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Compressed Natural Gas as an Alternative Fuel

for Automotive Vehicles

Flores, Arvin Christian
Ornopia, Elvin
Lazam, Billy Caleb A.

Chapter I
1.1 Overview/ Background
In the recent years, the world is moving from traditional gas to natural
gas, particularly Compressed Natural Gas or CNG, to combat the increasing
levels of pollutants and carbon emissions in the atmosphere (Panchal et al.
2014). One of the main targets of these environmental programs is to reduce
the high levels of carbon emission coming from the smoke belchers of the
country – the transport sector – using Compressed Natural Gas for vehicles
instead of the traditional gasoline which can account for the rapid increase of
harmful gases in the atmosphere (Camp 2013, par. 2). For this reason, the
ability to acquire and to use Compressed Natural Gas as an alternative gas is
significant for the environment because Compressed Natural Gas emits
cleaner smoke than other traditional gases and, thus, has the ability to









Compressed Natural Gas used as an alternative gas, has the ability to
dramatically reduce and slow down the increasing levels of pollutants and
carbon footprints in the atmosphere (Camp 2013, par. 7); it has more
advantages for both user and the environment compared to other fossil fuels
moreover, it has a great potential of becoming the primary source of energy
for vehicles in the future.
Natural gas is primarily composed of methane; the main products of
combustion of natural gas are carbon dioxide and water vapor: same
compounds that are exhaled when breathing. Coal and oil are composed of
much more complex molecules with higher carbon ratio and higher nitrogen
and sulfur contents (Brinson 2012). When combusted, coal and oil release a

The reduction of greenhouse gas and carbon emission in the environment has become the primary focus of most environmental programs in countries around the world. Coal and fuel oil release ash particles on the environment that are substance that do not burn. 1. 1. instead it was carried into the atmosphere and contributes to the pollution.3.2 Statement of the problem The pollution has been the cause for many problems encountered globally.higher level of harmful emissions that are dangerous to the environment.3. To determine the amount of carbon produced from burning Compressed Natural Gas and Gasoline . Burning natural gas releases a very small of those gasses that are harmful for the environment and contributes pollution to the surroundings.1 Main Objective .To determine the amount of carbon reduce by using compressed 1.4 natural gas compared to fossil fuels(gasoline) Significance of the study . 1. The levels of carbon emission in the atmosphere have been increasing due to the rampant burning of fossil fuels brought by the increasing population and needs of humanity.2 Specific Objectives To conduct test that will burn fuels using an automotive vehicle.To compare the fuel economy and emissions of Compressed Natural Gas from Gasoline. To determine the fuel economy from using CNG and Gasoline.3 Objectives 1. Burning of fuels is the main cause of the pollution and using alternatives such as Compressed Natural Gas would lessen the pollutants produced from the industry.

has the ability to dramatically lessen the increasing carbon footprints present in the environment. Other substances produced from the burning of fuel process was not tested in the conducted study. .5 Scope and limitations The researchers focused mainly on the amount of carbon produced from the Compressed Natural Gas and Gasoline. 1. The comparison of the gasoline and compressed natural gas as source of fuel is only limited to the effect on the Environmental concerns and Transportation economy.The ability to acquire and to use Compressed Natural Gas as an alternative gas is significant for the environment because Compressed Natural Gas emits cleaner smoke than other traditional gases and thus. The performance analysis of the fuel in the vehicle will not be considered. The test results will show figures based on the amount of carbon produced from each fuel.

hydrogen sulphide. sulfur dioxide. In fact. Natural gas usually needs to be processed before it can be used.Chapter II Review of related literature 2. nitrogen. and particles that drift into the atmosphere and contribute to air pollution. It is use to combat smog formation to those areas where the air quality is poor. they release high amounts of harmful emissions. When fossil fuels are burned. Burning natural gas than other fossil fuels emits fewer harmful pollutants and increase the reliance on potentially reduces emission of those many harmful pollutants. Natural gas as the cleanest fossil fuel was used in many ways to help reduce the emissions of pollutants into the environment. and solid particles. propane. ethane. Like other fossil fuels. and sulfur. it is the cleanest-burning fuel. The use of natural gas does not significantly contribute in the formation of the smog as it emits lower nitrogen oxide and doesn’t have particulate matters. pentanes. and occasionally helium and nitrogen may be present in a natural gas well. When it is extracted. natural gas can be burned for energy. butane. natural gas can contain a variety of elements and compounds other than methane. In order to be used for energy. Water. water vapor. carbon dioxide.1 Natural Gas and the Environment As evidenced in the Environment Protection Agency (2010). meaning it releases very few byproducts. and contain a high amount of carbon. they can release or emit different elements. compounds. The gas that is used for energy in our homes is almost pure methane. including nitrogen oxides. . the methane is processed and separated from the other components. Coal and oil are fossil fuels with very complex molecular formations. When they are burned.

it will not ignite and if it’s above fifteen percent natural gas. Leaks from indoors may be form a flammable mixture in a vicinity of an ignition source. CNG was a flammable gas but has a narrow flammability range making it an inherently safe fuel. it doesn’t have enough oxygen to allow it burns. aluminum or composite tanks built to last more than twenty years. It also rises and disperses and minimizes the ignition risk similar to the gasoline. 2. 2. On the other hand. CNG vehicles can be safe as a gasoline-powered vehicle by strict safety standard. Carbon dioxide and water vapor. Although burning natural gas still emits greenhouse gases. It is a non-toxic gas that even it spill or accidentally release it will not affect its surroundings. CNG being a gaseous fuel is mixed in the air easily and evenly. CNG was stored in a thick-walled steel. if the mixture is below five percent natural gas. It means that the concentration of CNG will be mixed in the air and became flammable if it’s between five to fifteen percent natural gas. it emits almost 30 percent less CO2 than oil.3 Is Natural Gas Cleaner Than Petroleum and Coal? . the methane in natural gas has a simple molecular make-up: CH4. When it is burned. CNG is primarily methane which greenhouse gasses could contributes to the global climate change if it leaked.2 Fueling Safely with Compressed Natural Gas According to the California Energy Commission (2006). are known as greenhouse gases. along with other gases such as ozone and nitrous oxide. The increasing amounts of greenhouse gases in the atmosphere are linked to global warming and could have disastrous environmental consequences. Natural gas is lighter than air and it will not be pool as a liquid or vapor on the ground. it emits only carbon dioxide and water vapor. Humans exhale the same two components when we breathe. and 45 percent less CO2 than coal.In contrast.

usually along city streets. petroleum fuel was the single largest source of energy in the United States. with 18. During the 19th century. Coal is the most abundant fossil fuel in the United States. or crude oil. In 1885 Robert Bunsen invented the Bunsen burner. In 2009. for centuries. Today. and generated almost half of all electricity in the country in 2009 as well as more than 40 percent of electricity produced globally. It’s cheap. which mixes gas with air to produce a steady flame for heat or cooking. according to the U.S. petroleum consumption is used for transportation.Coal has been used as a fuel for hundreds or even thousands of years. some types of lamps ran on natural gas. and each source of coal has naturally-occurring pollutants that can be released when the coal is burned or stored. Humans have known about petroleum. according to the U. more than two-thirds of U. all coal produces carbon dioxide when it is burned. Like all fossil and biofuels. when it was distilled into kerosene and found to be a good. natural gas is a popular fuel for heating homes. Energy Information Administration.S.000 barrels per day providing 37 percent of energy. However. and gasoline. coal quality varies substantially based upon where it is mined. Coal is also the source of countless mining and transportation accidents and steady supply of greenhouse gases. cheap alternative to burning whale oil in oil lamps.S. including radioactive materials and toxic metals like mercury.690. readily mined domestically. The most direct derivatives of petroleum include diesel and jet fuel. Some coals can produce more energy per pound. but the substance wasn’t considered terribly interesting until the mid 1800s. cooking. and . Petroleum use contributed 43 percent of 2009 energy-related carbon dioxide emissions. and coal fueled steam engines in trains long before the liquid fuel-powered engines of today’s cars were in use. Energy Information Administration. Today.

Some vehicles are powered by natural gas as well. Possible consequences include melting of polar ice caps. weather-related deaths. After the process. Natural gas is a product of animal and vegetable material.4 Environmental Effects Climate change on a global scale has been attributed to increased emissions of carbon dioxide (CO 2). natural gas is a starting material for many other goods like plastics. floods. Like petroleum. Therefore. chemicals. The combusted natural gas itself runs gas turbines. natural gas is more eco-friendly. and even hydrogen. an increase in sea level.2003). tornadoes. and food and water . Natural gas produces 43% fewer of carbon emissions and 30% less than petroleum. 2.powering clothes dryers. efficient to use and cleaner than coal and petroleum. Natural gas is an especially efficient fuel when burned in combined-cycle power plants. As they use natural gas for their energy in their work it produces carbon dioxide and nitrogen oxides that causes pollution but it produces small amount. Based on the statistics written on the article of Melanie J. Other forms of source of energy such as Petroleum and coal are example of non-renewable resources in the environment. A global average temperature rise of only 1C could have serious implications. Indirect effects include increases in infectious disease. Martin on the National Geographic website. and droughts. as well as for power plants and industries. where electricity is produced in two stages. and then the leftover heat is used to heat water for steam-turbines. heat waves. The process of extracting coal and petroleum is too risky because it can pollute the environment. the natural gas will go to the factory or power plant to generate energy to their work. and other biodegradable things (Martin 1996 . a greenhouse gas. In every process there are leakages that we can’t escape that is very dangerous to the community near its plantation. and increases in precipitation and severe weather events like hurricanes.

pollutants from cars contribute to various types of air pollution. When hydrocarbons and NOx combine in sunlight.5 Cars Emission and Global Warming According to the article of Linda B. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) commissioned this survey to collect and analyze . they produce ozone. High in the atmosphere. ozone protects us from the sun’s ultraviolet rays. 2. At normal levels. heart disease. birth defects and eye irritation. Air pollutants emitted from cars are believed to cause cancer and contribute to such problems as asthma. That said.6 CNG busses compared with Diesel buses The U. Other atmospheric effects of air pollution include urban smog and reduced visibility. Sulfur dioxide and nitrogen oxides combine with water in the atmosphere to cause acid rain. which is detrimental to forests and other vegetation. it contributes to smog and causes respiratory problems. Brinson in the website of How Stuffs Work. (2011). many scientists believe that burning fossil fuels such as gasoline causes greenhouse gas levels to spike. All these effects put a stress on ecosystems and agriculture. and aquatic life. Emissions from cars increase the levels of carbon dioxide (CO2) and other greenhouse gases in the atmosphere. leading to global warming. When holes in the atmosphere's ozone layer allows ozone to come closer to Earth. Acid rain also causes monuments and buildings to deteriorate. associated with ozone-forming nitrogen oxides and volatile organic compound emissions. soil. greenhouse gases keep some of the sun’s heat in the atmosphere and help warm the Earth. lakes.S. 2.shortages. and threaten our planet as a whole.

The study found that the average fuel economy in CNG buses is approximately 20% lower than in diesel buses. station maintenance and power costs. transit agencies with varying degrees of compressed natural gas (CNG) bus and station experience. station ownership and operation.S.06 per diesel gallon equivalent. This information helps DOE and NREL determine areas of CNG transit bus success and priority areas for which further technical or other assistance might be required to enable success. transit agencies that use CNG buses. bus fuel efficiency. Based on a recent 12-month period—and after adjusting for energy content. and fuel-cost subsidies —the average CNG cost was $1. The survey was conducted onsite. (2009-2010) Chapter III Theoretical consideration . Clean Vehicle Education Foundation (CVEF) staff and subcontractors developed a battery of questions and identified 10 transit agencies to represent all U. and geographic location. management system.S.experiential data from U. although there is reason to believe that this gap will be narrower for new CNG and diesel engines. accounting for the diversity in characteristics such as fleet size.

The main human activity that emits CO2 is the combustion of fossil fuels (coal. business. soil.  Electricity. Electricity is a significant source of energy in the United States and is used to power homes. In 2012.S.S. CO2 accounted for about 82% of all U. and animals). and industry. like forests. plants.Fuel is the power source of an engine which when burned. . CO2emissions and 31% of total U. and oil) for energy and transportation. accounting for about 38% of total U. The main sources of CO2emissions in the United States are described below. To produce a given amount of electricity. greenhouse gas emissions in 2012. the fuel will be converted to mechanical energy that will let the vehicle move at the driver’s will. oceans. natural gas. to remove CO2 from the atmosphere. The combustion of fossil fuels to generate electricity is the largest single source of CO2 emissions in the nation. burning coal will produce more CO2than oil or natural gas. While CO2 emissions come from a variety of natural sources. The type of fossil fuel used to generate electricity will emit different amounts of CO2. greenhouse gas emissions from human activities. Carbon dioxide is naturally present in the atmosphere as part of the Earth's carbon cycle (the natural circulation of carbon among the atmosphere. human-related emissions are responsible for the increase that has occurred in the atmosphere since the industrial revolution. Human activities are altering the carbon cycle—both by adding more CO2 to the atmosphere and by influencing the ability of natural sinks. The byproducts of the combustion process causes pollution. 3.1 Carbon Dioxide Emission Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. although certain industrial processes and land-use changes also emit CO2.S.

greenhouse gas emissions in 2012. plants. and land surface as it is both produced and absorbed by many microorganisms.S.S. emissions and removal of CO2 by these natural processes tend to balance.S. for example. This category includes transportation sources such as highway vehicles. Since the Industrial Revolution began around 1750. and rail. The combustion of fossil fuels such as gasoline and diesel to transport people and goods is the second largest source of CO2 emissions. Fossil fuel combustion from various industrial processes accounted for about 14% of total U. ocean. human activities have contributed . CO2 emissions and 12% of total U. Several processes also produce CO2 emissions through chemical reactions that do not involve combustion.  Industry. Many industrial processes emit CO2 through fossil fuel combustion. accounting for about 32% of total U. and animals. marine transportation. the production of metals such as iron and steel. the production and consumption of mineral products such as cement.greenhouse gas emissions in 2012.S. and the production of chemicals. Transportation. air travel. CO2 emissions and 27% of total U. However. Carbon dioxide is constantly being exchanged among the atmosphere. Note that many industrial processes also use electricity and therefore indirectly cause the emissions from the electricity production.

changing energy prices. Going forward. emission trends. new technologies. changes in emissions from fossil fuel combustion have historically been the dominant factor affecting total U.2 Emission and Trends Carbon dioxide (CO2) emissions in the United States increased by about 5% between 1990 and 2012.substantially to climate change by adding CO2 and other heat-trapping gases to the atmosphere. Transportation emissions also contributed to the 5% increase. . and an overall growth in emissions from electricity generation. which means that more CO2 is removed from the atmosphere. Since the combustion of fossil fuel is the largest source of greenhouse gas emissions in the United States. including population growth. largely due to an increase in miles traveled by motor vehicles. and stored in plants and trees.5% between 2005 and 2020. Between 1990 and 2012. the management of forests and nonagricultural land has acted as a net sink of CO2. changing behavior. Changes in CO2 emissions from fossil fuel combustion are influenced by many long-term and short-term factors. since 1990. 3. than is emitted. CO2 emissions in the United States are projected to grow by about 1. the increase in CO2 emissions corresponded with increased energy use by an expanding economy and population. economic growth. and seasonal temperatures. This sink offset about 15% of total emissions in 2012.S. In the United States.

1990-2012 . Carbon Dioxide Gas Emissions.Graph 3.2 U.S.

S. gasoline and kerosene. It shows that using natural gas.Note: All emission estimates from the Inventory of U. The Table 3.1 shows the CO2 (carbon dioxide) emissions coefficient of natural gas. . Greenhouse Gas Emissions and Sinks: 1990-2012. there is less emission of CO2.

1 .1 is s flowchart that shows the step-by-step process being followed by the researchers.Chapter IV Methodology 4. Diagram 4. Basically. Get two samples of fuels: natural gas and gasoline fill the tanks with the same volume of fuel Burn the Fuel using the Car engine in a close area Gather samples of the released byproduct of the substance Collect samples of the byproducts using Air quality tester compare the amount of substances released from the combustion. it is the summary of the research.1 Flowchart of the Processes The Diagram 4.

1 will show the data collected after following the processes stated on Diagram 4.1 .1 Type of Fuel Amount of Produced Pollutants from Combustion Carbon Dioxide Carbon Monoxide Gasoline Compressed Natural Gas Table 4.Table 4.

com/categories/5901/indoor-air-qualityiaq-meters 2. and Alarm • Auto Power Off • Easy calibration in fresh air Source: .instrumart. Max/Min with Time stamp.000ppm Temperature: -4 to 140°F (-20 to 60°C) Humidity: 10 to 95%RH • Continuous (20. Features: • Checks for Carbon Dioxide (CO2) concentrations • Maintenance free dual wavelength NDIR (non-dispersive infrared) CO2 sensor • Measurement ranges: CO2: 0 to 6. temperature. Source: www. dew point. humidity. Compressed Natural Gas (CNG) CNG is a readily available alternative to gasoline that's made by compressing natural gas to less than 1% of its volume at standard atmospheric pressure. and wet bulb.2 Materials/ Equipment The following are the materials to be used in this research: 1.cngnow. Air Quality Tester Measures carbon dioxide (CO2).000 sets) or manual (99 sets) datalogging • Data hold.

Gasoline Crude oil based petroleum product used to power internal combustion engines. CNG storage cylinders will be .3 The conversion of vehicles to Compressed Natural Gas (CNG) You may know by now that you don’t need to buy a new CNG-powered car to start using clean and safe CNG and reduce your carbon footprint. auto-manufactures have started building cars that either do not need gasoline or rely very little on the product. The liquid is highly flammable and evaporates as the engine uses it. Once installed. Due to increased demand for gasoline and crude.3. These components make CNG the primary fuel for your vehicle with gasoline as the back-up fuel. the engine will automatically switch between CNG and gasoline. 4. a fuel selection button will be installed that will allow the driver to manually select either CNG or gasoline. But do you know how CNG conversion is accomplished and how it works? At Action Alternative Fuels we will install compressed natural gas (CNG) components to your existing vehicle. however. Any vehicle running on gasoline and diesel can be converted to CNG.

Having a dual fuel system will ensure adequate fuel reserves in between natural gas fills. here are the step by step details: . or in the trunk for cabs and other cars. idling or parked. Some CNG systems will automatically switch to gasoline when the natural gas level reaches a preset low pressure setting. Stainless steel tubes and lines will transport the CNG to the regulator in the vehicle’s engine compartment to reduce the pressure.installed in the bed of the pickup truck in most cases. Drivers can switch from CNG to gasoline even while driving. Compared to having only a gasoline engine. this additional fuel reserve will extend the vehicle’s driving range. The CNG will then pass through a fuel-air mixer on its way to the intake manifold to be introduced for combustion. For an inside look at how a CNG/gasoline bi-fuel system works.

 The regulator accepts the CNG and reduces its pressure from 3. CNG leaves the storage cylinders and passes through the master manual shut-off.  The natural gas solenoid valve lets the natural gas flow from the regulator into the gas mixer or fuel injectors.600 psi to approximate atmospheric pressure. CNG is fed into the high pressure cylinders through the natural gas receptacle  When the engine needs natural gas.  CNG enters the engine chamber via the stainless steel high pressure line.  CNG mixes with air and flows down through the carburetor or fuel injection system and enters the engine’s combustion chambers. This same solenoid valve also shuts off the natural gas when the engine is stopped. .

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).howstuffworks. How Stuffs (n.nationalgeographic.Brinson. How much Air Pollution comes from cars? Retrieved from http://auto.d.htm . http://www.pdf http://education.