Showing papers in "Energy Sources Part A-recovery Utilization and Environmental Effects in 2008"
TL;DR: In this paper, a macroalga (Cladophora fracta) and a micro alga (Chlorella protothecoides) samples were used in this work.
Abstract: A macroalga (Cladophora fracta) and a microalga (Chlorella protothecoides) samples were used in this work. Most current research on oil extraction is focused on microalgae to produce biodiesel from algal oil. The biodiesel from algal oil in itself is not significantly different from biodiesel produced from vegetable oils. Algal oils, as well as vegetable oils, are all highly viscous, with viscosities ranging 10–20 times those of no. 2 diesel fuel. Transesterification of the oil to its corresponding fatty ester is the most promising solution to the high viscosity problem. Fatty acid (m)ethyl esters produced from natural oils and fats is called biodiesel. Generally, methanol has been mostly used to produce biodiesel as it is the least expensive alcohol. The oil proportion from the lipid fractions of Chlorella protothecoides is considerable higher than that of Cladophora fracta. The higher heating value of Chlorella protothecoides (25.1 MJ/kg) also is higher than that of Cladophora fracta (21.1 MJ/k...
323 citations
TL;DR: In this paper, the pyrolysis mechanisms of biomass structural constituents are studied. And the major organic components of biomass can be classified as cellulose, hemicelluloses, and lignin.
Abstract: The present work is a study on the pyrolysis mechanisms of biomass structural constituents. Biomass resources include wood and wood wastes, agricultural crops and their waste byproducts, municipal solid waste, animal wastes, waste from food processing, and aquatic plants and algae. The major organic components of biomass can be classified as cellulose, hemicelluloses, and lignin. The pyrolysis is thermal degradation of biomass by heat in the absence of oxygen, which results in the production of charcoal (solid), bio-oil (liquid), and fuel gas products. Thermal degradation of cellulose proceeds through two types of reaction: a gradual degradation, decomposition, and charring on heating at lower temperatures; and a rapid volatilization accompanied by the formation of levoglucosan on pyrolysis at higher temperatures. The hemicelluloses reacted more readily than cellulose during heating. Of the hemicelluloses, xylan is the least thermally stable, because pentosans are most susceptible to hydrolysis a...
190 citations
TL;DR: A review of the liquefaction mechanisms of biomass structural constituents can be found in this article, where the authors present a low-temperature, high-pressure thermochemical process using a catalyst.
Abstract: This article reviews the liquefaction mechanisms of biomass structural constituents. One pivotal study of such liquefaction processes was done in the 1970s funded by the Bureau of Mines of the United States. Liquefaction is a low-temperature, high-pressure thermochemical process using a catalyst. The process produces a marketable liquid product. In the case of liquefaction, macromolecule compounds in biomass are degraded into small molecules with or without catalyst in the aqueous medium or using organic solvent. Thus, obtained small molecules are unstable and reactive and can repolymerize into oily products with a wide range of molecular weight distribution. In the liquefaction process, the micellar-like broken-down fragments produced by hydrolysis are degraded to smaller compounds by dehydration, dehydrogenation, deoxygenation, and decarboxylation. These compounds once produced, rearrange through condensation, cyclization, and polymerization, leading to new compounds. Thermal depolymerization a...
157 citations
TL;DR: In this paper, a review is made of the alternative technological methods that could be used to produce hydrogen, such as electrochemical processes, thermochemical processes, photochemical process, photocatalytic processes, or photoelectrochemical processes.
Abstract: Hydrogen is a promising renewable fuel for transportation and domestic applications. Hence, in both the near term and long term, hydrogen demand is expected to increase significantly. Producing hydrogen, as well as any other synthetic fuel, will inevitably cost more energy than pumping up oil or using other fossil fuels. In this work, a review is made of the alternative technological methods that could be used to produce this fuel. Hydrogen can be generated in a number of ways, such as electrochemical processes, thermochemical processes, photochemical processes, photocatalytic processes, or photoelectrochemical processes. The thermal production process, which uses steam to produce hydrogen from natural gas or other light hydrocarbons, is most common. Steam reforming of natural gas is currently the least expensive method of producing hydrogen and is used for about half of the world's production of hydrogen. Approximately 95% of the hydrogen produced today comes from carbonaceous raw material, prim...
113 citations
TL;DR: In this article, the authors defined biodiesel as the monoalkyl esters of long-chain fatty acids derived from renewable feedstocks, such as vegetable oils or animal fats, for use in compression-ignition (diesel) engines.
Abstract: Biodiesel has been defined as the monoalkyl esters of long-chain fatty acids derived from renewable feedstocks, such as vegetable oils or animal fats, for use in compression-ignition (diesel) engines. Biodiesel has become more attractive because of its environmental benefits and the fact that it is made from renewable resources. Biodiesel is the first and only alternative fuel to petroleum diesel to have a complete evaluation of emission results. The emission-forming gasses, such as carbon dioxide and carbon monoxide from combustion of biodiesel hydrocarbons, generally are less than diesel fuel. Sulfur emissions are essentially eliminated with pure biodiesel. The exhaust emissions of sulfur oxides and sulfates from biodiesel were essentially eliminated compared to diesel. The smog-forming potential of biodiesel hydrocarbons is less than diesel fuel. The ozone-forming potential of the speciated hydrocarbon emissions was 50% less than that measured for diesel fuel.
106 citations
TL;DR: In this paper, the thermal degradation of low and high-density polyethylene (LDPE, HDPE) was performed using a thermogravimetric analyzer (TGA) in nitrogen atmosphere under nonisothermal conditions.
Abstract: Thermal decomposition kinetics of low- and high-density polyethylene (LDPE, HDPE) were investigated. Thermal degradation of raw and waste LDPE and HDPE was performed using a thermogravimetric analyzer (TGA) in nitrogen atmosphere under non-isothermal conditions. Heating rates between 5 and 50 K/min were employed in TGA experiments. First-order decomposition reaction was assumed, and for the kinetic analysis an integral method was used. The apparent activation energy (Ea) and the pre-exponential factor (ko) were evaluated. It was found that value of the kinetic parameters and apparent activation energy of HDPE were larger than the LDPE.
82 citations
TL;DR: The results demonstrate that all biodiesels assessed are biodegradable, with similar shaped curves with 80.4 to 91.2% biodegradation after 30 days, whereas the 2-D sample reached only 24.5%Biodegradation is degradation caused by biological activity, particularly by enzyme action leading to significant changes in the material's chemical structure.
Abstract: In this work, biodegradation of biodiesel samples were studied. Biodiesel is a renewable diesel fuel of domestic origin derived from a variety of fats and oils by a transesterification reaction. It...
75 citations
TL;DR: In this article, sawdust samples from poplar wood were liquefied by using glycerol and alkaline glycerols in the presence of 5% Na2CO3 and NaOH at different temperatures: 440, 460, 480, 500, 520, 540, and 560 K.
Abstract: In this study, sawdust samples from poplar wood were liquefied by using glycerol and alkaline glycerol in the presence of 5% Na2CO3 and 5% NaOH at different temperatures: 440, 460, 480, 500, 520, 540, and 560 K Byproducts from the liquefaction processes of the samples mainly included lignin and carbohydrate degradation products The degradation of lignin (delignification) occurs at lower temperatures than carbohydrates The degradation products have fuel values The yield of total liquefaction increases with increasing reaction temperature
68 citations
TL;DR: In this article, the authors present an overview of some positive impacts of the solar energy systems and negative impacts covered by environmental impact assessment, and present a model to evaluate the environmental impact of solar energy technologies.
Abstract: Solar energy technologies offer a clean, renewable, and domestic energy source, and are essential components of a sustainable energy future. Solar energy systems (i.e., photovoltaics, solar thermal) provide significant environmental benefits in comparison to the conventional energy sources. It is known that these systems have some minor negative impacts on the environment during their production and operation. This study presents an overview of some positive impacts of the solar energy systems and negative impacts covered by environmental impact assessment.
66 citations
TL;DR: The term modern biomass is generally used to describe the traditional biomass use through the efficient and clean combustion technologies and sustained supply of biomass resources, environmentally sound and competitive fuels, heat, and electricity using modern conversion technologies as discussed by the authors.
Abstract: The energy sources have been split into three categories: fossil fuels, renewable sources, and nuclear sources. Energy new and renewable resources will play an important role in the world's future. There are several reasons for biofuels to be considered as relevant technologies by both developing and industrialized countries. They include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. The term “modern biomass” is generally used to describe the traditional biomass use through the efficient and clean combustion technologies and sustained supply of biomass resources, environmentally sound and competitive fuels, heat, and electricity using modern conversion technologies. Modern biomass can be used for the generation of electricity and heat. Biofuels as well as green diesel produced from biomass by Fischer-Tropsch synthesis are the most modern biomass-based transportation fuels. Green diesel is a renewable replacement to...
64 citations
TL;DR: In this paper, a mixture of gases from organic waste materials is converted to methanol in a conventional steam-reforming/water-gas shift reaction followed by high-pressure catalytic methanoline synthesis.
Abstract: Methanol is mainly manufactured from natural gas, but biomass can also be gasified to methanol. Methanol can be produced from hydrogen-carbon oxide mixtures by means of the catalytic reaction of carbon monoxide and some carbon dioxide with hydrogen. Biosynthesis gas (bio-syngas) is a gas rich in CO and H2 obtained by gasification of biomass. Biomass sources are preferable for biomethanol than for bioethanol because bioethanol is a high-cost and low-yield product. This is a promising alternative, with a diversity of fuel applications with proven environmental, economic, and consumer benefits. A mixture of gases from organic waste materials is converted to methanol in a conventional steam-reforming/water-gas shift reaction followed by high-pressure catalytic methanol synthesis.
TL;DR: In this article, an interval-parameter linear programming approach is introduced to develop an intervalparameter energy systems model (IPEM) for supporting effective regional energy systems planning under uncertainty.
Abstract: Energy systems planning models are specifically developed for effective planning of energy activities in a regional, national, or global context. However, the planning process is fraught with uncertainties that may affect the effectiveness of the planning. In this study, an interval-parameter linear programming approach is introduced to develop an interval-parameter energy systems model (IPEM) for supporting effective regional energy systems planning under uncertainty. The developed methodology is then applied to a hypothetical regional energy system. The results strongly suggest that this innovative approach can effectively handle the uncertain information expressed as intervals in the energy planning process and provide more satisfactory solutions for the optimization problem of energy allocation and capacity expansion within a regional jurisdiction. Compared with other energy systems models, this model generates two schemes corresponding to the upper and the lower bounds of system objective, w...
TL;DR: In this paper, the main objective of the paper is to investigate hydrogen production from biomass via pyrolysis and gasification, and the results show that the yields of hydrogen from the pyrotechnics and the steam gasification increase with increase of temperature.
Abstract: The main objective in doing the present study is to investigate hydrogen production from biomass via pyrolysis and gasification. Hydrogen is currently derived from nonrenewable natural gas and petroleum but could in principle be generated from renewable resources such as biomass. It can be produced from biomass via two thermochemical processes: (1) gasification followed by reforming of the syngas, and (2) fast pyrolysis followed by reforming of the carbohydrate fraction of the bio-oil. Steam reforming of hydrocarbons, partial oxidation of heavy oil residues, selected steam reforming of aromatic compounds, and gasification of coals and solid wastes to yield a mixture of H2 and CO (syngas), followed by water-gas shift conversion to produce H2 and CO2, are well-established processes. The yields of hydrogen from the pyrolysis and the steam gasification increase with increase of temperature. In general, the gasification temperature is higher than that of pyrolysis and the yield of hydrogen from the ga...
TL;DR: There are four alternative fuels that can be relatively easily used in conventional diesel engines: vegetable oil, biodiesel, Fischer-Tropsch (F-T), and dimethyl ether (DME) as discussed by the authors.
Abstract: The alternate fuels are substitute fuel sources to petroleum. These fuels are important because they replace petroleum fuels; however, some still include a small amount of petroleum in the mixture. Almost all motor vehicles today are powered by either diesel or gasoline. Both fuels are mainly derived from petroleum. Diesel fuel consists of hydrocarbons with between 9 and 27 carbon atoms in a chain as well as a smaller amount of sulfur, nitrogen, oxygen, and metal compounds. There are four alternate fuels that can be relatively easily used in conventional diesel engines: vegetable oil, biodiesel, Fischer-Tropsch (F-T), and dimethyl ether (DME). Gasoline is a blend of hydrocarbons with some contaminants, including sulfur, nitrogen, oxygen, and certain metals. The four major constituent groups of gasoline are olefins, aromatics, paraffins, and napthenes. The main alternate fuels include alcohol, liquefied petroleum gas, compressed natural gas, hydrogen, and electricity for operation of gasoline-type...
TL;DR: In this article, the authors present a review of the production and characterization of biodiesel fuel from vegetable oils as well as the experimental work carried out via supercritical ethanol transesterification.
Abstract: This paper reviews the production and characterization of biodiesel fuel from vegetable oils as well as the experimental work carried out via supercritical ethanol transesterification. Biodiesel, which can be used as an alternative diesel fuel, is made from renewable biological sources such as vegetable oil and animal fats. More than 100 years ago, a brilliant inventor named Rudolph Diesel designed the original diesel engine to run on vegetable oil. There are more than 350 oil-bearing crops identified, among which only sunflower, safflower, soybean, cottonseed, rapeseed, and peanut oils are considered as potential alternative fuels for diesel engines. The major problem associated with the use of pure vegetable oils as fuels for diesel engines are caused by high fuel viscosity in compression ignition. Dilution, micro-emulsification, pyrolysis, and transesterification are the four techniques applied to solve the problems encountered with the high fuel viscosity. Dilution of oils with solvents and m...
TL;DR: In this article, experiments are conducted to investigate melting and solidification characteristics of calcium chloride hexahydrate (CaCl2.6H2O) as a phase change material (PCM).
Abstract: In this study, experiments are conducted to investigate melting and solidification characteristics of calcium chloride hexahydrate (CaCl2.6H2O) as a phase change material (PCM). In the present study, some parameters that affect the melting and the solidification time of PCM used to store low temperature energy have been observed experimentally. These parameters are inlet temperature and mass flow rate of water used as a heat transfer fluid (m = 2.51, 3.75, and 4.95 kg min−1), fin numbers inside the PCM. For this purpose, PCM has been stored constantly between the coaxial pipes and water adjusted to 45°C for the melting process and to 5°C for the solidification process, and was circulated by a pump through the inner pipe at the experimental setup. During the experiments, when the water mass flow rate is increased to 49 and 97% with respect to the starting mass flow rate (m = 2.51 kg min−1), a rate of 5 and 15% decrease at the melting time is obtained, respectively. As a result, it has been observe...
TL;DR: In this paper, the main objective of the paper is to assess and introduce the hydrothermal gasification of biomass wastes containing various quantities of the model compounds and real biomass, and the decomposition of biomass, as a basis of the HOG treatment of organic wastes, is introduced.
Abstract: Biomass is a useful feed material for energy and chemical resources. Hydrothermal gasification of biomass wastes has been identified as a possible system for producing hydrogen. Supercritical and subcritical water has attracted much attention as an environmentally benign reaction medium and reactant. The main objective of this study is to assess and introduce the hydrothermal gasification of biomass wastes containing various quantities of the model compounds and real biomass. The decomposition of biomass, as a basis of hydrothermal treatment of organic wastes, is introduced. To eliminate chars and tars formation and obtain higher yields of hydrogen, catalyzed hydrothermal gasification of biomass wastes is summarized.
TL;DR: In this paper, the authors proposed a new concept that uses waste vegetable oil and non-edible plant oils as biodiesel feedstock and not-toxic, inexpensive, and natural catalysts that overcome the limitation of the existing process.
Abstract: The production of biodiesel has received considerable attention throughout the world in the past few years. As an alternative to petrodiesel, biodiesel is a renewable fuel that is derived from vegetable oils and animal fats. However, the existing biodiesel production process is neither completely “green” nor renewable because it utilizes fossil fuels, mainly natural gas as an input for methanol production. Also the catalysts currently in use are highly caustic and toxic. The purpose of this article is to propose a new concept that uses waste vegetable oil and non-edible plant oils as biodiesel feedstock and non-toxic, inexpensive, and natural catalysts that overcome the limitation of the existing process. The economic benefit of the proposed method is also discussed. The new concept will render the biodiesel production process truly green.
TL;DR: In this paper, the authors defined the reaction of unsaturated aliphatic carbons chains in biolipids as a multi-step reaction process where primary products (conjugated diene hydroperoxides) decompose and chemically interact with each other to form numerous secondary oxidation products.
Abstract: The term biodiesel means the monoalkyl esters of long-chain fatty acids made from biolipids such as vegetable oils, animal fats, or algae. Chemical reactivity of biodiesel can be divided into oxidative and thermal instability. Many of the biolipids contain polyunsaturated fatty acid chains in that their double bonds have high chemical reactivity. The oxidative and thermal degradation occurs on the double bonds of unsaturated aliphatic carbons chains in biolipids. Oxidation of biodiesel results in the formation of hydroperoxides. The formation of the hydroperoxide follows a well-known peroxidation chain mechanism. The olefinic unsaturated fatty acid oxidation is a multi-step reaction process where primary products (conjugated diene hydroperoxides) decompose and chemically interact with each other to form numerous secondary oxidation products. The oxidative and thermal instability are determined by the amount and configuration of the olefinic unsaturation on the fatty acid chains. The viscosity of ...
TL;DR: In this paper, shape-stabilized phase change materials (PCMs) were constructed by encapsulating fatty acids (stearic acid, palmitic acid and myristic acid) as a PCM in an acrylic resin (Eudragit E) as supporting material and to determine latent heat thermal energy storage (LHTES) properties.
Abstract: This article aims to prepare novel shape-stabilized phase change materials (PCMs) by encapsulating fatty acids (stearic acid [SA], palmitic acid [PA], and myristic acid [MA]) as a PCM in an acrylic resin (Eudragit E) as supporting material and to determine latent heat thermal energy storage (LHTES) properties. The maximum percentage of all fatty acids in the shape-stabilized PCMs was found to be 70 wt% in which no fatty acid seepage was observed as the blends were heated over the melting points of the fatty acids. The optic microscope (OM) investigation demonstrated that fatty acid domains were coated by Eudragit E. Fourier transform infrared (FT-IR) results revealed that the interactions between Eudragit E and fatty acids were only adequate for adhesion of Eudragit E on fatty acid domains. Single phase was observed for the blends by OM, and interactions between the components were investigated by FT-IR spectroscopy. The melting and freezing temperatures and latent heats of the shape-stabilized P...
TL;DR: In this paper, transesterification reactions with magnesium oxide (MgO) in supercritical methanol of vegetable oil samples (rapeseed oil, soybean oil, and sunflower oil) have been studied to obtain biodiesel.
Abstract: In this experimental work, transesterification reactions with magnesium oxide (MgO) in supercritical methanol of vegetable oil samples (rapeseed oil, soybean oil, and sunflower oil) have been studied to obtain biodiesel. MgO as a catalyst can considerably improve the transesterification reaction of sunflower seed oil in supercritical methanol. The variables affecting the methyl ester yield during the transesterification reaction, such as the catalyst content, reaction temperature, and the molar ratio of vegetable oil to alcohol, were investigated and compared with those of non-catalyst runs. The catalytic transesterification ability of MgO is quite weak under ambient temperature. When MgO was added from 1.0% to 3.0%, the transesterification speed increased, while the catalyst content was further enhanced to 5% and the yield of methyl ester slowly plateaued. It was observed that increasing the reaction temperature had a favorable influence on methyl ester yield. In addition, for molar ratios rangi...
TL;DR: The pyrolysis products from corn stover were classified as paraffins, olefins, carbonyl compounds, aldehydes, alcohols, phenols, and ethers as discussed by the authors.
Abstract: Corn stover consists of the stalks, leaves, cobs, and husk. About 1 kg of stover is produced per kg of grain. The thermal conversion of biomass to organic liquid products can be accomplished using liquefaction and pyrolysis methods. Thermochemical conversion processes are promising means for converting corn stover into valuable products such as chemicals and fuels. Alkali salts, such as sodium carbonate and potassium carbonate, can act as hydrolysis of cellulose and hemicelluloses into smaller fragments. The heavy oil obtained from the liquefaction process is a viscous tarry lump. The pyrolysis products from corn stover were classified as paraffins, olefins, carbonyl compounds, aldehydes, alcohols, phenols, and ethers. The yields of paraffin, aldehyde, and phenol increased with increase of the pyrolysis temperature. Bioethanol is derived from alcoholic fermentation of sucrose or simple sugars, which are produced from biomass by hydrolysis process. It is possible that corn stover may be economical...
TL;DR: The thermochemical conversion processes such as pyrolysis, gasification, and steam gasification are available for converting the biomass to a more useful energy as mentioned in this paper, and the yields of hydrogen from the pyrotechnics and the steam gases increase with increase of temperature.
Abstract: Hydrogen is not a primary fuel. It must be manufactured from water with either fossil or nonfossil energy sources. Widespread use of hydrogen as an energy source could improve global climate change, energy efficiency, and air quality. The thermochemical conversion processes, such as pyrolysis, gasification, and steam gasification are available for converting the biomass to a more useful energy. The yield from steam gasification increases with increasing water-to-sample ratio. The yields of hydrogen from the pyrolysis and the steam gasification increase with increase of temperature. Hydrogen-powered fuel cells are an important enabling technology for the hydrogen future and more efficient alternatives to the combustion of gasoline and other fossil fuels. Hydrogen has the potential to solve two major energy problems: reducing dependence on petroleum and reducing pollution and greenhouse gas emissions.
TL;DR: The programming results indicate that reasonable and useful decision alternatives can be generated under different probabilities of violating the system constraints, and are useful for decision makers to gain an insight into the tradeoffs among environmental, economic and system reliability criteria.
Abstract: This article developed an inexact chance-constrained semi-infinite programming (ICCSIP) method for the energy management system under functional interval uncertainties. The approach not only considers the left-hand interval parameters, right-hand distribution information, and the probability of violating constraint, but also deals with functional interval uncertainty, which extends the range of the uncertainties. A regional energy management system is applied to illustrate the applicability of the ICCSIP approach. In consideration of energy sources allocation, fuel prices, and environmental regulations, a systematic planning of the regional energy structure is desired to bring a significant increase of economic benefit and improvement of environmental quality. This problem can be formulated as a programming model with an objective of minimizing the overall system costs subject to a number of environmental, economic and energy sources availability constraints. The programming results indicate that...
TL;DR: In this paper, the thermal properties of fatty acid/expanded graphite (EG) composites were measured by differential scanning calorimetry (DSC) method, and the results indicated that the melting and solidification temperatures of the composite PCMs were almost the same as those of pure fatty acids.
Abstract: The fatty acid/expanded graphite (EG) composites as phase change material (PCM) for latent heat thermal energy storage were prepared by means of vacuum impregnation method and their thermal properties and heat charging/discharging characteristics were determined. In the composites, the fatty acids (capric, lauric, and myristic acids) act as a phase change latent heat storage material, and the EG serves like an absorptive material that penetrates melted fatty acid into its porous structure. The maximum fatty acids absorption of EG was found as 80 wt% without melted fatty acid oozing from the composites. Thermal properties of fatty acid/EG composites were measured by differential scanning calorimetry (DSC) method. DCS results indicated that the melting and solidification temperatures of the composite PCMs were almost the same as those of fatty acids, and the latent heats of composites were little less than those of the pure fatty acids. The heat charging and discharging rate of the composites were ...
TL;DR: In this article, gas and liquid fuels from biomass by steam reforming were investigated, and the Fischer-Tropsch Synthesis (FTS) is used to synthesize long-chain hydrocarbons from CO and H2 gas mixture.
Abstract: In this study, gas and liquid fuels from biomass by steam reforming were investigated. The steam reforming process provides the opportunity to convert renewable biomass materials into clean fuel gases or synthesis gases. Synthesis gas includes mainly hydrogen and carbon monoxide which is also called as syngas (H2 + CO). Bio-syngas is a gas rich in CO and H2 obtained by gasification of biomass. The aim of Fischer-Tropsch Synthesis (FTS) is synthesis of long-chain hydrocarbons from CO and H2 gas mixture. The products from FTS are mainly aliphatic straight-chain hydrocarbons (CxHy). The distribution of the products depends on the catalyst and the process parameters such as temperature, pressure, and residence time. Typical operation conditions for the FTS are a temperature range of 475–625 K and pressures of 15–40 bar, depending on the process.
TL;DR: The kinematic viscosity and density values of biodiesel from tall oil fatty acids were 4.1-5.3 mm2/sec at 311.2 K and 0.878-0.885 kg/L at 288.7 K, respectively as discussed by the authors.
Abstract: Tall oil is a by-product of coniferous wood recovered in the Kraft pulping process. Fatty acids can be recovered from tall oil by vacuum distillation. Biodiesel is becoming a displacement alternative for petroleum diesel. Chemically, biodiesel is a fatty acid (m)ethyl ester. Fatty acid derivatives as alternative fuels have become more attractive recently because of their environmental benefits and the fact that they are made from renewable resources. After saponification, acidulation, and methylation procedures, methyl esters (biodiesel) of the fatty acids were obtained from the tall oil samples. The properties of the various individual fatty esters that comprise biodiesel determine the overall fuel properties of the biodiesel. The kinematic viscosity and density values of biodiesel from tall oil fatty acids were 4.1–5.3 mm2/sec at 311.2 K and 0.878–0.885 kg/L at 288.7 K, respectively.
TL;DR: In this paper, the potential for changes in climate to affect the significant onshore wind resource in the United Kingdom (UK) is explored using the regional climate change scenarios published by the UK Climate Impacts Programme in 2002.
Abstract: Wind power is currently the fastest growing renewable technology and will play a significant role in constraining the extent of climate change. However, the very fact that its ‘fuel source’ is driven by the climate may leave it exposed as climate changes over the coming decades. In this preliminary assessment, the potential for changes in climate to affect the significant onshore wind resource in the United Kingdom (UK) is explored using the regional climate change scenarios published by the UK Climate Impacts Programme in 2002. The scenarios indicate seasonal changes in potential wind production with winter production generally increasing while summer decreases.
TL;DR: In this article, the dependence of laser-induced breakdown spectroscopy (LIBS) for detection of trace elements has been studied for quantitative measurements of environmentally important trace metals such as magnesium, lead, copper, and calcium in oil samples.
Abstract: Parametric dependence of laser-induced breakdown spectroscopy (LIBS) for detection of trace elements has been studied. LIBS was applied for quantitative measurements of environmentally important trace metals such as magnesium, lead, copper, and calcium in oil samples. This work incorporates investigations of LIBS experimental parameters such as the distance between the plasma and optical fiber, sample rotation speed, laser pulse energy, gate delay, and position of the focal spot on the pellets. The optimized parameters are tested for the preparation of the calibration curves for Mg, Pb, Cu, and Ca. Limits of detection (LOD) of our LIBS system were also estimated for these elements. The system was applied for trace metals detection in Arabian crude oil residue samples which is not trivial to detect with conventional techniques.
TL;DR: An integrated fuzzy possibilistic-joint probabilistic mixed-integer programming model is developed and applied to the expansion planning of power generation under uncertainty, and its applicability has been demonstrated by the application to a hypothetic power generation problem.
Abstract: In this study, an integrated fuzzy possibilistic-joint probabilistic mixed-integer programming (FPJPMIP) model is developed and applied to the expansion planning of power generation under uncertainty. As an extension of existing fuzzy possibilistic programming and joint probabilistic programming, the FPJPMIP addresses system uncertainties in the model's left- and right-hand sides (with the expression of possibilistic and probabilistic distributions). Its applicability has been demonstrated by the application to a hypothetic power generation problem. The developed method is applied to a case of power generation expansion planning, where desirable solutions are obtained. Willingness to pay higher costs will promise system stability. A desire to reduce the costs will get into the risk of potential system failure.