Diesel vs. compressed natural gas for school buses: a cost-effectiveness evaluation of alternative fuels

Energy Policy ◽  
2005 ◽  
Vol 33 (13) ◽  
pp. 1709-1722 ◽  
Author(s):  
Joshua T. Cohen
Keyword(s):  
Cost Effectiveness ◽  
Natural Gas ◽  
Alternative Fuels ◽  
Effectiveness Evaluation ◽  
Compressed Natural Gas ◽  
School Buses

Comparative assessment of engine vibration, combustion, performance and emission characteristics between single and twin-cylinder diesel engines in unifuel and dual-fuel mode

2021 ◽  
pp. 1-39
Author(s):  
Akash Chandrabhan Chandekar ◽  
Sushmita Deka ◽  
Biplab K. Debnath ◽  
Ramesh Babu Pallekonda
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Load Condition ◽  
Alternative Fuel ◽  
Dual Fuel ◽  
Cylinder Pressure ◽  
Compressed Natural Gas ◽  
Single Cylinder ◽  
Engine Vibration ◽  
Single Cylinder Engine

Abstract The persistent efforts among the researchers are being done to reduce emissions by the exploration of different alternative fuels. The application of alternative fuel is also found to influence engine vibration. The present study explores the potential connection between the change of the engine operating parameters and the engine vibration pattern. The objective is to analyse the effect of alternative fuel on engine vibration and performance. The experiments are performed on two different engines of single cylinder and twin-cylinder variants at the load range of 0 to 34Nm, with steps of 6.8Nm and at the constant speed of 1500rpm. The single cylinder engine, fuelled with only diesel mode, is tested at two compression ratios of 16.5 and 17.5. While, the twin-cylinder engine with a constant compression ratio of 16.5, is tested at both diesel unifuel and diesel-compressed natural gas dual-fuel modes. Further, in dual-fuel mode, tests are conducted with compressed natural gas substitutions of 40%, 60% and 80% for given loads and speed. The engine vibration signatures are measured in terms of root mean square acceleration, representing the amplitude of vibration. The combustion parameters considered are cylinder pressure, rate of pressure rise, heat release rate and ignition delay. At higher loads, the vibration amplitude increases along with the cylinder pressure. The maximum peak cylinder pressure of 95bar is found in the case of the single cylinder engine at the highest load condition that also produced a peak vibration of 3219m/s2.

Risk-Based Technology Method for the Safety Assessment of Marine Compressed Natural Gas Fuel Systems

2001 ◽  
Vol 38 (03) ◽  
pp. 193-207
Author(s):  
Robb Wilcox ◽  
Mark Burrows ◽  
Sujit Ghosh ◽  
Bilal M. Ayyub
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
New Technologies ◽  
Formal System ◽  
Diesel Oil ◽  
Coast Guard ◽  
System Safety ◽  
Compressed Natural Gas ◽  
Marine Application ◽  
Marine Vessels

The introduction of alternative fuels (other than diesel oil or gasoline) for some commercially operated marine vessels presents a problem to marine regulators and designers since accepted standards and U.S. Coast Guard policy have not been established. Establishing safe design criteria is a common problem with the introduction of new technologies, novel concepts, and complex systems. In order to determine design safety for novel marine concepts such as compressed natural gas (CNG) fuel, a formal system safety approach may be used. Risk-based technologies (RBT) provide techniques to facilitate the proactive evaluation of system safety through risk assessment, risk control, risk management, and risk communication. The proposed outfitting of a CNG fuel system on the Kings Pointer training vessel is discussed as a specific marine application of CNG fuel and an appropriate situation for applying system safety techniques.

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 Analysis of alternative motor-vehicle fuels

2021 ◽  
Vol 2094 (5) ◽  
pp. 052005
Author(s):  
M A Kovaleva ◽  
V G Shram ◽  
T N Vinichenko ◽  
E G Kravtsova ◽  
D G Slashchinin ◽  
...  
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Motor Vehicle ◽  
Oil Refining ◽  
Engine Fuel ◽  
Liquefied Petroleum Gas ◽  
Compressed Natural Gas ◽  
Gas Engine ◽  
Advantages And Disadvantages ◽  
Market Expansion

Abstract In this paper, the analysis of alternative fuels is carried out: electricity, hydrogen, biofuels (bioethanol, biodiesel, biogas), solar energy, compressed air, gas engine fuel (compressed natural gas, liquefied petroleum gas, liquefied natural gas). The advantages and disadvantages of their use are indicated according to the criteria of environmental safety, cost, and infrastructure development. It is revealed that at the moment, gas-engine fuel, in particular liquefied petroleum gas and compressed natural gas, is most suitable for the transfer of the fleet. The economic and environmental effect of the market expansion is associated with the high environmental friendliness of this type of fuel, low price, large natural reserves, the development of the petrochemical industry of the country, the reduction of financial costs for the repair and reconstruction of physically and morally outdated oil refining and liquid fuel production enterprises, promising technical and technological solutions to transport problems.

The Potential for the Use of Natural Gas and Propane As Alternative Fuels in the Marine Industry

2013 ◽  
Author(s):  
Par Neiburger
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Alternative Fuels ◽  
Alternative Fuel ◽  
Liquefied Natural Gas ◽  
Road Vehicles ◽  
Compressed Natural Gas ◽  
Gaseous Fuels ◽  
Diesel Vehicles ◽  
Marine Industry

Liberator Engine Company, LLC designs, develops and produces alternative fuel engines for vehicles around the globe. The Company’s 6.0 Liter Liberator™ gaseous fuels engine will have the ability to operate on Compressed Natural Gas, Liquefied Natural Gas or Liquid Propane Gas: clean, domestic, economical fuels. The Liberator engine will target OEM on road vehicles, as well as off road applications. The Liberator engine is also an excellent choice for the repower of existing diesel vehicles. The 6.0L Liberator™ engine will serve as a replacement engine for vehicle currently operating on a Cummins 5.9L diesel engine or Mercedes diesel 6.0L engine. Paper published with permission.

scholarly journals SI engine performance, lubricant oil deterioration, and emission: A comparison of liquid and gaseous fuel

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402093045
Author(s):  
Muhammad Usman ◽  
Muhammad Wajid Saleem ◽  
Syed Saqib ◽  
Jamal Umer ◽  
Ahmad Naveed ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Specific Energy ◽  
Alternative Fuels ◽  
Specific Energy Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compressed Natural Gas ◽  
Lubricant Oil ◽  
Brake Power

Considering the importance of alternative fuels in IC engines for environment safety, compressed natural gas has been extensively employed in SI engines. However, scarce efforts have been made to investigate the effect of compressed natural gas on engine lubricant oil for a long duration. In this regard, a comprehensive analysis has been made on the engine performance, emissions, and lubricant oil conditions using gasoline ( G)92 and compressed natural gas at different operating conditions using reliable sampling methods. The key parameters of the engine performance like brake power and brake-specific energy consumption were investigated at 80% throttle opening within 1500–4500 range of r/min. For the sake of emission tests, speed was varied uniformly by varying the load at a constant throttle. Furthermore, the engine was run at high and low loads for lubricant oil comparison. Although compressed natural gas showed a decrease in brake-specific energy consumption (7.94%) and emissions content, ( G)92 performed relatively better in the case of brake power (39.93% increase). Moreover, a significant improvement was observed for wear debris, lubricant oil physiochemical characteristics, and additives depletion in the case of compressed natural gas than those of ( G)92. The contents of metallic particles were decreased by 23.58%, 36.25%, 42.42%, and 66.67% for iron, aluminum, copper, and lead, respectively, for compressed natural gas.

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