Search results for "Natural Ga"
showing 10 items of 77 documents
The Sacred Fire
2012
The fire on Mount Parnassus that gave rise to the temple of the Oracle of Delphi was not the only spontaneous outflow of natural gas known to the Ancient World. People in ancient India, Persia and China knew about these fen fires, and there they also used to attribute them to supernatural causes, at least until 500 BC, when the Chinese built the first gas pipelines––using bamboo!––many centuries ahead of the West, as on many other occasions.
Demand and Supply Model for the Natural Gas Supply Chain in Colombia
2018
Natural gas is considered the transitional fuel for excellence between fossil and renewable sources, considering its low cost, greater efficiency and lesser effects on the environment. This has led to increased demand levels worldwide, requiring the intervention of public and private actors to meet such demand. In this research, we study the natural gas supply chain in Colombia using system dynamics modelling. The results allow to contrast both the behaviour of the production and transport levels and the behaviour of the demand from the consumption sectors, allowing to identify capacity levels to be developed considering implementation times and percentages of coverage in the supply.
Reliable TDC position determination: a comparison of different thermodynamic methods through experimental data and simulations
2008
It is known to internal combustion researcher that the correct determination of the crank position when the piston is at Top Dead Centre (TDC) is very important, since an error of 1 crank angle degree (CAD) can cause up to a 10% evaluation error on indicated mean effective pressure (IMEP) and a 25% error on the heat released by the combustion: the TDC position should be then known within a precision of 0.1 CAD. This task can be accomplished by means of a dedicated capacitive sensor, which allows a measurement within the required 0.1 degrees precision. Such a sensor has a substantial cost and its use is not really fast; a different approach can be followed using a thermodynamic method, whose…
Case studies - Research and technological solutions to prevent sand production in the gas wells from the Getic Depression
2021
A frequent challenge encountered in the exploitation of mature gas fields located in the Getic Depression is sand production. Causes of sand production are mainly related to degree of rock consolidation, lithology, increasing water production and production rates. The effects of sand production are multiple such us low productivity of the gas wells, accumulation into the surface equipment, erosion of downhole and surface equipment, plugging the perforation zone and casing damage. The current paper will address the sand production- challenges and new perspectives in remedial work of wells which are producing from gas reservoirs located in Getic Depression. The article presents through some c…
Simulator for a Natural Gas Storage Realised in Depleted Deposit
2014
The present paper presents the implementation of a numerical model for a natural storage transformed into a deposit which takes into consideration the geometry of the storage, the properties of the rocks and in which the movements of the gases can be described. The model is two-dimensional nonstationary and allows the dynamic simulation of the processes of injection and extraction. The location of the wells and their flows can be thus studied and optimized to maximize the amount of the stored gases. The presented model allows the quick finding of solutions for a whole cycle of storage in a short time so that it could be used successfully in the operation process.
Exergy Recovery during LNG Regasification: Electric Energy Production - Part Two
2009
In liquefied natural gas (LNG) regasification facilities, for exergy recovery during regasification, an option could be the production of electric energy recovering the energy available as cold. In a previous paper, the authors propose an innovative process which uses a cryogenic stream of LNG during regasification as a cold source in an improved combined heat and power (CHP) plant. Considering the LNG regasification projects in progress all over the World, an appropriate design option could be based on a modular unit having a mean regasification capacity of 2 × 109 standard cubic meters/year. This paper deals with the results of feasibility studies, developed by the authors at DREAM in the…
Sensitivity analysis and process optimization of a natural gas dehydration unit using triethylene glycol
2019
Abstract Dehydration of natural gas by absorption using triethylene glycol (TEG) is a common industrial offshore procedure to ensure the compliance with the required water dew point specifications for midstream transportation. Two thermodynamic models, the UMR-PRU and the TST/NRTL, are applied for the process simulation while a preliminary economic evaluation has been conducted revealing that both yield overall similar results as for the fixed capital cost which is found to be in good agreement with reported literature values. Moreover, sensitivity analysis of several operational parameters of the process has been performed and optimized values are suggested aiming to reduce its energy requ…
European Natural Gas Seasonal Effects on Futures Hedging
2015
Abstract This paper is the first to discuss the design of futures hedging strategies in European natural gas markets (NBP, TTF and Zeebrugge). A common feature of energy prices is that conditional mean and volatility are driven by seasonal trends due to weather, demand, and storage level seasonalities. This paper follows and extends the Ederington and Salas (2008) framework and considers seasonalities in mean and volatility when minimum variance hedge ratios are computed. Our results show that hedging effectiveness is much higher when the seasonal pattern in spot price changes is approximated with lagged values of the basis (futures price minus spot price). This fact remains true for short …
A Study on the Use of Combustion Phase Indicators for MBT Spark Timing on a Bi-Fuel Engine
2007
The performance of a spark ignition engine strongly depends on the phase of the combustion process with respect to piston motion, and hence on the spark advance; this fundamental parameter is actually controlled in open-loop by means of maps drawn up on the test bench and stored in the Electronic Control Unit (ECU). Bi-fuel engines (e.g. running either on gasoline or on natural gas) require a double mapping process in order to obtain a spark timing map for each of the fuels. This map based open-loop control however does not assure to run the engine always with the best spark timing, which can be influenced by many factors, like ambient condition of pressure, temperature and humidity, fuel p…
Experimental Determination of Liquefied Petroleum Gas–Gasoline Mixtures Knock Resistance
2014
The results of previous experimental researches showed that great advantages can be achieved, both in terms of fuel consumption and pollutant emissions, in bifuel vehicles by means of the double-fuel combustion, i.e., the simultaneous combustion of gasoline and a gaseous fuel, such as liquefied petroleum gas (LPG) or natural gas (NG). The substantial increase in knock resistance pursued by adding LPG to gasoline, which allowed to maintain an overall stoichiometric proportion with air also at full load, is not documented in the scientific literature and induced the authors to perform a proper experimental campaign. The motor octane number (MON) of LPG–gasoline mixtures has been hence determi…