scholarly journals Influence of Temperature and Pressure Change on Adiabatic and Isothermal Methanation Processes

2012 ◽  
Vol 9 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Jekaterina Porubova ◽  
Marco Klemm ◽  
Isabel Kiendl ◽  
Karlis Valters ◽  
Darja Markova ◽  
...  
Keyword(s):  
Natural Gas ◽  
Pressure Change ◽  
Theoretical Modelling ◽  
Transport Sector ◽  
Temperature And Pressure ◽  
Pressure Changes ◽  
The Impact ◽  
Different Sources ◽  
Thermodynamic Equilibrium Calculations

Abstract Energy plans of many countries anticipate an increased use of biomethane for energy supply, i.e., in power and heat production as well as in the transport sector. Existing infrastructure of natural gas storage, supply and application provides a good platform to facilitate transfer to biomethane utilization on a larger scale. One key element of the biomethane system is the upgrade of the biomass-derived synthesis gas originating from different sources, to a quality of natural gas (SNG - Synthesis Natural Gas) via the methanation process for further injection into the natural gas grid.. The maximisation of efficiency of the methanation process is of critical importance in order to make biomethane technology viable for wider application. The aim of the study was to improve efficiency of the methanation process by finding the optimum temperatures and pressure. Theoretical modelling of adiabatic and isothermal methanation processes by using thermodynamic equilibrium calculations was introduced as a method for the study. The results show the impact of temperature and pressure changes on the overall efficiency of methane production. It can be concluded from the study that knowledge about the relation between temperature, pressure and the efficiency of the methanation process makes it possible to optimize the process under various biomass synthesized gas input conditions.

scholarly journals Avoided Mortality Associated with Improved Air Quality from an Increase in Renewable Energy in the Spanish Transport Sector: Use of Biofuels and the Adoption of the Electric Car

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1603
Author(s):  
Ana R. Gamarra ◽  
Yolanda Lechón ◽  
Marta G. Vivanco ◽  
Mark Richard Theobald ◽  
Carmen Lago ◽  
...  
Keyword(s):  
Air Quality ◽  
Health Impact ◽  
Air Pollutant ◽  
Transport Sector ◽  
Population Exposure ◽  
Baseline Scenario ◽  
Premature Deaths ◽  
Electric Car ◽  
The Impact

This paper assesses the health impact, in terms of the reduction of premature deaths associated with changes in air pollutant exposure, resulting from double-aim strategies for reducing emissions of greenhouse gases and air pollutants from the transport sector for the year 2030 in Spain. The impact on air quality of selected measures for reducing emissions from the transport sector (increased penetration of biofuel and electric car use) was assessed by air quality modeling. The estimation of population exposure to NO2, particulate matter (PM) and O3 allows for estimation of associated mortality and external costs in comparison with the baseline scenario with no measures. The results show that the penetration of the electric vehicle provided the largest benefits, even when the emissions due to the additional electricity demand were considered.

Analysis of Hot Oil Pipeline Stress Influencing Factors

2014 ◽  
Vol 887-888 ◽  
pp. 899-902
Author(s):  
Xiao Nan Wu ◽  
Shi Juan Wu ◽  
Hong Fang Lu ◽  
Jie Wan ◽  
Jia Li Liu ◽  
...  
Keyword(s):  
Crude Oil ◽  
High Viscosity ◽  
Analysis Model ◽  
Long Distance ◽  
Oil Pipeline ◽  
Software Analysis ◽  
Key Points ◽  
Temperature And Pressure ◽  
Pressure Changes ◽  
The Impact

In order to reduce the viscosity of crude oil for transport, we often use the way of heating delivery for high pour point, high wax, and high viscosity oil. Crude oil at high temperature, through long-distance transmission, the temperature and pressure changes on the piping stress greater impact. In this paper, in order to explore the main factor of hot oil pipeline stress and the location of key points, we build the XX hot oil pipeline stress analysis model used CAESAR II software, analysis of the impact of changes in temperature and pressure on piping stress when hot oil pipeline running, draw hot oil pipeline stress distribution, clearly identifies the location of key points of stress concentration, and we have come to that temperature is a major factor in generating pipe stress.

Optimum Combustion Chamber Geometry for a Compression Ignition Engine Retrofitted to Run Using Compressed Natural Gas (CNG)

2013 ◽  
Vol 315 ◽  
pp. 552-556 ◽  
Author(s):  
Shahrul Azmir Osman ◽  
Ahmad Jais Alimin ◽  
V.S. Liong
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Negative Impact ◽  
Petroleum Products ◽  
Compression Ignition Engine ◽  
Compressed Natural Gas ◽  
Engine Cylinder ◽  
The Impact

The use of natural gas as an alternative fuels are motivated from the impact in deteriorating quality of air and the energy shortage from petroleum products. Through retrofitting, CI engine runs on CNG, will be able to reduce the negative impact mainly on the use of petroleum products. However, this required the modification of the combustion chamber geometry by reducing the compression ratio to value that suits combustion of CNG. In this present studies, four different shapes and geometries of combustion chamber were designed and simulate using CFD package powered by Ansys workbench, where k-ε turbulence model was used to predict the flow in the combustion chamber. The results of turbulence kinetic energy, velocity vectors and streamline are presented. The enhancement of air-fuel mixing inside the engine cylinder can be observed, where the design with re-entrance and lower center projection provide better results compared to other combustion geometries designs.

scholarly journals Studies of the Impact of Hydrogen on the Stability of Gaseous Mixtures of THT

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6441
Author(s):  
Anna Huszal ◽  
Jacek Jaworski
Keyword(s):  
Natural Gas ◽  
Distribution Network ◽  
Experimental Tests ◽  
Gaseous Mixtures ◽  
Odorant Molecule ◽  
Measurement Devices ◽  
The Stability ◽  
The Impact ◽  
Hydrogen Additive

One of the most important requirements concerning the quality of natural gases, guaranteeing their safe use, involves providing the proper level of their odorization. This allows for the detection of uncontrolled leakages of gases from gas networks, installations and devices. The concentration of an odorant should be adjusted in such a manner that the gas odor in a mixture with air would be noticeable by users (gas receivers). A permanent odor of gas is guaranteed by the stability of the odorant molecule and its resistance to changes in the composition of odorized gases. The article presents the results of experimental research on the impact of a hydrogen additive on the stability of tetrahydrothiophene (THT) mixtures in methane and in natural gas with a hydrogen additive. The objective of the work was to determine the readiness of measurement infrastructures routinely used in monitoring the process of odorizing natural gas for potential changes in its composition. One of the elements of this infrastructure includes the reference mixtures of THT, used to verify the correctness of the readings of measurement devices. The performed experimental tests address possible changes in the composition of gases supplied via a distribution network, resulting from the introduction of hydrogen. The lack of interaction between hydrogen and THT has been verified indirectly by assessing the stability of its mixtures with methane and natural gas containing hydrogen. The results of the presented tests permitted the identification of potential hazards for the safe use of gas from a distribution network, resulting from changes in its composition caused by the addition of hydrogen.

scholarly journals The effect of the mixing of water from different sources in the water supply system on tap water quality – a full-scale technical investigation case study

2018 ◽  
Vol 19 (1) ◽  
pp. 303-312
Author(s):  
A. Szuster-Janiaczyk ◽  
J. Bylka
Keyword(s):  
Water Quality ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Low Flow ◽  
Quality Of Water ◽  
Tap Water Quality ◽  
The Impact ◽  
Different Sources

Abstract The paper presents a detailed analysis of the quality of water pumped into a network and sampled from 39 monitoring points located on the network. A difference in the quality of water sampled from two different sources was demonstrated, as well as the impact of the mixing of the two waters in the water distribution system (WDS) on tap water quality. A mathematical model was used to identify the zones of water mixing and the areas of unfavourable hydraulic conditions (low flow rates and long retention times).

Preliminary Results for a New Final Package Test to Assess the Quality of Sterile Package Systems

2004 ◽  
Vol 25 (1) ◽  
pp. 26-29 ◽  
Author(s):  
Hartmut Dunkelberg ◽  
Silke Wedekind
Keyword(s):  
Bacterial Count ◽  
Pressure Change ◽  
Test Method ◽  
Airborne Bacteria ◽  
Mechanical Device ◽  
Mechanical Pressure ◽  
Packaging System ◽  
Laboratory Errors ◽  
Pressure Changes

AbstractObjectives:To develop a microbial test method to ascertain the passage of airborne bacteria through the medical device packaging System after sterilization, and to apply this test method to flexible packages under mechanical pressure changes.Methods:Petri dishes filled with nutrient agar were integrated into the packaging unit prior to sterilization. We examined paper packaging consisting of 1 (single-paper packaging [P]), 2 (double-paper packaging [PP] and textile and paper double packaging [TP]), and 3 (double packaging with transport packaging [TPP]) layers. After sterilization, the test packages were pressed five times per minute for 1 or 3 hours by a mechanical device weighing 1 kg. This exposure took place in rooms with an average airborne bacterial count of 35 (room 1) or 440 (room 2) CFU/m3. The packaging was opened following culture at 37° C for 48 hours to determine the number of colonies formed.Results:The proportion of contaminated packages rose with the duration of mechanical stress and increased airborne bacteria concentration. Thus, mechanical pressure change for 3 hours resulted in the contamination of 60% (P), 15% (PP), 0% (TP), and 0% (TPP) of the packages in room 1, whereas 100% (P), 65% (PP), 73% (TP), and 0% (TPP) of the packages in room 2 were contaminated.Conclusions:This test method allows sterile packaging Systems to be tested for contamination under practical conditions without extensive laboratory preparation. Contamination as a resuit of laboratory errors can be ruled out almost certainly.

scholarly journals MODELING AND ASSESSMENT OF THE IMPACT OF LAND USE IN THE WESTERN RIF REGION, MOROCCO, ON WATER QUALITY

2021 ◽  
Vol XLVI-4/W5-2021 ◽  
pp. 225-230
Author(s):  
G. Fattah ◽  
F. Ghrissi ◽  
J. Mabrouki ◽  
N. Al-Jadabi
Keyword(s):  
Land Use ◽  
Surface Layer ◽  
Surface Water ◽  
Surface Waters ◽  
Chemical Parameters ◽  
Physical And Chemical ◽  
The Impact ◽  
Different Sources

Abstract. The Western Rif is a rural area characterized by rock extraction and agriculture. As a result, the surface of the land in the region is exposed to different sources of contamination which alters the quality of the soil. Leaching of the soil and runoff to surface water may impact the quality of surface water used by local people. A mapping of the land use by GIS of an area located at the level of the western Rif was carried out then an analysis of the interactions between the uses of the land; the practices, the quality of the surface layer of the soil and the quality of the water were made. Thanks to the processing of satellite images and to samples on the ground and assays of the physic-chemical parameters of soils and water (T °, pH, MES, turbidity, Nitrate, nitrite, phosphorus, nitrogen, etc.). The results of these analyzes revealed that these activities lead to an alteration in the quality of the surface layer of the soil, its characterization of which changes depending on the land use. Surface water is endowed with the components identified in the soil. This reveals that land use has generally negative physical and chemical impacts on surface waters.

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