Economic feasibility of small wind turbines for domestic consumers in Egypt based on the new feed-in tariff

This paper provides an overview of the wind power potential at different regions in Egypt, along the Mediterranean and Red Sea, and the Western desert. A further technical and economic assessment is conducted for the electricity generation with 8 different small wind turbines at 17 locations. The annual electricity generation from selected wind turbines is evaluated. The obtained data are presented and discussed investigating the net present value and the payback period analyzing the profitability of selected wind turbines. The dependence of the turbine profitability from the feed-in tariff is specifically addressed

Poplar from phytoremediation as a renewable energy source:gasification properties and pollution analysis

Biomass gasification is a very efficient process to produce clean energy in the form of a fuel gas (syngas). Hazelnut shells and poplar have good energy production potential and they are abundant in nature. Hazelnut shells have the characteristics of a very good fuel and poplar is among the fastest growing trees; furthermore, poplar demonstrated the capability to absorb organic contaminants (i.e. heavy metals) from the soil in which they are cultivated. However, poplar is not usually used for biomass gasification and its potential is not fully assessed. Here, 3 types of biomass, hazelnut shells (HS), simple poplar (P) and poplar coming from a phytoremediation procedure (PHYP), were chosen as representative samples to be characterized and tested in a steam gasification process carried out on a bench scale fluidized bed gasifier. A comparison is reported on gasification results, such as gas composition, tar production and gas yield for the biomass feedstocks mentioned above. It was concluded that hazelnut shells and poplar (P and PHYP) could be easily gasified in a fluidized bed gasifier, thus producing a good quality gas with low polluting by-products. The PHYP sample showed lower tar content and higher gas yield. It is guessed that Ca and Mg, found in higher quantities in the PHYP sample, could have had a catalytic effect in tar reforming thus producing lower quantity of heavy hydrocarbons

Experimental measurement technique for the assessment of the fuel crossover diffusion coefficient in the membrane electrode assembly of a direct methanol fuel cell

Since the cross-over still seems to be the main issue of the direct methanol fuel cells, an experimental evaluation of the diffusive cross-over is performed. Even if the relationship of the rate through the membrane is the sum of the three terms of diffusive, osmotic and drag, the diffusive component is also present at open circuit lowering the Open Circuit Voltage of the single cell up to 50 % with respect to the Nernst potential. The goal of the research is to develop a direct measurement technique of the crossover that can provide the effective values of the parameters that characterize the membrane electrode assembly. The experimental set up consists in the pressure, flow and temperature control and acquisition using Labview. A sensitive analysis for three values of temperatures at 60°C, 65°C and 70°C is performed for first. Then, a small overpressure was generated in the cathode side by a valve located at the cathode outlet. A set of pressure were analysed for 0, 30 and 90 mbar of overpressure at the cathode. The tested fuel cell has a commercial Nafion 117 membrane and carbon paper gas diffusion layers 700 cm2 large. Preliminary results show that the differential concentration term seems to be significantly larger than the osmotic term. The diffusion coefficients are useful for fuel cell modelling and for the calibration of the operating conditions in the sensor less DMFC systems

Experimental and computational investigation of a new solar integrated collector storage system

The paper discusses a combined experimental-numerical analysis of an innovative solar thermal device to be used as an Integrated Collector Storage (ICS) system providing domestic hot water. In this equipment the collector acts also as a storage unit, without requiring an external vessel. Due to its simple configuration, the ICS device was successfully used in several circumstances, especially in extreme situations such as in post-earthquake tent cities or to reach remote users in Africa. In order to assess the efficiency of this collector, the draw-off process was investigated measuring the value of the mean temperature of the water discharging from the tap as cold water filled the collector. In the present configuration the draw-off is not completely optimised and a detailed analysis was carried out in order to investigate the mixing of cold and hot water in the solar collector during the discharge phase. A series of thermocouples was placed in selected positions around the shield of the collector to investigate the evolution of the near wall temperature. Furthermore, a numerical analysis based on Large-Eddy Simulation (LES) of the mixing process inside the collector was carried out using an open source, in-house, finite-volume computational code. Even if some restrictive hypotheses were made on the thermal boundary conditions and the absence of stratification, the LES results gave interesting findings to improve the collector performance

Unsteady cfd analysis of erosion mechanism in the coolant channels of a rotating gas turbine blade

The two-phase flow in a rotating wedge mimicking the final portion of a blade turbine internal cooling channel is here presented and discussed focusing on unsteady motion and erosion mechanisms. The rotation axis is placed to properly reproduce a configuration with a very strong deviation (90°). The flow field was modelled by using the well known k---f unsteady-RANS model based on the elliptic-relaxation concept. The model was modified by some of the authors to take into account the influence of turbulence anisotropy as well as rotation. The model was applied to the well-established and fully validated T-FlowS code. A systematic comparison of rotating and non-rotating case was carried out to show the influence of Coriolis force on flow and erosion mechanisms. The rotational effects strongly changed the flow behaviour within the channel, affecting both the unsteady flow and the particles trajectories. In the rotating case, there is no recirculation on the tip region; besides, position of the small recirculation regions above each pedestals change. These, and other minor effects, affect the particle motion thus resulting in a different erosion pattern

Assessment of CO2 bubble generation influence on direct methanol fuel cell performance

Fuel cells fed directly by liquid methanol represent a class of suitable devices for supply portable small power applications. To become a market attractive technology some issues must be properly addressed and resolved. The presence of gaseous CO2 generated in the anode channels is the main issue as it can hinder the free surface of the Gas Diffusion Layer reducing the active area and the methanol flux through the porous media towards the catalyst layer. In this work the influence of gas phase fraction on the cell performance and the relationship with the operating parameters such as air flow rate, methanol-water solution flow rate and current density is investigated. The characterization of CO2 bubbles flow in the anode channel is carried out

Assessment of innovative reforming procedures for biogas obtained from organic fraction of solid municipal waste

In the present paper reforming technologies for the treatment of biogas from municipal solid wastes are discussed. An approach based on the well-known ASPEN Plus software was adopted for the simulation of the whole process, assuming equilibrium conditions for the reactions development. The well-established steam-reforming, the dry reforming and an innovative two-steps reforming (including the basics of both models) were considered. A preliminary assessment was carried out comparing the predictions and experimental results of the steam-reforming procedure of diesel fuel. Then, the validated model was applied to the different schemes. The dry reforming (at 800 °C) showed better reforming efficiency if compared to steam reforming (at 600°C). However, carbon deposition occurs when dry reforming is in play. On the other hand, the two-steps technique demonstrated to be able to solve the problem of carbon deposition guaranteeing a very good efficiency

Composite Polymers Development and Application for Polymer Electrolyte MembraneTechnologies—A Review

Nafion membranes are still the dominating material used in the polymer electrolyte membrane (PEM) technologies. They are widely used in several applications thanks to their excellent properties: high proton conductivity and high chemical stability in both oxidation and reduction environment. However, they have several technical challenges: reactants permeability, which results in reduced performance, dependence on water content to perform preventing the operation at higher temperatures or low humidity levels, and chemical degradation. This paper reviews novel composite membranes that have been developed for PEM applications, including direct methanol fuel cells (DMFCs), hydrogen PEM fuel cells (PEMFCs), and water electrolysers (PEMWEs), aiming at overcoming the drawbacks of the commercial Nafion membranes. It provides a broad overview of the Nafion-based membranes, with organic and inorganic fillers, and non-fluorinated membranes available in the literature for which various main properties (proton conductivity, crossover, maximum power density, and thermal stability) are reported. The studies on composite membranes demonstrate that they are suitable for PEM applications and can potentially compete with Nafion membranes in terms of performance and lifetime

Economic Feasibility of Small Wind Turbines for Domestic Consumers in Egypt Based on the New Feed-in Tariff

Abstract This paper provides an overview of the wind power potential at different regions in Egypt, along the Mediterranean and Red Sea, and the Western desert. A further technical and economic assessment is conducted for the electricity generation with 8 different small wind turbines at 17 locations. The annual electricity generation from selected wind turbines is evaluated. The obtained data are presented and discussed investigating the net present value and the payback period analyzing the profitability of selected wind turbines. The dependence of the turbine profitability from the feed-in tariff is specifically addressed