PROSPECTS FOR OBTAINING GAS MOTOR FUEL FROM BIOGAS OF ANAEROBIC DIGESTION OF AGRICULTURAL WASTE

2021 ◽  
Vol 3 (144) ◽  
pp. 22-31
Author(s):  
Viktor S. Grigor’yev ◽  
◽  
Il’ya V. Romanov
Keyword(s):  
Anaerobic Digestion ◽  
Gas Hydrates ◽  
Process Model ◽  
Organic Waste ◽  
Agricultural Waste ◽  
Motor Fuel ◽  
Hydrate Formation ◽  
Research Purpose ◽  
Industrial Complex ◽  
Mixed Gas

The ability of gas hydrates to concentrate gas into a solid chelate structure and the properties of self-preservation of gas hydrates at negative temperatures allows us to consider the possibility of developing a method for the utilization of biogas, environmentally safe storage and transportation of biomethane. (Research purpose) The research purpose is in substantiation the technological possibilities of obtaining synthetic mixed gas hydrates of biogas components, their storage and transportation based on the analysis of the existing regularities of the formation of gas hydrates in time, temperature and external pressure. (Materials and methods) The article presents the accumulated results of studies of the process of obtaining artificial hydrates of natural gas and methane- containing gas mixtures at various initial static pressures and temperatures. The object of research to substantiate the parameters of artificial creation of gas hydrates is biogas obtained during anaerobic thermophilic fermentation of organic waste at an existing experimental biogas plant. Mixed feed SK-8 with a humidity of 90-92 percent was used as an organic substrate of constant composition. The composition of biogas was studied using the Optima-7 Biogas gas analyzer. (Results and discussion) The article presents a process model and a technical appearance of an installation for producing gas motor fuel from the biogas of anaerobic digestion of organic waste of the agro-industrial complex. The hydrate formation time depends on the increase in the interfacial surface and the movement of gas bubbles relative to the liquid, which can be regulated by acting on the hydrate formation zone (shock wave, electromagnetic, mechanical, chemical, temperature). (Conclusions) The research results can be used in modeling processes in two-phase media during the formation of gas hydrates and the creation of installations for their production.

METHODS FOR THE PREPARATION OF ORGANIC AGRICULTURAL WASTE FOR FURTHER PROCESSING IN A SUPERCRITICAL WATER ENVIRONMENT

2021 ◽  
Vol 2 (143) ◽  
pp. 85-90
Author(s):  
Il’ya V. Romanov ◽  
◽  
Viktor S. Grigor’yev
Keyword(s):  
Supercritical Water ◽  
Water Oxidation ◽  
Organic Waste ◽  
Agricultural Waste ◽  
Water Environment ◽  
Research Purpose ◽  
Grinding Process ◽  
Industrial Complex ◽  
Fibrous Materials ◽  
Wet Grinding

The problem of waste disposal is always acute in all areas of production activity, especially for the agro-industrial complex. Supercritical water oxidation is the most environmentally friendly method for processing organic waste and persistent organic pollutants. In the process of recycling and disposal, along with the harmfulness, one of the main indicators is the initial state of the waste and its suitability for different disposal technologies. (Research purpose) The research purpose is in choosing and justifying the most energy-efficient method of grinding, taking into account the fact that the organ-containing waste under study (buckwheat husk, sunflower, rice) is soft, elastic and fibrous materials. (Materials and methods) The crushing of organic waste to prepare it for further processing was carried out by different methods in roller, ball, knife and colloid mills. A set of sieves with square cells according to GOST 2715-75, a drying cabinet SHS-80-01 SPU, analytical scales Acculab ALC-210d4 (weighing error of no more than 0.5 percent of the sample weight) were used to evaluate the fractional composition of the obtained material. (Results and discussion) At a concentration of 100 grams of husk per 1 liter of water after 30 minutes of wet grinding, the passage of particles through the sieve is 87.1 percent. The article presents the advantage of wet grinding in a knife mill, reveals mathematical dependencies that allow predicting the grinding process to obtain the product of the required dispersion. (Conclusions) The grinding of organ-containing waste in a knife mill by wet grinding is the most optimal technology for preparing this waste for further processing in a supercritical water environment. The obtained mathematical dependencies allow us to predict the grinding process.

Energy-saving technologies of technical service and processing of organic waste

2020 ◽  
pp. 65-75
Author(s):  
Anatoliy V. Fedotov
Keyword(s):  
Wastewater Treatment ◽  
Diesel Engine ◽  
Energy Saving ◽  
Organic Waste ◽  
Research Purpose ◽  
Industrial Complex ◽  
Technical Service ◽  
Supercritical Conditions ◽  
Drilling Rig ◽  
Aluminum Oxyhydroxide

Agricultural production in the Russian Federation is several times more energy-and material-intensive than in developed countries. (Research purpose) The research purpose is evaluation of the effectiveness of energy-saving technologies for technical maintenance of equipment using nanostructured aluminum oxyhydroxide and hydrothermal processing of agricultural waste in supercritical conditions. (Materials and methods) Nanostructured aluminum oxyhydroxide (boehmite) was produced by hydrothermal synthesis from aluminum powders. Tribological studies were carried out on a four-ball friction machine, a special device from WAGNER, on friction machines 2070 SMT-1M and MTU. Bench-in run was carried out on the D-240 engine and gearbox of a mobile drilling rig. The crushed solid waste of the agro-industrial complex was used as adsorbents for organic wastewater pollution. Their joint processing was carried out under hydrothermal supercritical conditions. (Results and discussion) It has been shown that nanostructure boehmite has antifriction, antiwear and extreme pressure properties. The possibility of its use as a product for running of a diesel engine has been found. The application of the boehmite in oils accelerates the running-in of a diesel engine, provides savings in material, labor and energy resources. For running-in of power transmission units, an additive containing bemite, surfactant, talc and kaolin reduced the running-in time of the drilling rig gearbox by 2.5 times. The article shows that the crushed plant waste of the agro-industrial complex, such as buckwheat husk, rice, and sunflower can be effectively used as adsorbents for the localization of pollution and wastewater treatment of agricultural enterprises. Subsequent processing of the adsorbent saturated with organic matter under hydrothermal supercritical conditions ensures the complete processing of organic substances to produce purified water and a high-enthalpy vapor-gas mixture or combustible gases, depending on the processing conditions. (Conclusions) Energy-saving technologies for the technical service of a diesel engine and transmission units can be based on the use of tribotechnical materials containing nanostructure boehmite. Technological solutions for energy-saving technologies for processing solid and liquid organic waste can consist in adsorption wastewater treatment followed by hydrothermal treatment in supercritical conditions.

scholarly journals Influence of Gas Supply Changes on the Formation Process of Complex Mixed Gas Hydrates

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3039
Author(s):  
Mengdi Pan ◽  
Judith M. Schicks
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Formation Process ◽  
Gas Flow ◽  
Hydrate Formation ◽  
Experimental Investigations ◽  
Gas Composition ◽  
Mixed Gas ◽  
Hydrate Phase ◽  
Gas Supply

Natural gas hydrate occurrences contain predominantly methane; however, there are increasing reports of complex mixed gas hydrates and coexisting hydrate phases. Changes in the feed gas composition due to the preferred incorporation of certain components into the hydrate phase and an inadequate gas supply is often assumed to be the cause of coexisting hydrate phases. This could also be the case for the gas hydrate system in Qilian Mountain permafrost (QMP), which is mainly controlled by pores and fractures with complex gas compositions. This study is dedicated to the experimental investigations on the formation process of mixed gas hydrates based on the reservoir conditions in QMP. Hydrates were synthesized from water and a gas mixture under different gas supply conditions to study the effects on the hydrate formation process. In situ Raman spectroscopic measurements and microscopic observations were applied to record changes in both gas and hydrate phase over the whole formation process. The results demonstrated the effects of gas flow on the composition of the resulting hydrate phase, indicating a competitive enclathration of guest molecules into the hydrate lattice depending on their properties. Another observation was that despite significant changes in the gas composition, no coexisting hydrate phases were formed.

Selective trapping of CO2 gas and cage occupancy in CO2–N2 and CO2–CO mixed gas hydrates

2018 ◽  
Vol 54 (34) ◽  
pp. 4290-4293 ◽  
Author(s):  
Claire Petuya ◽  
Françoise Damay ◽  
Sarah Desplanche ◽  
David Talaga ◽  
Arnaud Desmedt
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Gas Hydrates ◽  
Hydrate Formation ◽  
Gas Mixtures ◽  
Clathrate Hydrate ◽  
Mixed Gas ◽  
Co2 Gas ◽  
Carbon Dioxide Separation

New carbon dioxide separation and capture technology, thanks to clathrate hydrate formation from pressurized ice with (carbon monoxide and nitrogen containing) gas mixtures.

scholarly journals Thermodynamic Modeling Of Electrolytic Solutions of Ionic Liquids for Gas Hydrates Inhibition Applications

2021 ◽  
Vol 81 (2) ◽  
pp. 110-123
Author(s):  
Ali Qasim ◽  
Jeremy Heurtas ◽  
Muhammad Saad Khan ◽  
Bhajan Lal ◽  
Azmi Mohammad Shariff ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Gas Hydrates ◽  
Oil And Gas ◽  
Binary Solution ◽  
Hydrate Formation ◽  
Absolute Error ◽  
Economic Loss ◽  
Average Absolute Error ◽  
Mixed Gas ◽  
Gas Hydrate Formation

The formation of hydrates in oil and gas transmission pipelines can cause blockage inside them and disrupt the normal flow. It may cause safety problems along with economic loss. To avoid these problems, it is necessary to have knowledge about gas hydrate formation. In this regard, hydrate liquid vapor equilibrium (HLVE) modeling can prove to be of significance as it predicts the phenomenon accurately. Dickens and Quinby-Hunt model is used to predict HLVE points. The experimental data has been obtained from open literature concerning inhibition of gas hydrates. The electrolytic binary solution mixtures of ionic liquids and quaternary ammonium salts (QAS) with commercial hydrate inhibitors have been taken into consideration. Methanol and mono ethylene glycol (MEG) are commercially used inhibitors. The gases forming hydrates include CO2, CH4 and mixed gas (CO2/CH4/N2). The experimental results are compared with the results obtained through modeling. The results show the applicability of the model as in case of QAS+MEG solution mixture hydrates with CO2, it shows a good fit. The HLVE findings by model for CH4 hydrates with EMIM-Cl+MEG solution mixture showed an average absolute error of less than 1% which is acceptable. The binary solution mixtures of NaCl+MEG, NaCl+MeOH and CaCl2+MeOH with tertiary gas mixture rich in CO2 were also modeled to find and compare the HLVE points from literature. It is found that the selected model is more suitable to be used in low pressure conditions and at high pressure, average absolute error (AAE) between experimental and modeling values is also high. It shows the suitability of the model and it can be further used in case of ionic compounds to predict hydrate inhibition behavior.

scholarly journals The organic waste fractions ratio optimization in the anaerobic co-digestion process for the increase of biogas yield

2018 ◽  
Vol 22 (Suppl. 5) ◽  
pp. 1525-1534
Author(s):  
Ana Momcilovic ◽  
Gordana Stefanovic ◽  
Predrag Rajkovic ◽  
Nenad Stojkovic ◽  
Biljana Milutinovic ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Organic Waste ◽  
Ph Value ◽  
Lignin Content ◽  
Renewable Energy Sources ◽  
Agricultural Waste ◽  
Animal Origin ◽  
Biogas Yield ◽  
Digestion Process ◽  
Organic Fractions

Biogas obtained by anaerobic digestion process from various organic fractions of waste is increasingly used as a renewable energy sources for the generation of electricity and heat. The quantity of biogas produced by anaerobic digestion depends on many factors: types and characteristics of organic waste, elemental composition of waste, C/N ratio, pH value, inhibitors, retention time, content of nutrients, etc. In addition to the selection of parameters that influence the process of anaerobic digestion, biogas yield can also be influenced by choosing the optimal combination and ratio of organic fractions of waste. In this paper, an analysis of the influential parameters in the process of anaerobic digestion was per-formed on biogas yields and an overview of the essential characteristics of waste (elementary composition, C/N ratio, lignin content, etc.) for different fractions of organic waste (organic municipal waste, various types of waste of animal origin, as well as agricultural waste). In order to choose the optimal mixing ratio of different fractions of organic waste for maximum biogas yield, a mathematical model has been developed using the multi-criteria optimization method. The boundary conditions set for the multi-criteria optimization was the C/N ratio in the range of 20 to 30 and the minimum content of the lignin in the substrate. The application of the developed model was carried out on the case study of the city of Nis, and the optimal mix of different types of organic waste was determined, as well as the optimal amount of each waste fraction and biogas yield.

Removal of nutrients from Organic Liquid Agricultural Waste using filamentous algae.

2020 ◽  
Author(s):  
Gonzalo Flores-Morales ◽  
Mónica Díaz ◽  
Patricia Arancibia-Avila ◽  
Michelle Muñoz-Carrasco ◽  
Pamela Jara-Zapata ◽  
...  
Keyword(s):  
Organic Waste ◽  
Low Cost ◽  
Organic Liquid ◽  
Agricultural Waste ◽  
Filamentous Algae ◽  
Tertiary Treatment ◽  
Nutrient Reduction ◽  
Algae Removal ◽  
Algae Growth ◽  
Waste Effluents

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

Highly-efficient Anaerobic Digestion of Refractory Organic Waste Using Subcritical Water Hydrolysis as Pretreatment Process

2012 ◽  
Vol 48 (1) ◽  
pp. 23-27
Author(s):  
TOMONAO MIYASHIRO ◽  
QINGHONG WANG ◽  
YINGNAN YANG ◽  
KAZUYA SHIMIZU ◽  
NORIO SUGIURA ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Organic Waste ◽  
Subcritical Water ◽  
Highly Efficient ◽  
Water Hydrolysis ◽  
Subcritical Water Hydrolysis

Does Local Structure Bias How a Crystal Nucleus Evolves?

2018 ◽  
Author(s):  
Kyle Hall ◽  
Zhengcai Zhang ◽  
Christian Burnham ◽  
Guang-Jun Guo ◽  
Sheelagh Carpendale ◽  
...  
Keyword(s):  
Local Structure ◽  
Molecular Level ◽  
Hydrate Formation ◽  
Mixed Gas ◽  
Local Structures ◽  
Surrounding Environment ◽  
Gas Hydrate Formation ◽  
Significant Research ◽  
Crystal Phases ◽  
Recent Experimental Work

<p>The broad scientific and technological importance of crystallization has led to significant research probing and rationalizing crystallization processes, particularly how nascent</p> <p>crystal phases appear. Previous work has generally neglected the possibility of the molecular-level dynamics of individual nuclei coupling to local structures (e.g., that of the nucleus and its</p> <p>surrounding environment). However, recent experimental work has conjectured that this can occur. Therefore, to address a deficiency in scientific understanding of crystallization, we have</p> <p>probed the nucleation of prototypical single and multi-component crystals (specifically, ice and mixed gas hydrates). Here, we establish that local structures can bias the evolution of nascent</p> <p>crystal phases on a nanosecond timescale by, for example, promoting the appearance or disappearance of specific crystal motifs, and thus reveal a new facet of crystallization behaviour.</p> <p>Analysis of the crystallization literature confirms that structural biases are likely present during crystallization processes beyond ice and gas hydrate formation. Moreover, we demonstrate that</p> <p>structurally-biased dynamics are a lens for understanding existing computational and experimental results while pointing to future opportunities.</p>

Does Local Structure Bias How a Crystal Nucleus Evolves?

2018 ◽  
Author(s):  
Kyle Hall ◽  
Zhengcai Zhang ◽  
Christian Burnham ◽  
Guang-Jun Guo ◽  
Sheelagh Carpendale ◽  
...  
Keyword(s):  
Local Structure ◽  
Molecular Level ◽  
Hydrate Formation ◽  
Mixed Gas ◽  
Local Structures ◽  
Surrounding Environment ◽  
Gas Hydrate Formation ◽  
Significant Research ◽  
Crystal Phases ◽  
Recent Experimental Work

<p>The broad scientific and technological importance of crystallization has led to significant research probing and rationalizing crystallization processes, particularly how nascent</p> <p>crystal phases appear. Previous work has generally neglected the possibility of the molecular-level dynamics of individual nuclei coupling to local structures (e.g., that of the nucleus and its</p> <p>surrounding environment). However, recent experimental work has conjectured that this can occur. Therefore, to address a deficiency in scientific understanding of crystallization, we have</p> <p>probed the nucleation of prototypical single and multi-component crystals (specifically, ice and mixed gas hydrates). Here, we establish that local structures can bias the evolution of nascent</p> <p>crystal phases on a nanosecond timescale by, for example, promoting the appearance or disappearance of specific crystal motifs, and thus reveal a new facet of crystallization behaviour.</p> <p>Analysis of the crystallization literature confirms that structural biases are likely present during crystallization processes beyond ice and gas hydrate formation. Moreover, we demonstrate that</p> <p>structurally-biased dynamics are a lens for understanding existing computational and experimental results while pointing to future opportunities.</p>

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