Qatar Foundation Annual Research Conference Proceedings Volume 2018 Issue 1
- تاريخ المؤتمر: 19-20 Mar 2018
- الموقع: Qatar National Convention Center (QNCC), Doha, Qatar
- رقم المجلد: 2018
- المنشور: ١٢ مارس ٢٠١٨
141 - 142 of 142 نتائج
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Profitability Analysis for a Distributed Grid Connected Photovoltaic System in Qatar
مزيد أقلالمؤلفون: Omar EllabbanQatar is emerging as one of the most dynamic and innovative economies in the Middle East over the last decades. The rapid expansion in the industrial sector, as the key economic driver, in addition to, the strong growth in construction sector, driven by large government investments, alongside the rapidly increasing population and rising living standards put continuously increasing pressures on domestic energy consumption leading to the escalating demand for electricity. To meet these challenges, Qatar has started thinking for long term plans for reducing it dependency on fossil fuels and implementing energy conservation measures as part of its 2030 National Vision. Therefore, Qatar start investing large amounts of money in supporting research and development in the renewable energy sector, in particular, the photovoltaic (PV) technologies for electricity production due to the high level of insolation resulted from its geographical location in the subtropical ridge. Plans are underway to generate 2% of the national electricity production from solar photovoltaic systems by 2020, and 20% by 2030. Solar PV is one of the four main direct solar-energy technologies, in addition to, the concentrating solar power (CSP), solar thermal and solar fuels. Solar PV has various applications and the majority of the installed PV systems are grid connected either through small-scale rooftop (up to ten kWs) or ground-mounted systems installed on residential or commercial properties (ten kW to one MW), or through utility-scale PV farms (one MW or more). Solar PV systems are being installed everywhere around the globe and in developed countries the fastest growing sector is the distributed, grid-connected, rooftop systems. The motivation for individuals to install their own PV system can vary; early solar adopters chose to own solar PV system because of environmental concerns, or a desire to reduce their reliance on the electric power grid. In recent years due to the rapid decline in PV system installed price, the market for solar photovoltaic systems is growing rapidly into a mature industry welcoming an entirely new class of consumers motivated by the prospect of saving money on their electricity bills and making a responsible investment in their home. The projective of this work is creating a Profitability Analysis Tool (PAT) for PV systems in the context of distributed, grid-connected buildings. An economic evaluation model will be designed to evaluate the electrical energy production from PV systems taking into account all the operational incomes as well as all the expenses for the implementation, operation and maintenance of the PV system during its entire lifetime based on discounted cash flow analysis. The proposed profitability analysis tool will help the investors (home owners) to evaluate their solar PV investment through a wide range of economic inductors such as, Net Present Value (NPV), Internal Rate of Return (IRR), Simple Payback Time (SPT), Benefit to Cost Ratio (BCR) and Profitability Index (PI). The proposed profitability analysis tool gives the investors the ability to investigate different financing methods (combination between equity and debt) in addition to evaluating the advantages of applying different proposed governmental incentives (subsidies and tax incentives). Furthermore, since the variations in discount rate, tariff rate, installation and maintenance cost per kW and solar insolation will have a great impact in the profitability analysis, a sensitivity analysis using Monte Carlo simulation will be included in the proposed profitability analysis tool to highlight the impact of these variations. Furthermore, this Monte Carlo based sensitivity analysis will act as a guide for governmental policy designers to navigate their way to increase distributed solar PV adaptation in Qatar.
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Chitosanbased nanocomposite for the inhibition of sulfate reducing bacteria: Towards “green” biocides for microbial influenced corrosion
مزيد أقلالمؤلفون: Abdul Rasheed Pathath, Khadeeja Abdul Jabbar and Dr Khaled MahmoudMicrobial Influenced Corrosion (MIC) is a process influenced by various microorganisms especially by sulfate reducing bacteria (SRB) which affects the kinetics of corrosion procedure under anaerobic conditions. About 20% of the annual corrosion damages of metals may be produced by microbial activities especially due to anaerobic corrosion influenced by SRB. MIC is the main contributor of corrosion problems and a leading cause of pipeline failure in oil and gas industries. SRBs are main microorganisms that can anaerobically generate sulfide species causing biocorrosion in the injection networks. Moreover, the produced H2S gas is toxic, corrosive, and responsible for a variety of environmental problems. Additionally, the presence of SRB can result in health and safety risks to workers due to sulfide production. In order to prevent this, oil-producing companies use high concentrations of biocides to disinfect the water and inhibit excessive biofilm formation caused mainly by (SRB). However, traditional biocides may be harmful to environment by forming harmful disinfection byproducts. Also the biocide treatment having other disadvantages like low efficiency against biofilms, release of disinfection byproducts and its high cost. Theses disadvantages can be solved by the use of green biocides including nanomaterials which has very low toxicity, environmental acceptability, safety and ease of use etc. Several nanomaterials have been utilized to inhibit the growth of different microorganisms and can be a possible alternative for controlling SRB biofilm and its corrosion. Here, we introduced an environmentally benign approach to use a green biocide; chitosan-ZnO nanocomposite against SRB induced MIC towards carbon steel. The nanoparticles of chitosan and ZnO were prepared independently and treated together to form the chitosan-ZnO nanocomposite. The nanocomposite was synthesized with different percentage of ZnO initial content and characterized by SEM, TEM, FTIR, TGA etc. The average size of chitosan nanoparticles were in between 40-60 nm and it clearly shows the distribution of ZnO NPs in the chitosan nanoparticles matrix. The particles in chitosan-ZnO nanocomposite were found with almost spherical morphology. The electrodes were made of carbon steel S150 was used for all the experiments. S150 carbon steel electrode of exposed area of 8 mm diameter used for the corrosion experiments after hot mounting process followed by polishing and grinding process. The electrodes were incubated with SRB containing media with and without nanocomposites and kept in a shaking incubator at 37° under inert atmosphere. The effect of the chitosan-ZnO nanocomposite on corrosion inhibition was studied by varying the concentrations of nanocomposites under optimized bacterial concentration and experimental conditions. The surface features and the elemental analysis of the biofilm and corrosion product were evaluated by SEM as well as XPS in different time intervals and compared with the control samples. The surface features of the corroded electrodes was investigated by SEM and profilometry after removing the corrosion product by using a simple chemical treatment procedure. The effect of chitosan-ZnO nanocomposite on corrosion behavior of carbon steel against SRB was investigated by electrochemical impedance spectroscopy, corrosion potential, polarization resistance and polarization curve measurements at different time intervals. It was found that the chitosan-ZnO nanocomposite inhibits the SRB biofilm formation and corrosion. The results of the electrochemical analysis showed that the chitosan-ZnO nanocomposite (10% ZnO content) at 250 ppm concentration having highest corrosion inhibition and can be used an effective corrosion inhibition agent against SRB induced MIC. References Wang, H. F., et al. Materials Chemistry and Physics 124, 791-794, (2010).Vanaei, H. R., et al. International Journal of Pressure Vessels and Piping 149, 43-54, (2017). Xu, D. et al. Engineering Failure Analysis 28, 149-159, (2013).
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