International Journal of Renewable Energy Technology (13 papers in press)
Selection of the best barrier solutions for liquid displacement gas collecting meter to prevent gas solubility in microbial electrolysis cells (MECs)
by Abudukeremu Kadier, K. Chandrasekhar, Mohd Sahaid Kalil
Abstract: Microbial Electrolysis Cells (MECs) are a novel technology aiming at producing hydrogen from biomass or wastewater. The collection and preservation of the gas generated in the MECs is the first and most important operation in gas measuring techniques. There are several techniques for the quantitative evaluation of gas production in MECs, such as owen method, respirometer, and gas bag methods. However, the costs associated with these methods could make MEC technology scale-up expensive and impractical. This work describes evaluation of commonly used biogas measurement techniques and analyzes potential errors associated with liquid displacement gas measurement. Inaccuracy mainly due to CO2, and CH4 dilution in displaceable liquids was evaluated by testing solubility of CO2 in twelve different barrier solutions. 95% saturated NaCl (pH 0.5) solution exhibited lower CO2 solubility among the tested solutions. These results indicate that gas production in MECs can be accurately tested using an inexpensive, simple gas meter.
Keywords: hydrogen production; Microbial Electrolysis Cell (MEC); gas meter; liquid displacement method; Gas Chromatography (GC); barrier solutions; solubility test.
Microbial Fuel Cell - A Source of Renewable Energy : A Review
by Virendra Singh, Akanksha Saxena, Asha Gupta, Savitri Singh, Vidushi Kaul, Narendra Kumar
Abstract: Energy crisis in world is increasing every year due to depletion of fossil fuels as well as continued increase in the prices. There is an urgent need to identify an alternate fuel or a renewable source for energy production. Hence, microbial fuel cells (MFCs) can play a major role in producing bioelectricity using organic and biodegradable waste. The traditional MFCs consisted of anode and cathode compartments. MFCs are of two types single chambered and double chambered. Microorganisms actively use organic substrate for their metabolism, and bioelectricity generated. Apart from the bioelectricity production, MFCs has many applications like in wastewater treatment, in biosensor, in bio-hydrogen production, in bio-methane production etc. Besides the advantages of this technology, MFCs have some limitations such as low voltage, power and current density. To overcome these limitations, the different components of MFC such as electrodes and proton exchange membrane modified to explore the other possible practical options. Besides that, this research update describes the improvement and advancement of MFCs with their advantageous and futuristic application with different parameters affecting the bioelectricity production.
Keywords: Microbial fuel cells; Wastewater treatment; Electricity generation; Biohydrogen; Biosensor.
Need of Turbocharging: With Focus on Producer Gas Fueled Internal Combustion Engines A Review
by VIVEK KULKARNI, Anil T.R., Rajan NKS
Abstract: The vital need for the reduction of harmful environmental impact during energy production necessitates research for efficient, economically feasible energy developing techniques. Hence much greater emphasis is being placed on reducing the fuel consumption of engines due to global move to reduce CO2 emissions. One of them is the use of gaseous fuel, namely Producer Gas (PG), as full supplement fuel in internal combustion engines. The earlier studies on use of PG in engines for power generation have reported a de-rating in their delivered peak power. Since PG can be obtained from various biomass gasification sources, the literature also suggests a varying de-rating of 20-40% on different spark ignited engines used by different researchers. To overcome this difficulty, turbocharging is known to be a better option to recover the power loss from a given engine size. This paper emphasizes on the need of turbocharger for producer gas fueled spark ignited internal combustion engine.
Keywords: Producer Gas; Turbocharger; Spark ignited engine; Compressor; Turbine; De-rating.
Optimal Active and Reactive Power Control of Wind Turbine Driven DFIG using TLBO Algorithm and Artificial Neural Networks
by Mahmoud ElKholy, Hamed Metwally, Garib M. Regal, Mohamed Sadek
Abstract: This paper investigates the optimal active and reactive power control capabilities for typical WT driven DFIG. The main objective is to determine the optimal rotor voltage to extract certain active and reactive power from the DFIG over wide ranges of wind speed. TLBO algorithm is a new heuristic optimization technique, used to obtain the optimum rotor voltages to achieve reference active and reactive powers overall operating points. ANN controller is used as an adaptive controller to predict the value of rotor voltage for all operating points. The ideal power curve of a 2 MW wind turbine has been estimated to design the active power controller. The stator reactive power control capability with the range of
Keywords: (Doubly fed induction generator; active and reactive power control; teaching learning based optimization; artificial neural network).
Design and Optimization of Enzymatic Saccharification for Bioethanol Production from Parthenium hysterophorus Biomass using Response Surface Methodology
by Shivani Bhagwat, Anil Kumar
Abstract: The critical conditions for saccharification of polysaccharides from pre-treated biomass of Parthenium hysterophorus were carried out using response surface methodology based on Plackett-Burman and Box-Behnken design. In this study, temperature, moisture contents, pH, substrate loading, enzyme loading and incubation time were taken into consideration for optimization of the conditions before fermentation. Using Plackett-Burman design, regression was predicted to be 95.26%. The adjusted regression and predicted regression were 89.58% and 72.71%, respectively indicating coincidence. Box-Behnken design was employed to investigate optimum conditions from the factors deduced by Plackett-Burman design (PBD). The parameters taken for the second order polynomial equation analysis were temperature, pH, enzyme loading and substrate loading, where regression was predicted as 0.97. The standard deviation and coefficient of variation (CV%) were calculated to be 24.31 and 7.80%, respectively. The predicted regression and adjusted regression were 0.86 and 0.94, respectively indicating good agreement with the predicted model. It was found that 30oC temperature, pH 4.5, enzyme loading of 1.0 ml and substrate loading of 1.0 g was the optimum conditions for maximum release of fermentable sugars. 8% of substrate loading rate was maintained for the experiment. Ethanol yield was 70% of the maximum theoretical yield based on pretreated biomass after 72 h using optimum conditions.
Keywords: Biofuel; Box-Behnken design; Cellulose degradation; Enzymatic saccharification; Fermentation; Gas chromatography; Plackett-Burman Design; Saccharomyces cerevisiae; Statistical Modelling; Scanning electron microscopy.
Special Issue on: New and Renewable Energy Resources
Evaluation of Generation of Electricity from Wastewater Using Microbial Fuel Cell
by Kamal Ahamad, Nihal Singh, Abhijeet Das
Abstract: Microbial fuel cells (MFC) have received significant attention worldwide for its capacity to produce electricity as well as removal of waste compounds. The present work aims to evaluate the performance of MFC by varying parameters - electrode surface area and substrate. A comparison was made with the performance output of two-chamber, h-shaped unit MFC and three two chamber, h-shaped MFC connected in series. Performance of MFC were also evaluated by varying the surface area of the electrodes in both anode and cathode chamber as well as varying the substrate i.e. cooked rice, cerelac and sugar given to the anode chamber. MFCs connected in series gives better voltage output compared to single unit MFC. Electrode surface area in the anode chamber plays an important role in electricity generation. The sudden exchange of substrate from cerelac to cooked rice and vice versa does not showed any significant improvement in the performance of MFCs.
Keywords: Microbial fuel cell; Electricity; Substrate; Electrode.
APPLICATION OF ANFIS AND LIFTING WAVELET TRANSFORM FOR CLASSIFICATION OF SOLAR RADIATION
by Manju Khanna, N.K. Srinath, J.K. Mendiratta
Abstract: With increase in demand for green energy in commercial applications, need for classification of solar radiation at a site has gained importance. Present work exploits application of wavelet transform and ANFIS to classify solar radiation data, which can be exploited for optimal use of solar radiation
Keywords: wavelet transform; ANFIS; photo-voltaic; singular value decomposition; feature extraction; multi-level resolution.
Pine Needle Biomass Gasification Based Electricity and Cold Storage Systems for Rural Himalayan Region: Optimal Size & Site
by Arvind Singh Bisht, N.S. Thakur
Abstract: Pine trees cover large portions of the Himalayan region. Every summer session dry pine needles fall from the trees and cover the forest floor, which is a serious cause of uncontrolled frequent forest fires here in this region.
Due to the widespread availability of pine needles (forest biomass) in the Himalayan region, it can not only produce electricity (through gasification) for immediate local consumption and the national grid system but with the implementation of CHP and CHCP technology it can also contribute to local dairies, food processing industries and for cold storage. Using pine needles in electricity generation will not only save the environment, by preventing forest fires but also contribute to the energy demands of the region and preserve the local vegetable, fruits and milk product without any additional cost.
The objective of this study is to find out the optimal gasification system range to serve a particular locality with respect to local pine needle availability and produced refrigeration capacity.
Keywords: cold storage; optimization; gasification; Himalayan region; pine needles.
Comparative energetic and exergetic studies of vapour compression and vapour absorption refrigeration cycles
by Suman Chattopadhyay, Dibyendu Roy, Sudip Ghosh
Abstract: In this study, two types of refrigeration cycles, a vapour compression refrigeration (VCR) cycle and a vapour absorption refrigeration (VAR) cycle, have been modeled and analyzed. Both the cycles have same operating cooling loads and both operate between the same temperature limits. R134a has been considered as refrigerant for the VCR cycle whereas LiBr-H2O has been considered as the working fluid for the VAR cycle. Energetic and exergetic performances have been evaluated for both the cycles and compared. The effects of condenser temperature, evaporator temperature and environmental dead state temperature on the performances of these cycles are also discussed. Energy analysis reveals that the coefficient of performance (COP) of the VCR cycle is considerably higher than that of VAR cycle. However, exergy analysis reveals that the exergetic coefficient of performance (ECOP) of the VAR cycle is very close to that of VCR cycle. For environmental dead state temperature beyond 35oC, the exergetic performance of VAR cycle is better than that of VCR cycle. The maximum exergy destruction occurs at the evaporator for the VCR cycle but for VAR cycle, the maximum exergy destruction occurs at the generator.
Keywords: Coefficient of performance; Energy; Exergy; Refrigeration.
An Experimental Investigation of PCM based Thermal Energy Storage System using Diesel Engine Exhaust-gas
by C. U.M.A. MAHESWARI, R. MEENAKSHI REDDY
Abstract: Waste heat recovery is one of the energy conservation options. About 30% of heat produced by diesel engines that are coupled to electric power generators are carried away by exhaust gases as waste part of the heat energy produced. In the present work, CFD and experimental analysis was made to study the utilization of the waste heat energy carried by exhaust gases to obtain hot water used for various purposes in commercial buildings, hostels etc. For the heat recovery from exhaust gases, use of phase change materials (PCM) is considered and these PCMs store the energy in the form of sensible and latent heat. The main advantage of PCM is that about large quantity of thermal energy can be stored in a small volume of PCM. Experimental test was carried out using concentric cylinder type of Thermal Energy Storage System (TESS) with Stearic acid as PCM. Exhaust gases from diesel engine was made to flow inside the inner cylinder and in between the inner and outer cylinders in which PCM is filled. The effect of fins (cylindrical) arranged on the outer periphery of inner cylinder is also studied. Fin arrangement increases the heat transfer rate by reducing the charging time of TESS. Exhaust gases from a diesel engine are used as heat source to the PCM to store thermal energy in the form of sensible and latent heat. Theoretical, numerical and experimental results were compared and found that the values are closer about 10%. The performance of the TESS is evaluated by calculating performance characteristics such as charging and discharging rates of the system and 14% of heat can be recovered from the 30% energy being wasted.
Keywords: Waste Heat Recovery; Thermal Energy Storage System; Phase Change Material; Latent Heat; Concentric Cylinder.
Optimisation of energy storage for an electricity system in the Indian scenario
by MOHAMMAD ZEESHAN
Abstract: The purpose of any electrical network is to provide electrical power reliably wherever it is needed, avoiding any loss of load. To do this effectively, electricity networks usually consist of various different types of plants, giving a generation portfolio. Energy storage plays a very vital role in renewable energy generation and allows for supply and demand. The action of the energy storage should allow for a reduction of the overall system fuel cost while still meeting the load demand. The fuel cost supply curve is plotted to estimate energy storage in order to minimise the overall system fuel cost. We have used the historical data for the electricity demand from the website of Central electricity authority of India. The energy storage is optimised to minimise the overall fuel cost for the system in order to maximise profit.
Keywords: Optimiziation; Energy; Storage; Scheduling; fuel; Generation;.
CFD simulation of thermoelectric generator installed on waste heat recovery system
by Krishna Kumar Purohit, P.M. Meena
Abstract: In present research work thermoelectric generation is numerically solved for waste heat recovery based hot junction point. All experiments are designed as per DOE methodology Taguchi Method. In first part of this study, CFD simulation is performed for waste heat exchanger run on IC engine exhaust gas. Total nine cases are designed for this task using Taguchi method. Wall temperature is response variable for CFD work. In second part CFD based results are carrying forward to FEM simulation which was conduct for thermoelectric generation numerical work. Same nine cases are used for this task also. It is found that number of fins used in WHRS is not the prime factor, but mass flow rate is the main factor for this study. S/N ratio and ANOVA analysis is performed for wall temperature and current density of TEG system.
Keywords: Thermoelectric generator; CFD simulation; Taguchi Method; Linear Regression model equation; ANOVA analysis.
FAST and Simulink Based Simulation Investigation of Wind Turbine Faults
by H. Malik, S.K. Mishra
Abstract: This paper shows the application of simulations of investigation of wind turbines imbalance faults. Our proposed model of wind turbine is imitated both in normal and faulty conditions of wind turbine based on TurbSim and FAST (Fatigues, Aerodynamics, Structure and Turbulences). The imbalance fault in furl is created by changing rotor furl and/or tail furl angle (with variation of +10, +5 and -5 degree) apart from required position, which generate uneven direction of WT. Fast Fourier Transform (FFT) is applied for transforming the time-domain simulation results of whole shaft torque of the wind turbine into frequency domain. For comparing the healthy and faulty operating scenarios of wind turbine, Power Spectrum Density (PSD) plots are developed. Thereafter, energy entropy has been evaluated to compare both the conditions. Obtained results presents that created blade imbalance increases the energy level of the recorded signal. Our research work provides the online diagnosis of wind turbine faults through simulation investigation using FAST and Simulink.
Keywords: Simulink; FAST; Blade Imbalance; Imbalance Fault; Power Spectrum Density (PSD); Simulation; Wind Turbine.