scholarly journals Thermodynamic Discrimination Between Energy Sources for Chemical Reactions

2020 ◽  
Author(s):  
Zachary Schiffer ◽  
Aditya Limaye ◽  
Karthish Manthiram
Keyword(s):  
Energy Source ◽  
Equilibrium Constant ◽  
Chemical Reactions ◽  
Process Parameters ◽  
Energy Analysis ◽  
Energy Sources ◽  
Chemical Transformations ◽  
Universal Equation ◽  
Specific Data ◽  
Case Basis

Chemical transformations traverse large energy differences, yet the choice of energy source to drive a chemical reaction is often decided on a case-by-case basis; there is no fundamentally-driven, universal framework with which to analyze and compare the choice of energy source for chemical reactions. In this work, we present a reaction-independent expression for the equilibrium constant as a function of temperature, pressure, and voltage. With a specific set of axes, all reactions can be represented by a single (x,y) point and a quantitative divide between electrochemically and thermochemically driven reactions is visually evident. In addition, we show that our expression has a strong physical basis in work and energy fluxes to the system, although more specific data about reaction operation is necessary to provide a quantitative energy analysis. Overall, this universal equation and facile visualization of chemical reactions enables quick and informed justification for electrochemical versus thermochemical energy sources without knowledge of detailed process parameters.

scholarly journals Thermodynamic Discrimination Between Energy Sources for Chemical Reactions

2020 ◽  
Author(s):  
Zachary Schiffer ◽  
Aditya Limaye ◽  
Karthish Manthiram
Keyword(s):  
Energy Source ◽  
Equilibrium Constant ◽  
Chemical Reactions ◽  
Process Parameters ◽  
Energy Analysis ◽  
Energy Sources ◽  
Chemical Transformations ◽  
Universal Equation ◽  
Specific Data ◽  
Case Basis

Chemical transformations traverse large energy differences, yet the choice of energy source to drive a chemical reaction is often decided on a case-by-case basis; there is no fundamentally-driven, universal framework with which to analyze and compare the choice of energy source for chemical reactions. In this work, we present a reaction-independent expression for the equilibrium constant as a function of temperature, pressure, and voltage. With a specific set of axes, all reactions can be represented by a single (x,y) point and a quantitative divide between electrochemically and thermochemically driven reactions is visually evident. In addition, we show that our expression has a strong physical basis in work and energy fluxes to the system, although more specific data about reaction operation is necessary to provide a quantitative energy analysis. Overall, this universal equation and facile visualization of chemical reactions enables quick and informed justification for electrochemical versus thermochemical energy sources without knowledge of detailed process parameters.

Net Energy for Concentrated Solar Power in Chile

2008 ◽  
Author(s):  
Rodrigo Escobar ◽  
Teresita Larrain
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Solar Energy ◽  
Fossil Fuel ◽  
Energy Analysis ◽  
Renewable Energy Sources ◽  
Continuous Operation ◽  
Energy Sources ◽  
Net Energy ◽  
Concentrated Solar Power

The Chilean Energy Policy calls for 15 percent of new power generation capacity to come from renewable energy sources from 2006 to 2010, and then a 5% of electric energy generated from renewable energy sources with gradual increases in order to reach 10% by 2024. Neither the government nor the power generation sector plans mention solar energy to be part of the renewable energy initiative. Part of this apparent lack of interest in solar energy might be due to the absence of a valid solar energy database, adequate for energy system planning activities. Monthly means of solar radiation are used in order to estimate the solar fraction for a 100 MW plant for four given locations. Our analysis considers two cases: operation during sunlight hours, and continuous operation during 24 hours a day. A net energy analysis for concentrated solar power (CSP) plants in Chile is then performed, considering the energy costs of manufacturing, transport, installation, operation and decommissioning. The results indicate that the CSP plants are a net energy source in three of the four locations, when operating in sunlight-only mode. This is due to the lower radiation levels available at that location, which implies a high fossil fuel back-up fraction. In the continuous operation mode, the CSP plants become fossil fuel plants with solar assistance, and therefore all locations display negative net energy. Based on this result, the back-up fraction required for the plants to be net energy sources is estimated from the EROEI as function of the back-up fraction. It is estimated that the net energy analysis is a useful tool for determining under which conditions a CSP plant becomes a net energy source, and thus can be utilized in order to define geographical locations and operation conditions where they can be considered renewable energy sources.

Net Energy Analysis for Concentrated Solar Power Plants in Chile

2008 ◽  
Author(s):  
Rodrigo Escobar ◽  
Teresita Larrai´n
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Fossil Fuel ◽  
Energy Analysis ◽  
Solar Power ◽  
Renewable Energy Sources ◽  
Continuous Operation ◽  
Energy Sources ◽  
Net Energy ◽  
Concentrated Solar Power

The Chilean Energy Policy calls for 15 percent of new power generation capacity to come from renewable energy sources from 2006 to 2010, and then a 5% of electric energy generated from renewable energy sources with gradual increases in order to reach 10% by 2024. Concentrated solar power is an interesting alternative to help achieving those objectives, as it is estimated that northern Chile has high radiation levels, coupled with high values of the local clearness index and availability of flat terrain. The present report investigates the net energy attributes of parabolic trough plants installed in the Atacama Desert. Monthly means of solar radiation are used in order to estimate the solar fraction for a 100 MW plant at three different locations. Our analysis considers three cases: operation during sunlight hours only, with and without fossil fuel back-up, and continuous operation during 24 hours a day. The net energy analysis for concentrated solar power (CSP) plants is then performed, considering the energy costs of manufacturing, transport, installation, operation and decommissioning. The results indicate that the CSP plants are a net energy source when operating in sunlight-only mode and that the energy payback time is a linear function of the total operation time when utilizing fossil fuel back-up. In the continuous operation mode, the CSP plants become fossil fuel plants with solar assistance, and therefore all locations display negative net energy. Based on this result, the back-up fraction required for the plants to be net energy sources is estimated from the EROEI as function of the back-up fraction. It is estimated that the net energy analysis is a useful tool for determining under which conditions a CSP plant becomes a net energy source, and thus can be utilized in order to define geographical locations and operation conditions where they can be considered renewable energy sources.

Biotransformation of Coumarins by Filamentous Fungi: An Alternative Way for Achievement of Bioactive Analogs

2019 ◽  
Vol 16 (6) ◽  
pp. 568-577 ◽  
Author(s):  
Jainara Santos do Nascimento ◽  
João Carlos Silva Conceição ◽  
Eliane de Oliveira Silva
Keyword(s):  
Filamentous Fungi ◽  
Chemical Reactions ◽  
Biological Activities ◽  
Chemical Transformations ◽  
Chemical Structures ◽  
Pattern Structures ◽  
Pharmacological Interest ◽  
Aspergillus Sp ◽  
The Impact ◽  
Related Compounds

Coumarins are natural 1,2-benzopyrones, present in remarkable amounts as secondary metabolites in edible and medicinal plants. The low yield in the coumarins isolation from natural sources, along with the difficulties faced by the total synthesis, make them attractive for biotechnological studies. The current literature contains several reports on the biotransformation of coumarins by fungi, which can generate chemical analogs with high selectivity, using mild and eco-friendly conditions. Prompted by the enormous pharmacological interest in the coumarin-related compounds, their alimentary and chemical applications, this review covers the biotransformation of coumarins by filamentous fungi. The chemical structures of the analogs were presented and compared with those from the pattern structures. The main chemical reactions catalyzed the insertion of functional groups, and the impact on the biological activities caused by the chemical transformations were discussed. Several chemical reactions can be catalyzed by filamentous fungi in the coumarin scores, mainly lactone ring opening, C3-C4 reduction and hydroxylation. Chunninghamella sp. and Aspergillus sp. are the most common fungi used in these transformations. Concerning the substrates, the biotransformation of pyranocoumarins is a rarer process. Sometimes, the bioactivities were improved by the chemical modifications and coincidences with the mammalian metabolism were pointed out.

Studi Analisa Potensi Sumber Air sebagai Pembangkit Listrik Tenaga Mikrohidro (PLTMH) di Karungan Kelurahan Mamburungan Timur Kota Tarakan

2021 ◽  
Vol 4 (2) ◽  
pp. 22-26
Author(s):  
Hadi Santoso ◽  
Eris Santoso ◽  
Ruslim Ruslim
Keyword(s):  
Energy Source ◽  
Alternative Energy ◽  
Renewable Energy Sources ◽  
Water Discharge ◽  
Electrical Energy ◽  
Water Source ◽  
Energy Sources ◽  
Hydro Power ◽  
The People ◽  
City Water

The supply of electrical energy in Tarakan City, North Kalimantan, still relies on diesel power which uses a limited number of petroleum energy sources. There is a need for research related to renewable energy sources that have the potential to become alternative energy for the people of Tarakan City. Water is an energy source that has great potential to generate electricity. The energy source that should be taken into account is micro-hydro which can be used as a Micro-hydro Power Plant (PLTMH). A survey of micro-hydro sources in Tarakan City, precisely in the Karungan area, East Mamburungan Village, has been carried out with the direct measurement method of water discharge and the relationship with the power generated. The result shows the water source has a discharge 0.00034 m3/ s, the water velocity of 0.035 m/s and generates power only up to 1.1 watts. Based on the power obtained, the water source in this place cannot be used as a source of micro-hydro energy, but has the potential as a source of pico-hydro energy.

scholarly journals Viability of Peranakan Etawah Liquid Semen Preserved in Tris Substituted with Various Energy Sources

2020 ◽  
Vol 25 (2) ◽  
pp. 68
Author(s):  
Nurul Afzan Hilda Zakiya ◽  
A H Yanti ◽  
T R Setyawati
Keyword(s):  
Energy Source ◽  
Artificial Insemination ◽  
Block Design ◽  
Egg Yolk ◽  
Energy Sources ◽  
Randomized Block Design ◽  
Frozen Semen ◽  
Semen Preservation ◽  
Semen Extender ◽  
Fresh Semen

The use of liquid semen for artificial insemination program of Etawah crossbreed goat (PE) is an alternative to replace frozen semen which is constrained by limited and expensive facilities. Production of liquid semen is faster than frozen semen, but the viability of liquid semen which preserved with a standard extender such as tris egg yolk is very short. The purpose of this study was to determine the viability of PE goat semen in egg yolk tris substituted with energy sources such as glucose, galactose, and mannose and to determine the most efficient energy source for semen preservation. This research was conducted from August to September 2018 at the Artificial Insemination Center in Lembang, West Java. This study was designed in a randomized block design (RBD) consist of three experimental groups divided into five groups. Fresh semen of PE goats were preserved using extender which energy source has been modified. Results showed that using glucose in PE goat semen extender produced the best motility among other groups (64.29 ± 9.2%). The highest viability was found in extender with fructose substitution (86.76 ± 2.3%). The longest viability of liquid semen was found in the extender with glucose substitution. It lasted for six days.

scholarly journals Utilizing Sewage Wastewater Heat in District Heating Systems in Serbia - Effects on Sustainability

2021 ◽  
Author(s):  
Marija Živković ◽  
Dejan Ivezic
Keyword(s):  
Energy Source ◽  
Wastewater Treatment ◽  
Carbon Dioxide Emission ◽  
District Heating ◽  
Primary Energy ◽  
Energy Sources ◽  
Heating Systems ◽  
Current State ◽  
District Heating Systems ◽  
Treatment Facilities

Abstract Transformation of the heating sector is recognized as being essential for ensuring reliable and affordable energy services provided with reduced consumption of energy sources, diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated as a big advantage of district heating systems. Despite many advantages, sewage wastewater heat is still a mostly unused resource at the global level and a totally unused energy source in Serbia, while data about the potential of this energy source are lacking. This research proposes a methodology for the determination of the technical potential of waste heat from wastewater treatment facilities for use in district heating systems by heat pump application. Data from existing wastewater treatment facilities are used for providing data for replication in cities without wastewater treatment plants but with district heating systems. An estimation of the recoverable heat energy potential of wastewater is used for evaluation of some effects that could be obtained through its full utilization for heat production in the existing district heating systems. Three groups of indicators are selected for analysis focusing on district heating systems' energy performance (primary energy factor, specific heat consumption per degree day and heating area), the security of energy supply (import dependency, Shannon Wiener diversification index, the share of renewables) and environmental impact (carbon dioxide emission coefficient). Values of the selected indicators are determined for the current state of district heating systems and for the possible future state that could be achieved after full utilization of sewage wastewater potential. The proposed methodology is applied to Serbia, as a case study. It has been shown that all analyzed indicators for the projected future would have more preferable values compared to the values that correspond to the current state of the district heating systems. The use of this renewable energy source should provide primary energy savings of 5% per year, reduction of carbon dioxide emission of 6.5% per year, reduction of import dependency of DH systems of 9.8% and improved diversification of energy sources of 21%.

Monitoring of chemical transformations by mass spectrometry

2015 ◽  
Vol 7 (17) ◽  
pp. 6947-6959 ◽  
Author(s):  
Chun-Chi Chen ◽  
Po-Chiao Lin
Keyword(s):  
Mass Spectrometry ◽  
Chemical Reactions ◽  
Reaction Mechanisms ◽  
Chemical Transformations

During the last several decades, mass spectrometry (MS) has rapidly developed as a practical technique that can be used to monitor chemical reactions and investigate reaction mechanisms.

Use of the Savonius Wind Turbine for the Needs of Public Lighting

2014 ◽  
Vol 1008-1009 ◽  
pp. 179-182
Author(s):  
Iveta Gressová
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Wind Energy ◽  
Wind Turbine ◽  
Energy Use ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Geothermal Heat ◽  
Current Generation ◽  
Savonius Wind Turbine

Our planet gives us many mineral sources, but they have a big disadvantage. They are finite. Non-renewable energy sources are enough only for decades, exceptionally for centuries. Current generation is aware of the importance of using other energy sources, such as sunlight, wind, rain, tides, waves and geothermal heat. These energy sources are renewable. It means that they come from sources, which are naturally replenished on a human timescale. One of these sources is wind energy. Use of this kind of energy source needs an initial investment, but it can reduce cost of running a household and other sectors. This article is about Savonius wind turbine and its use for the needs of public lighting.

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