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In this work two energy saving methods are presented for the separation of a minimum boiling point azeotrope by using an intermediate entrainer. Extractive distillation column configurations with conventional, thermally integrated and dividing-wall columns are used for comparison. These configurations are designed, rigorously simulated and optimized to minimize the Total Annual Cost and to reduce...
An analysis of thermodynamic constraints shows that the low concentration of carbon dioxide in ambient air does not pose stringent limits on air capture economics. The thermodynamic energy requirement is small even using an irreversible sorbent-based process. A comparison to flue gas scrubbing suggests that the additional energy requirement is small and can be supplied with low-cost energy. In general,...
An innovative dual-mode thermochemical sorption energy storage method is proposed for seasonal storage of solar thermal energy with little heat losses. During the charging phase in summer, solar thermal energy is stored in form of chemical bonds resulting from thermochemical decomposition process, which enables the stored energy to be kept several months at ambient temperature. During the discharging...
Hydrate based gas separation (HBGS) process with silica sand and silica gel as contact medium was employed to capture CO 2 from fuel gas mixture. Gas uptake measurement at three different pressures (7.5, 8.5 and 9.0 MPa) and 274.15 K were conducted for hydrate formation kinetics and overall conversion of water to hydrate, rate of hydrate formation were determined. Water conversion of up to...
Undesirable output-oriented Data Envelopment Analysis (DEA) models with different return of scales are used to study the CO 2 (Carbon dioxide) emissions performance of the transport sector throughout China's 30 administrative regions. Empirical results show that the number of efficient regions has decreased since 2004, hitting the lowest record in 2006, and improving slightly afterwards. The...
In the coming decades, copper scarcity is likely to result in deteriorating ore quality, which in turn will lead to a higher GER (gross energy requirement) for copper production. In this study, this increasing GER and the effect it has on the EROI (energy return on investment) of wind turbine technologies have been analysed. The GER of copper in a 2050 100% renewable energy system will be a factor...
This paper proposed a thermal efficiency model theoretically based on an ideal ORC to analyze the influence of working fluid properties on the thermal efficiency, the optimal operation condition and exergy destruction for various heat source temperatures were also evaluated utilizing pinch point analysis and exergy analysis. The proposed model exhibits excellent agreements with the theoretical data...
Renewable resources represent an opportunity for environmentally preferred generation of electricity that supports energy security and independence; however integrating renewable technologies is not without challenges. Renewable resources have limitations that can include location, capacity, cost and availability. California is proactive in the implementation of renewable energy through legislation...
The circulating fluidized bed is of increasing importance for gas–solid and gas–catalytic reactions, for drying, and recently its use in solar energy capture and storage has been advocated. In all applications, the supply or withdrawal of heat is a major issue, and the heat transfer coefficient from the gas–solid suspension to the heat transfer surface needs to be determined as design parameter. The...
The need to reduce CO 2 emissions requires a great economical effort to optimize the processes and solve the main technical and economic problems which still limit a large-scale diffusion of this kind of carbon capture and storage (CCS) technologies.In this paper, the main results of a techno-economic comparison between ultra supercritical pulverized coal combustion (USC) and integrated gasification...
This study investigates the use of ANN (artificial neural networks) modelling to predict BSFC (break specific fuel consumption), exhaust emissions that are CO (carbon monoxide) and HC (unburned hydrocarbon), and AFR (air–fuel ratio) of a spark ignition engine which operates with methanol and gasoline. To obtain training and testing data, a number of experiments were performed with a four-cylinder,...
Dimethyl ether (DME) seems to be a potential approach for improving the cold start performance for spark-ignited (SI) engines. In this paper, the cold start performance of an SI engine fueled with pure DME was experimentally investigated and compared with that of the original SI gasoline engine. The engine was successfully cold started with pure DME and pure gasoline, respectively. The test results...
The effects of slip flow on heat transfer and entropy generation by considering the conjugate heat transfer problem in microchannels are studied, analytically. The heat transfer equations in the fluid and the finite thickness walls of the microchannel are solved analytically using thermal boundary conditions of the third kind at the outer surfaces of the walls and continuity of temperature and heat...
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