Energy-efficient methane production from macroalgal biomass through chemo disperser liquefaction

Tamilarasan, K.,Kavitha, S.,Rajesh Banu, J.,Arulazhagan, P.,Yeom, Ick Tae Elsevier 2017 Bioresource technology Vol.228 No.-

<P><B>Abstract</B></P> <P>In this study, an effort has been made to reduce the energy cost of liquefaction by coupling a mechanical disperser with a chemical (sodium tripolyphosphate). In terms of the cost and specific energy demand of liquefaction, the algal biomass disintegrated at 12,000rpm for 30min, and an STPP dosage of about 0.04g/gCOD was chosen as an optimal parameter. Chemo disperser liquefaction (CDL) was found to be energetically and economically sustainable in terms of liquefaction, methane production, and net profit (15%, 0.14gCOD/gCOD, and 4 USD/Ton of algal biomass) and preferable to disperser liquefaction (DL) (10%, 0.11 gCOD/gCOD, and -475 USD/Ton of algal biomass).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Chemo disperser liquefaction boost up disintegration synergistically. </LI> <LI> This modernistic method induces solubilization at DSE of 3312.6kJ/kg TS. </LI> <LI> Kinetic study represents rapid disintegration rate by this incentive process. </LI> <LI> Chemo disperser liquefaction archived a higher biodegradability (0.14gCOD/gCOD). </LI> <LI> Net profit of about 4 USD/per ton of algae biomass was achieved. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Cost-effective, low thermo-chemo disperser pretreatment for biogas production potential of marine macroalgae <i>Chaetomorpha antennina</i>

Tamilarasan, K.,Kavitha, S.,Selvam, Ammaiyappan,Rajesh Banu, J.,Yeom, Ick Tae,Nguyen, Dinh Duc,Saratale, Ganesh Dattatraya Elsevier 2018 ENERGY Vol.163 No.-

<P><B>Abstract</B></P> <P>In this study, a novel attempt has been made to generate energy-efficient biomethane from marine macroalgae (<I>Chaetomorpha antennina)</I> by coupling thermochemical liquefaction with a disperser (thermo-chemo disperser (TCD) liquefaction). A temperature of (80 °C), pH 11 and disperser g-force of 1613 g were considered optimal parameters for effective solubilization and energy-efficient methane generation. This combinative liquefaction considerably reduced the treatment time and specific energy from 60 to 15 min and 6294 to 800 kJ/kg TS. The highest volatile fatty acids (VFA) accumulation of 890 mg/L was recorded in TCD compared to a thermo disperser (TD) (750 mg/L) and disperser (D) (322 mg/L) during anaerobic fermentation. TCD enhances the methane production potential of macroalgal biomass and a higher methane production of 215 mL/g VS was achieved for TCD compared to TD (149 mL/g VS) and D samples (100 mL/g VS), respectively. Cost analysis confirmed the field applicability of TCD liquefaction with a net profit of 90 USD/ton of marine macroalgae. A high energy ratio of 1.5 was achieved with the proposed mode of pretreatment (TCD) compared to TD (0.95) and D (0.28) pretreatment. Therefore, <I>C. antennina</I> is considered a suitable feedstock for methane generation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Thermo chemo disperser aided liquefaction enhance the disintegration efficiently. </LI> <LI> Combined pretreatment had achieved higher liquefaction at 800 kJ/kg TS of energy. </LI> <LI> Kinetic analysis explains that rate was improved in combined pretreatment. </LI> <LI> Energy ratio of about 1.5 was achieved in thermo chemo disperser pretreatment. </LI> </UL> </P>

Multi-response optimization of Nd:YAG laser cutting parameters of Ti-6Al-4V superalloy sheet

A. Tamilarasan,D. Rajamani 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

This study proposes a multi-response optimization approach for the Nd: YAG laser cutting parameters of titanium superalloy sheet (Ti-6Al-4V). The Box-Behnken design was utilized to plan the experiments, and response surface methodology was employed to develop experimental models. Four input parameters, including pulse width, pulse energy, cutting speed, and gas pressure, were set during the experiment, and kerf deviation and metal removal rate were considered as the performance characteristics. Pores, dross, and striation lines were observed on the kerf wall of the laser-cut surface through scanning electron microscopy. With the suitable mathematical models established, a search optimization procedure based on the use of desirability function was used to optimize the performance characteristics. A confirmation experiment was also conducted to validate the optimized process parameters. The relative error is less than ±2 %, thus confirming the feasibility and effectiveness of the adopted approach.

Determination and Correlation of Excess Enthalpies of Mixing of Ethyl Acetate/Benzene Mixtures Containing Dissolved Inorganic Salts at 303.15 K

Rengasamy, Tamilarasan,Arun, Anand Prabu,Muniswamy, Raajenthiren,Mahendradas, Dharmendira Kumar,Yoo, Chang Kyoo The Society of Chemical Engineers, Japan 2009 Journal of chemical engineering of Japan Vol.42 No.7

<P>This communication presents the effect of five dissolved inorganic salts (sodium chloride, NaCl; calcium chloride, CaCl<SUB>2</SUB>; zinc chloride, ZnCl<SUB>2</SUB>; cadmium chloride, CdCl<SUB>2</SUB>; ammonium chloride, NH<SUB>4</SUB>Cl) on the enthalpy of mixing (<I>H</I><SUP>E</SUP>) of ethyl acetate/benzene binary system at 303.15 K; enthalpy measurements were performed using an isothermal displacement calorimeter with vapor space. The excess enthalpy of mixing of this system is significantly reduced in the presence of NH<SUB>4</SUB>Cl and NaCl; however, changes in the excess enthalpy of mixing were insignificant in the presence of CaCl<SUB>2</SUB>, ZnCl<SUB>2</SUB>, and CdCl<SUB>2</SUB>. The experimental values of <I>H</I><SUP>E</SUP> were fitted into the Redlich–Kister equation, and deviations from the ideal value and binary parameters were calculated. The importance of solute–solvent interactions was demonstrated from the decrease in the excess enthalpy of mixing in the negative direction with an increase in the NaCl concentration.</P>

Heat transfer enhancement and pressure drop analysis in a helically coiled tube using Al₂O₃ / water nanofluid

P. C. Mukesh Kumar,J. Kumar,R. Tamilarasan,S. Sendhil Nathan,S. Suresh 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.5

In this experimental investigation, the heat transfer and pressure drop analysis of a shell and helically coiled tube heat exchanger by using Al₂O₃ / water nanofluids have been carried out under turbulent flow condition. The Al₂O₃/ water nanofluids of 0.1%, 0.4%, and 0.8%particle volume concentration have been prepared by using two step method. The tube side experimental Nusselt number of 0.1%, 0.4%and 0.8% nanofluids were found to be 28%, 36% and 56%, respectively higher than water. These enhancements are due to higher thermalconductivity of nanofluid, better fluid mixing and strong secondary flow formation in coiled tube. The pressure drop of 0.1%, 0.4%and 0.8% were found to be 4%, 6%, and 9%, respectively higher than water. The increase in pressure drop is due to increase in nanofluidviscosity while adding nanoparticles. The measurement of nanofluid thermal performance factor is found to be greater than unity. It isconcluded that the Al₂O₃ nanofluid can be applied as a coolant in helically coiled tube heat exchanger to enhance heat transfer with negligiblepressure drop.

Lipid extraction from natural plant source of Adenanthera pavonina using mixed solvent by superheated extractor

Ramachandran Kasirajan,Renganathan Sahadevan,Sivakumar Pandian,Suganya Tamilarasan 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3

The lipid content was extracted from the saga seed by superheated condition and soxhlet apparatus. Themixture of hexane, chloroform and methanol was utilized as a mixed solvent for these extraction operations. Differentparameters such as different solvent, temperature, mean particle size and solvent flow have been examined. The optimizedlipid extraction was achieved as 26.2 wt% by using superheated condition from the saga seed powder at 90 oCfor 120min. Then the fatty acids profile of the optimized Adenanthera pavonina oil were analyzed by gas chromatography. Unsaturated fatty acid was high as 83.7% compared with saturated fatty acid barely 15.4% by relative.

Surfactant coupled sonic pretreatment of waste activated sludge for energetically positive biogas generation

Ushani, U.,Rajesh Banu, J.,Tamilarasan, K.,Kavitha, S.,Tae Yeom, Ick Elsevier 2017 Bioresource technology Vol.241 No.-

<P><B>Abstract</B></P> <P>The objective of this study was to evaluate the effect of dioctyl sodium sulphosuccinate (DOSS, a surfactant) on lysis rate of sludge and specific energy required for sonic pretreatment of waste activated sludge (WAS). Different ultrasonic power levels, WAS concentrations, DOSS dosages, and specific energy levels were used to compare pretreatment efficiencies. At an optimum time of 10min with ultrasonic power level of 160W, DOSS coupled sonic pretreatment resulted in better lysis rate (24.7%) of sludge than sonic pretreatment (17.6%). Biodegradability estimation through non-linear regression modeling revealed that DOSS coupled ultrasound pretreatment of sludge showed better biodegradability with higher hydrolysis constant (about 0.25d<SUP>−1</SUP>) than sonic pretreatment (0.19d<SUP>−1</SUP>). Nearly six times less energy was required for DOSS coupled ultrasound pretreatment compared to that required for sonic pretreatment. Therefore, DOSS coupled ultrasound pretreatment makes the pretreatment process energetically positive.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel attempt to minimize energy demand of ultrasonication through surfactant. </LI> <LI> Lysis rate of about 24.7% was obtained with 0.05g/gSS of DOSS. </LI> <LI> Biodegradability rate constant of 0.25d<SUP>−1</SUP> was attained for coupled pretreatment. </LI> <LI> Coupled pretreatment saves considerable amount of energy than sonic pretreatment. </LI> <LI> Coupled pretreatment makes the disintegration process energetically positive. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

CFD analysis of heat transfer and pressure drop in helically coiled heat exchangers using Al2O3 / water nanofluid

P. C. Mukesh Kumar,K. Palanisamy,J. Kumar,R. Tamilarasan,S. Sendhilnathan 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

In this investigation, the heat transfer coefficient and pressure drop of a helically coiled tube heat exchanger handling Al2O3/ waternanofluids is made by using computational fluid dynamics fluent (CFD) software package. This was done under laminar flow conditionin the Dean number (De) range of 1650-2650 and the nanoparticles volume concentration of 0.1%, 0.4% and 0.8%. The effect of someimportant parameters such as nanoparticle volume concentration and Dean number (De) on heat transfer and pressure drop is studied. The coiled tube side Nusselt number (Nu) is found to be 30% higher than water at maximum De. The maximum pressure drop is found to be9% higher than water. It is also found that the Nu and pressure drop significantly increase with increasing particle volume concentrationand De. It is also found that the experimental friction factor increases with increasing the particle volume concentration and De. The CFDNu and pressure drop results have been compared with the experimental and theoretical results. On comparison, it is found that the CFDsimulation results show good agreement with the experimental and theoretical results. It is concluded that the CFD approach gives goodprediction for heat transfer coefficient and pressure drop in a shell and helically coiled tube heat exchanger using Al2O3/ water nanofluids. The average relative error between experimental Nu, pressure drop results and CFD results are found to be 8.5% and 9.5% respectively.

Magnetoresistance in silicon based ferrite magnetic tunnel junction

S. Ravi,A. Karthikeyan,N. Angel Nesakumari,K.S. Pugazhvadivu,K. Tamilarasan 한국물리학회 2014 Current Applied Physics Vol.14 No.3

We report magnetoresistance for silicon based magnetic tunnel junction. We used cobalt ferrite & cobalt nickel ferrite as free layer and pinned layer. The magnetoresistance measured at room temperature through silicon by fabricating FM/Si/FM magnetic tunnel junction. Magnetoresistance shows a loop type behavior with 3.7%. We have successfully demonstrated spin tunneling through silicon with ferrite junction that opens the door for potential candidate for spintronics devices. The spin-filtering effect for this double spin-filter junction is also discussed.