Showing papers in "Energies in 2008"
TL;DR: In this article, a local restaurant in Halifax, Nova Scotia, Canada was used for the transesterification of waste cooking oil and the final biodiesel esters were determined by gas chromatography.
Abstract: As crude oil price reach a new high, the need for developing alternate fuels has become acute. Alternate fuels should be economically attractive in order to compete with currently used fossil fuels. In this work, biodiesel (ethyl ester) was prepared from waste cooking oil collected from a local restaurant in Halifax, Nova Scotia, Canada. Ethyl alcohol with sodium hydroxide as a catalyst was used for the transesterification process. The fatty acid composition of the final biodiesel esters was determined by gas chromatography. The biodiesel was characterized by its physical and fuel properties including density, viscosity, acid value, flash point, cloud point, pour point, cetane index, water and sediment content, total and free glycerin content, diglycerides and monoglycerides, phosphorus content and sulfur content according to ASTM standards. The viscosity of the biodiesel ethyl ester was found to be 5.03 mm 2 /sec at 40 o C. The viscosity of waste cooking oil measured in room temperature (at 21° C) was 72 mm
507 citations
TL;DR: Pimentel et al. as mentioned in this paper argued that using food crops such as corn grain to produce ethanol raises major nutritional and ethical concerns, and that using corn for ethanol increases the price of U.S. beef, chicken, pork, eggs, breads, cereals, and milk more than 10% to 30%.
Abstract: David Pimentel *, Alison Marklein, Megan A. Toth, Marissa Karpoff, Gillian S. Paul, Robert McCormack, Joanna Kyriazis and Tim Krueger 5126 Comstock Hall, Cornell University, Ithaca, NY 14853, USA * Author to whom correspondence should be addressed; E-mail: Dp18@cornell.edu Received: 29 July 2008 / Accepted: 11 September 2008 / Published: 16 September 2008 __________________________________________________________________________________ Abstract: The rapidly growing world population and rising consumption of biofuels are increasing demand for both food and biofuels. This exaggerates both food and fuel shortages. Using food crops such as corn grain to produce ethanol raises major nutritional and ethical concerns. Nearly 60% of humans in the world are currently malnourished, so the need for grains and other basic foods is critical. Growing crops for fuel squanders land, water and energy resources vital for the production of food for human consumption. Using corn for ethanol increases the price of U.S. beef, chicken, pork, eggs, breads, cereals, and milk more than 10% to 30%. Keywords: agriculture, biofuels, energy, food security, fossil fuels, natural resources, renewable energy. __________________________________________________________________________________ 1. Introduction With shortages of fossil energy, especially oil and natural gas, and heavy biomass energy consumption occurring in both developed and developing countries, a major focus has developed worldwide on biofuel production [1-3]. Emphasis on biofuels has developed globally, including those made from crops such as corn, sugarcane, and soybean, considered by some researchers as renewable energy sources. Wood and crop residues also are being used as fuel [4]. Though it may seem beneficial to use renewable plant materials for biofuel, the use of crop residues and other biomass for biofuels raises concerns about major environmental impacts [5].
138 citations
TL;DR: Cardoso et al. as discussed by the authors proposed the use of free fatty acids (FFAs) as a valuable alternative that would make their production costs more competitive than petroleum-derived fuel.
Abstract: Abiney L Cardoso, Soraia Cristina Gonzaga Neves and Marcio J da Silva * Departament of Chemistry, Federal University of Vicosa, Vicosa, Minas Gerais, Brazil, 36570-000 * Author to whom correspondence should be addressed; E-Mail:silvamj2003@ufvbr Received: 5 August 2008; in revised form: 16 September 2008 / Accepted: 17 September 2008 / Published: 24 September 2008 Abstract: The production of biodiesel from low-cost raw materials which generally contain high amounts of free fatty acids (FFAs) is a valuable alternative that would make their production costs more competitive than petroleum-derived fuel Currently, the production of biodiesel from this kind of raw materials comprises a two-stage process, which requires an initial acid-catalyzed esterification of the FFA, followed by a base-catalyzed transesterification of the triglycerides Commonly, the acid H
114 citations
TL;DR: Hamouda et al. as discussed by the authors showed that IFT and contact angle measurements indicate an increase in water wetness as temperature increases, which contradict the results obtained by relative permeability experiments.
Abstract: Aly A. Hamouda* and Omid Karoussi Department of Petroleum Engineering, University of Stavanger, 4036 Stavanger, Norway * Author to whom correspondence should be addressed; E-mail: aly.hamouda@uis.no Received: 23 April 2008; in revised form: 30 May 2008 / Accepted: 2 June 2008 / Published: 6 June 2008 Abstract: It is customary, for convenience, to use relative permeability data produced at room temperature. This paper shows that this practice underestimates oil recovery rates and ultimate recovery from chalk rocks for high temperature reservoirs. Above a certain temperature (80°C in this work) a reduction of oil recovery was observed. The reduction in oil recovery is reflected by the shift of relative permeability data towards more oil-wet at high temperature (tested here 130°C). However, both IFT and contact angle measurements indicate an increase in water wetness as temperature increases, which contradict the results obtained by relative permeability experiments. This phenomenon may be explained based on the total interaction potential, which basically consists of van der Waals attractive and short-range Born repulsive and double layer electrostatic forces. The fluid/rock interactions is shown to be dominated by the repulsive forces above 80°C, hence increase fine detachment enhancing oil trapping. In other words the indicated oil wetness by relative permeability is misleading. Keywords: Temperature, Relative Permeability, Oil Recovery, Wettability (Contact angle), Interfacial tension (IFT), Fluid/rock interaction 1. Introduction Improving oil recovery is recognized as the major target and challenge at the different stages of an oil field development. Among several methods in oil recovery, thermal recovery has been used to increase the mobility of oil specifically in heavy crude oil reservoirs. Babadagli [1-2] compared the
80 citations
TL;DR: In this article, the origins of carbon trading in Europe and the functioning of the European Union Emission Trading Scheme (EU ETS) and the workings of several spot, futures and options markets where European Union Allowances are traded are reviewed.
Abstract: Since the entry into force of the Kyoto Protocol, carbon trading has been in continuous expansion. In this paper, we review the origins of carbon trading in order to understand how carbon trading works in Europe and, specifically, the functioning of the European Union Emission Trading Scheme (EU ETS) and the workings of several spot, futures and options markets where European Union Allowances are traded. As well, the linking of the EU ETS with the other United Nations carbon markets is also studied.
55 citations
TL;DR: The shift to a bio-based economy for the Netherlands is not only required because of climate change, but also for industrial strategy reasons as mentioned in this paper, and it is precisely to these sectors that a biobased economy will offer new opportunities.
Abstract: The shift to a bio-based economy for the Netherlands is not only required because of climate change, but also for industrial strategy reasons. Traditional strongholds of the Dutch economy like the Rotterdam harbour, the agricultural sector (including the greenhouse sector, and food and feed industries) and the petrochemical industry will be affected by the new economic realities, and it is precisely to these sectors that a bio-based economy will offer new opportunities.
27 citations
TL;DR: In this paper, the authors argue that "Crops for biofuels squanders cropland, water, and energy resources vital for food production needed for people" and that bio-fuel crops for bio-energy squander croplands, water and energy.
Abstract: Crops for biofuels squanders cropland, water, and energy resources vital for food production needed for people.
21 citations
TL;DR: The journal Energies (ISSN 1996-1073) as mentioned in this paper is a journal dedicated to thermodynamics, information theory, and diversity preservation, with a long-standing research interest in thermodynamics.
Abstract: As a scientist with a long-standing research interest in thermodynamics, information theory and diversity preservation, I would like to start publishing the journal Energies (ISSN 1996-1073).[...]
8 citations
TL;DR: In this article, the interaction of guest molecules ranging from pentan-1-ol to octan- 1-ol with α-cyclodextrin (α-CD) in water of has been studied calorimetrically at 283.15, 288.15 and 308.15 K with an isoperibolic titration calorimeter designed in their laboratory.
Abstract: The interaction of guest molecules ranging from pentan-1-ol to octan-1-ol with α-cyclodextrin (α-CD) in water of has been studied calorimetrically at 283.15, 288.15, 293.15, 298.15 and 308.15 K with an isoperibolic titration calorimeter designed in our laboratory. The calorimetric method employed allows the determination of the thermodynamic parameters characterizing the binding process, ΔG°m, ΔH°m, ΔS°mand ΔCp°, namely free energy, enthalpy, and calorific capacity. These results show that in the temperature range investigated, the entropy change increased with chain length. This is in line with what is expected for a hydrophobic dehydration process. However, that effect is not expected to lead to the more pronounced negative CH2-increment observed for nc > 5 or 6. As for many other ligand binding processes, we can observe a significant enthalpy - entropy compensation for this system, both with respect to temperature and structure.
3 citations
TL;DR: The International Energy Agency (IEA) was founded in the early 1970s and is an energy policy advisor to 27 countries as discussed by the authors, including the United States and the European Union.
Abstract: The International Energy Agency, headquartered in Paris, was founded in the early 1970s and is an energy policy advisor to 27 countries.[...]
1 citations