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Abstract: Using energy systems analysis, we examine the potential to reduce CO2 emissions and oil use by integrating motor biofuel production with pulp mills. BLG-DME (black liquor gasification with di-methyl ether production) is compared with solid biomass gasification with BIG-FT (solid biomass gasification with Fischer-Tropsch fuel production). The studied systems are expanded with stand-alone production of biomass-based electricity and motor fuel so that they yield the same functional unit in terms of motor fuel and electricity as well as pulp or paper product, in order to facilitate comparison. More motor biofuel can be produced in integration with the studied mills with BLG-DME than with BIG-FT because the black liquor flow is large compared with other fuel streams in the mill and the integration potential for BIG-FT is limited by the mill’s heat demand. When both systems are required to produce the same functional unit, the BLG-DME system achieves higher system efficiency and larger reductions in CO2 emissions and oil use per unit of biomass consumed. In general, integration of motor biofuel production with a pulp mill is more efficient than stand-alone motor biofuel production. Larger reductions in CO2 emissions or oil use can, however, be achieved if biomass replaces coal or oil in stationary applications. [Copyright &y& Elsevier]

Abstract: Standalone diesel generating system utilized in remote areas has long been practiced in Malaysia. Due to highly fluctuating diesel price, such a system is seemed to be uneconomical, especially in the long run if the supply of electricity for rural areas solely depends on such diesel generating system. This paper would analyze the potential use of hybrid photovoltaic (PV)/diesel energy system in remote locations. National Renewable Energy Laboratory’s (NREL) HOMER software was used to perform the techno-economic feasibility of hybrid PV/diesel energy system. The investigation demonstrated the impact of PV penetration and battery storage on energy production, cost of energy and number of operational hours of diesel generators for the given hybrid configurations. Emphasis has also been placed on percentage fuel savings and reduction in carbon emissions of different hybrid systems. At the end of this paper, suitability of utilizing hybrid PV/diesel energy system over standalone diesel system would be discussed mainly based on different solar irradiances and diesel prices. [Copyright &y& Elsevier]

Growing demand for fossil fuels and related environmental issues have directed global attention towards development of alternative fuels from renewable sources. In this regard, biodiesel synthesized from vegetable oils and animal fats has shown potential as alternative to diesel fuel owing to its comparable fuel properties and combustion characteristics. However, higher oxygen content in biodiesel has raised some technical issues for its long term utilization in engines. Subsequently, the second generation liquid hydrocarbon fuels are being developed via catalytic deoxygenation of fatty acids present in vegetable oils. Presently, the research focus is on the pathways for catalytic deoxygenation like hydrodeoxygenation, decarboxylation, and decarbonylation. In hydrodeoxygenation, use of hydrogen gas and sulfided metal catalysts ensure higher conversion of vegetable oil into hydrocarbon fuel compared to the other two pathways. On the contrary, decarboxylation and decarbonylation are mostly hydrogen-free processes ensuring economical production of hydrocarbon fuel from vegetable oils. Hence, the techno-economical issues related to deoxygenation process need to be addressed for its commercial viability. Further, key operating parameters like nature of catalysts and supports, catalyst amount, reaction temperature, reaction atmosphere, hydrogen partial pressure, feed type, feed rate, type of solvent, H 2 /fatty acid molar ratio etc. are reported to have substantial influence on the hydrocarbon yield and selectivity. This review paper expounds a comparative assessment on the various deoxygenation pathways with their reaction mechanisms to opt for the suitable pathway for conversion of vegetable oils into hydrocarbon fuels based on yield and selectivity of the desired product, ease of use, economy etc. It also explicates the influence of various operating parameters to obtain optimum hydrocarbon conversion and selectivity during catalytic deoxygenation of vegetable oils and related feedstock. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a methodology of sizing optimization of a stand-alone hybrid wind/PV/diesel energy system is presented. This approach makes use of a deterministic algorithm to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the total cost of the system is minimized while guaranteeing the availability of the energy. The collection of 6months of data of wind speed, solar radiation and ambient temperature recorded for every hour of the day were used. The mathematical modeling of the main elements of the hybrid wind/PV/diesel system is exposed showing the more relevant sizing variables. A deterministic algorithm is used to minimize the total cost of the system while guaranteeing the satisfaction of the load demand. A comparison between the total cost of the hybrid wind/PV/diesel energy system with batteries and the hybrid wind/PV/diesel energy system without batteries is presented. The reached results demonstrate the practical utility of the used sizing methodology and show the influence of the battery storage on the total cost of the hybrid system. [Copyright &y& Elsevier]

The Diesel refrigeration cycle using an ideal quantum gas as the working substance is called quantum Diesel refrigeration cycle, which is different from Carnot, Ericsson, Brayton, Otto and Stirling refrigeration cycles. For ideal quantum gases, a corrected equation of state, which considers the quantum behavior of gas particles, is used instead of the classical one. The purpose of this paper is to investigate the effect of quantum gas as the working substance on the performance of a quantum Diesel refrigeration cycle. It is found that coefficients of performance of the cycle are not affected by the quantum degeneracy of the working substance, which is the same as that of the classical Diesel refrigeration cycle. However, the refrigeration load is different from those of the classical Diesel refrigeration cycle. Lastly, the influence of the quantum degeneracy on the performance characteristics of the quantum Diesel refrigeration cycle operated in different temperature regions is discussed. [Copyright &y& Elsevier]

Abstract: This paper highlights the effect of emissions regulations on in-use emissions from heavy-duty vehicles powered by different model year engines. More importantly, fuel economy data for pre- and post-consent decree engines are compared. The objective of this study was to determine the changes in brake-specific emissions of NO x as a result of emission regulations, and to highlight the effect these have had on brake-specific CO2 emission; hence, fuel consumption. For this study, in-use, on-road emission measurements were collected. Test vehicles were instrumented with a portable on-board tailpipe emissions measurement system, WVU''s Mobile Emissions Measurement System, and were tested on specific routes, which included a mix of highway and city driving patterns, in order to collect engine operating conditions, vehicle speed, and in-use emission rates of CO2 and NO x . Comparison of on-road in-use emissions data suggests NO x reductions as high as 80% and 45% compared to the US Federal Test Procedure and Not-to-Exceed standards for model year 1995–2002. However, the results indicate that the fuel consumption; hence, CO2 emissions increased by approximately 10% over the same period, when the engines were operating in the Not-to-Exceed region. [Copyright &y& Elsevier]