Compressed Natural Gas Research Papers (original) (raw)

Air quality crisis in cities is mainly due to vehicular emissions. Transportation systems are increasing everywhere and the improvements in technology are insufficient to counteract growth. This paper examines the effect of vehicular emission on urban air quality and human health, and focuses on the unique features of an Indian mega city regarding its air pollution. A fact-finding survey was conducted to evaluate the status of air pollution at traffic intersections and the problem arising out of vehicular emissions in the study area. All the key pollutants are in excess of permitted levels. The severe detrimental effects of this pollution are reviewed. The problems have reached threatening dimensions. Vulnerable analysis (VA) has been carried out to evaluate the air pollution stress at different locations within the study area. Options for controlling mobile sources emissions are discussed and a strategic motor vehicle control strategy has been proposed to mitigate the air pollution in the city. Replacement of old vehicles, reformulating diesel fuel, introduction of liquid petroleum gas (LPG) and compressed natural gas (CNG), massive improvements in infrastructure and radical traffic management measures are among the actions that will need to be brought together to achieve this objective.

- by
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- Air Quality, IT Management, Air pollution, Traffic Management

This study investigates and proposes the use of gas automobile fuels (LPG & CNG) as transport fuel in Nigeria, by showing the policies and incentives that have been utilized by other countries and an analysis of the cost efficiency and environmental effect of the use of auto-gas fuels. The use of CNG and LPG as auto fuel in Nigeria presents benefits with regards to efficiency and environmental friendliness will be highlighted in this research work with emphasis on the economic advantage. Demand for natural gas is likely to overtake other fossil fuels due to its availability, accessibility, versatility and cleanliness. This research shows that adopting gas automobile fuels (LPG & CNG) as an automotive fuel has few barriers but in the long run is very viable in terms of emissions of Green-house gases to the environment and financially economical. From the study, we suggest that policies and incentives would be helpful for the implementation of auto-gas as a transport fuel with regards...

- by Adewale E . ADEGORIOLA
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- Transportation Economics, Energy, Transportation, Nigeria

After being besieged by dilemmas related to mixing homogeneity and air-fuel ratio control of the former air-fuel mixers [1, 2], a new air-fuel mixer called Throttle Body Injection Mixer (TBIM), which is of electronic fuel controlled, was developed. To study the mixing characteristics of TBIM, effect of various manifold absolute pressures (MAPs) and air flowrates (Q a ) on TBIM need to be determined. Therefore, the objective of this work is to study the effect of various MAPs and Q a on TBIM in a compressed natural gas (CNG) motorcycle through both the experimental work and Computational Fluid Dynamics (CFD) modelling. Experimental work was first carried out to investigate the MAPs at varying throttle angles for several engine speeds, followed by the corresponding Q a , which was attained through CFD modelling. The findings obtained were then verified through literature support. It was found that both the MAPs and Q a obtained exhibited a good agreement in the trending of graphs with the former works .

- by Zulkefli Yaacob
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- Computation Fluid Dynamics, Compressed Natural Gas

Combustion and emission characteristics of a port-injection SI turbocharged engine fueled with several H 2 =CNG blend ratios (0-50 vol%) under various ignition timings were investigated. The results show that with the increase of hydrogen addition, the maximum brake toque timing decreases and the indicated thermal efficiency increases; the MBT gets close to the top dead center and the indicated thermal efficiency increases with decreased load. The combustion duration is reduced by increasing the hydrogen fraction in HCNG (hydrogen enriched compressed natural gas) mixture. The NO x , CO and HC emissions all descend with the increase of spark advance angle, and ascend with the increase of the load.

- by Junjun Wang
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- Engineering, Hydrogen Energy, CHEMICAL SCIENCES, Compressed Natural Gas

Urban air pollution from road transport is a growing concern in many developing country cities. With rising incomes, motorized transport is expected to continue to increase in the coming years, further threatening air quality. Poor air quality in turn has been shown to have serious effects on public health. The World Health Organization estimated that 650,000 people died prematurely from urban air pollution in developing countries in 2000. The need to tackle air pollution from transport is widely acknowledged. But the menu of options available is varied and can be daunting. Are there key questions that should be answered to guide policymaking? Under what conditions are the different mitigation measures likely to achieve pollution reduction? Are there critical steps to be taken or underlying conditions that must be met, without which pollution reduction is unlikely? Which mitigation measures are robust, which may be implemented successfully, and which are still in the area of pilot testing? This report is an abridged version of the full report and is intended as a companion to it. It was prepared to provide guidelines and principles for answering the questions above and other related questions. Given the varying nature of air pollution, pollution sources, and available resources, answers and even key policy questions will differ from country to country. Hence, the report does not attempt to provide precise prescriptions applicable to all circumstances. It rather draws on lessons from international experience to propose a framework in which policy selection and implementation should occur. The three sectors most closely linked to vehicular air pollution are environment, transport, and energy. The report places a special emphasis on how to coordinate policies across the three and how to reconcile their sometimes conflicting objectives and demands in order to achieve environmental improvement. We hope that this report will stimulate and contribute to a discussion on how best to coordinate policies across different sectors to their mutual benefit in an environmentally sustainable manner.

- by Masami Kojima
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- Engineering, Environmental Science, Air Quality, Economic Development

In this paper, analytical expressions for stress concentration factors in pipes subjected to internal pressure and axial force are derived for a number of design cases based on classical shell theory. The effect of fabrication tolerances in simple butt welds is assessed. Analyses based on classical mechanics are compared with results from axisymmetric finite element analyses for verification of the presented methodology. Stress concentration factors are presented for circumferential butt welds in pipes welded together from pipes with different thicknesses, welds at buckling arrestors, welds at flanged connections in pipelines, and welds at ring stiffeners on the inside and the outside of the pipes. It also includes stress concentration factors at end closures in pipes for gas storage. Larger pipes are fabricated from plates with a longitudinal weld. This fabrication process introduces out-of-roundness in the pipes. The actual out-of-roundness is a function of internal pressure. An analytical expression for the bending stress in the pipe wall due to this out-of-roundness is presented. The derived stress concentration factors can be used together with a hot spot stress S-N curve for calculation of fatigue damage.

- by Inge Lotsberg
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- Engineering, Civil Engineering, Design, Manufacturing

This work investigates the behavior under burst pressure testing of a pressure vessel liner. The liner was produced with a polymer blend of 95 wt.% low linear density polyethylene (LLDPE) and 5 wt.% of high density polyethylene (HDPE). The liner is to be used in an allcomposite carbon/epoxy compressed natural gas (CNG) shell, manufactured by the filament winding process, with variable composite thickness. Experimental hydrostatic tests were conducted on reduced scale and actual liner models. Design and failure prediction of the composite laminate shell and the polymeric liner were conducted based on Tsai-Wu and von Mises criteria, respectively, using commercial Finite Element Analysis (FEA) software. Simulation and testing were both important in order to define adequate production parameters for the polymeric liner so that it could be successfully used in a composite pressure vessel.

In this paper, a decision-based scheme is developed to improve the competitiveness and efficiency of compressed natural gas (CNG) shipping. A database of CNG ships of different size and speed is built off-line at conceptual design level, which provides technical and economic information sufficient to optimize the fleet composition. This goal is reached by generating a number of feasible fleets from the logistics viewpoint and ranking them by giving priority to CNG shipping tariff. To this end, a built-in code is implemented which integrates the logistics strategy with the menu of CNG ships to solve the decision-making model. A case study shows that usage of the proposed scheme facilitates correct decisions aimed at reducing the overall capital investment and improves the reliability and economic efficiency of the CNG shipping system.

This study investigates the use of artificial neural network (ANN) modelling to predict brake power, torque, break specific fuel consumption (BSFC), and exhaust emissions of a diesel engine modified to operate with a combination of both compressed natural gas CNG and diesel fuels. A single cylinder, four-stroke diesel engine was modified for the present work and was operated at different engine loads and speeds. The experimental results reveal that the mixtures of CNG and diesel fuel provided better engine performance and improved the emission characteristics compared with the pure diesel fuel. For the ANN modelling, the standard back-propagation algorithm was found to be the optimum choice for training the model. A multi-layer perception network was used for non-linear mapping between the input and output parameters. It was found that the ANN model is able to predict the engine performance and exhaust emissions with a correlation coefficient of 0.9884, 0.9838, 0.95707, and 0.9934 for the engine torque, BSFC, NO x and exhaust temperature, respectively.

- by Talal Yusaf
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- Engineering, Economics, Engine Performance, Diesel engine

The alternatives to the oil based fuels for transportation are considered and analysed. These are the synthetic fuels, made from coal, the liquid petroleum gases of propane and butane, compressed natural gas and methanol. The problems associated with the use of electric vehicles are discussed; the main problem being that of range.The possible use of hydrogen as a fuel is

- by Ramadhas as
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- Civil Engineering, Biodiesel, BIOETHANOL, Urban And Regional Planning

The aim of this paper is to carry out a comparative study with regard to energy consumption and greenhouse gas emissions, in respect of two types of engines with three different fuels. The fuels analysed are diesel, biodiesel 30% (B30) and compressed natural gas (CNG). The engines tested were a spark ignition engine (Otto cycle) and two compression ignition engines (Diesel cycle), the first fed with CNG and the last two with B30 and diesel. What is new about this study is its scope of application concerning refuse collection services in the city of Madrid. The tests were carried out on refuse trucks of the FCC Company along actual urban routes in the city of Madrid. Also taken into account were the energy input and the greenhouse gases emitted for each of the paths taken by the fuels analysed, from resource recovery to delivery to the vehicle tank.

- by alvaro gomez
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- Engineering, Economics, Energy Consumption, Comparative Study

Stranded natural gas has a huge economic implications for Nigeria since there are 184 TCF stranded gas reserves in the country. Oil currently accounts for over 90 percent of Nigeria's foreign exchange earnings, there is therefore, hope for increased revenue from natural gas, if the gas being flared is monetized. Monetizing stranded gas reserves requires access to distribution infrastructure. It becomes necessary and appropriate for Nigeria to put in place these infrastructure as to develop her vast stranded natural gas reserves to serve her economy, strengthen regional cooperation, and meet expanding demand in the world market. This paper presents current technologies for monetizing stranded gas, and assessment of Nigeria's achievements in monetizing stranded natural gas reserves. The monetization technologies and projects reviewed are liquefied natural gas (LNG), gas-to-liquids (GTL), compressed natural gas (CNG), gas-to-wire (gas-fired power generation), and gas-to-solid.

- by Anthony Kerunwa
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- Renewable Energy, Gas Hydrates, Liquefied Natural Gas, Compressed Natural Gas

The Canadian hydrogen safety program (CHSP) is a project initiative of the Codes & Standards Working Group of the Canadian transportation fuel cell alliance (CTFCA) that represents industry, academia, government, and regulators. The Program rationale, structure and contents contribute to acceptance of the products, services and systems of the Canadian Hydrogen Industry into the Canadian hydrogen stakeholder community. It facilitates trade through fair insurance policies and rates, effective and efficient regulatory approval procedures and accommodation of the interests of the general public. The Program integrates a consistent quantitative risk assessment methodology with experimental (destructive and non-destructive) failure rates and consequence-of-release data for key hydrogen components and systems into risk assessment of commercial application scenarios. Its current and past six projects include Intelligent Virtual Hydrogen Filling Station (IVHFS), Hydrogen clearance distances, comparative quantitative risk comparison of hydrogen and compressed natural gas (CNG) refuelling options; computational fluid dynamics (CFD) modeling validation, calibration and enhancement; enhancement of frequency and probability analysis, and Consequence analysis of key component failures of hydrogen systems; and fuel cell oxidant outlet hydrogen sensor project. The Program projects are tightly linked with the content of the International Energy Agency (IEA) Task 19 Hydrogen Safety.

- by A. Tchouvelev
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- Engineering, Computational Fluid Dynamics, Modeling, Fluid Dynamics

Undoubtedly, the changes spark ignition engines (hereinafter SI engines, Otto engines) have undergone under the last 20-25 years has been due to pressure from emission standards and fuel economy requirements becoming ever stricter. These regulations have equally influenced the every stage (from 1st to 5th generation) of LPG technology development while looking back in retrospective. Increasing emphasis on liquefied petroleum gas (LPG) as a clean, relatively low in cost and abundant energy source to provide affordable fuel-efficient transportation, encourages the search for the optimum approach to management of fuel, air and combustion to achieve the best results in vehicle power, fuel efficiency and low gaseous waste products. The development undertaken since then is still a "work in progress" leading to the course of establishing the new systems, including those for Otto engines with direct gaseous fuel injection as well as direct liquid LPG injection.

- by Laurencas Raslavicius and +1
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- Engineering, Liquefied Natural Gas, Compressed Natural Gas, Liquefied petroleum gas

Activated carbons offer a large spectrum of pore structures and surface chemistry for adsorption of gases, which are being used to design practical pressure swing and thermal swing adsorption processes for separation and purification of gas mixtures. The activated carbons are often preferred over the zeolitic adsorbents in a gas separation process because of their relatively moderate strengths of adsorption for gases, which facilitate the desorption process. Three commercial applications of activated carbons, (a) trace impurity removal from a contaminated gas, (b) production of hydrogen from a steam-methane reformer off gas, and (c) production of nitrogen from air, are reviewed. Four novel applications of activated carbons for gas separation and purification are also described. They include, (a) separation of hydrogenhydrocarbon mixtures by selective surface flow of larger hydrocarbon molecules through a nanoporous carbon membrane produced by carbonization of a polymer matrix, (b) gas drying by pressure swing adsorption using a water selective microporous carbon adsorbent produced by surface oxidation of a hydrophobic carbon, (c) removal by selective adsorption and in-situ oxidation of trace volatile organic compounds from air by using a carbon adsorbent-catalyst composite, and (d) storage of compressed natural gas on high surface area carbons.

- by Shivaji Sircar
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- Engineering, Design practice, Carbon, Surface Chemistry

As little as 1 ppm SO, present in the exhaust of a lean bum natural gas engine strongly inhibits the oxidation of CH4 over a Pd containing catalyst. Non-methane emissions oxidation, such as C2H6. CsHs and CO, are also inhibited by low SO, concentrations, but to a lesser extent than CH, emissions. The mechanism for SO, inhibition indicates a 1 : 1 selective adsorption of SO, on PdO for palladium on a non-sulfating support such as SiOa. Deactivation is therefore very rapid. In contrast, palladium on sulfating supports, that is y-AlzOa, deactivate more slowly and can tolerate more SO, because the SO, is also adsorbed onto the carrier. The activation energy for methane oxidation is dramatically increased after SO, poisoning for all Pd catalysts, while the Arrhenius pre-exponential term is relatively constant, indicating a transformation from very active PdO sites to less active PdO-SO, sites. Platinum catalysts are considerably less active than Pd as evidenced by a much lower pre-exponential term, but are more resistant to deactivation by SO,. Non-methane hydrocarbon and particulate emissions standards for lean bum natural gas engines for the United States can be met with Pd catalysts. However, the non-enforced methane emissions standards are not met. For the European truck test cycle, methane emissions standards are met since the test cycle heavily weights the hotter modes where Pd-SO, is sufficiently active. 0 1997 Elsevier Science B.V.

- by R. Farrauto
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- Environmental Engineering, Chemical Engineering, Natural Gas, United States

In this paper, a numerical study to simulate and analyze the combustion process occurred in a compressed natural gas direct injection (CNG-DI) engine by using a multi-dimensional computational fluid dynamics (CFD) code was presented. The investigation was performed on a single cylinder of the 1.6-liter engine running at wide open throttle at a fixed speed of 2000 rpm. The mesh generation was established via an embedded algorithm for moving meshes and boundaries for providing a more accurate transient condition of the operating engine. The combustion process was characterized with the eddy-break-up model of Magnussen for unpremixed or diffusion reaction. The modeling of gaseous fuel injection was described to define the start and end of injection timing. The utilized ignition strategy into the computational mesh was also explained to obtain the real spark ignition timing. The natural gas employed is considered to be 100% methane (CH 4 ) with three global step reaction scheme. The CFD simulation was started from the intake valves opening until the time before exhaust valves opening. The results of CFD simulation were then compared with the data obtained from the single-cylinder engine experiment and showed a close agreement. For verification purpose, comparison between numerical and experimental work are in the form of average in-cylinder pressure, engine power as well as emission level of CO and NO.

Particulate matter (PM) sampling for both coarse and fine fractions was conducted in a semi-residential site (AECD) in Dhaka from February 2005 to December 2006. The samples were analyzed for mass, black carbon (BC), and elemental compositions. The resulting data set were analyzed for sources by Positive Matrix Factorization (EPA-PMF). From previous studies, it is found that, the air quality became worse in the dry winter period compared to the rainy season because of higher particulate matter concentration in the ambient air. . Therefore, seasonal source contributions were determined from seasonally segregated data using EPA-PMF modeling so that further policy interventions can be undertaken to improve air quality.

- by Philip Hopke
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- Environmental Engineering, Air Quality, Air pollution, Seasonality

The addition of CNG fuel in conventional diesel engines has increased the efficiency of engines and reduces diesel fuel consumption. The CNG fuel injected into the combustion chamber through inlet air system. The objective of this paper is to investigate of how airflows and CNG fuels are mixed and enter to the engine cylinder. This paper method is based on CFD simulation. The simulation of incoming airflow and CNG fuel on modified diesel engines that are developed with the addition of an inlet valve opening are expected to provide an overview of the effect of inlet valve lift on a dual fuel engine. The structural stress approach by varying the opening of the inlet valve during the default condition of 7.28 mm, 3.64 mm, 10.92 mm, and 14.56 mm. The investigation results shown that at the time of opening at 14.56 indicates the average increase air speed and increase the mass of airflow and fuel. Result shown that the power from the valve opening 14.56 mm has been increase.

- by IAEME Publication and +1
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- Compressed Natural Gas, Dual Fuel Engine, Air Fuel Mixing

This paper presents experimental results of a new compressed natural gas direct injection (CNG-DI) engine that has been developed from modification of a multi cylinder gasoline port injection (PI) engine. The original gasoline-PI engine was also modified to a CNG bi-fuel system. The test results obtained from CNG fuel using two different systems (i.e. bi-fuel and DI) have been investigated and compared with the original gasoline engine. The objective of this investigation is to compare the test results between CNG-DI, with CNG-BI and gasoline-PI engines with the same displacement volume. It was found that the CNG-DI engine produces similar brake power at 6000 rpm and wide open throttle (WOT) but produces higher brake power at part load condition as compared to the original gasoline. The CNG-BI engine produces 23% lower brake power than the CNG-DI engine. The average brake specific fuel consumption (BSFC) of the CNG-DI engine was 0.28% and 8% lower than gasoline-PI and CNG-BI engines respectively. The CNG-DI engine reduces 42% NOx emission as compared to the base engine. However, the CNG-DI engine produces higher HC and CO emissions as compared to the base engine. This paper discusses a review on the direct injection (DI) natural gas engine with new information along with other investigations.

- by Bonnie Dorr
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- Mechanical Engineering, Energy, Renewable energy resources, Marine Diesel Engines

This study assesses the fire safety risks associated with compressed natural gas (CNG) vehicle systems, comprising primarily a typical school bus and supporting fuel infrastructure. The study determines the sensitivity of the results to... more

- by M. Modarres
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- Multidisciplinary, Risk Analysis, Natural Gas, Probabilistic Risk Assessment

This paper quantifies the expected pre-combustion and combustion emissions of greenhouse gases from Australian heavy vehicles using alternative fuels. We use the term exbodied emissions for these full fuel-cycle emissions. The fuels examined are low sulfur diesel (LSD), ultra-low sulfur diesel (ULS), compressed natural gas (CNG), liquefied natural gas (LNG), liquefied petroleum gas (LPG), ethanol (from lignocellulose), biodiesel and waste

- by Tim Grant
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- Environmental Engineering, Atmospheric sciences, Life Cycle, Greenhouse Gas Emissions
- by Ibrahim Al Jabberi
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- Business, Business Administration, LNG, Energy

This paper presents characteristics of a new catalytic converter (catco) to be used for natural gas fuelled engine. The catco were developed based on catalyst materials consisting of metal oxides such as titanium dioxide (TiO 2 ) and cobalt oxide (CoO) with wire mesh substrate. Both of the catalyst materials (such as TiO 2 and CoO) are inexpensive in comparison with conventional catalysts (noble metals) such as palladium or platinum. In addition, the noble metals such as platinum group metals are now identified as human health risk due to their rapid emissions in the environment from various resources like conventional catalytic converter, jewelers and other medical usages. It can be mentioned that the TiO 2 /CoO based catalytic converter and a new natural gas engine such as compressed natural gas (CNG) direct injection (DI) engine were developed under a research collaboration program. The original engine manufacture catalytic conveter (OEM catco) was tested for comparison purposes. The OEM catco was based on noble metal catalyst with honeycomb ceramic substrate. It is experimentally found that the conversion efficiencies of TiO 2 /CoO based catalytic converter are 93%, 89% and 82% for NO x , CO and HC emissions respectively. It is calculated that the TiO 2 /CoO based catalytic converter reduces 24%, 41% and 40% higher NO x , CO and HC emissions in comparison to OEM catco respectively. The objective of this paper is to develop a low-cost three way catalytic converter to be used with the newly developed CNG-DI engine. Detailed review on catalytic converter, low-cost catalytic converter development characteristics and CNGDI engine test results have been presented with discussions.

A thermodynamic model is developed and validated for the prediction of the combustion process and pollutant formation in s.i. engines, fuelled by gasoline and compressed natural gas. Attention is focused on the main physical and chemical phenomena to allow a reliable evaluation of the burning rate and of the specie concentrations, including intermediates such as CO, O, H, and OH. A new correlation for laminar flame speed of methane-air mixtures is derived by interpolating more than 1000 different conditions at high pressure and temperature, computed by a detailed chemical approach. Successively an extended dissertation about the fundamental mechanisms which govern the pollutant formation in the turbulent premixed combustion which characterizes the s.i. engines is given. The conclusion of such analysis is the definition of a new reduced chemical scheme, based on the application of partial-equilibrium and steadystate assumptions for the radicals and the solution of a transport equation for each specie which is kinetically controlled. Finally the proposed schemes and formulations were embedded into the developed quasi-D model and into a CFD code, to simulate a s.i. engine fuelled by gasoline and CNG, allowing a deeper understanding of the reliability of the simplifications made in the quasi-dimensional model and a comprehensive investigation of several physical and chemical properties, whose experimental measurement is not usually available. Computed results were compared with the available experimental data of in-cylinder pressure histories and engine emissions for two different engine configurations.

- by Gianluca D'Errico
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- High Pressure, Kinetics, Steady state, Compressed Natural Gas

Hydrogen energy carrier Hydrogen enriched Compressed Natural Gas "HCNG" HySolThane project a b s t r a c t The Algerian transport sector is still largely dependent on petroleum. Pollution emitted by this sector is constantly increasing with the expansion of the automobile fleet. Thus, there is a pressing need for use of cleaner and economically viable alternative fuels. Therefore, the use of Hydrogen enriched Compressed Natural Gas (HCNG) is expected to play a significant role to reach this target. When hydrogen and natural gas are used together in an internal combustion engine, large benefits are possible. Algeria has significant resources and potential to introduce this new fuel. The development of HCNG as a transportation fuel allows an entry point for hydrogen in the transportation sector. The aim of this paper is to discuss strategic ways to introduce HCNG as road fuel, in Algeria. Two fundamental strategic elements were designed to introduce the Hydrogen Enriched Natural Gas as a transportation fuel. These are, the development of compressed natural gas as a road fuel, and the completion of the MedHySol project. The MedHySol project includes the production and the distribution of solar produced hydrogen, and involves the project HySolThane intended for the development of HCNG fuel road with 8% vol of Hydrogen in Natural Gas. (F. Amrouche).

- by Fethia Amrouche and +2
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- Engineering, Internal Combustion Engine, Natural Gas, Hydrogen Energy

Today's world is facing global warming as one of its main issues. A rise in carbon dioxide and other greenhouse gases concentration in the atmosphere causes this problem. A suggested method for controlling the level of greenhouse gases in the atmosphere is prevention of flaring gas. In this work, three methods are proposed to recover gas instead of conventional burning in a flare at the Asalooye Gas Refinery. These methods aim to minimize environmental and economical disadvantages of burning flare gas. The proposed methods are: 1) Gas-to-Liquid (GTL) production, 2) electricity generation with a gas turbine and, 3) compression and injection into the refinery pipelines. In order to find the most suitable method the required equipments for the three aforementioned methods are simulated. These simulations determine the amount of flare gas, the number of GTL barrels, the power generated by the gas turbine and the required compression horsepower. The results of the simulation show that 48,056 barrels per day of valuable GTL products is produced by the first method. The second method provides 2130 MW electricity and the third method provides a compressed natural gas with 129 bar pressure for injection to the refinery pipelines. In addition, the economics of the flare gas recovery methods are studied and compared. The results show that for the 356.5 MMSCFD of gas flared from the Asalooye Gas Refinery, GTL production provides the greatest rate of return. However, GTL requires the greatest capital investment. Gas compression yields the next highest rate of return and due to the lower capital requirements is the best choice for the Asalooye Gas Refinery. This new process is a suitable alternative to conventional gas flaring which prevents harmful environmental effects through emission of significant amounts of carbon dioxide in the atmosphere.

- by shreyansh sutaria
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- Engineering, Carbon Dioxide, GAS TURBINE, Global Warming

The use of CNG in Bangladesh is increasing day by day due to the environmental benefits as well as economic benefits. In the last decade, the importance of environment conservation has assumed great significance. Even in Bangladesh the last couple of years have witnessed a greater devotion and awakening towards the protection of the environment. Pollution due to petroleum products used in transportation is an ever-increasing problem for Bangladesh like other country. So alternative solution of energy source is trying to use, thus pressure on Compressed Natural Gas (CNG) has been increased. Though, the environmental problem is solved but the stock of gas is simultaneously decreasing. The purpose of the study is to make coordination between the environmental awareness concept and the use of the natural gas should be connected in such a manner to achieve the success of Bangladesh.

- by AKM Nazrul Islam
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- Renewable Energy, Compressed Natural Gas

Due to abundance of natural gas, the use of natural gas for automotive use, particularly for internal combustion engine (ICE), is more practical and cheaper than their future successors. Even though natural gas is a cleaner fuel than other fossil fuels and has a higher octane number and can lead to higher thermal efficiency, its low carbon number makes it less attractive as compared to gasoline and diesel. Based on its potential, an engine referred to as compressed natural gas direct injection engine (CNGDI) was designed, developed and tested to operate on compressed natural gas (CNG) as monofuel directly and centrally injected into the engine. Computational and experimental works have been performed to investigate the viability of the design. Computational fluid dynamics (CFD) simulations and experimental works with homogenous combustion showed that the results were in good agreement. From experimental works, it is found that combustion characteristics could be improved by using a stratified charge piston configuration with some drawback on performance. In terms of exhaust emissions, stratified configuration causes slight increase in the emission of CO, CO 2 and NO x , which highlight a need for further study on this issue.

- by Gilles L Bourque
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- Mechanical Engineering, Chemical Engineering, High Pressure, Modeling

Increasing concerns over energy security and stricter legislation on automotive exhaust emission limits have triggered greater efforts in utilizing alternatives to petroleum-based fuels. Compressed natural gas (CNG) is one of the promising candidates in terms of emissions and price. In this paper, methane, the major constituent of natural gas (NG), in used to fuel a Ricardo E6 engine and run in a port injection operation with open-valve and close-valve injection. The compression ratio is set at 10.5:1. Methane at 30 bar was supplied to the injector and injection length was adjusted to achieve the desired air fuel ratio (AFR). The minimum advance for best torque (MBT) was determined for 1100rpm speed by measuring the indicated mean effective pressure (IMEP) for combustion at spark advance between 14 o CA and 35 o CA BTDC. The result is clearly demonstrated that the performance of the open valve port injection (OVPI) is superior to the one of the close valve port injection (CVPI) with better IMEP, fuel conversion efficiency, indicated power and volumetric efficiency. The observation indicates that OVPI shows steadiness of peak pressures shifts toward top dead centre (TDC) as spark ignitions were advanced compared to CVPI. In terms of combustion characteristics, the OVPI operation yields shorter ignition delay and overall burning duration even at the same phasing angle. Therefore, the open valve operation is preferable for NG port injection due to the fact that injections take place while intake valve is open. It accelerates the charge flow into the cylinder causing higher volumetric efficiency and avoiding the back pressure that happen when high pressure methane is injected while intake valve closes.

- by shahrir abdullah
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- High Pressure, Energy Security, Natural Gas, Legislation

Quasi-dimensional model Laminar burning velocity Numerical simulation a b s t r a c t Spark ignition engines fuelled by hydrogen enriched compressed natural gas (HCNG) have many advantages compared to traditional gasoline, diesel and natural gas engines, especially in emission control. Experimental researches have been continuously conducted to improve HCNG engine's configuration and control strategy aimed at making full use of this new fuel. With the same target, this work presents a predictive model used to simulate the working cycle of HCNG engines which is applicable for variable hydrogen blending ratios. The fundamentals of the thermodynamic model, the turbulent flame propagation model and related equation were introduced. Considering that the most important factor influencing the applicability of the model for variable hydrogen blending ratio is the laminar flame speed, the methods of how to deal with the laminar burning velocity in the model were then described in some more detail. After the determination of model constants by calibration, simulation results were compared with experimental cylinder pressure data for various hydrogen blending ratios, spark timings and equivalence ratios. The results show that simulation and experimental results match quite well except for extremely fuel lean conditions where problems of incomplete combustion become severe.

- by Junjun Wang
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- Engineering, Experimental Research, Natural Gas, Numerical Simulation

This paper addresses the interactions between homogeneous and heterogeneous reactions for different hydrocarbons namely, compressed natural gas (CNG), liquefied petroleum gas (LPG), butane and dimethyl ether (DME) over platinum. Experiments are performed to study the effects of varying the temperature of the incoming mixture (T jet ), its equivalence ratio (Ø) and the Reynolds number (Re), on the reactivity limits. Computational fluid dynamic (CFD) calculations using detailed chemical kinetics for both the platinum surface and gas phase are completed for a range of methane-air mixtures to resolve the impact of varying T jet , Ø and Re on the compositional structure of the flow. Comparison between numerical and experimental results is performed where relevant.

- by Assaad Masri
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- Mechanical Engineering, Chemical Engineering, Surface Chemistry, Chemical Kinetics

Resources Board, El Monte, California 91731 without the vehicle running) were measured throughout this study and were helpful in determining the incremental increase in pollutant emissions. Also, the on-site determination of VOCs,... more

Noise pollution due to road traffic is a major global concern because of its negative impact on the quality of life in communities everywhere. In Republic of Serbia, traffic noise has become an increasingly noticeable and serious problem in large cities like Belgrade, Novi Sad, Niš, Kragujevacand Kraljevo.To resolving the current situation, in cities where exists the intensive noise pollution from diesel vehicles, as a special contribution to reducing noise in road traffic, we were studied the replacement of the existing city busses with new propulsion system on natural gas, resulting in less noise emission. The reduction of noise emission was confirmed during parallel tests of the buses with drive on diesel and natural gas. Intensive noise measurements were conducted according to the Regulation UN ECE 51R.

The Energy Sector Management Assistance Program (ESMAP) is a global technical assistance partnership administered by the World Bank and sponsored by bilateral official donors, since 1983. ESMAP's mission is to promote the role of energy in poverty reduction and economic growth in an environmentally responsible manner. Its work applies to low-income, emerging, and transition economies and contributes to the achievement of internationally agreed development goals. ESMAP interventions are knowledge products including free technical assistance, specific studies, advisory services, pilot projects, knowledge generation and dissemination, trainings, workshops and seminars, conferences and roundtables, and publications. ESMAP work is focused on four key thematic programs: energy security, renewable energy, energy-poverty and market efficiency and governance. GOVERNANCE AND OPERATIONS ESMAP is governed by a Consultative Group (the ESMAP CG) composed of representatives of the World Bank, other donors, and development experts from regions which benefit from ESMAP's assistance. The ESMAP CG is chaired by a World Bank Vice President, and advised by a Technical Advisory Group (TAG) of independent energy experts that reviews the Programme's strategic agenda, its work plan, and its achievements. ESMAP relies on a cadre of engineers, energy planners, and economists from the World Bank, and from the energy and development community at large, to conduct its activities.

- by Masami Kojima
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- Natural Resources, LNG, Energy efficiency, Electricity

- by Taib Iskandar Mohamad
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- High Pressure, Energy Security, Natural Gas, Legislation

Compressed gas Dispensing 70-MPa a b s t r a c t A hydrogen dispensing facility capable of providing rapid 70-MPa vehicle fills became operational in May 2011 as the first such hydrogen dispensing facility in Northern California. The facility is operated by the University of California e Berkeley in support of fuel cell vehicle research with automakers, regional and state agencies, and industrial groups.

- by Timothy LIPMAN and +1
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- Engineering, Hydrogen Energy, CHEMICAL SCIENCES, Compressed Natural Gas

The findings, interpretations, and conclusions expressed in this paper are entirely those of the author(s) and should not be attributed in any manner to the World Bank, to its affiliated organizations, or to member of its Board of executive Directors or the countries they represent. The World Bank does not guarantee the accuracy of the data included in this publication and accepts no responsibility for any consequence of their use. The boundaries, colors, denominations and any other information shown on any map in this volume do not imply, on the part of the World Bank Group any judgment on the legal status of any territory, or any endorsement or acceptance of such boundaries.

- by Masami Kojima
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- Engineering, South Asia, Global Warming, Trade Policy

This study aims to examine the potential substitute natural gas (SNG) production by integrating black liquor gasification (BLG) island with a small wheat straw-based non-wood pulp mills (NPM), which do not employ the black liquor recovery cycle. For such integration, it is important to first build knowledge on expected improvements
in an overall integrated non-wood pulp mill energy system using the key performance indicators. O2-blown circulating fluidized bed (CFB) gasification with direct causticization is integrated with a reference small NPM to evaluate the overall performance. A detailed economic analysis is performed together with a sensitivity analysis based on variations in the rate of return due to varying biomass price, total capital investment, and natural gas prices. The quantitive results showed considerable SNG production but significantly reduced electricity
production. There is a substantial CO2 abatement potential combining CO2 capture and CO2 mitigation from SNG use replacing compressed natural gas (CNG) or gasoline. The economic performance through sensitivity analysis reflects significant dependency on both substitute natural gas production and natural gas market price. Furthermore, the solutions to address the challenges and barriers for the successful commercial implementation of BLG based polygeneration system at small NPMs are discussed. The system performance and discussion on the real application of integrated system presented in this article form a vital literature source for future use by large number of small non-wood pulp industries.

- by Dr. Abdul-Sattar Nizami and +1
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- Environmental Engineering, Chemical Engineering, Environmental Science, Energy Economics

This research attempted to analyze the environmental impact of two available non-conventional vehicle technologies, highlighting the benefits in terms of emissions and fuel consumption reduction with respect to conventional vehicles. Moreover, tests were compared with predicted emissions of the conventional gasoline technology provided by the kinematic model developed. Results show that cold start strongly affects the emissions of CO, THC and NO X , which become very low during hot driving cycle. The existing emission model cannot be used to obtain a satisfactory prediction for hybrid car. But it could be proved that KEM emission model allows us to predict emission factor for conventional car and compressed natural gas. However, it is concluded that new experimental campaign with new technological cars might be interesting for future model developments.

- by Livia Ragione and +2
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- Kinematics, Predictive models, Compressed Natural Gas, Computing and Information Technology

This paper presents experimental results of a new compressed natural gas direct injection (CNG-DI) engine that has been developed from modification of a multi cylinder gasoline port injection (PI) engine. The original gasoline-PI engine was also modified to a CNG bi-fuel system. The test results obtained from CNG fuel using two different systems (i.e. bi-fuel and DI) have been investigated and compared with the original gasoline engine. The objective of this investigation is to compare the test results between CNG-DI, with CNG-BI and gasoline-PI engines with the same displacement volume. It was found that the CNG-DI engine produces similar brake power at 6000. rpm and wide open throttle (WOT) but produces higher brake power at part load condition as compared to the original gasoline. The CNG-BI engine produces 23% lower brake power than the CNG-DI engine. The average brake specific fuel consumption (BSFC) of the CNG-DI engine was 0.28% and 8% lower than gasoline-PI and CNG-BI engines respectively. The CNG-DI engine reduces 42% NOx emission as compared to the base engine. However, the CNG-DI engine produces higher HC and CO emissions as compared to the base engine. This paper discusses a review on the direct injection (DI) natural gas engine with new information along with other investigations. © 2011 Elsevier Ltd.
http://ac.els-cdn.com/S0360544211002349/1-s2.0-S0360544211002349-main.pdf?_tid=c2bf5f32-a9c6-11e3-b389-00000aab0f01&acdnat=1394615868_af9452d9cda4f71e98e5cd80760b3339
http://www.sciencedirect.com/science/article/pii/S0360544211002349

- by Masjuki Haji Hassan
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- Renewable energy resources, Marine Diesel Engines, Power, Natural Gas

Gas asli termampat (CNG) merupakan bahan api alternatif yang paling berjaya dan digunakan dengan meluas bagi kenderaan terkini yang berada di pasaran. Kenderaan pacuan petrol bagi tujuan ini biasanya dilengkapkan dengan kit penukar gas asli bagi membolehkan operasian dwi-bahan api di antara CNG dan petrol. Pendekatan secara uji kaji ini difokuskan ke atas penggunaan bahan api, emisi ekzos dan kos bahan api di antara operasian gas asli dan petrol. Rig ujian terdiri dari sebuah sistem enjin teksi dwi-bahan api menggunakan 1500 cc dengan 12 injap sistem karburetor adalah dibina khusus. Penggunaan bahan api dan emisi ekzos yang setara diperolehi pada kelajuan putaran seminit (rpm) enjin yang berbeza ketika operasian menggunakan bahan api CNG dan petrol secara berasingan. Pengoperasian rpm enjin tanpa bebanan diubahsuai dari kedudukan pegun kepada kedudukan melebihi 5000 rpm untuk memperolehi profil penggunaan bahan api dan emisi ekzos. Kedua-dua data yang diperolehi ini kemudiannya digu...

- by Zulkifli Abdul Majid
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- Engineering, Carbon Dioxide, Natural Gas, Carbon Monoxide

The fraction of total crude oil produced domestically shrunk from 75% in 1970 to 39% in 2002 (2) and is predicted to continue to drop (see NOMENCLATURE IN THE PETROLEUM INDUSTRY). Imported products also continue to grow. In 2002, the United States imported 130 10 6 L/day of gasoline and gasoline components. In the 1970s, two Organization of Petroleum Exporting Countries (OPEC) embargoes resulted in rapid increases in the price of crude oil and therefore motor fuels. These increases triggered programs designed to develop alternative sources of fuels such as coal (qv), oil shale (qv), and natural gas (see FUELS, SYNTHETIC, GASEOUS FUELS; GAS NATURAL). In 2001, as a result of lower price volatility and improved energy efficiencies, the inflation adjusted cost of driving an average passenger car is about 40% lower than it was in 1960 (3). Today, alternative transportation fuels are being considered as replacements for traditional petroleum based fuels based on their perceived potential to improve the security of energy supply and to reduce emissions of greenhouse gases. Among alternative fuels under consideration are hydrogen, natural gas and biofuels such as ethanol and esterified edible oils. (see also AIR POLLUTION; EXHAUST CONTROL, AUTOMOTIVE).

- by Albie Hochhauser
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- Environmental Science, DISTRIBUTION, Volatility, Natural Gas