International Journal of Advanced Renewable Energy Research
Volume:1 Issue: 7, 2012

This work investigated the production of bio oil from plum seed (Zyziphus jujuba) by fixed bed pyrolysis technology. A fixed bed pyrolysis system has been designed and fabricated for production of bio oil. The major components of the system are: fixed bed reactor, liquid condenser and liquid collector. Nitrogen gas was used to maintain the inert atmosphere in the reactor where the pyrolysis reaction takes place. The feedstock considered in this study is plum seed as it is available waste material in Bangladesh. The reactor is heated by means of a cylindrical biomass external heater. Rice husk was used as the energy source. The products are oil, char and gas. The parameters varied are reactor bed temperature, running time and feed particle size. The parameters are found to influence the product yields significantly. The maximum liquid yield of 39 wt% at 5200C for a feed particle size of 2.36-4.75 mm and a gas flow rate of 8 liter/min with a running time of 120 minute. The pyrolysis oil obtained at these optimum process conditions are analyzed for some of their properties as an alternative fuel. The density of the liquid was closer with diesel. The viscosity of the plum seed liquid was lower than that of the conventional fuels. The calorific value of the pyrolysis oil is one half of the diesel fuel.

This paper presents the simultaneous coordinated designing of the UPFC robust power oscillation damping controller and the conventional power system stabilizer. On the basis of the linearized Phillips-Herffron model, the coordinated design problem of PSS and UPFC damping controllers over a wide range of loading conditions and system configurations is formulated as an optimization problem with the eigenvalue-based multiobjective function which is solved by a particle swarm optimization algorithm (PSO) that has a strong ability to find the most optimistic results. The stabilizers are tuned to simultaneously shift the undamped electromechanical modes to a prescribed zone in the s-plane. To ensure the robustness of the proposed simultaneous coordinated controllers tuning, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed method is demonstrated through eigenvalue analysis, nonlinear time-domain simulation and some performance indices studies under various disturbance conditions of over a wide range of loading conditions. The results of these studies show that the PSO based simultaneous coordinated controller has an excellent capability in damping power system oscillations and enhance greatly the dynamic stability of the power system.

In this paper we used the grid-connected PV system to supply the agriculture area in Iran. Now Iran''s rural and remote areas is supplied through the public network that has voltage drop during peak times or use diesel generator as a supplement. Diesel power would not be the better option because of fuel''s high cost and immediate and long term effects on environment due to carbon emissions. In this paper we aim to replace the diesel generator with grid-connected PV system and reduce the voltage drop at peak times. With Consideration pollution penalty in Iran, a real Cost of Energy (COE) could be obtained. The HOMER software used for our analysis.

Advances in material processing cause that new solar cell technologies are emerging. Emerging photovoltaic solar cell technologies such as thin film solar cells tend to be cheaper than silicon cells made in standard technologies. Thin film PV technologies face a number of hurdles as they advance towards low-cost goals that are competitive with traditional sources of electricity. The US Department of Energy cost goal for thin films is about $0.33/Wp, which is based on a module efficiency goal of about 15% and module manufacturing costs of about $50/m2. This paper investigates the issues associated with achieving the opportunities for manufacturing cost reductions& improvement in cell efficiency. Key areas such as capital costs, deposition rates, layer thickness, materials costs, yields, substrates, and front and cell efficiency will be examined. One major conclusion is that materials costs must be reduced because they will dominate in mature technologies. Another is that module efficiency could be the overriding parameters if different thin films each optimize their manufacturing to a similar level.

In this study, the variation of steady-state combustion rate (otherwise called Normalized Burn Rate, NBR) with the density, moisture content and geometry of saw dust, palm fibre and rice husk briquettes, burned in free air was investigated. The quest for alternative fuel for heating and cooking as a result of depletion of fossil fuel and environmental pollution associated with it burning has necessitated the need to improve on the use of loose agro-waste as alternative. Cylindrical briquettes were used through out the experiment except for the effect of geometry where cylindrical briquettes with central hole and cylindrical solid briquettes were used. The briquettes were formed by compression of the pulp in the mould with an Instron compression test machine at a pressure range between 1.5 and 7.5Nmm2 which formed briquettes with densities between 200 and 500kgm-3. The results show that the NBR for the three briquette samples: wood saw dust, palm fibre and rice husk respevtively, were found to decrease as the density and moisture content increases. It was observed that hollow briquette had a higher NBR than solid briquette of the same pressure and relaxed diameter with saw dust having the highest variation and rice husk the least. The results show that briquettes could be a viable alternative to wood fuel.