scholarly journals Optimization of biogas composition in experimental studies

2019 ◽  
Vol 112 ◽  
pp. 02007 ◽  
Author(s):  
Radostin Dimitrov ◽  
Zdravko Ivanov ◽  
Penka Zlateva ◽  
Veselin Mihaylov

The article is focused on the potential and application of biogas, as an alternative fuel from Renewable Energy Sources, for use mainly in gas-generator stations. Biogas fuel is basically a mixture of methane and carbon dioxide. Its composition depends on the type of raw material used for its production. Methane concentration in biogas is between 50÷80%. To be possible engine to work with maximum efficiency with different biogas fuels, it is necessary to modify specific adjustment parameters depending on the concentration of methane in the mixture. This requires the creation of a biogas simulation system for different concentrations of the main components. The aim is to investigate and determine the optimum and permissible biofuel blend concentrations and their impact on engine performance and fuel consumption. Biogas can be used as a fuel to produce electricity, heat or steam or as fuel for internal combustion engine, and its use will help to reduce harmful emissions into the atmosphere.

2021 ◽  
Vol 1045 ◽  
pp. 67-78
Author(s):  
Pavlo Saik ◽  
Roman Dychkovskyi ◽  
Vasyl Lozynskyi ◽  
Volodymyr Falshtynskyi ◽  
Edgar Caseres Cabana ◽  
...  

The paper represents the studies of the process of carbonaceous raw material gasification. The initial material is represented by bituminous coal of grade H with the carbon (C) content of 79.2-85.3 %. Experimental studies have been used to substantiate the parameters of combustible generator gases (СО, Н2, СН4) output depending on the temperature of a reduction zone of the reaction channel and gas flow velocity along its length. It has been identified that the volume of the raw material input to be used for gasification process changes in direct proportion depending on the amount of burnt-out carbon and blow velocity. The gasification is intensified in terms of equal concentration of oxygen and carbon in the reaction channel of an underground gas generator. The gasification rate is stipulated by the intensity of chemical reactions, which depend immediately on the modes of blow mixture supply. Moreover, they depend directly on the intensity of oxygen supply to the coal mass and removal of the gasification products.


Author(s):  
A. A. Kondratiuk ◽  

The paper presents the results of theoretical and experimental studies of the environmental characteristics of internal combustion engines of commercial and municipal vehicles operating on the Diesel cycle using a hydrogen additive. The analysis of literature sources has confirmed that there are different data regarding harmful emissions when using hydrogen additives for internal combustion engines running on the Diesel cycle. Therewith, data on harmful emissions of nitrogen oxides NOx differ significantly. The results of theoretical and experimental studies of the environmental characteristics of internal combustion engines of commercial and municipal vehicles operating on a Diesel cycle using a hydrogen additive, allow to assert the adequacy of the model, since the error between the theoretical and experimental data did not exceed 14,5 %. It has been found out that the concentration of NOx emissions in an internal combustion engine using a hydrogen additive, working on a Diesel cycle, has decreased by 52 %.The research results confirm the prospects of using a hydrogen additive, which is done for the first time for internal combustion engines running on the Diesel cycle in commercial and municipal vehicles. This guarantees increased environmental safety in urban agglomerations.


2021 ◽  
Vol 03 (04) ◽  
pp. 123-129
Author(s):  
Ismatov J.F. ◽  
◽  
Jalilov J.Kh. ◽  

The rapid depletion of fossil fuels and the steady increase in human energy consumption, leading to environmental pollution, are creating a situation characterized as an energy-environmental degradation. For this reason, extensive research is being conducted to address the problem of reducing the consumption of non-renewable energy sources and pollution of the environment with toxic waste. In such cases, the concept of hydrogen energy, ie the use of hydrogen as a source of energy on a large industrial scale and in road transport, is important. The prospects for the use of hydrogen for automobile engines can be summarized as follows. First of all, environmental friendliness, renewability and unrestricted raw material reserves, as well as unique engine performance; these allow hydrogen to be used without drastic changes to modern engine designs.


2020 ◽  
Vol 42 (2) ◽  
pp. 5-17
Author(s):  
Yu.F. Sniezhkin ◽  
R.О. Shapar

The article substantiates the relevance of processing thermolabile materials into dried foods, as one of the alternative options for fresh fruits and vegetables. It is noted that drying, as a method of conservation, is characterized by high energy intensity and increased requirements for the quality and safety of the final product. The naturalness of the dried products and the environmental cleanliness of the process come to the fore. The criteria of quality and efficiency of the process are combined into a single task: increasing the efficiency of the drying process and creating energy-efficient equipment. The analysis of heat and mass transfer during convective drying allowed us to establish methods and ways to improve the energy efficiency of the process. Based on a synthesis of theoretical and experimental studies, the optimal heat and humidity parameters of dehydration were determined, according to which the temperature of the material during drying does not exceed the maximum permissible value. This contributes to the preservation of valuable nutrients in the final product. Prevention of excess material temperature above the acceptable level is confirmed by the nature of the change in the numerical value of the Rebinder effect and is provided by drying in multi-stage dehydration modes, including high-temperature high-moisture method using zone drying installations of tunnel and belt type, as well as heat-pump drying installations with low heat consumption. It was emphasized that the drying of thermolabile materials is carried out in an environment of pure hot air without the use of inert and chemically synthesized substances. Non-contact air heating is carried out using traditional fuels as well as secondary and renewable energy sources. It is noted that the design features of the drying equipment make it possible to distribute the intensity of the thermal effect on the material, depending on its moisture content into zones, and also automatically maintain and control these parameters for a specific type of raw material. The adopted recirculation system of the drying agent helps prevent emissions of waste coolant and reduces thermal pollution of the environment.


Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.


Author(s):  
Muntasir Muntasir ◽  
Pius Weraman

Community Partnership Program in small home industry of making fish floss brand "Savitri" and "Tiaras" inKupang city in the form of application of electric centrifugation filter model has been implemented. One of the problemsin the production of Savitri and Tiaras fish floss is that there is still a lot of oil in the frying product which is only drainedon a simple sieve and then placed for some time on traditional tools of filter and paper that can cause low quality and lowquality, so it is necessary to reduce the oil yield frying fish floss product. In order to increase the added value and sellingvalue of the products, it is necessary synergy between Universities and Partners in the form of application of the results ofscience and technology to the public. The main components of the composer of the versatile filter are the cylindrical plateas the bucket of the filter, the cylinder filter, the electric dynamo as the centrifuge system rotator and the load-bearingconstruction. The method of this program is the provision of materials, design and manufacture of tools, demonstrationtools and the provision of a versatile filter cylinder system centrifuge model by the team, simulation tools, specialcounseling at the location of partners and suggestions as a follow-up in the endurance of production. The output of thisprogram can provide added value in the form of the use of this tool can improve labor efficiency, increase productivitypartners by producing 40 kg to 50 kg raw material, raw fish marlin, fish meat after cleaning, processed, fried, in andpacked into 80-100 packs of fish floss with the price of Rp. 40,000.00 per package weighing 250 grams. With estimatedpartners will earn a profit of Rp 3,200,000 - 4,000,000.00 per production or 12,800,000.00 - 16,000,000.00 per month incash and consumptions, as well as the abundance of non-greasy, clean and hybrid fish products


2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4992
Author(s):  
Ruimeng Shi ◽  
Xiaoming Li ◽  
Yaru Cui ◽  
Junxue Zhao ◽  
Chong Zou ◽  
...  

Nickel slags can be produced through ferronickel preparation by the pyrometallurgical processing of laterite nickel ores; however, such techniques are underutilized at present, and serious environmental problems arise from the stockpiling of such nickel ores. In this study, a modification to the process of ferronickel preparation by the direct reduction of carbon bases in laterite nickel ores is proposed. The gangue from the ore is used as a raw material to prepare a cementitious material, with the main components of tricalcium silicate and tricalcium aluminate. By using FactSage software, thermodynamic calculations are performed to analyze the reduction of nickel and iron and the effect of reduction on the formation of tricalcium silicate and tricalcium aluminate. The feasibility of a coupled process to prepare ferronickel and cementitious materials by the direct reduction of laterite nickel ore and gangue calcination, respectively, is discussed under varying thermodynamic conditions. Different warming strategies are applied to experimentally verify the coupled reactions. The coupled preparation of ferronickel and cementitious materials with calcium silicate and calcium aluminate as the main phases in the same experimental process is realized.


2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.


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