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Records with Keyword: Technoeconomic Analysis
Techno-economic System Analysis for SOFC/GT Hybrid System Accounting for Degradation Effects
Haoxiang Lai, Thomas Adams II
October 30, 2018 (v1)
Keywords: Modeling and simulation, Process design, SOFC/GT Hybrid, Technoeconomic Analysis
Solid oxide fuel cells (SOFCs) produce power with higher efficiency and lower greenhouse gas emission than conventional power production systems such as coal/natural gas power plants. However, a major challenge with SOFCs is that they degrade over time, leading to a short lifetime and limiting their commercialization. When operated in constant power mode—the most common way of baseload power production—the lifetime of an SOFC is as short as around 1.5 years. As an SOFC starts to degrade, the fuel rate and current density must increase in order to compensate and keep power production at a constant level. This compounds the problem by actually increasing the rate of degradation further, resulting in an exponentially increasing degradation rate and therefore a short lifetime.
It has recently been found that by operating the SOFC differently with constant voltage instead of power, the degradation rate can be slowed such that the cell lifetime can be increased to around 13-14 years. In th... [more]
Optimal Component Sizing for Peak Shaving in Battery Energy Storage System for Industrial Applications
Rodrigo Martins, Holger C. Hesse, Johanna Jungbauer, Thomas Vorbuchner, Petr Musilek
September 21, 2018 (v1)
Keywords: Energy Storage, linear programming, battery aging modelling, lithium-ion battery, peak-shaving, Technoeconomic Analysis
Recent attention to industrial peak shaving applications sparked an increased interest in battery energy storage. Batteries provide a fast and high power capability, making them an ideal solution for this task. This work proposes a general framework for sizing of battery energy storage system (BESS) in peak shaving applications. A cost-optimal sizing of the battery and power electronics is derived using linear programming based on local demand and billing scheme. A case study conducted with real-world industrial profiles shows the applicability of the approach as well as the return on investment dependence on the load profile. At the same time, the power flow optimization reveals the best storage operation patterns considering a trade-off between energy purchase, peak-power tariff, and battery aging. This underlines the need for a general mathematical optimization approach to efficiently tackle the challenge of peak shaving using an energy storage system. The case study also compares t... [more]
Effect of Moisture Content on Lignocellulosic Power Generation: Energy, Economic and Environmental Impacts
Karthik Rajendran
July 31, 2018 (v1)
Keywords: energy analysis, life-cycle assessments, lignocellulose, power generation, Technoeconomic Analysis
The moisture content of biomass affects its processing for applications such as electricity or steam. In this study, the effects of variation in moisture content of banagrass and energycane was evaluated using techno-economic analysis and life-cycle assessments. A 25% loss of moisture was assumed as a variation that was achieved by field drying the biomass. Techno-economic analysis revealed that high moisture in the biomass was not economically feasible. Comparing banagrass with energycane, the latter was more economically feasible; thanks to the low moisture and ash content in energycane. About 32 GWh/year of electricity was produced by field drying 60,000 dry MT/year energycane. The investment for different scenarios ranged between $17 million and $22 million. Field-dried energycane was the only economically viable option that recovered the investment after 11 years of operation. This scenario was also more environmentally friendly, releasing 16-gCO₂ equivalent/MJ of electricity prod... [more]
Techno-economic comparison of Acetone-Butanol-Ethanol fermentation using various extractants
Giancarlo Dalle Ave, Thomas A. Adams II
June 12, 2018 (v1)
Keywords: Acetone, Butanol, Cost of CO2 Emissions Avoided, Ethanol, Extraction, Fermentation, Technoeconomic Analysis
This work compares various chemicals for use as extractants in second-generation Acetone-Butanol-Ethanol fermentation on economic and environmental bases. Both non-toxic and toxic extractants are considered in this study. The combinative extractive-distillation separation process was modelled using a combination of Microsoft Excel 2013, MATLAB 2015 and Aspen Plus v8.8. Separation trains were designed and optimized for each extractant to best take advantage of extractant properties. Upstream units considered in this analysis include: biomass (switchgrass) solids processing, biomass pre-treatment and saccharification, and fermentation. Downstream processes considered include utility generation and wastewater treatment. The cost of CO2 equivalent emissions avoided (CCA) was used as the metric to compare the environmental impact of each process as compared to conventional petroleum-based gasoline. The economic and environmental best extractant is shown to be 2-ethyl-hexanol with a minimum... [more]
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