Search

In Algeria, the residential sector registries a high rate of energy consumption which requires an important action for rationalizing this charge and integrating renewable energies. Particularly, the geothermal energy with its less intermittence presents an attractive candidate to reinforce energy-saving and building thermal comfort. In this paper, geothermal energy is used to create a favorable environment for creating a better life inside a semi-buried building during the very hot period in the desert climate of southern Algeria. The cooled room is buried in rocky soil until 3 m depth, and only 0.5 m of the room high is above the ground level. The upper parts of southern and northern room walls are provided by small windows for aeration and lighting purposes. Inside room the air flow is modeled by Navier-Stocks and energy equations. The computational domain is taken as 3D design, and the prediction of temperature is calculated by ANSYS-Fluent code. For the base case, at 2 m height, the indoor temperature fluctuates between 30 and 33°C which is in good concordance with experimental data. For reducing the indoor temperature, some simple design modifications are introduced and a small ventilation system is installed. The new results show that the indoor temperature does not exceed 25 °C at the height of 2 m, therefore the temperature for height between 2 and 3 m it fluctuates between 25 and 26 °C. This indoor thermal behavior ensures acceptable cooling with negligible electricity consumption. [ABSTRACT FROM AUTHOR]

Abstract: A single phase computational fuel cells model is presented to elucidate three-dimensional interactions between mass transport and electrochemical kinetics in proton exchange membrane (PEM) fuel cells with straight gas channels. The governing differential equations are solved over a single computational domain, which consists of a gas channel, gas diffusion layer, and catalyst layer for both the anode and cathode sides of the cell as well as the solid polymer membrane. Emphasis is placed on obtaining a basic understanding of how three-dimensional flow and transport phenomena in the air cathode impact the electrochemical process in the flow field. The complete cell model has been validated against experimentally measured polarization curve, showing good accuracy in reproducing cell performance over moderate current density interval. Fully three-dimensional results of the flow structure and species profiles are presented for cathode flow field. The effects of pressure on oxygen transport and water removal are illustrated through main axis of the flow structure. The model results indicate that oxygen concentration in reaction sites is significantly affected by pressure increase which leads to rising fuel cells power. [Copyright &y& Elsevier]

[Display omitted] • SONATRACH incurs LPG sales losses from electricity outages added to expensive bills. • PV-based CAES with flared LPG recovery was proposed to achieve network independence. • System power control was based on Aspen HYSYS industrial process simulator Software. • It was observed an increase in power output by over 100 % or 10 MW vs. 4.5 MW input. • In addition, the proposed CAES system saved 30 % of power network operating costs. The Algerian National Company for the Transport and Marketing of Hydrocarbons (SONATRACH) provides crude oil, natural gas, condensate, and liquefied petroleum gas (LPG), which recorded an average invoiced electricity consumption of 1.3 M$/yr from 2017 to 2022 for Region of Transport Haoud El-Hamra (RTH) alone. LPG SP1 ELR1 (Pumping Station 1 of Expansion Line 1 at Alrar-Hassi R'mel), as one of the RTH pumping stations, indicated a considerable electricity supply through three 220 KV overhead electrical lines, reduced to 5.5 KV using the transformers to ensure a station input power of around 4.5 MW, representing a loss of 21 % of annual consumption. However, the input power is never fully utilized by the station and paid on average 391.6 K$/yr added to equipping the station with transformers at an extra cost of 1.78 M$ and the power outages from the grid resulting in significant losses of 105.6 K$/h in pumped LPG sales. This paper presents the first process study of a photovoltaic (PV) and electrical grid-assisted Compressed Air Energy Storage (CAES) system integrated into the LPG SP1 ELR1 with the flared LPG recovery to achieve electrical independence, and it includes a system analysis on process optimization, cost, and environmental impact. The study discusses a combination of PV, electrical grid, and, in particular, the CAES process simulated using ASPEN HYSYS software to control its output power, including three scenarios: without air thermal energy recovery (ATER), with ATER, and with LPG thermal energy recovery (LPG-TER). According to the results, the CAES with LPG-TER demonstrated a more than 100 % increase in power delivery, corresponding to approximately 10 MW of generated power compared to input power of 4.5 MW, thus exceeding the needs of the pumping station by two times. In addition, the comparison with the literature-mentioned competing systems underscores the system's superiority, with a 32 %, 55 %, and 66–68 % improvement over D-CAES, I-CAES, and A-CAES, respectively. The study revealed that achieving power grid independence through the CAES system resulted in annual capital and operating cost savings of 2.22 M$/yr. Adopting the CAES system can significantly reduce CO 2 emissions from natural gas combustion to power the grid, resulting in a 29 % decrease in combined emissions from LPG and natural gas. The study's extended findings to similar SONATRACH pumping stations show a reducing CO 2 emissions by 22.17 % and savings of 3679 MW/yr. Beyond SONATARCH, the system offers savings and flaring reduction from 100 MW/day and 5.28 bbl/day up to 42400 MW/day and 2329.5 bbl/day. [ABSTRACT FROM AUTHOR]

Large reductions in carbon dioxide (CO 2 ) emissions are needed to mitigate the impacts of climate change. Electric power plants and refineries were the largest CO 2 emission sources in Algeria. One option to reduce CO 2 emissions is carbon dioxide capture and storage (CCS), which can be used to generate electricity with processes of geothermal heat extraction. The objective of this study is to analyse the spatial distribution of CO 2 emission sources, and to identify the most suitable locations for integrating this technology. For these suitable locations, dioxide carbon emissions were quantified. This quantification is used to evaluate the potential for both electric and hydrogen production and to estimate the levelized cost of electrolytic hydrogen. For this reason, Geographical Information System (GIS) based methodology with combining several criteria is used. These criteria include spatially varied CO 2 emission sources, potential geothermic and demand of electrical energy (considering the existing production sources and the consumption of electrical energy for each city). GIS is used for creating new multi-layer information. It also offers a highly flexible, easily updateable database and display tool that facilitates the spatial analyses. As a result, the most suitable areas were located extensively in northeast and southwest part of Algeria. The northeast site was characterised by geothermal gradient of 6 °C/100 m and has the most important electric and hydrogen potential, while in the second site the electric and hydrogen production is low than the first. In addition, the cost of hydrogen production at the northeast site is more competitive. [ABSTRACT FROM AUTHOR]

Abstract: This article considers Algeria as a case study for the evaluation of the solar hydrogen production potential. The study relates to the design of a hydrogen generating station by water electrolysis whose energy resources are solar. The electricity supply is done by a solar tower power plant. The numerical simulation of the hydrogen production for the installation proposed is made while being based on the characteristic equations governing the electrolysis of water, hydraulic pumping system and the solar tower. The hydrogen production rate is given for various values of the solar radiation and several sites of Algeria. The results obtained by the established computer code, and of which the required goal is the determination of the most favorable conditions for a better production of hydrogen, are presented and discussed. [Copyright &y& Elsevier]