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The synthesis of biodiesel from Jatropha curcas by transesterification is kinetically controlled. It depends on the molar ratio, reaction time, and temperature, as well as the catalyst nature and quantity. The aim of this study was to explore the transesterification of low-cost, inedible J. curcas seed oil utilizing both homogenous (potassium hydroxide; KOH) and heterogenous (calcium oxide; CaO) catalysis. In this effort, two steps were used. First, free fatty acids in J. curcas oil were reduced from 12.4 to less than 1 wt.% with sulfuric acid-catalyzed pretreatment. Transesterification subsequently converted the oil to biodiesel. The yield of fatty acid methyl esters was optimized by varying the reaction time, catalyst load, and methanol-to-oil molar ratio. A maximum yield of 96% was obtained from CaO nanoparticles at a reaction time of 5.5 h with 4 wt.% of the catalyst and an 18:1 methanol-to-oil molar ratio. The optimum conditions for KOH were a molar ratio of methanol to oil of 9:1, 5 wt.% of the catalyst, and a reaction time of 3.5 h, and this returned a yield of 92%. The fuel properties of the optimized biodiesel were within the limits specified in ASTM D6751, the American biodiesel standard. In addition, the 5% blends in petroleum diesel were within the ranges prescribed in ASTM D975, the American diesel fuel standard.

This case provides an overview of the electric power industry in the United States, including history, regulation, markets, competition, nuclear power, the environment, the economy, and new technologies.

Microbial fuel cell (MFC) is an emerging biotechnology to convert the organic substrates in wastewater to electricity by anaerobic electrogenic bacteria. The main challenge for MFC research is to elucidate the fundamental mechanisms of electron generation and transfer and to apply these mechanisms to improve the power production in the engineering operation. This study extensively investigated the effects of three inocula (Geobacter sulfurreducens, soil, and wastewater) on the power production and electrochemical characteristics (i.e., internal resistances, Coulombic Efficiency) of MFCs. The results showed that the extents of bacterial adhesion varied between mixed cultures (soil) and pure cultures (G. sulfurreducens). The voltage output increased 30% when bacterial adhesion was well-developed in the soil inocula. Meanwhile, the inoculum types clearly affected the internal resistance (R(in)) and power production of MFCs. Pure culture inoculum (G. sulfurreducens) had the lowest R(in) (165 Omega) and the highest Coulombic Efficiency (CE, 25.8%) and Energy Conversion Efficiency (ECE, 7.2%), while the mixed culture inocula (soil) with the high concentration of nonelectrogenic bacteria, exhibited the highest R(in) (620 Omega), lowest CE (9.2%) and lowest ECE (2.4%). Additionally, a second-order correlation was established between the anode potential (P(A)) and power output while an exponential correlation was established between the difference between anode and cathode potentials (DeltaP(C-A)) and power output.

Energy conservation potential of the evaporative roof cooling technique for a cinema house in a composite climate (characterized by Delhi) has been evaluated. Thermal loads due to heat conduction through the building envelope, the required ventilation and the occupants have been taken into account. Life-cycle-cost analysis has been employed to evaluate the cost effectiveness of this energy conservation technique. It is seen that evaporative cooling on the roof leads to a net saving of 14% in the initial investment and 17% in the annual cost.

Abstract Emission of thermal radiation from a surface can be controlled spectrally and spatially, and the polarization and coherence of the radiation field can be modified. Of the various methods available for altering the radiation properties from a surface, paint and coatings possess a clear advantage regarding the cost, ease of application and simplicity. In this paper, we comprehensively review the capabilities of paint and coating technologies for emission control and for possible new energy-related applications. We also present an overview of the involved theories, common design and fabrication methods and possible future research opportunities to optimize these paints and coatings for spectral selectivity for specific applications.

The effect of external EGR on knock was evaluated using a CFR engine. Combustion pressure was sampled on a time basis. A band pass filter in the time domain was applied to the pressure cycles. Five knock indices were calculated for each combustion cycle. The problem to quantify knock intensity was focused. At this extent, measurements were carried out on standard iso-octane-n-heptane blends in the test conditions used for the determ of the Motor Method Octane Number (MON). Knock intensity was varied acting on compression ratio. For each index, the conditions of absence of knock were determined using motored cycles. The indices were compared and one of them, showing the lowest C.O.V., was selected for further measurements. The effect of EGR on test fuels having different composition was evaluated varying the compression ratio, at fixed ignition timing. In this way, the same level of detonation, obtained in the absence of EGR, was realized with different amounts of external EGR. Percent variation of compression ratio was used to compare the ability of fuels, having different octane number, to tolerate compression ratio increase in presence of EGR. In particular, the tests were carried out on a matrix of twelve fuels with three levels of EGR. The results show that with all tested fuels the percent increase of compression ratio is strongly dependent on EGR.

With fewer emissions, higher efficiency, and quicker response than traditional coal-fired thermal power plants, the combined-cycle units (CCUs), as gas-fired generators, have been increasingly adapted in the U.S. power system to enhance the smart grids operations. Meanwhile, due to the inherent uncertainties in the deregulated electricity market, e.g., intermittent renewable energy output, unexpected outages of generators and transmissions, and fluctuating electricity demands, the electricity price is volatile. As a result, this brings challenges for an independent power producer (served in the self-scheduling mode) owning CCUs to maximize the total profit when facing the significant price uncertainties. In this paper, a data-driven risk-averse stochastic self-scheduling approach is presented for the CCUs that participate in the real-time market. The proposed approach does not require the specific distribution of the uncertain real-time price. Instead, a confidence set for the unknown distribution is constructed based on the historical data. The conservatism of the proposed approach is adjustable based on the amount of available data. Finally, numerical studies show the effectiveness of the proposed approach.

In this paper, recent achievements in the application of the lattice Boltzmann method (LBM) to complex fluid flows are reported. More specifically, we focus on flows through reactive porous media, such as the flow through the substrate of a selective catalytic reactor (SCR) for the reduction of gaseous pollutants in the automotive field; pulsed-flow analysis through heterogeneous catalyst architectures; and transport and electro-chemical phenomena in microbial fuel cells (MFC) for novel waste-to-energy applications. To the authors’ knowledge, this is the first known application of LBM modeling to the study of MFCs, which represents by itself a highly innovative and challenging research area. The results discussed here essentially confirm the capabilities of the LBM approach as a flexible and accurate computational tool for the simulation of complex multi-physics phenomena of scientific and technological interest, across physical scales.