M.P. Sharma

Kinetics of acid base catalyzed transesterification of Jatropha curcas oil

Out of various non-edible oil resources, Jatropha curcas oil (JCO) is considered as future feedstock for biodiesel production in India. Limited work is reported on the kinetics of transesterification of high free fatty acids containing oil. The present study reports the results of kinetic study of two-step acid base catalyzed transesterification process carried out at an optimum temperature of 65 °C and 50 °C for esterification and transesterification respectively under the optimum methanol to oil ratio of 3:7 (v/v), catalyst concentration 1% (w/w) for H₂SO₄ and NaOH. The yield of methyl ester (ME) has been used to study the effect of different parameters. The results indicate that both esterification and transesterification reaction are of first order with reaction rate constant of 0.0031 min⁻¹ and 0.008 min⁻¹ respectively. The maximum yield of 21.2% of ME during esterification and 90.1% from transesterification of pretreated JCO has been obtained.

Capacitors Required for Maximum Power of a Self-Excited Single-Phase Induction Generator Using a Three-Phase Machine

This paper aims to determine the optimal capacitors required for maximum output power of a single-phase self-excited induction generator (SEIG), using a three-phase machine feeding inductive as well as capacitive loads. The generator consists of a three-phase star-connected induction machine with three capacitors and a single-phase load. The algorithm, which gives directly the values of the optimal capacitors for the maximum power output and the maximum power available, has been developed using the steady-state model of the SEIG and sequential unconstrained minimization technique (SUMT). The variations of the maximum power output with power factor (pf) of loads (both inductive and capacitive) and speed of the SEIG have been presented. The voltage regulation of the generator is small due to the effect of the two series capacitors. Experimental results have shown the effectiveness and accuracy of the developed algorithm.

Design of an Optimal Hybrid Energy System Model for Remote Rural Area Power Generation

This paper deals with the design of a hybrid energy system consisting of wind, photovoltaic, biomass and small/micro hydro to supply continuous power to the load. A diesel generator is added to ensure continuous power supply and to take care of intermittent nature of wind and photovoltaic. The paper reports the results of optimization of hybrid energy system model of a remote area of Jaunpur block of Uttaranchal state of India. The model has been developed with the objective of minimizing cost function based on demand and potential constraints and optimized using computer programme developed in C++. The economic analysis has resulted in the calculation of capital cost, cost of energy for different types of resources and optimized cost of hybrid energy system. To consider the fluctuation in the discharge and power generation from SHP, the EPDF has been varied from 1.0 to 0.0. The EPDF is Electric Power Delivery Factor (also called optimizing power factor) has maximum value equal tol.

Modelling of Hybrid Energy System for Off Grid Electrification of Clusters of Villages

Hybrid energy systems are increasingly being applied in areas where grid extension is considered uneconomical. Their costs can be minimized through proper equipment sizing and load matching. This paper reports the results of optimization of hybrid energy system model for remote area in India. For this purpose, the Jaunpur block of Uttaranchal state of India has been selected as remote area. The model is developed with the objective of minimizing cost function based on demand and potential constraints. The model has been optimized using LINDO software 6.10 version. From the economic analysis, the capital cost, cost of energy for different types of resources, optimized cost of hybrid energy system are determined. In order to consider the fluctuation in the discharge and power generation from SHP, the EPDF has been varied from 1.0 to 0.0. The EPDF is electric power delivery factor and also called optimizing power factor and is maximum equal to 1.

Fischer–Tropsch synthesis with Co/SiO2–Al2O3 catalyst and steady-state modeling using artificial neural networks

This paper reports the results of an experimental study involving Fischer–Tropsch synthesis on Co/SiO2–Al2O3 catalyst. The objective of the study was to find the reaction conditions for achieving an optimal selectivity with respect to C+5-liquid hydrocarbons. The experimental data on reaction conversion and steady-state concentrations of different product species has been used to develop artificial neural-network-based models which are generic and can be used for predicting the reaction behaviour under different operating conditions.

Hybrid energy system sizing incorporating battery storage: An analysis via simulation calculation

In practical decentralized hybrid energy systems, there are often different renewable/conventional generators and battery storage. An over sizing of the system components significantly elevates the overall cost of the hybrid energy system. In this context the correct and cost effective system sizing as well as efficient system operation is important. In order to determine the optimal sizing of system components, a mixed integer linear mathematical programming model (time-series) has been developed, based on the evaluation of optimized system unit cost for a hybrid energy generation system consisting of small/micro hydro, biogas, biomass, photovoltaic array, a battery bank and a fossil fuel generator. An optimum control algorithm written in C++, based on combined dispatch strategy, allowing easy handling of the models and data of energy system components is presented. The sizing result of the components is based on a trade-off between the optimized cost of the system and other techno-economics parameters, as determined by the algorithm in conjunction with a time-series model. To demonstrate the use of model and algorithm, an application example is also presented.

Oxidation, Thermal, and Storage Stability Studies of Jatropha Curcas Biodiesel

The present work reports the results of the study of the effect of metal contaminants on the oxidation, thermal, and storage stability of Jatropha curcas biodiesel (JCB) with and without antioxidants. Taking Pyrogallol (PY) as the most effective antioxidant based on the earlier work of the authors, JCB was mixed with different transition metals—Fe, Ni, Mn, Co, and Cu in different concentrations. Induction period (IP) was measured using Rancimat method (EN 14112). The ASTM D6468 and thermogravimetric analysis (TGA) methods are used for evaluating the thermal behavior of JCB. Based on results, several correlations are developed for assessing the oxidation, thermal, and storage stability. For the purpose of optimization, response surface methodology (RSM) is used. A comparison between the experimental values and those predicted by the correlation shows that all the data points lie within ±10% deviation lines of the experimental results. The optimized concentration of PY for 2 ppm metal-contaminated biodiesel to have an IP of 6 hr is 326.96, 361.64, 386.15, 417.24, and 600 ppm for Fe, Ni, Mn, Co, and Cu, respectively. From the experiments it is found that if metal concentration is 0, then, 200 ppm of PY is sufficient to make biodiesel stable for 6 months. If metal (Fe) concentration is 2 ppm or more, then 800 ppm PY is sufficient to make biodiesel stable for 5.5 months. This is the first study of its kind being reported in the literature in which RSM is used for design of experiment for developing the correlation for oxidation, thermal, and storage stability. The models developed by RSM will be highly useful for predicting the optimum antioxidant concentration to impart maximum fuel stability in JCB.

Mirabilis Leaves -- a Potential Source of Methane

Abstract Mirabilis leaves and cattle dung were digested anaerobically in a batch digester to produce biogas. Mirabilis leaves produced about 400 litres of gas per kg of dry matter, double the volume produced by cattle dung (200 litres kg−1 of dry matter) under similar experimental conditions. The methane content of the gas produced by Mirabilis leaves was 69% (v/v) and that of cattle dung was 62%. The total reduction of volatile matter in Mirabilis leaves was 42·6%, compared with 22·9% in cattle dung.

Optimization of Conversion of High Free Fatty Acid Jatropha curcas Oil to Biodiesel Using Response Surface Methodology

A five-level-four-factor central composite design (CCD) with 54 assays was employed to study the effect of catalyst concentration (NaOH), reaction temperature, reaction time, and methanol/oil molar ratio on the methyl esters yield from Jatropha curcas oil (JCO) during its transesterification. Using response surface methodology (RSM), a quadratic polynomial equation was obtained for Jatropha curcas biodiesel (JCB) yield by regression analysis. Verification experiments confirmed the validity of the predicted model. The high free fatty acids (FFAs) (14.6%) of JCO could be reduced to 0.34% by acid-catalyzed esterification and a JCB yield of 98.3% was obtained with methanol/oil ratio (11 : 1) using NaOH as catalyst (1% w/w) in 110 min time at 55°C temperature. The predicted value of JCB yield is found to be in good agreement with the experimental value at the optimum level of input parameters. The properties of the biodiesel, thus, produced conform to the ASTM and IS specifications, making it an ideal alternative fuel for diesel engines. The model can be effectively used in oil industry to maximize the biodiesel yield from given oil.

Hybrid Energy System for Remote Area - An Action Plan for Cost Effective Power Generation

Hybrid energy systems (HES), which utilize different renewable resources such as wind, solar, biomass, small/micro hydro, with fossil fuel powered diesel/petrol generator to provide electric power, are well suited for remote rural areas. This paper presents a general methodological framework for the formulation of an action plan for the small-scale hybrid energy system for remote area. The action plan is the output of a six stage procedure: (a) Selecting cluster of villages, (b) Demand assessment, (c) Resource assessment, (d) Estimation of unit cost of different resources, (e) Sizing and optimization, and (f) Model formulation. The action plan is formed on the basis of cost effective modelling for remote rural area that is minimization of energy production cost. A numerical example is included to demonstrate the action plan.