution has drawn attention due to its ample r... more ABSTRACT Extraction of α-toluic acid from aqueous solution has drawn attention due to its ample range of biological, antibacterial, analgesic, and virucidal properties. In the present paper, reactive separation of α-toluic acid with tri-n-butyl phosphate dissolved in triglycerides of fatty acids such as castor oil, soybean oil and sunflower oil has been investigated to evaluate the performance of the diluents and extractants in reactive extraction process. The experimental results were presented as overall distribution coefficient (KD), loading factor (ϕ), extraction efficiency (E%), and overall equilibrium constant (Eαβ) and observed in the range of data 4.4-45.7, 0.006-0.066, 81.6-97.9, and 15.1-28.1, respectively. Further relative basicity approach has been extended to represent the experimental results. The model is best suited to experimental results. The use of triglycerides of fatty acids (natural diluents) such as castor oil, soybean oil and sunflower oil can reduce the toxicity up to certain levels. Hence, all three diluents can be used to avoid the toxicity effect.

Chinese Journal of Engineering, 2014

Journal of Chemistry, 2013

ABSTRACT Ginger is of high value and export oriented commodity crop, which plays an important rol... more ABSTRACT Ginger is of high value and export oriented commodity crop, which plays an important role in agricultural sector. Proper drying techniques are required to capitalize this crop. In the present study, the effect of chemical pretreatment of alkaline ethyl oleate on drying behaviour of ginger was investigated and compared with untreated ginger at selected temperatures of 45, 55, and 65°C at a constant air velocity of 1.8 m/s. The drying rate curves showed that drying occurred in falling rate period and the drying times of pretreated ginger were shorter than those of untreated ginger. Thin-layer drying models such as Newton, Page, Modified Page, Henderson and Pabis, and Wang and Singh were evaluated based on statistical criteria. The Page model was found to be a better model for describing the drying kinetics of the ginger. The rehydration capacity of pretreated sample was more than that of untreated sample and increased with drying temperature. The transport of water during drying was temperature dependent and described by Fick’s equation. The effective diffusivity varied from to m2/s and to m2/s with drying temperature for untreated and pretreated ginger slices, respectively.

ABSTRACT In the present paper, experimental data on extractive desulfurization of liquid fuel usi... more ABSTRACT In the present paper, experimental data on extractive desulfurization of liquid fuel using 3-butyl-4-methylthiazolium thiocyanate [BMTH]SCN is presented. The Fourier transform infrared (FTIR), H-1 NMR, and 13C NMR analyses have been discussed for the molecular confirmation of synthesized [BMTH]SCN. Further, conductivity, solubility, and viscosity analyses of [BMTH]SCN were performed. The effects of reaction time, reaction temperature, sulfur compounds, ultrasonication, and recycling of [BMTH]SCN without regeneration on removal of dibenzothiophene from liquid fuel were also investigated. In the extractive desulfurization process, the removal of dibenzothiophene in octane was 81.2% for mass ratio of 1:1 in 30 min at 30 degrees C under the mild reaction conditions. Thiazolium ionic liquids could be reused five times without a significant decrease in activity. Also, the desulfurization of real fuels, multistage extraction was examined. The data and results provided in present paper explore the significant insights of thiazolium based ionic liquids as novel extractant for extractive desulfurization of liquid fuels.

Procedia Engineering, 2013

ABSTRACT Ionic Liquids (ILs), a new class of green solvents, have recently been undergoing intens... more ABSTRACT Ionic Liquids (ILs), a new class of green solvents, have recently been undergoing intensive research on the removal of thiophenic sulfur species (e.g., dibenzothiophene) from liquid fuels because of the limitations of the tradition hydrodesulfurization process in removing these species. In this work, deep extractive desulfurization of liquid fuels by different ionic liquids are studied and employed as promising extractants for the model liquid fuel containing dibenzothiophene (DBT). 1-butyl-3-methylimidazolium chloride [Bmim]Cl was the most promising and novel ionic liquid and performed the best among the studied ionic liquids under the same operating conditions. It can remove dibenzothiophene from the liquid fuel in the single stage extraction process with the maximum desulfurization efficiency 77.15% under mild reaction conditions. It was also found that [Bmim] Cl can be reused without regeneration with considerable extraction efficiency.

International Journal of Hydrogen Energy, 2014

Industrial & Engineering Chemistry Research, 2015

Journal of Energy, 2013

ABSTRACT A new class of green solvents, known as ionic liquids (ILs), has recently been the subje... more ABSTRACT A new class of green solvents, known as ionic liquids (ILs), has recently been the subject of intensive research on the extractive desulfurization of liquid fuels because of the limitation of traditional hydrodesulfurization method. In present work, eleven Lewis acid ionic liquids were synthesized and employed as promising extractants for deep desulfurization of the liquid fuel containing dibenzothiophene (DBT) to test the desulfurization efficiency. [Bmim]Cl/FeCl3 was the most promising ionic liquid and performed the best among studied ionic liquids under the same operating conditions. It can remove dibenzothiophene from the model liquid fuel in the single-stage extraction process with the maximum desulfurization efficiency of 75.6%. It was also found that [Bmim]Cl/FeCl3 may be reused without regeneration with considerable extraction efficiency of 47.3%. Huge saving on energy can be achieved if we make use of this ionic liquids behavior in process design, instead of regenerating ionic liquids after every time of extraction.

Ultrasonics sonochemistry, Jan 20, 2015

The present study estimates the prediction capability of response surface methodology (RSM) and a... more The present study estimates the prediction capability of response surface methodology (RSM) and artificial neural network (ANN) models for biodiesel synthesis from sesame (Sesamum indicum L.) oil under ultrasonication (20kHz and 1.2kW) using barium hydroxide as a basic heterogeneous catalyst. RSM based on a five level, four factor central composite design, was employed to obtain the best possible combination of catalyst concentration, methanol to oil molar ratio, temperature and reaction time for maximum FAME content. Experimental data were evaluated by applying RSM integrating with desirability function approach. The importance of each independent variable on the response was investigated by using sensitivity analysis. The optimum conditions were found to be catalyst concentration (1.79wt%), methanol to oil molar ratio (6.69:1), temperature (31.92°C), and reaction time (40.30min). For these conditions, experimental FAME content of 98.6% was obtained, which was in reasonable agreeme...