Sustainable Alternative Energy Source Research Articles

Energy harvesting from pavement via polyvinylidene fluoride: hybrid piezo-pyroelectric effects

In the USA, there are over 4 million miles (6 million km) of roadways and more than 250 million registered vehicles. Energy lost in the pavement system due to traffic-induced vibration and deformation is enormous. If effectively harvested, such energy can serve as an alternative sustainable energy source that can be easily integrated into the transportation system. It is well known that most piezoelectric materials are also pyroelectric materials, which convert temperature change into electricity. However, the potential of polyvinylidene fluoride (PVDF) as a hybrid piezo-pyroelectric energy harvester has been seldom studied. The uniqueness of this study lies in that the electrical responses of PVDF under coupled mechanical and thermal stimulations are investigated. Through a series of well controlled experiments, it is found that there exists an interesting coupling phenomenon between piezoelectric and pyroelectric effects of PVDF: the voltage generated by simultaneous mechanical and thermal stimulations is the algebraic sum of voltages generated by separate stimulations. This means that there is neither strengthening nor weakening coupling effect when the piezoelectric and pyroelectric phenomena are coupled. This also makes the modeling process of the hybrid piezoelectric and pyroelectric effect straightforward. An estimation of power generation through piezoelectric and pyroelectric effect is conducted, and the overall effects of temperature on hybrid piezo-pyroelectric energy harvesting are discussed.

Giant Seebeck effect in Ge-doped SnSe.

Thermoelectric materials may contribute in the near future as new alternative sources of sustainable energy. Unprecedented thermoelectric properties in p-type SnSe single crystals have been recently reported, accompanied by extremely low thermal conductivity in polycrystalline samples. In order to enhance thermoelectric efficiency through proper tuning of this material we report a full structural characterization and evaluation of the thermoelectric properties of novel Ge-doped SnSe prepared by a straightforward arc-melting method, which yields nanostructured polycrystalline samples. Ge does not dope the system in the sense of donating carriers, yet the electrical properties show a semiconductor behavior with resistivity values higher than that of the parent compound, as a consequence of nanostructuration, whereas the Seebeck coefficient is higher and thermal conductivity lower, favorable to a better ZT figure of merit.

Nanostructured Bi2Te3 Prepared by a Straightforward Arc-Melting Method.

Thermoelectric materials constitute an alternative source of sustainable energy, harvested from waste heat. Bi2Te3 is the most utilized thermoelectric alloy. We show that it can be readily prepared in nanostructured form by arc-melting synthesis, yielding mechanically robust pellets of highly oriented polycrystals. This material has been characterized by neutron powder diffraction (NPD), scanning electron microscopy (SEM), and electronic and thermal transport measurements. A microscopic analysis from NPD data demonstrates a near-perfect stoichiometry of Bi2Te3 and a fair amount of anharmonicity of the chemical bonds. The as-grown material presents a metallic behavior, showing a record-low resistivity at 320 K of 2 μΩ m, which is advantageous for its performance as a thermoelectric material. SEM analysis shows a stacking of nanosized sheets, each of them presumably single-crystalline, with large surfaces perpendicular to the c crystallographic axis. This nanostructuration notably affects the thermoelectric properties, involving many surface boundaries that are responsible for large phonon scattering factors, yielding a thermal conductivity as low as 1.2 W m−1 K−1 around room temperature.

Techno-economic analysis of bioethanol production from rice straw by liquid-state fermentation

Renewable energy is the latest approach of the Malaysian government in an effort to find sustainable alternative energy sources and to fulfill the ever increasing energy demand. Being a country that thrives in the service and agricultural sector, bioethanol production from lignocellulosic biomass presents itself as a promising option. However, the lack of technical practicality and complexity in the operation system hinder it from being economically viable. Hence, this research acquired multiple case studies in order to provide an insight on the process involved and its implication on production as well as to obtain a cost analysis of bioethanol production. The energy input and cost of three main components of the bioethanol production which are the collection, logistics, and pretreatment of rice straw were evaluated extensively. The theoretical bioethanol yield and conversion efficiency obtained were 250 L/t and 60% respectively. The findings concluded that bioethanol production from rice straw is currently not economically feasible in Malaysia’s market due to lack of efficiency in the pretreatment phase and overbearing logistics and pretreatment costs. This work could serve as a reference to future studies of biofuel commercialization in Malaysia.

BIOFUELS AS PROMISING FUELS

The use of fossil fuels results in global warming and pollution. In comparison with fossil fuels biofuels represent an eco-friendly, biodegradable, sustainable, cost-competitive and promising alternative energy source. They contain high energy content and do not contribute to greenhouse effect. Therefore, using cheap or renewable resources as the feedstock for biofuels production has a great potential in terms of a major contribution to future energy supply. The production and use of biofuels is already well established and a further promotion of these fuels such as lipid biofuels (bioethanol, pure plant oils and biodiesel) and gas biofuels (biomethane, biohydrogen) mainly depends on non-technical issues, such as policies and cost–effectiveness. Biofuels will definitely stay for the foreseeable future and still can continue to provide the earth and the human population with a relatively clean source of energy with several benefits such as economic benefits of providing employment and health benefits of reduced carbon emissions, leading to cleaner air. With increasing sophistication of technology and intense research and development done, one can safely infer that biofuel will become more appealing and applicable for use on a globally commercial level. As such, biofuel is acknowledged as the Earth’s future energy source. Until a newer and cleaner energy source is discovered, scientists will definitely persist in researching and enhancing biofuels to make them more cost-effective, while still being environmentally friendly.

Use of Orthogonal Array Composite Designs to Study Lipid Accumulation in a Cell-Free System

Author(s): Jaynes, J; Zhao, Y; Xu, H; Ho, CM | Abstract: The development of clean, sustainable alternative energy sources is increasingly important. One promising alternative to depleting fuel reserves is algae-based biodiesel fuel, which is both non-toxic and renewable. Despite the tremendous potential of algae-based biodiesel fuel, it has not yet been profitable because of the high cost per unit area of large cultivation. We present a novel application of Orthogonal Array Composite Designs (OACDs) to optimize lipid production of a cell-free system for algae. An OACD consists of a two-level fractional factorial design and a three-level orthogonal array. We start with an initial screening experiment based on six chemicals using an OACD with 50 runs. Based on this experiment, two chemical compounds were removed and a follow-up 25-run OACD with four chemicals was performed. Our analysis shows that only three chemicals – nitrogen, magnesium, and phosphate – are essential for lipid accumulation, and a range of optimum combinations of these three chemicals is identified. The lipid accumulation for these three chemical combinations is substantially higher in comparison to the commercial medium, which contains 16 chemicals and soil water. This leads to a reduced cost of the chemical medium and increased efficiency of biodiesel production from the algal-based cell-free system, which can be used to significantly expand the use of biodiesel as a viable alternative to fossil fuels. Copyright © 2015 John Wiley a Sons, Ltd.

Earth-air heat exchanger as a green retrofit for Chandīgarh—a critical review

The natural resources of the Earth are being exploited beyond its sustainable capacity. The building industry consumes nearly 40 % of the global energy requirement. A major portion of this is used in meeting air-conditioning requirements. The present scenario demands increased energy efficiency, i.e., indoor thermal comfort with minimal energy consumption in buildings. Thus, the development of new green technologies, which allows the use of sustainable alternative sources of energy, is the need of the hour. Earth-air heat exchangers (EAHE), which make use of a passive means for the heating and cooling of buildings, are becoming a promising technology in the construction of green buildings. EAHE utilizes the thermal energy contained in the soil at certain depths for meeting the cooling/heating requirement of buildings, reducing the consumption of conventional energy for built environments. The present paper addresses issues of applicability of EAHE in Chandīgarh (India) based upon literature review particularly in Indian context and keeping in mind the nature of soil and climatic conditions of the city.

Japan's New Plan to Become a Hydrogen Society: Will Japan Succeed?

Japan’s government and industry have jointly decided to implement a Hydrogen Society plan, starting in 2015, with completion by or beyond 2040. This decision was made in the aftermath of the 2011 Earthquake and Tsunami disaster, which forced Japan to look for alternative sources of sustainable energy. The Hydrogen Society plan consists of three phases: Phase 1 is an extension of the current fuel cell program, which includes broader diffusion of fuel cells into the global market accompanied by dramatic cost reduction of both hydrogen and fuel cells. Phase 2 envisions the large-scale introduction of hydrogen power generation and the establishment of a wide-spread hydrogen supply infrastructure. Phase 3 would establish a zero-carbon emission hydrogen supply system throughout the manufacturing process. This article reviews the details of the plan, investigates the rationale for the decision, examines the implementation approach, and provides a brief look at possible outcomes.

Design and Fabrication of a Double Chamber Microbial Fuel Cell for Voltage Generation from Biowaste

Electrical energy needs in Pakistan are expected to continue to rise. The use of petroleum as a source of energy still dominates, although oil reserves in Pakistan are increasingly being depleted. Therefore, there is a need to develop alternative source of sustainable energy, such as, Microbial Fuel Cell (MFC). MFC shows another type of renewable energy by changing natural matter into power with the help of microbes. In the current study, an attempt has been made to find the effect of molar concentration of salt bridge on electron transferring potential and to find the efficiency of bioelectricity generation by yeasts such as Hansenula anomala and Saccharomyces cerevisiae. Maximum current of 1.9 mV and 1.4 mV was generated by yeasts Hansenula anomala and Saccharomyces cerevisiae in 1M potassium chloride salt bridge with duration of 96 hrs. This work also demonstrates the feasibility of using yeasts Hansenula anomala and Saccharomyces cerevisiae for current generation, in a mediator less MFC. During the metabolism the fuels like glucose gets oxidized when they pass through the metabolic cycle. The possibility of alternative sources is one particular method of generating power is with the help of microbial fuel cell, which can minimize the usage of fossil fuels. MFCs can produce energy directly from biomass (electricity production) or producing hydrogen from biomass (fuel production). Biological fuel cell converts the chemical energy of carbohydrates such as sugar and alcohol indirectly into electrical energy.

Impact of Salt Concentrations on Electricity Generation using Hostel Sludge Based Duel Chambered Microbial Fuel Cell

Electrical energy needs in Pakistan are expected to continue to rise. The use of petroleum as a source of energy still dominates, although oil reserves in Pakistan are increasingly being depleted. Therefore, there is a need to develop alternative source of sustainable energy, such as Microbial Fuel Cell (MFC). MFC shows another type of renewable energy by changing natural matter into power with the help of microbes. In the present study, varied salt concentrations of a salt bridge in novel MFC design were analyzed. Sewage sludge was utilized, which contains a lot of organic materials and is additionally one of the major sources of ecological contamination, as substrate MFC. Saccharomyces cerverciae sp. (44 g) was used as a biocatalyst. Methylene blue (10 ml) was used as a mediator and potassium ferricyanide (100 ml) was used as an oxidizing agent for the conversion of sewage sludge into voltage generation using lab-scale double chamber MFC. Varied salt concentrations (1M, 3M and 5M of KCl and NaCl) of salt concentrations of salt bridge in a novel MFC design were analyzed. The maximum generated voltage, current, power, power density and current density with 1M KCl were 0.451 V, 0.0451, 0.0175561 mW, 0.000226001 mW/m2, 10.5166661 μA/m2 respectively. The MFC was run for a period of 1 day and readings were noted at regular intervals. The results obtained were helpful in designing an optimized MFC.

Challenges for the production of bioethanol from biomass using recombinant yeasts.

Lignocellulose biomass, one of the most abundant renewable resources on the planet, is an alternative sustainable energy source for the production of second-generation biofuels. Energy in the form of simple or complex carbohydrates can be extracted from lignocellulose biomass and fermented by microorganisms to produce bioethanol. Despite 40 years of active and cutting-edge research invested into the development of technologies to produce bioethanol from lignocellulosic biomass, the process remains commercially unviable. This review describes the achievements that have been made in generating microorganisms capable of utilizing both simple and complex sugars from lignocellulose biomass and the fermentation of these sugars into ethanol. We also provide a discussion on the current "roadblocks" standing in the way of making second-generation bioethanol a commercially viable alternative to fossil fuels.

Deep eutectic solvents as a new class of draw agent to enrich low abundance DNA and proteins using forward osmosis

The present study explores the osmotic energy potentials of deep eutectic solvents as an efficient and sustainable alternative energy source for protein and DNA enrichment using forward osmosis (FO).

Rapid liquefaction of giant miscanthus feedstock in ethanol–water system for production of biofuels

Energy issues nowadays are one of the critical priorities for the United States. There is a strong desire and tremendous efforts employed towards replacing fossil fuels with sustainable alternative sources of energy. In this study, hydrothermal liquefaction with ethanol and water as co-solvents was applied on giant miscanthus (Miscanthus giganteus) perennial biomass feedstock. Four temperatures and six ethanol ratios were chosen for the study. The optimum combination of temperature and water/ethanol ratio was 280°C and 50%, respectively. The effect of time, biomass to solvent ratio and catalyst type was studied as well. The best liquefaction results without applying catalysts (53% oil yield and 8% solid residue) were obtained after 15min. When zinc chloride was used as catalyst, more than 52% of oil yield with 1% solid residue was obtained after 5min. The crude bio-oil chemical composition was identified by using gas chromatography/mass spectrometry (GC/MS).

The use of hydrogen as a fuel for inland waterway units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

Performance Optimization of Microbial Fuel Cell (MFC) Using Lactobacillus bulgaricus

Electrical energy needs in Indonesia are expected to continue to rise. The use of petroleum as a source of energy still dominates, although oil reserves in Indonesia are increasingly being depleted. Therefore, there is a need to develop alternative sources of sustainable energy, such as microbial fuel cell (MFC). In this study, Lactobacillus bulgaricus was used as an electricity producer in a dual-chamber MFC reactor. We investigated the maximum electrical energy by varying the bacterial optical density (OD), the operational time of MFC, the reactor volume, the electrolyte solution, and the configuration of MFC reactor. In this study, the maximum electrical energy (201.8 mW/m 2 ) was generated at an OD of 0.5 in an MFC reactor series using potassium permanganate as the electrolyte solution.

First Principle Calculations of Transition Metal Oxide, AgAlO2, as Active Photocatalyst: Sustainable Alternative Sources of Energy

First Principle Calculations of Transition Metal Oxide, AgAlO2, as Active Photocatalyst: Sustainable Alternative Sources of Energy

Exposure to wood smoke increases arterial stiffness and decreases heart rate variability in humans

BackgroundEmissions from biomass combustion are a major source of indoor and outdoor air pollution, and are estimated to cause millions of premature deaths worldwide annually. Whilst adverse respiratory health effects of biomass exposure are well established, less is known about its effects on the cardiovascular system. In this study we assessed the effect of exposure to wood smoke on heart rate, blood pressure, central arterial stiffness and heart rate variability in otherwise healthy persons.MethodsFourteen healthy non-smoking subjects participated in a randomized, double-blind crossover study. Subjects were exposed to dilute wood smoke (mean particle concentration of 314±38 μg/m3) or filtered air for three hours during intermittent exercise. Heart rate, blood pressure, central arterial stiffness and heart rate variability were measured at baseline and for one hour post-exposure.ResultsCentral arterial stiffness, measured as augmentation index, augmentation pressure and pulse wave velocity, was higher after wood smoke exposure as compared to filtered air (p < 0.01 for all), and heart rate was increased (p < 0.01) although there was no effect on blood pressure. Heart rate variability (SDNN, RMSSD and pNN50; p = 0.003, p < 0.001 and p < 0.001 respectively) was decreased one hour following exposure to wood smoke compared to filtered air.ConclusionsAcute exposure to wood smoke as a model of exposure to biomass combustion is associated with an immediate increase in central arterial stiffness and a simultaneous reduction in heart rate variability. As biomass is used for cooking and heating by a large fraction of the global population and is currently advocated as a sustainable alternative energy source, further studies are required to establish its likely impact on cardiovascular disease.Trial registrationClinicalTrials.gov, NCT01488500

A novel strategy for hydrous-ethanol utilization: Demonstration of a spark-ignition engine fueled with hydrogen-rich fuel from an onboard ethanol/steam reformer

In this paper, an onboard reformer and a dual-fuel (hydrous-ethanol and gasoline) supply system were designed to examine experimentally the reforming performance of hydrous-ethanol for an on-line, operating engine, and a series of optimization and comparison experiments were conducted. The results show that HE75 (75% hydrous-ethanol, i.e., ethanol with 25% water volume content) conversion first increases and later decreases with the temperature and reaches its peak at a temperature of approximately 675 K. The effects of the flow rate and temperature on the product distribution are minimal. Compared to the prototype gasoline-fueled engine, the average decreases of the equivalent specific fuel consumption, NOx emissions, CO emission and total hydrocarbon emissions for the optimized engine fueled with hydrogen-rich reformates are 6%, 70%, 50% and 80%, respectively. This preliminary experiment suggests that the utilization of hydrous, rather than anhydrous, ethanol in a spark ignition engine by the onboard steam reforming of ethanol may represent a sustainable alternative energy source.

Consequences and Countermeasures in a Nuclear Power Accident: Chernobyl Experience

Despite the tragic accidents in Fukushima and Chernobyl, the nuclear power industry will continue to contribute to the production of electric energy worldwide until there are efficient and sustainable alternative sources of energy. The Chernobyl nuclear accident, which occurred 26 years ago in the former Soviet Union, released an immense amount of radioactivity over vast territories of Belarus, Ukraine, and the Russian Federation, extending into northern Europe, and became the most severe accident in the history of the nuclear industry. This disaster was a result of numerous factors including inadequate nuclear power plant design, human errors, and violation of safety measures. The lessons learned from nuclear accidents will continue to strengthen the safety design of new reactor installations, but with more than 400 active nuclear power stations worldwide and 104 reactors in the Unites States, it is essential to reassess fundamental issues related to the Chernobyl experience as it continues to evolve. This article summarizes early and late events of the incident, the impact on thyroid health, and attempts to reduce agricultural radioactive contamination.

Optimal angles for harvesting solar electricity in some African cities

In recent years, the quest for renewable and sustainable energy has been extensive while solar energy has been on the vanguard of sustainable alternative and renewable energy sources due to its clean nature and cost effectiveness for most human activities such as water pumping and electric power generation, amongst others. The off beam installation of Photovoltaic (PV) modules has posed a severe challenge to the optimal functioning of these PV cells despite the abundance of solar irradiation receivable in most African cities. This paper presents the Optimal Inclination Angles (OIA) for mounting PV modules in the absences of a mechanized or automated solar tracking device, for optimum yield in solar electricity generation for some selected African cities using the Photovoltaic Geographic Information Systems (PVGIS) dataset. The OIA of the selected African cities has been identified for optimal solar irradiation exploitation and if the modules are mounted on a horizontal plane, it is expected that considerable amount of solar irradiation would not be harnessed as it has been estimated using the difference from the Irradiation on OIA (Hopt) and the Irradiation on horizontal plane (Hh), whose difference shows that the northern African cities, Algiers, Rabat and Tripoli, are seen to have high levels in unutilized solar irradiation of 780 Wh/m 2, 760 Wh/m 2 and 680 Wh/m 2 respectively while Harare, Lusaka, Maiduguri, Khartoum, Maputo and Luanda would have considerably high levels in untapped solar irradiation of 360Wh/m 2, 330 Wh/m 2, 180 Wh/m 2, 260 Wh/m 2, 570 Wh/m 2 and 80 Wh/m 2 respectively if PV modules are mounted on horizontal plane. However cities such as Bangui, Abidjan and Mogadishu have quite low levels in unexploited solar irradiation of 40 Wh/m 2, 70 Wh/m 2 and 10 Wh/m 2 respectively when PV modules are mounted on horizontal plane. These differences show the amount of solar irradiation which if adequately harnessed, adds to the solar energy potentials of the region.