scholarly journals Создание ZnO нанокатализатора, фиксированного на подложке, и перспективы фотокаталитического получения биогаза из растительных отходов

2021 ◽  
Vol 129 (6) ◽  
pp. 787
Author(s):  
И.Ю. Денисюк ◽  
Д.А. Морозова ◽  
Ю.А. Игнатьева ◽  
М.В. Успенская
Keyword(s):  
Carbon Dioxide ◽  
Renewable Energy ◽  
Chemical Reactions ◽  
Waste Disposal ◽  
Zinc Acetate ◽  
Agricultural Waste ◽  
Reaction Vessel ◽  
Photocatalytic Decomposition ◽  
Laboratory Setup ◽  
Radiation Sources

In this work discuss the production of biofuels from agricultural waste, such as sugars, alcohols, organic acids, by obtaining hydrogen and biogas from them during photocatalytic decomposition. Possible chemical reactions during photocatalysis are presented using the example of photocatalytic decomposition of methanol into hydrogen and carbon dioxide. Experiments on the preparation of nanostructured ZnO by the hydrothermal method in a solution containing zinc acetate and urotropin have been carried out. The obtained ZnO immobilized on a substrate is supposed to be used as a photocatalyst. A possible design of a reaction vessel and radiation sources for a laboratory setup for producing biogas from model solutions are considered. Key words: photocatalysis, biogas, ZnO, nanowires, waste disposal, renewable energy.

Assessment of bioenergy development potential in agricultural enterprises

2020 ◽  
pp. 165-171
Author(s):  
Iryna Hryhoruk
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Agricultural Waste ◽  
General Structure ◽  
Geographical Location ◽  
Economic Assessment ◽  
Energy Resources ◽  
Industrial Complex ◽  
Renewable Energy Resources ◽  
Energy Potential

Exhaustion of traditional energy resources, their uneven geographical location, and catastrophic changes in the environment necessitate the transition to renewable energy resources. Moreover, Ukraine's economy is critically dependent on energy exports, and in some cases, the dependence is not only economic but also political, which in itself poses a threat to national security. One of the ways to solve this problem is the large-scale introduction and use of renewable energy resources, bioenergy in particular. The article summarizes and offers methods for assessing the energy potential of agriculture. In our country, a significant amount of biomass is produced every year, which remains unused. A significant part is disposed of due to incineration, which significantly harms the environment and does not allow earning additional funds. It is investigated that the bioenergy potential of agriculture depends on the geographical distribution and varies in each region of Ukraine. Studies have shown that as of 2019 the smallest share in the total amount of conventional fuel that can be obtained from agricultural waste and products suitable for energy production accounts for Zakarpattya region - 172.5 thousand tons. (0.5% of the total) and Chernivtsi region - 291.3 thousand tons. (0.9%). Poltava region has the greatest potential - 2652.2 thousand tons. (7.8%) and Vinnytsia - 2623.7 thousand tons. (7.7%). It should be noted that the use of the energy potential of biomass in Ukraine can be called unsatisfactory. The share of biomass in the provision of primary energy consumption is very small. For bioenergy to occupy its niche in the general structure of the agro-industrial complex, it is necessary to develop mechanisms for its stimulation. In addition, an effective strategy for the development of the bioenergy sector of agriculture is needed. The article considers the general energy potential of agriculture, its indicative structure. The analysis is also made in terms of areas. In addition, an economic assessment of the possible use of existing potential is identified.

scholarly journals Agricultural Residue Management for Sustainable Power Generation: The Poland Case Study

2021 ◽  
Vol 11 (13) ◽  
pp. 5907
Author(s):  
Valerii Havrysh ◽  
Antonina Kalinichenko ◽  
Anna Brzozowska ◽  
Jan Stebila
Keyword(s):  
Power Generation ◽  
Spatial Distribution ◽  
Renewable Energy ◽  
Renewable Energy Sources ◽  
Agricultural Waste ◽  
Energy Utilization ◽  
Evaluation Methodology ◽  
Energy Sources ◽  
Energy Potential ◽  
Agricultural Residue

The European Union has set targets for renewable energy utilization. Poland is a member of the EU, and its authorities support an increase in renewable energy use. The background of this study is based on the role of renewable energy sources in improving energy security and mitigation of climate change. Agricultural waste is of a significant role in bioenergy. However, there is a lack of integrated methodology for the measurement of its potential. The possibility of developing an integrated evaluation methodology for renewable energy potential and its spatial distribution was assumed as the hypothesis. The novelty of this study is the integration of two renewable energy sources: crop residues and animal husbandry waste (for biogas). To determine agricultural waste energy potential, we took into account straw requirements for stock-raising and soil conservation. The total energy potential of agricultural waste was estimated at 279.94 PJ. It can cover up to 15% of national power generation. The spatial distribution of the agricultural residue energy potential was examined. This information can be used to predict appropriate locations for biomass-based power generation facilities. The potential reduction in carbon dioxide emissions ranges from 25.7 to 33.5 Mt per year.

Some chemical reactions of sulfur hexafluoride with silicon containing species stimulated by cw CO2 laser radiation

1979 ◽  
Vol 44 (7) ◽  
pp. 2092-2095 ◽  
Author(s):  
Josef Pola ◽  
Pavel Engst ◽  
Milan Horák
Keyword(s):  
Laser Radiation ◽  
Chemical Reactions ◽  
Carbon Disulfide ◽  
Sulfur Hexafluoride ◽  
Initial Pressure ◽  
Reaction Vessel ◽  
Silicon Tetrachloride ◽  
Vibrationally Excited ◽  
Cw Co2 Laser ◽  
Co2 Laser Radiation

The CO2 cw laser induced interaction of sulfur hexafluoride with chlorine, silicon tetrachloride, trichlorosilane, and methyltrichlorosilane in a glass reaction vessel has been investigated. The reaction of SF6 with glass surface yielding silicon tetrafluoride and thionyl fluoride was observed. It is inhibited by the products and its rate increases with growing initial pressure (0.6-5.3 kPa) of SF6. Presumed vibrationally excited or dissociated SF6 undergoes the same reaction in the presence of chlorine and silicon tetrachloride, too. The reaction is suppressed by the addition of trichlorosilane and methyltrichlorosilane; in these cases SiF4, SiCl4 and HCl, or SiF4, SiCl4, HCl, acetylene and carbon disulfide are formed. The products indicate a non-sensitizing action of SF6 and a specific reaction channel for the formation of CS2 not attainable by pyrolysis.

THE KINETICS OF THE OXIDATION OF GASEOUS ACETALDEHYDE

1932 ◽  
Vol 7 (2) ◽  
pp. 149-161 ◽  
Author(s):  
W. H. Hatcher ◽  
E. W. R. Steacie ◽  
Frances Howland
Keyword(s):  
Carbon Dioxide ◽  
Formic Acid ◽  
Induction Period ◽  
Reaction Vessel ◽  
Oxidation Products ◽  
Main Reaction ◽  
Chain Mechanism ◽  
Subsequent Reaction ◽  
A Chain ◽  
Kinetics Of

The kinetics of the oxidation of gaseous acetaldehyde have been investigated from 60° to 120 °C. by observing the rate of pressure decrease in a system at constant volume. A considerable induction period exists, during which the main products of the reaction are carbon dioxide, water, and formic acid. The main reaction in the subsequent stages involves the formation of peroxides and their oxidation products. The heat of activation of the reaction is 8700 calories per gram molecule. The indications are that the reactions occurring during the induction period are heterogeneous. The subsequent reaction occurs by a chain mechanism. The chains are initiated at the walls of the reaction vessel, and are also largely broken at the walls.

scholarly journals Stan i perspektywy wykorzystania biogazu jako nośnika energii do zastosowań stacjonarnych i środków transportu

2012 ◽  
Vol 10 (3) ◽  
pp. 97-118
Author(s):  
Krzysztof Biernat ◽  
Izabela Różnicka
Keyword(s):  
Carbon Dioxide ◽  
Renewable Energy ◽  
Hydrogen Sulfide ◽  
Energy Balance ◽  
Sewage Sludge ◽  
Motor Fuel ◽  
International Programs ◽  
Biogas Upgrading ◽  
Compressed Natural Gas ◽  
Production Of Hydrogen

Both governmental and international programs support the promotion of biofuels and aim to increase the limit of renewable energy used in the fuel energy balance. Biogas is produced during the anaerobic methane fermentationprocess and it is known as a significant source of renewable energy, contributing to agriculture and environmental protection. Three types of biogas can be distinguished: biogas from sewage sludge, biogas collected from land`fils, andagricultural biogas. There are several possibilities of using upgraded biogas. Biogas can be used in cogeneration systems to provide heat and electricity, in transportation as a motor fuel and in the production of biohydrogen. Biogas upgrading process leads to a product which is characterized by the same parameters as compressed natural gas. Direct biogas use in the production of hydrogen is possible because of prior purification from traces like hydrogen sulfide, except carbon dioxide, by which the reaction can proceed in the desired manner.

scholarly journals PRODUCTION OF EXTRACTS FROM VEGETABLE RAW MATERIALS BY CARBON DIOXIDE

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
K. Gafurov ◽  
B. Muhammadiev ◽  
Sh. Mirzaeva ◽  
F. Kuldosheva
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Co2 ◽  
Raw Materials ◽  
Maximum Yield ◽  
Volumetric Flow Rate ◽  
Extraction Process ◽  
Raw Material ◽  
Critical Conditions ◽  
Plant Materials ◽  
Laboratory Setup

The unique properties of supercritical carbon dioxide as a solvent are widely used for extraction. In supercritical media, the dissolution of molecules of various chemical nature is possible. The purpose of this investigation was to study the extraction process and obtain extracts from valuable regional plant materials by applying CO2 extraction under pre- and supercritical conditions. The objects of research were: ground seeds of melon, pumpkin and licorice roots, as well as mint leaves, mulberry and jida flowers. For extraction, a laboratory setup was used that allows extraction when the CO2 is supplied by a high-pressure plunger pump in the sub- and supercritical state using a heat pump. The pressure range is 3-15 MPa, temperatures 295–330 K, and the volumetric flow rate above the critical CO2 is 800–900 g. Experiments with ground seeds of melon and pumpkin showed that as a result of 4 sequentially performed extraction cycles on a single load with supercritical CO2 parameters ( 315–330 K; 3–7.5 MPa) the decrease in the mass of melon seeds was 90 g (pumpkins 80 g). During the total extraction time (2.5 hours), 20 kg of CO2 were pumped through the reactor (25 l at 290 K and 6.8 MPa), while the average oil content in the extract was 4 g per 1 kg of CO2 (3.0 g per 1 l of SС-CO2) In experiments with jida flowers, the maximum amount of solid extractable substance (2% by weight of the raw material) was obtained at a temperature in the extractor of 308 K and a pressure of 7.5 MPa. Upon extraction under critical conditions in collection 2, the liquid phase was absent; only a yellow-green paste was released in it. According to the results of experiments with mint leaves, the maximum yield of a greenish liquid was observed at T = 315 K and P = 4 MPa., Mulberry - at T = 306 K and P = 6.0 MPa. The results of the extraction of oils and extracts from ground seeds of melon, pumpkin and licorice roots, as well as mint leaves, mulberries and jida flowers confirm that the maximum yield of the extracted substance is achieved with supercritical CO2 parameters in the extractor (310 K, 7.5 MPa). When liquid CO2 is extracted (300 K and 6-8 MPa), up to 2% of a yellow substance is extracted, which does not differ in appearance from a supercritical extract.

scholarly journals Optimum Renewable Fraction for Grid-connected Photovoltaic in Office Building Energy Systems in Indonesia

2018 ◽  
Vol 9 (4) ◽  
pp. 1866 ◽  
Author(s):  
Ayong Hiendro ◽  
Ismail Yusuf ◽  
F. Trias Pontia Wigyarianto ◽  
Kho Hie Khwee ◽  
Junaidi Junaidi
Keyword(s):  
Carbon Dioxide ◽  
Renewable Energy ◽  
Energy Systems ◽  
Building Energy ◽  
Office Building ◽  
Pv System ◽  
Optimum Result ◽  
Pv Systems ◽  
Building Energy Systems

<span lang="EN-US">This paper analyzes influences of renewable fraction on grid-connected photovoltaic (PV) for office building energy systems. The fraction of renewable energy has important contributions on sizing the grid-connected PV systems and selling and buying electricity, and hence reducing net present cost (NPC) and carbon dioxide (CO<sub>2</sub>) emission. An optimum result with the lowest total NPC for serving an office building is achieved by employing the renewable fraction of 58%, in which 58% of electricity is supplied from the PV and the remaining 42% of electricity is purchased from the grid. The results have shown that the optimum grid-connected PV system with an appropriate renewable fraction value could greatly reduce the total NPC and CO<sub>2</sub> emission.</span>

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