Water tolerance of ethanol-gasoline blends of various proportions is investigated using cosolvents such as TBA (tert-butyl alcohol), cyclohexane, heptane, acetone, iso-octane, and toluene at 300 K. Miscibility was studied using a simple experimental method for various proportions of water-ethanolgasoline blends with and without co-solvents. Results of water tolerance for each co-solvent are presented in this paper for stable mixture at room temperature.

The biomass feedstock needs to be available in a manner that is sustainable as well as renewable. However, obtaining reliable and cost effective supplies of biomass feedstock produced in a sustainable manner can prove to be difficult. Traditional biomass, mainly in the form of fallen leaves, fuel wood or dried dung, has long been the renewable and sustainable energy source for cooking and heating. Present study accounts for the biomass of fallen leaves of Shorea robusta, also known as sal, sakhua or shala tree, in the campus of BIT Mesra (Ranchi). These leaves are being gathered and burnt rather than being sold commercially. They contain water to varying degrees which affects their energy content. Hence, measurement of moisture content is critical for its biomass assessment. The leaves were collected, weighed, oven dried at 100 oC until constant weight, then dry sample was reweighed to calculate the moisture content that has been driven off. By subtraction of moisture content from the initial weight of leaves, biomass was calculated. Using Differential Scanning Calorimeter (DSC) the heat content of the leaves was calculated and the elemental analysis of leaf was done by CHNSO elemental analyser. Further, total biomass and carbon content of Sal tree was calculated using allometric equations so as to make a comparison to the biomass stored in dried fallen leaves.

Pulse Detonation Engine (PDE) is considered to be a propulsive system of future air vehicles. The main objective is to minimizing the Deflagration to Detonation transition run-up distance and time by placing Shchelkin spiral with varying pitch length. Here we have considered blockage-area ratio is 0.5 as optimal value from review of previous studies. In the present study the detonation initiation and propagation is modeled numerically using commercial CFD codes GAMBIT and FLUENT. The unsteady and two-dimensional compressible Reynolds Averaged Navier-Stokes equation is used to simulate the model. Fuel-air mixture of Hydrogen-air is used for better efficiency of PDE. It is very simple straight tube with Shchelkin spirals, one of the methods which is used to initiate detonation is creation of high pressure and temperature chamber region with 0.5cm from closed end of tube where shock will generate and transition into low pressure and temperature region propagates towards end of the tube. Two different zones namely high and low pressure zones are used as interface in modeling and patching has been used to fill the zones with hydrogen and oxygen with different pressure and temperatures hence shock leads to propagate inside the combustion chamber.

This paper presents a ‘Computer Aided Design (CAD)’ model for energy efficient design of offshore structures. In the CAD model preliminary dimensions and geometric details of an offshore structure (i.e. semi-submersible) are optimized to achieve a favorable range of motion to reduce the energy consumed by the ‘Dynamic Position System (DPS)’. The presented model allows the designer to select the configuration satisfying the user requirements and integration of Computer Aided Design (CAD) and Computational Fluid Dynamics (CFD). The integration of CAD with CFD computes a hydrodynamically and energy efficient hull form. Our results show that the implementation of the present model results into an design that can serve the user specified requirements with less cost and energy consumption.

Pulse detonation engines are the modern propulsive device which provides high thrust. They are unsteady propulsive devices which has multi cycle operations in it. In this multi cycle process for every cycle fuel and air are initiated and a shock wave is generated in combustion chamber in form of deflagration. Combustion chamber is maintained with high pressure and high temperature which leads to combustion of reactants. This deflagration transmits to detonation with high velocity and increasing Mach number. Deflagration propagates forward by taking all unburned species and products formed after combustion. Propagation of Deflagration – Detonation Transition (DDT) shock wave studies is a pioneering research concept. In the present study, simulation of PDE with Shchelkin spiral geometry is considered with two mass flow inlets has been used in which one is for fuel inlet and other for oxidizer. Geometry and meshing has been done in Gambit. Fuel used is gaseous fuel hydrogen and oxidizer is air mixture of O2, N2 work has been performed for different mass flow rates of fuel and oxidizer. Energy equation, Species transport equation to be solved in Fluent. Comparison results of DDT in parameters of mach number, velocity, pressure and temperatures depending on different time steps have been observed.

Over the past decade, there is an increasing interest in alcohol based fuels around the world due to the ease of handling, blending and the potential of production using renewable resources. Butanol is one of the suitable alternative candidate for IC engines due to its lower heating value (32 MJ/kg) in comparison to other alcohol based fuels such as ethanol (26.8 MJ/kg) and methanol (20 MJ/kg). The present study was carried out to evaluate the performance and emission characteristics of a single cylinder carbureted engine fuelled with the following gasoline-butanol blends ranging from 5%, 10%, 15% and 20% of butanol by volume. During the tests negligible reduction in the performance characteristics were observed for gasoline-butanol blends in comparison to conventional gasoline. The emission characteristics of gasoline-butanol blends were observed to be superior to that of conventional gasoline. In the overall picture, the performance of gasoline-butanol blends indicated promising results as a substitute to conventional gasoline.

Co-cracking of Jatropha oil (JO) and bagasse (BA) in the presence of ZSM-5 catalyst was investigated in a fixed bed tubular batch reactor under atmospheric pressure. It was observed that ZSM-5 increases the gaseous product yield though the liquid yield is not much affected. From the GC-MS characterization of the liquid yield it was observed that liquid yield mainly consisted of compounds in the carbon number range of C12-C22 as compared to thermally co-cracked liquid. This indicates that the presence of ZSM-5 catalyst leads to polycondensation, recombination and rearrangement reactions taking place during co-cracking process.

The Carbon dioxide (CO2) is one of the primary greenhouse gases emitted by various human activities. CO2 is naturally present in the atmosphere as part of carbon cycle. Human activities are altering the carbon cycle by adding or removing CO2 to the atmosphere. The main human activity that emits the CO2 is combustion of fossil fuels for energy and transportation. Compression ignition (CI) engines emit high amount of CO2 emission as it is the end product of complete combustion of hydrocarbon fuels. Moreover, they emit higher NOx (nitrogen oxides) and PM (particulate matter) emissions and have higher fuel consumption. In the present study, experimental investigations were carried out on a CI engine under dual fuel mode with biodiesel as a pilot fuel and compressed natural gas (CNG) as a main fuel. The effects of 10 % and 20 % CNG energy shares on performance and emission characteristics of the engine at rated (100%) loads were studied. Experimental results indicate the beneficial of CNG addition on improvement in the engine efficiency, and reduction in NOx and CO2 emissions. The NOx and CO2 emissions decreased by 14.24 % and 30 % respectively at the rated load with biodiesel + CNG (20 % energy share) as compared to base diesel. No knocking combustion was observed during the tests which confirm the smooth operation. The dual fuel operation with combination of CNG-biodiesel is an effective method to reduce NOx and CO2 emissions with an additional benefit of lower specific energy consumption.

This paper presents a view on comparative study of use of diesel fuel with B20 biodieselblend (Diesel (80 %, by vol.) and Cotton seed oil (20 %, by vol.)) derived from Cotton seeds. As higher NOx emission and higher brake specific fuel consumption are main challenges for effective utilization of biodiesel fuel in a diesel engine, there is alarming need to find out the long term solution to reduce NOx emission for better utilization of biodiesel fuel in a diesel engine. Exhaust gas recirculation (EGR) is one of the useful technologies to reduce the NOx emission of a diesel engine. In the present research work test is conducted on 3 KW single cylinder, four stroke, water cooled, variable compression ratio (VCR) computerized diesel engine using diesel and B20 cotton seed biodiesel blend to study the effect of exhaust gas recirculation on performance and emissions characteristics of a diesel engine in terms of fuel consumption, thermal efficiency and emissions such as hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and carbon dioxide (CO2) of a diesel engine. The constant engine speed of 1500 rpm was maintained through-out the experiment test. The exhaust gas recirculation was varied as 4% and 6 % at different loading conditions with diesel and B20 biodiesel. The results show that the significant reduction in oxides of nitrogen (NOx) with 4 % and 6 % EGR for B20 whereas marginal increment in CO and HC emissions.

The work carried out in this project is based on analytical study. The performance parameters of a natural circulation solar collector have been evaluated using the empirical relations formulated and discussed in the literature. The study emphasizes on the method of evaluation of optimum mass flow rate of water in a Solar Collector for a given inlet and outlet temperature of water flowing through the collector. The mass flow rate of water in the collector has been evaluated using an iteration method. An excel spreadsheet has been prepared to calculate the mass flow rate.

The economic development of a country is highly dependent on the supply of fossil fuels which are constrained by its limited availability and pollution characteristics. India is among the world’s fourth-largest petroleum consumer due to which the vehicular emissions increased eight times over the last two decades. Due to the environmental awareness and depletion of fossil fuel reserves, attention has been given to find an alternative energy source. Among the alternatives existing, Biodiesel is the one which is less polluting and eco-friendly. So it can be used in industrial, commercial, agricultural and other sectors as a substitute for diesel. Biodiesel can be produced from crude vegetable oil, non-edible oil, frying oils (waste), animal tallow and algae by a process of chemical reaction called Transesterification. Biodiesel is also known as methyl or ethyl esters of the feedstock from which it is produced. It is miscible with diesel oil which allows the use of blends of petro diesel and biodiesel in any percentage. The C.I. engines fuelled with biodiesel perform more or less in the same fashion as that with the conventional fuel. Comparative to diesel, biodiesel has high Cetane number and lower compressiability. Additionally, the heat release rate of biodiesel is slightly lower than diesel owing to low calorific value, low volatility and high viscosity. The problem of high viscosity can be eradicated by transesterification process and by adding additives which help us to store the biodiesel for a longer duration of time without any decay. Exhaust emissions are significantly reduced with the use of biodiesel or its blends. The present paper investigates the potential of Mahua (Madhuca Indica) oil for biodiesel production as it can be extracted from seeds of Mahua tree which are indigenous to India. It can grow even in dry regions and are found abundantly in several parts of India.

In resent year, increased environmental awareness and energy shortages have encouraged researchers to investigate the possibility of using alternate fuels. The purpose of finding the alternate sources is to minimize the consumption of conventional fossil fuels and in turn to reduce the degradation of environmental quality to a great extent. The use of bio-based fuels like biogas produced from biomass and bio-wastes is a valuable energy source which is sustainable that can be manufactured from locally available waste streams thereby solving the local waste problem. Local wastes (organic wastes) contain enough energy to contribute significantly to energy supply especially the rural regions of developing countries. Biogas is a clean and environment friendly fuel produced from anaerobic digestion of agro, animal or human wastes. The biogas has about 60 % methane and 40 % carbon dioxide with small traces of H2S. The use of H2S leads to formation of SO2 which combines with the water vapor to form acids and hence corrode the metals. Thus, raw biogas as such cannot be used for powering vehicular I.C engine. In the present work, an attempt has been made to upgrade the quality of raw biogas by removing CO2 and H2S, thus enriching its methane content up to the natural gas level and to study the performance of four stroke S.I engine aspirating upgraded biogas as primary fuel and its emission characteristics.

Biofuels produced by algae may provide a feasible alternative to fossil fuels like petroleum sourced fuels. However, looking to limited fossil fuel associated with problems, intensive efforts have been given to search for alternative biofuels like biodiesel. Algae are ubiquitous on earth, have potential to produce biofuel. However, technology of biofuel from algae facing a number of hurdles before it can compete in the fuel market and be broadly organized. Different challenges include strain identification and improvement of algal biomass, both in terms of biofuel productivity and the production of other products to improve the economics of the entire system. Algal biofuels could be made more cost effective by extracting other valuable products from algae and algal strains. Algal oil can be prepared by culture of algae on municipal and industrial waste waters. Photobioreactors methods provide a controlled environment that can be tailored to the specific demands of high production of algae to attain a consistently good yield of biofuel. The algal biomass has been reported to yield high oil contents and have good amount of the biodiesel production capacity. In this article, it has been attempted to review to elucidate the approaches for making algal biodiesel economically competitive with respect to petrodiesel. Consequently, R & D work has been carried out for the growth, harvesting, oil extraction and conversion to biodiesel from algal sources.

The present work is focused to characterize numerically the merged and non-merged flame emanating from the cavities in downstream of twin cavity Annular Trapped Vortex Combustor (ATVC).The isotherm corresponding to the auto-ignition temperature is used to locate the merging point of the flame in the mainstream region along the combustor length. In present study, the cavity flame is said to be merged only if this isotherm corresponding to self-ignition temperature of methane is located within 20 percentage of the combustor length from aft wall of cavities. It is interesting to note that on increasing the power loading parameter (PLP) in mainstream for a constantpower loading parameter ratio (outer to inner cavity), the merging point gets shifted towards the cavity aft-wall. This leads to the reduction of combustor length and subsequent reduction in overall weight of the gas turbine engine.

In the present computational investigation, the characteristics of heat transfer from cylinders in cross flow of air has been reported, using the commercial CFD software, FLUENT. Unsteady, constant heat flux condition has been applied at the surface and the turbulent flows were simulated using k-kl-? turbulence model. Comparing for single cylinder, with k-? (standard), k-? (SST) and SA models, the k-kl-? model has been found best suitable models for simultaneous computation of flow field and heat transfer parameters. The results were also compared with experiments performed as well as from reported literatures for Reynolds number range 1.1x104 = Re = 4.1x104 to prove the capabilities of k-kl-? model. High aspect ratio (18.75) and very low blockage ratio (0.053), has been used to conduct experiments. An analysis of data revealed that the average deviation from the experimental as well as reported values is less than 1%.

Three dimensional conservation equations of mass, momentum and energy are solved numerically to determine the heat transfer and fluid flow characteristics of a rectangular winglet type fin-and-tube heat exchanger. The flow is assumed to be laminar and the surface of the tube is maintained at a constant temperature. The winglets are placed in “common flow up” configuration. This configuration results considerable separation delay and improves heat transfer in the near wake of the tubes. A moderate attack angle (10°) of the winglet has been used so far in this study and it is expected that higher angle of attack will result in higher heat transfer performance. In comparison to the baseline case (without winglets) it is found that the heat transfer performance increases significantly by using winglets with rise in pressure drop. It is also found that by increasing the number of winglets and changing the position of winglets has a significant effect on heat transfer performance.

Microalgal cells has been utilized as a rich source of food, feed and fuel. The process of concentrating algal cells from water suspension is called harvesting. This article deals with the algal biomass harvesting by flocculation process using acrylamide grafted guar gum. Acrylamide has been successfully grafted onto the backbone of guar gum by microwave initiated method in which microwave radiation alone (without chemical free radical initiator) is used to initiate the grafting reaction. Simultaneously with the synthesis of graft copolymer, water removal capability of various grades of GGg-PAM have also been studied as a flocculant for algal biomass harvesting through standard jar test procedure for collection of algal biomass. The collected biomass can be hand carried. The collected biomass has been characterized in terms of crude fat content and elemental composition. Calorific value of this collected biomass has also been theoretically calculated.

The Andaman and Nicobar Islands located southeast of Bay of Bengal in the Indian Ocean comprises of several small islands separated by sea over large distances which makes it impractical for electrifying all the islands by a single grid. A population of 380,581 (Census, 2011) living in these group of islands get their electricity demand catered through Diesel Generator Sets from 34 power houses with an aggregate capacity of 67.8 MW. Unavailability of any form of conventional fossil fuel reserves in the islands makes the diesel supplied in barges from southeastern coast of India as a sole lifeline for its power generation. Hence there is an urgent need for the development of a self sustainable model from non conventional energy resources to not only cater for the power demands but also to reduce the GHG emissions related with diesel powered generator sets. This paper discusses a self sustainable model for Andaman and Nicobar Islands that would cater the electrical demand through hydrogen produced from waste biomass resource which has a potential of replacing 86.65% of the diesel utilized in the diesel generator sets. The reduction in both the GHG emission and the cost of power generation would be evaluated to understand the impact of the self sustainable model on the environment and the livelihood of the local population of Andaman and Nicobar Islands.

Proton exchange membrane (PEM) fuel cells are one of the most emerging alternative energy technologies under development. A novel proton exchange membrane sulfonated polyethersulfone (SPES) was developed by homogeneous method using phthalic anhydride as catalyst and chlorosulfonic acid as sulfonating agent to control the sulfonation reaction. The method of sulfonation was optimized by varying the reaction time and concentration of the catalyst. The structure of the SPES was studied by 1H-Nuclear Magnetic Resonance, Fourier Transform Infra Red Spectroscopy and X-ray diffraction. The extent of sulfonation was determined by ion exchange capacity studies. The thermal and mechanical stabilities were studied using thermogravimetric analysis (TGA) and Dynamic Mechanical Analysis (DMA) respectively. DMA results show that the storage modulus increased with increase in degree of sulfonation (DS) and water uptake of SPES increased with DS. The proton conductivity of SPES (34% DS) measured by impedance spectroscopy was found to be 0.03S/cm at 80%RH and 100°C. Also, current-voltage polarization characteristics of SPES membranes offer a favourable alternative PEM due to the thermal stability and cost effective than perfluorinated ionomers.