Environment and Economic Assessment of CNG and Gasoline Engines: An Experimental Analysis

2021 ◽  
Author(s):  
Sridhar Sahoo ◽  
Dhananjay Kumar Srivastava

Abstract The application of alternative fuels in automobile engines is gaining more popularity among the scientific community than ever. Most of the research emphasis is on the performance and combustion aspect of the engine. The environmental and economic evaluation of these fuels is also equally important for sustainability, which is relatively unexplored and needs to be evaluated. The present work compares the environmental and economic aspects of a spark ignition (SI) engine fueled with gasoline and compressed natural gas (CNG). To study the environmental impact, regulated and unregulated emissions coming out from the engine exhaust were compared. For economic assessment, annual fuel consumption and associated fuel cost were compared under similar engine operating conditions. The economic cost associated with the environmental impact was calculated based on carbon dioxide emissions and compared using carbon pricing. Experiments on an SI engine were performed at various engine loads to achieve a range of operating conditions to evaluate fuel consumption and engine-out emissions. Results show that a CNG fueled engine has 12.7% lower brake specific fuel consumption than the gasoline engine, which leads to 56% lower fuel cost. It is due to the cumulative effect of higher calorific value and the lower fuel price of CNG compared to gasoline. Additionally, average environment emission and associated cost due to carbon dioxide (CO2) emission reduced by 29% using CNG over gasoline. This study shows that CNG can lead to lesser fuel consumption and its associated fuel and environment cost compared to gasoline.

2019 ◽  
Vol 26 (3) ◽  
pp. 31-38
Author(s):  
Wojciech Gis ◽  
Maciej Gis ◽  
Piotr Wiśniowski ◽  
Mateusz Bednarski

Abstract Limiting emissions of harmful substances is a key task for vehicle manufacturers. Excessive emissions have a negative impact not only on the environment, but also on human life. A significant problem is the emission of nitrogen oxides as well as solid particles, in particular those up to a diameter of 2.5 microns. Carbon dioxide emissions are also a problem. Therefore, work is underway on the use of alternative fuels to power the vehicle engines. The importance of alternative fuels applies to spark ignition engines. The authors of the article have done simulation tests of the Renault K4M 1.6 16v traction engine for emissions for fuels with a volumetric concentration of bioethanol from 10 to 85 percent. The analysis was carried out for mixtures as substitute fuels – without doing any structural changes in the engine's crankshafts. Emission of carbon monoxide, carbon dioxide, hydrocarbons, oxygen at full throttle for selected rotational speeds as well as selected engine performance parameters such as maximum power, torque, hourly and unit fuel consumption were determined. On the basis of the simulation tests performed, the reasonableness of using the tested alternative fuels was determined on the example of the drive unit without affecting its constructions, in terms of e.g. issue. Maximum power, torque, and fuel consumption have also been examined and compared. Thus, the impact of alternative fuels will be determined not only in terms of emissions, but also in terms of impact on the parameters of the power unit.


Author(s):  
Jonathan Hall ◽  
Benjamin Hibberd ◽  
Simon Streng ◽  
Michael Bassett

The complexity of modern powertrain development is demonstrated by the combination of requirements to meet future emission regulations and test procedures such as the real driving emissions, the reductions in the fuel consumption and the carbon dioxide emissions as well as the expectations of customers that there must be a good driving performance. Gasoline engine downsizing is already established as a proved technology to reduce the carbon dioxide emissions of automotive fleets. Additionally, alternative fuels such as natural gas offer the potential to reduce significantly both the tailpipe carbon dioxide emissions and the other regulated exhaust gas emissions without compromising the driving performance and the driving range. This paper presents results showing how the positive fuel properties of natural gas can be fully utilised in a heavily downsized engine. The engine was modified to cope with the significantly higher mechanical and thermal loads when operating at high specific outputs on compressed natural gas. In this study, peak cylinder pressures of up to 180 bar and specific power output levels of 110 kW/l were realised. It is also shown that having cylinder components specific to natural gas can yield significant reductions in the fuel consumption and, in conjunction with a variable-geometry turbine, a port-fuelled compressed-natural-gas engine can achieve a impressive low-speed torque (a brake mean effective power of 2700 kPa at 1500 r/min) and good transient response characteristics. The results achieved from the test engine while operating on compressed natural gas are compared with measurements from the baseline gasoline-fuelled direct-injection engine. In addition, a comparison between port fuel injection and direct injection of compressed natural gas is presented. This also includes an investigation into the specific performance challenges presented by port-fuel-injected compressed natural gas. The potential carbon dioxide savings offered by this heavily downsized compressed-natural-gas engine, of up to 50% at peak power and 20–40% for the driving-cycle region (including real-driving-emissions testing), are presented and discussed.


2021 ◽  
Vol 2130 (1) ◽  
pp. 012001
Author(s):  
L Grabowski

Abstract Simulation studies can be used to determine the fuel consumption and carbon dioxide emissions of city buses. The operating conditions of such vehicles are characterised by a very high variability of vehicle speed due to the large number of stops along the route of the bus. During vehicle testing, driving cycles are used to replicate the real-world conditions and to achieve repeatable test conditions. Such a driving cycle is a profile of speed represented as a function of time or as a function of distance. The speed profile over time can be an advantageous determinant, based on laboratory tests, for estimating fuel consumption and pollutant emissions of city buses. The research subject of this paper was the simulation of bus driving under simulated urban traffic conditions, carried out by means of the VECTO software. VECTO is a tool designed to perform the calculations of fuel consumption and carbon dioxide emissions of vehicles. It enables to model the powertrain of trucks and buses and to carry out simulations on various routes defined by driving cycles. The test object was a mega class bus, equipped with a 225 kW engine. The bus has three axles, including the rear drive axle. The scope of research included four cycles: urban, interurban, urbandelivery and interurban. Each of these was analysed in terms of speed and road gradient. The aim of this work was to perform a simulation study of the effect of the vehicle traffic conditions on the amount of CO2 emitted and fuel consumption. The obtained results were analysed.


2021 ◽  
Author(s):  
Amir Al Ghatta ◽  
James D. E. T. Wilton-Ely ◽  
Jason P. Hallett

Process simulations allow the evaluation of the emissions and selling price for the production of the key monomer FDCA based on different feedstocks and solvent systems, alongside considerations of safety and current process development.


2021 ◽  
Vol 11 (4) ◽  
pp. 1616
Author(s):  
Antonina Rita Limongi ◽  
Emanuele Viviano ◽  
Maria De Luca ◽  
Rosa Paola Radice ◽  
Giuliana Bianco ◽  
...  

The need to safeguard our planet by reducing carbon dioxide emissions has led to a significant development of research in the field of alternative energy sources. Hydrogen has proved to be the most promising molecule, as a fuel, due to its low environmental impact. Even if various methods already exist for producing hydrogen, most of them are not sustainable. Thus, research focuses on the biological sector, studying microalgae, and other microorganisms’ ability to produce this precious molecule in a natural way. In this review, we provide a description of the biochemical and molecular processes for the production of biohydrogen and give a general overview of one of the most interesting technologies in which hydrogen finds application for electricity production: fuel cells.


Author(s):  
Jongsup Hong ◽  
Ahmed F. Ghoniem ◽  
Randall Field ◽  
Marco Gazzino

Oxy-fuel combustion coal-fired power plants can achieve significant reduction in carbon dioxide emissions, but at the cost of lowering their efficiency. Research and development are conducted to reduce the efficiency penalty and to improve their reliability. High-pressure oxy-fuel combustion has been shown to improve the overall performance by recuperating more of the fuel enthalpy into the power cycle. In our previous papers, we demonstrated how pressurized oxy-fuel combustion indeed achieves higher net efficiency than that of conventional atmospheric oxy-fuel power cycles. The system utilizes a cryogenic air separation unit, a carbon dioxide purification/compression unit, and flue gas recirculation system, adding to its cost. In this study, we perform a techno-economic feasibility study of pressurized oxy-fuel combustion power systems. A number of reports and papers have been used to develop reliable models which can predict the costs of power plant components, its operation, and carbon dioxide capture specific systems, etc. We evaluate different metrics including capital investments, cost of electricity, and CO2 avoidance costs. Based on our cost analysis, we show that the pressurized oxy-fuel power system is an effective solution in comparison to other carbon dioxide capture technologies. The higher heat recovery displaces some of the regeneration components of the feedwater system. Moreover, pressurized operating conditions lead to reduction in the size of several other critical components. Sensitivity analysis with respect to important parameters such as coal price and plant capacity is performed. The analysis suggests a guideline to operate pressurized oxy-fuel combustion power plants in a more cost-effective way.


2019 ◽  
Vol 16 (1) ◽  
pp. 148-160
Author(s):  
Olga Piterina ◽  
Alexander Masharsky

Abstract Research purpose. The high-speed railway (HSR) construction project in the Baltic States is the largest joint infrastructure project since the restoration of independence of Latvia, Lithuania and Estonia. Rail Baltica (RB) is considered as the most energy-efficient project having the lowest environmental impact. However, the issue of energy consumption of the project was not sufficiently addressed either in the investment justification of the RB construction or in the relevant research works regarding the project. The aim of the current research is to determine the indicators of energy consumption and carbon dioxide (CO2) emissions intensity of the Latvian section of RB, since they are the key factors of the quantitative assessment of sustainability. Design/Methodology/Approach. Critical analysis of the academic research works and reports of the official international organizations dedicated to the topic of energy consumption and CO2 emissions of HSR was conducted prior to the calculation of the above-mentioned indicators. The method of calculation based on International Union of Railways (UIC) was used in order to conduct the cluster analysis within the framework of current work. The main points considered are electricity consumption, carbon dioxide emissions, and level of passenger and freight demand. Statistical databases of UIC and International Energy Agency were used. Findings. The calculations carried out by the authors of the given article demonstrate substantial figures of CO2 emissions intensity for Latvian section of the project related to the train load rate and traffic intensity which is evened out only by the CO2 emissions factor in Latvia. Originality/Value/Practical implications. On this basis the authors present the directions for future research required for the development of the effective strategy for the Latvian Republic with the aim of achieving the increase in the RB project’s ecological efficiency.


Sign in / Sign up

Export Citation Format

Share Document