scholarly journals Fundamentals and Principles of Solid-State Electrochemical Sensors for High Temperature Gas Detection

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Elena Gorbova ◽  
Fotini Tzorbatzoglou ◽  
Costas Molochas ◽  
Dimitris Chloros ◽  
Anatoly Demin ◽  
...  

The rapid development of science, technology, and engineering in the 21st century has offered a remarkable rise in our living standards. However, at the same time, serious environmental issues have emerged, such as acid rain and the greenhouse effect, which are associated with the ever-increasing need for energy consumption, 85% of which comes from fossil fuels combustion. From this combustion process, except for energy, the main greenhouse gases-carbon dioxide and steam-are produced. Moreover, during industrial processes, many hazardous gases are emitted. For this reason, gas-detecting devices, such as electrochemical gas sensors able to analyze the composition of a target atmosphere in real time, are important for further improving our living quality. Such devices can help address environmental issues and inform us about the presence of dangerous gases. Furthermore, as non-renewable energy sources run out, there is a need for energy saving. By analyzing the composition of combustion emissions of automobiles or industries, combustion processes can be optimized. This review deals with electrochemical gas sensors based on solid oxide electrolytes, which are employed for the detection of hazardous gasses at high temperatures and aggressive environments. The fundamentals, the principle of operation, and the configuration of potentiometric, amperometric, combined (amperometric-potentiometric), and mixed-potential gas sensors are presented. Moreover, the results of previous studies on carbon oxides (COx), nitrogen oxides (NOx), hydrogen (H2), oxygen (O2), ammonia (NH3), and humidity (steam) electrochemical sensors are reported and discussed. Emphasis is given to sensors based on oxygen ion and proton-conducting electrolytes.

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 923
Author(s):  
Mohsen Saffari Pour ◽  
Ali Hakkaki-Fard ◽  
Bahar Firoozabadi

The application of incinerators for the municipal solid waste (MSW) is growing due to the ability of such instruments to produce energy and, more specifically, reduce waste volume. In this paper, a numerical simulation of the combustion process with the help of the computational fluid dynamics (CFD) inside a portable (mobile) incinerator has been proposed. Such work is done to investigate the most critical parameters for a reliable design of a domestic portable incinerator, which is suitable for the Iranian food and waste culture. An old design of a simple incinerator has been used to apply the natural gas (NG), one of the available cheap fossil fuels in Iran. After that, the waste height, place of the primary burner, and the flow rate of the cooling air inside the incinerator, as the main parameters of the design, are investigated. A validation is also performed for the mesh quality test and the occurrence of the chemical reactions near the burner of the incinerator. Results proved that the numerical results have less than 5% error compared to the previous experimental and numerical approaches. In addition, results show that by moving the primary burner into the secondary chamber of the incinerator, the temperature and the heating ability of the incinerator could be affected dramatically. Moreover, it has been found that by increasing the flow rate of the cooling air inside the incinerator to some extent, the combustion process is improved and, on the other hand, by introducing more cooling air, the evacuation of the hazardous gases from the exhaust is also improved.


2016 ◽  
Vol 23 (4) ◽  
pp. 531-543 ◽  
Author(s):  
Petr Sedlak ◽  
Petr Kubersky ◽  
Pavel Skarvada ◽  
Ales Hamacek ◽  
Vlasta Sedlakova ◽  
...  

Abstract Electrochemical amperometric gas sensors represent a well-established and versatile type of devices with unique features: good sensitivity and stability, short response/recovery times, and low power consumption. These sensors operate at room temperature, and therefore have been applied in monitoring air pollutants and detection of toxic and hazardous gases in a number of areas. Some drawbacks of classical electrochemical sensors are overcome by the solid polymer electrolyte (SPE) based on ionic liquids. This work presents evaluation of an SPE-based amperometric sensor from the point of view of current fluctuations. The sensor is based on a novel three-electrode sensor platform with solid polymer electrolytes containing ionic liquid for detection of nitrogen dioxide − a highly toxic gas that is harmful to the environment and presenting a possible threat to human health even at low concentrations. The paper focuses on using noise measurement (electric current fluctuation measurement) for evaluation of electrochemical sensors which were constructed by different fabrication processes: (i) lift-off and drop-casting technology, (ii) screen printing technology on a ceramic substrate and (iii) screen printing on a flexible substrate.


2012 ◽  
Vol 616-618 ◽  
pp. 1133-1136 ◽  
Author(s):  
Ji Zhong Zhu ◽  
Kwok Cheung

Every type of energy utilization for electricity generation has environmental consequences. The main consequences of burning fossil fuels and of nuclear power are well-known. Renewable energy sources (wind, solar, biomass, hydroelectric, geothermal, etc.) are generally thought of as harmless, but this doesn’t mean they have no environmental consequences at all. Most of them have a significant aesthetic impact and require large areas of land. Some also have a significant impact on the eco-system (birds, fishes, etc.). This paper summarizes the environmental issues caused by all kinds of renewable energy sources.


ICR Journal ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 76-96
Author(s):  
Shahino Mah Abdullah

The rise in world energy consumption has caused an alarming shortage of fossil fuels and an increase in carbon emissions. It has also led to various environmental issues, especially climate change, which threaten humanity’s access to food, water, shelter, energy and health. The growth of the human population combined with rapid development has caused excessive carbon emissions, while the conventional ways of energy production and utilisation need serious reconsideration. This article, therefore, draws attention to the vital role that human beings, as vicegerents of the Earth (khalifah), have in managing natural resources. It highlights the pivotal position of humans in the world, as trustees who bear great responsibility for maintaining the natural environment. At the same time, this article also draws attention to the Islamic concept of moderation (wasatiyyah) and its practice to improve the consumption of resources by reducing wastage and pollution. The concept of moderation in the context of consuming natural resources is generally supported by the advancements in maqasid al-shariah (higher objectives of Islamic law) that have included the significance of environmental preservation This article also seeks to inform the development of Renewable Energy (RE) in the context of the Islamic concern for inclusive well-being. Several policy actions capable of promoting the concept of I’mar al-ard (building of the Earth) and smart energy consumption are proposed to address environmental issues in our policy recommendations towards the end.


2019 ◽  
Vol 8 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Muhammad Khairul Afdhol ◽  
Hafni Zulaika Lubis ◽  
Chalidah Pratiwi Siregar

Global demand for energy needs has increased due to the rapid development of the human population, raising the industrial prosperity in developing countries. Primary energy demand is still supplied from fossil fuels, such as oil, coal and natural gas. The utilization of fossil fuels will continuously enhance the effect of greenhouse gases in the atmosphere. On the other hand, the extent of the tea plantation area in Indonesia reached 53,009 Ha, so that it will reproduce a waste too. Thus, spent tea as bioetanol. In addition it contains cellulose fibres are quite high, environmentally friendly and economical. Bioethanol as motor vehicle fuels can reduce the addition of CO2 at atmosphere because the use of biomass for the production and usage of bioethanol can be considered as a closed cycle. According to this principle the buyer of CO2 from fuel combustion bioethanol originating from the CO2-based biomass will be reabsorbed by plants through photosynthesis reactions. As a result of this whole process is not accounted for emissions of CO2 liquid gas a greenhouse gas into the atmosphere. Bioethanol-cellulosa can reduce greenhouse gas emissions amounted to 80%. The process into products bioethanol via hydrolysis, fermentation, distillation and characterization using Gas Chromatography-Mass Spectrometry (GC-MS). Them is the optimal bioethanol levels produced from fermented inoculant 1% amounting to 8.2% and optimal levels of bioethanol produced from hydrolysis of 8% H2SO4 results amounted to 8.2%, thus optimumsitas the ethanol produced from 8% acid and 1% inoculant apply to have levels of ethanol amounted to 8.2%. The product program could be developed into bioethanol solvent to dissolve the oil that is waxy crude oil.


Author(s):  
Numchok Manmai ◽  
Yuwalee Unpaprom ◽  
Ramaeshprabu Ramaraj ◽  
Keng-Tung Wu

The use of fossil fuels, as well as the environmental issues associated with their burning, has pushed for the development of clean, renewable energy sources. Biofuels made from lignocellulosic biomass are considered a carbon-neutral and sustainable method. As the demand for non-petroleum fuels grows, more attention will be placed on developing a cost-competitive liquid transportation biofuel like ethanol. This study was conducted to produce bioethanol utilizing the SHF (separate hydrolysis and fermentation) technique from corn stove lignocellulose. Pretreatment with sodium hydroxide at various concentrations was also studied. The influence of enzymatic saccharification, fermentation time, and substrate concentration on sugar yield and, eventually, ethanol production was investigated. Fermentation was carried out by using the enzymatically saccharified hydrolysate and monoculture of Saccharomyces cerevisiae. The results reveal that pretreatment with 2% NaOH followed by 48 hours of hydrolysis produced the maximum bioethanol production (30.21 ±0.13 g/L). This study findings indicated that alkali-pretreated corn stove might be used as a feedstock for bioethanol production, reducing reliance on fossil fuels.


2021 ◽  
Vol 9 ◽  
Author(s):  
Mohammad Alhuyi Nazari ◽  
Mohamed Salem ◽  
Ibrahim Mahariq ◽  
Khaled Younes ◽  
Bashar B. Maqableh

Renewable energy sources have been used for desalination by employing different technologies and mediums due to the limitations of fossil fuels and the environmental issues related to their consumption. Solar energy is one of the most applicable types of renewable sources for desalination in both direct and indirect ways. The performance of solar desalination is under effects of different factors which makes their performance prediction difficult in some cases. In this regard, data-driven methods such as artificial neural networks (ANNs) would be proper tools for their modeling and output forecasting. In the present article, a comprehensive review is provided on the applications of different data-driven approaches in performance modeling of solar-based desalination units. It can be concluded that by employing these methods with proper inputs and structures, the outputs of the solar desalination units can be reliably and accurately forecasted. In addition, several recommendations are produced for the upcoming work in the relevant areas of the study.


Author(s):  
B.S. Soroka ◽  
V.V. Horupa

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.


Author(s):  
Bhargavi Munnaluri ◽  
K. Ganesh Reddy

Wind forecasting is one of the best efficient ways to deal with the challenges of wind power generation. Due to the depletion of fossil fuels renewable energy sources plays a major role for the generation of power. For future management and for future utilization of power, we need to predict the wind speed.  In this paper, an efficient hybrid forecasting approach with the combination of Support Vector Machine (SVM) and Artificial Neural Networks(ANN) are proposed to improve the quality of prediction of wind speed. Due to the different parameters of wind, it is difficult to find the accurate prediction value of the wind speed. The proposed hybrid model of forecasting is examined by taking the hourly wind speed of past years data by reducing the prediction error with the help of Mean Square Error by 0.019. The result obtained from the Artificial Neural Networks improves the forecasting quality.


2017 ◽  
Vol 68 (11) ◽  
pp. 2676-2681
Author(s):  
Mihaela Gabriela Dumitru ◽  
Dragos Tutunea

The purpose of this work was to investigate the physicochemical properties of watermelon seeds and oil and to find out if this oil is suitable and compatible with diesel engines. The results showed that the watermelon seeds had the maximum length (9.08 mm), width (5.71mm), thickness (2.0 mm), arithmetic mean diameter (5.59 mm), geometrical mean diameter (4.69 mm), sphericity (51.6%), surface area (69.07), volume 0.17 cm3 and moisture content 5.4%. The oil was liquid at room temperature, with a density and refractive index of 0.945 and 1.4731 respectively acidity value (1.9 mgNaOH/g), free fatty acid (0.95 mgNaOH), iodine value (120 mgI2/100g), saponification value (180 mgKOH/g), antiradical activity (46%), peroxide value (7.5 mEqO2/Kg), induction period (6.2 h), fatty acid: palmitic acid (13.1%), stearic acid (9.5 %), oleic acid (15.2 %) and linoleic acid (61.3%). Straight non food vegetable oils can offer a solution to fossil fuels by a cleaner burning with minimal adaptation of the engine. A single cylinder air cooled diesel engine Ruggerini RY 50 was used to measure emissions of various blends of watermelon oil (WO) and diesel fuel (WO10D90, WO20D80, WO30D70 and WO75D25). The physic-chemical properties of the oil influence the combustion process and emissions leading to the reduction of NOX and the increase in CO, CO2 and HC.


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