Atanu K Paul | National Institute of Technology Andhra Pradesh (original) (raw)

Papers by Atanu K Paul

Fuel, 2023

As petroleum recovery has progressed historically, the portion of heavier crudes and bottom of th... more As petroleum recovery has progressed historically, the portion of heavier crudes and bottom of the barrel residues from the refining process has increased. These crudes are challenging to process, leaving vacuum residues with large fractions of ash and refractory sulfur due to high asphaltene content. Asphaltenes are known to form coke in catalytic upgraders and deactivate refining catalysts. Asphaltenes, which are present in significant amounts in heavy crudes, are the cause of reduction of combustion efficiency, clogging of refinery pipes, and particulate matter emissions. Asphaltenes can be removed from heavy crudes by solvent deasphalting. But the requirement of a high solvent to oil ratio limits its commercial viability. To lower the requirement of solvent, this study investigates deasphalting of heavy fuel oil (HFO) with n-heptane, n-hexane, and n-pentane by microwaveassisted, ultrasound-assisted, and supercritical solvent deasphalting methods. Among the different methods investigated, the microwave-assisted method was found to be more efficient and removed 88 and 80 wt% of asphaltenes from HFO with heptane and hexane, respectively. Microwave irradiation selectively heats asphaltenes in microwave transparent non-polar solvents and increases the degree of collision of asphaltenes for aggregation and thus precipitation. Besides, resins are readily solubilized by the solvent under microwave heating and thus they are unable to act as peptizing agents of asphaltenes. The optimization of process parameters such as solvent to HFO ratio, microwave power, and holding time was investigated for microwave-assisted deasphalting using Central Composite Design (CCD) and artificial neural network (ANN). The optimum removal of asphaltene was observed when the solvent to HFO ratio, microwave power, and holding time were kept at 3, 150 W, and 20 min, respectively. Deasphalting also significantly improved the quality of HFO by dropping the viscosity along with the sulfur and nitrogen contents of HFO. The outcomes of this study are significant for the petrochemical industry as potentially improved crude oil processing with lower solvent to HFO ratios can be achieved in a more effective, economical manner using microwave assistance.

Journal of Thermal Analysis and Calorimetry, 2017

Oilseed crop with high oil content and promising ecological adaptability are potential sources fo... more Oilseed crop with high oil content and promising ecological adaptability are potential sources for competitive biodiesel production. This study investigates the scope of utilizing biodiesel development through the methyl and ethyl ester from soybean and mustard oil as an alternative fuel. Methyl and ethyl esters of oils having different fatty acids compositions such as soybean (SOME and SOEE) and mustard oil (MUME and MUEE) were prepared by transesterification with methanol and ethanol in the presence of an alkali-KOH catalyst. The gas chromatographic (GC) analysis of oil samples revealed that primary fatty acid composition in soybean oil was linoleic acid (C 18:2 , 51.93%), followed by oleic acid (C 18:1 , 22.82%), palmitic acid (C 16:0 , 11.56%), linolenic acid (C 18:3 , 5.95%) and stearic acid (C 18:0 , 4.32%). Whereas, the main components in mustard oil were erucic acid (C 22:1 , 32.81%), oleic acid (C 18:1 , 24.98%), eicosenoic acid (C 20:1 , 10.44%), linolenic acid (C 18:3 , 8.61%) and palmitic acid (C 16:0 , 2.80%). The physicochemical properties (acid value, iodine value, calorific value, flash point, pour point etc.) of methyl and ethyl ester samples were estimated and found to be within the acceptable range of ASTM D6751 standards specifications. The prepared esters and oil samples were examined for cold flow properties by differential scanning calorimetry (DSC). Results revealed better cold flow properties for MUME (-2.55°C) and MUEE (-3.10°C) than SOME (3.21°C) and SOEE (1.83°C) due to more unsaturated fatty acid content in MU. Thermal and oxidative stability of samples was determined by thermogravimetric analysis (TG) and differential thermal analysis (DTA). The thermal and oxidative stability ranking of the samples was in the order of oil [ methyl esters [ ethyl esters.

Synthesis of waste cooking oil (WCO) based lubricant basestock was prepared via epoxidation, usin... more Synthesis of waste cooking oil (WCO) based lubricant basestock was prepared via epoxidation, using sulfuric acid (SA) as a homogeneous acid catalyst. Response surface methodology (RSM) was adopted as an optimization tool to study and optimize the effects of reaction variables on maximum oxirane oxygen content (OOC) of the epoxidised WCO. Interaction of the process parameters, such as hydrogen peroxide to ethylenic unsaturation molar ratio, catalyst loading (wt%) and reaction time (h) was examined by ANOVA using Design expert software (DOE, version 7.0.1). The optimum OOC of epoxidised WCO was found to be 4.7 mass% under the experimental conditions of 60°C, 6 h of reaction time, 1.5 g of catalyst loading and 1:2 molar ratio of C=C bonds/ H2O2. The product was confirmed by FTIR, 1H/13C-NMR, and OOC. Thermo-oxidative stability was found by thermo gravimetric analysis (TGA) and cold flow behavior of the end product was estimated by differential scanning calorimetry (DSC). Significant physico-chemical properties of the prepared lubricant basestock was evaluated at optimum condition using standard methods. Further, ANN modeling was carried out by using identical data set. The results of the study revealed that the chemically modified WCO derivatives also can act as potential biolubricant basestock.

In the present study chemical modification of glutinous rice starch was carried out using 1-Buatn... more In the present study chemical modification of glutinous rice starch was carried out using 1-Buatnol-hydrochloric acid with varying time and temperature. The changes in physico-chemical, dynamic rheological and morphological properties of starch during hydrolysis was investigated. There was a significant increase in water solubility of starch due to modification; however, swelling and sedimentation value decrease after modification. The peak, hold and final viscosity of modified starches were decreased significantly as compared to native starch. Thermal properties and dynamic rheological properties of rice starch were changed with the change in time and temperature during modification. The storage (G) modulus, loss (G) modulus, dynamic viscosity () and complex viscosity (*) of modified starches were varied significantly. Analysis of microstructure revealed that the hydrolysis altered morphology of starch granules. The hydrolysis was affected the surface properties and granule size of rice starch. These results suggested that 1-butanol–HCl hydrolysis of glutinous rice starch can be a preferred way of modification.

The present study aims to maximize the conversion of microalgae oil to fatty acid methyl ester (F... more The present study aims to maximize the conversion of microalgae oil to fatty acid methyl ester (FAME) using supercritical methanol (SCM) transesterification by sequential hybrid optimization using response surface methodology (RSM), artificial neural network (ANN) and genetic algorithm (GA). The three process parameters selected for the optimization of SCM transesterification were temperature (240 to 300 °C), time (15 to 45 min) and MeOH: oil molar ratio (15:1 to 45:1). Initial experiments performed according to the central composite design (CCD) generated matrix of RSM and further validated by ANN. The 1 H-NMR analysis confirms the formation of methyl esters. Moreover, the corresponding regression coefficient (R 2) for the model were 0.97 and 0.99 for RSM and ANN, respectively indicated excellent fit of the model to the experimental data. Furthermore, the final optimized condition for FAME conversion efficiency of RSM and ANN predicted models were 98.01% and 98.15%, respectively. The fitness function for GA was obtained from ANN predicted model equations and presented as globally optimized (GA conditions) reaction conditions for SCM: temp-285.21 °C, time-26.57 min and MeOH: oil molar ratio – 23.47. The predicted percent conversion efficiency of GA optimized conditions was 99.16% whereas, the experimental optimum FAME conversion reached to 98.12%. Additionally, the gas chromatography mass spectroscopy (GCMS) analysis revealed the presence of palmitic (28%), oleic (33%), linoleic (8%) and other saturated and unsaturated fatty acids. The other biodiesel properties such as acid value, iodine value, cetane number, calorific value, etc. were also analyzed and exhibited an analogous trend with standard ASTM D6571 standards.

The present study deals with the performance and emissions of conventional diesel fuel and biodie... more The present study deals with the performance and emissions of conventional diesel fuel and biodiesel produced from waste cooking oil and their blends (B10, B15). The waste cooking oil methyl esters synthesis has been (WCOME) carried out by a single step alkali catal-ysed transesterification reaction. Significant physico-chemical properties have been measured and compared against the ASTM D6751 standards. The tests have been performed on a single cylinder, direct injection diesel engine at a constant speed 1500 ± 50 rpm. During the tests, brake thermal efficiency, specific fuel consumption, exhaust gas temperature, exhaust emissions are measured. The experimental results revealed that, relative to diesel, WCOME fuel blends show 1.7–4.14 % decrease in the brake thermal efficiency and 2.18–5.57 % increase in the brake specific fuel consumption due to higher density and kinematic viscosity of WCOME, which reduces the fuel atomization rate. Moreover, most of the constituents of exhaust gas such as CO (13.67–16.89 %) and HC (4.35–11.84 %) along with greenhouse gas such as CO 2 (8.34–17.39 %) are reduced in case of all the blends. However, an increase in the NOx emissions (0.3–4.2 %) is mainly due to the higher cetane number of fuel blends, which decreases the ignition delay. The results of this study revealed that WCOME blends show fewer exhaust emissions with a little compromise in the performance of the engine.

Oilseed crop with high oil content and promising ecological adaptability are potential sources fo... more Oilseed crop with high oil content and promising ecological adaptability are potential sources for competitive biodiesel production. This study investigates the scope of utilizing biodiesel development through the methyl and ethyl ester from soybean and mustard oil as an alternative fuel. Methyl and ethyl esters of oils having different fatty acids compositions such as soybean (SOME and SOEE) and mustard oil (MUME and MUEE) were prepared by transesterification with methanol and ethanol in the presence of an alkali-KOH catalyst. The gas chromatographic (GC) analysis of oil samples revealed that primary fatty acid composition in soybean oil was linoleic acid (C 18:2 , 51.93%), followed by oleic acid (C 18:1 , 22.82%), palmitic acid (C 16:0 , 11.56%), linolenic acid (C 18:3 , 5.95%) and stearic acid (C 18:0 , 4.32%). Whereas, the main components in mustard oil were erucic acid (C 22:1 , 32.81%), oleic acid (C 18:1 , 24.98%), eicosenoic acid (C 20:1 , 10.44%), linolenic acid (C 18:3 , 8.61%) and palmitic acid (C 16:0 , 2.80%). The physicochemical properties (acid value, iodine value, calorific value, flash point, pour point etc.) of methyl and ethyl ester samples were estimated and found to be within the acceptable range of ASTM D6751 standards specifications. The prepared esters and oil samples were examined for cold flow properties by differential scanning calorimetry (DSC). Results revealed better cold flow properties for MUME (-2.55 °C) and MUEE (-3.10 °C) than SOME (3.21 °C) and SOEE (1.83 °C) due to more unsaturated fatty acid content in MU. Thermal and oxidative stability of samples was determined by thermogravimetric analysis (TG) and differential thermal analysis (DTA). The thermal and oxidative stability ranking of the samples was in the order of oil [ methyl esters [ ethyl esters.

The rheological properties of oil depends on many factors that include shear rate, shear stress, ... more The rheological properties of oil depends on many factors that include shear rate, shear stress, temperature, chemical properties, concentration, time, pressure, additive or surfactants and catalyst. Vegetable oil viscosity studies have generally focused on the non-food application especially lubrication and biodiesel industry. In these studies it has been tried to develop a Rheological models, to the use of oils to substitute as diesel fuel or bio lubricant. Rheological properties of oils (or Vegetable oil) are also significant in the view of nutrition and food process. The fundamental parameter, obtained in the rheological study was viscosity, used to characterize the fluid texture. In common vegetable oils are made up of 98% triglycerides while the remaining 2% consists of phospholipids and different types of hydrocarbons. The viscosity of oils is directly related to the level of unsaturation and the length of the fatty acid chains. The viscosity tends to decrease when there is an improvement in terms of number of double bonds and grows with an increase in the length of the hydrocarbon chain and according to the level of polymerisation in the oil. This work has the objectives of evaluating the rheological behaviour of Waste Cooking Oil (WCO). The properties of oil samples were determined using Interfacial Rheometer (Anton-Paar Model: MCR 301) by varying temperature from 25-80°C and shear rate range of 0.1-100 s-1. Rheological behaviour was also studied for Waste Cooking Oil Methyl Ester (WCOME) and its Blends (5%, 10% and 15%). It was observed from the experimental study that the WCOME has less viscosity than WCO and the values in descending order as sequentially were WCO (26.813 mPa-s), WCOME (2.686 mPa-s), 15% WCOME Blend (1.784 mPa-s), 10% WCOME Blend (1.676 mPa-s), 5% WCOME Blend (1.526 mPa-s) and pure diesel (1.212 mPa-s) at 40°C. The temperature also has effect on the viscosity of WCO and it was observed that upon increasing temperature, viscosity decreases gradually. In this study it was also found that WCO, it’s ME and blends follows Newtonian behaviour (Power law index, n varies from 0.90997 to 0.99995) in the range of 0.1-100 s-1 shear rate.

An attempt has been made in the present study to explore the effectiveness and dosages of Dodecyl... more An attempt has been made in the present study to explore the effectiveness and dosages of Dodecyl Benzene Sulfonic Acid Sodium Salt Purified, {C18H29NaO3S}(DBSA) as an additive on the rheological characteristics of Coal Water Slurry (CWS). Coal Water Slurry (CWS) having four different sized coal particle namely, i) -355 μm+300 μm ii) -300 μm.+250 μm iii) -250 μm +212 μm & iv) -212 μm+180 μm of different solids concentration (35wt. %, 40 wt. % & 45 wt. %) were prepared to study the rheological characteristics by using Bohlin CVO 100 Rheometer . To study the effectiveness and optimum dosages of additive on the rheology of CWS, six different weight percentage of DBSA (0.25, 0.5, 0.75, 1.00, 1.25 & 1.5 weight %) were used. From this study we showed that 0.75 wt.% DBSA can be most effective choice having minimum viscosity resulting the minimum frictional head loss.

It is now known to all that calcium silicate brick popularly known as fly ash sand-lime brick is ... more It is now known to all that calcium silicate brick popularly known as fly ash sand-lime brick is a promising alternative material in place of red clay bricks. Not only it has better compressive strength but also has necessary resistance to the effect of alkaline soil and salinity. Similarity in areas where the weathering effects are prominent such as sea-shore, alkaline soils and waste lands, this brick is the ideal for making building. The fly ash bricks can be used conveniently by PWD, CPWD, Housing Boards, Government Buildings and in other Constructional Activities. In spite of its various advantages it is not accepted in the construction field. In this paper the characteristics of fly ash bricks and the reasons for which it is not widely accepted have been described.

Thesis Chapters by Atanu K Paul

Inverse fluidization is a technique in which solid particles having lower density than that of th... more Inverse fluidization is a technique in which solid particles having lower density
than that of the liquid are kept in suspension by the downward flow of continuous liquid
phase. Inverse fluidization has several advantages such as high mass transfer rates due to
reduced film thickness resulting from rotation due to low inertia, minimum carry over of
coated microorganisms due to less solids attrition, efficient control of bio-film thickness
and ease of re-fluidization in case of power failure. These significant advantages found
many applications of inverse fluidized beds in biochemical processes like ferrous iron
oxidation and aerobic and anaerobic biological wastewater treatment like treatment of
wine distillery wastewater. Even though, the applications of the inverse fluidized bed
technique to industrial processes are fast growing, much information on hydrodynamics,
mass transfer and chemical reaction is not yet available. Two phase (liquid – solid)
inverse fluidized beds are used for anaerobic biological processes due to their high mass
transfer potential.
The studies on the hydrodynamics and mass transfer of two-phase inverse
fluidization were performed only in the last few decades one of the most important recent
applications of inverse fluidized beds is in the field of bioreactor engineering. Inverse
fluidization is used in biotechnology as the basics of a new type of bioreactor, the so
called inverse fluidized bed bioreactor are among the most efficient application for
aerobic and anaerobic wastewater treatment Penicillin Production and Phenol
degradation.
The inverse fluidization system gained significant importance during the last few
decades in the field of environmental, biochemical engineering, and oil water separation.
The hydrodynamics of the inverse fluidization have been studies by Karamanev
and Nikolov (1996), Ulaganathan and Krishnaiah (1996), Ramos et al. (1998), Banerjee
et al. (1999), Vijaya Lakshmi et al. (2000), and Renganathan and Krishnaiah (2003, 2004,
2007) using water-solid system. They proposed empirical correlations to predict the
minimum inverse fluidization velocity. Fan et al. (1982), Karamanev and Nikolov (1992),
Biswas and Ganguly (1997), Bendict (1998), Lee (2001), Renganathan and Krishnaiah
(2005) reported the bed expansion characteristics in two phase downward fluidization
and predicted their bed expansion data in terms of Richardson and Zaki equation.
It is very much essential to study on hydrodynamic characteristics such as
pressure drop and minimum inverse fluidization velocity for successful analysis, design
and operation of inverse fluidization bed.
Experiments will be carried out using four polyethylene particles having different
densities, different diameter and sphericity with different concentrated aqueous solutions
of SCMC as fluidizing liquid. Minimum fluidization velocity will be estimated from the
experimental data. An empirical correlation will be developed for the minimum
fluidization velocity as a function of physical and dynamic variables of the system.

The aim of this study was to understanding of the effect of additives onrheology of coal.water sl... more The aim of this study was to understanding of the effect of additives onrheology of
coal.water slurries (CWS) of different concentrations. Experiments have been carried
out on the coal samples that were taken from Durgapur Steel Plant (DSP / SAIL). In
addition to the determination of the physico-chemical properties of the coal samples,
their proximate analysis was done. The pulps of different solids percentage (35wt. %,
40 wt. % & 45 wt. %) composed of coal particles were used to determine the effect of
solid weight percentage on the viscosity of the slurry. Four different sized coal
particle were prepared for this study, i) -44+52 Mesh (-355 ƒÊm+300 ƒÊm), ii) -52+60
Mesh (-300 ƒÊm+250 ƒÊm), iii) -60+72 Mesh (-250 ƒÊm +212 ƒÊm) & iv) -72+85 Mesh
(-212 ƒÊm+180 ƒÊm). The Sieves are Standard BS-410 MESH. The effect of additives
(Dodecyl Benzene Sulfonic Acid Sodium Salt Purified, C18H29NaO3S) on the
viscosity of coal water slurry was studied. Six different weight percentage of DBSA
(0.25, 0.5, 0.75, 1.00, 1.25 & 1.5 wt %) were prepared to show the effect on viscosity
on different slurry concentrations of CWS. It was shown that 0.75 wt% DBSA has
major effect on reducing of viscosity of CWS. It was also shown that finer particles
were more viscous than course particle.
Slurry is a non-Newtonian fluid, the flow curve of which is different from that
of clear water. Four different models were tested for fitting the rheological test curve.
It was shown that Power Law (or Oswald model) model fit very accurately with the
value of correlation coefficient (r) nearly equals to unity.
Pipe line transportation also studied on two different pipe sizes (1 inch
diameter pipe & . inch diameter pipe) to show the effect of different sized and
different weight percentage coal water slurry on pressure drop.
Prediction of viscosity and pressure drop also been studied by Artificial
Neural Network Modelling.

Fuel, 2023

Journal of Thermal Analysis and Calorimetry, 2017

Oilseed crop with high oil content and promising ecological adaptability are potential sources fo... more Oilseed crop with high oil content and promising ecological adaptability are potential sources for competitive biodiesel production. This study investigates the scope of utilizing biodiesel development through the methyl and ethyl ester from soybean and mustard oil as an alternative fuel. Methyl and ethyl esters of oils having different fatty acids compositions such as soybean (SOME and SOEE) and mustard oil (MUME and MUEE) were prepared by transesterification with methanol and ethanol in the presence of an alkali-KOH catalyst. The gas chromatographic (GC) analysis of oil samples revealed that primary fatty acid composition in soybean oil was linoleic acid (C 18:2 , 51.93%), followed by oleic acid (C 18:1 , 22.82%), palmitic acid (C 16:0 , 11.56%), linolenic acid (C 18:3 , 5.95%) and stearic acid (C 18:0 , 4.32%). Whereas, the main components in mustard oil were erucic acid (C 22:1 , 32.81%), oleic acid (C 18:1 , 24.98%), eicosenoic acid (C 20:1 , 10.44%), linolenic acid (C 18:3 , 8.61%) and palmitic acid (C 16:0 , 2.80%). The physicochemical properties (acid value, iodine value, calorific value, flash point, pour point etc.) of methyl and ethyl ester samples were estimated and found to be within the acceptable range of ASTM D6751 standards specifications. The prepared esters and oil samples were examined for cold flow properties by differential scanning calorimetry (DSC). Results revealed better cold flow properties for MUME (-2.55 °C) and MUEE (-3.10 °C) than SOME (3.21 °C) and SOEE (1.83 °C) due to more unsaturated fatty acid content in MU. Thermal and oxidative stability of samples was determined by thermogravimetric analysis (TG) and differential thermal analysis (DTA). The thermal and oxidative stability ranking of the samples was in the order of oil [ methyl esters [ ethyl esters.