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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

To determine the fuel economy from using CNG and Gasoline. 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.4 natural gas compared to fossil fuels(gasoline) Significance of the study . 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.To determine the amount of carbon reduce by using compressed 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.higher level of harmful emissions that are dangerous to the environment.3. 1. 1.3 Objectives 1. 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 .3. To determine the amount of carbon produced from burning Compressed Natural Gas and Gasoline . instead it was carried into the atmosphere and contributes to the pollution. 1.2 Statement of the problem The pollution has been the cause for many problems encountered globally. Coal and fuel oil release ash particles on the environment that are substance that do not burn.To compare the fuel economy and emissions of Compressed Natural Gas from Gasoline.2 Specific Objectives To conduct test that will burn fuels using an automotive vehicle.

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 test results will show figures based on the amount of carbon produced from each fuel. has the ability to dramatically lessen the increasing carbon footprints present in the environment. The performance analysis of the fuel in the vehicle will not be considered. Other substances produced from the burning of fuel process was not tested in the conducted study. 1.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.5 Scope and limitations The researchers focused mainly on the amount of carbon produced from the Compressed Natural Gas and Gasoline. .

compounds.1 Natural Gas and the Environment As evidenced in the Environment Protection Agency (2010). and occasionally helium and nitrogen may be present in a natural gas well. Water. and particles that drift into the atmosphere and contribute to air pollution. Natural gas usually needs to be processed before it can be used. and solid particles. they can release or emit different elements. When it is extracted. In order to be used for energy. natural gas can be burned for energy. carbon dioxide. water vapor. When they are burned. the methane is processed and separated from the other components. sulfur dioxide. Like other fossil fuels. meaning it releases very few byproducts. The gas that is used for energy in our homes is almost pure methane. hydrogen sulphide. It is use to combat smog formation to those areas where the air quality is poor. ethane. natural gas can contain a variety of elements and compounds other than methane. they release high amounts of harmful emissions. including nitrogen oxides. and contain a high amount of carbon. it is the cleanest-burning fuel. nitrogen.Chapter II Review of related literature 2. Natural gas as the cleanest fossil fuel was used in many ways to help reduce the emissions of pollutants into the environment. . 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. butane. In fact. and sulfur. pentanes. propane. Coal and oil are fossil fuels with very complex molecular formations. 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.

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

Petroleum use contributed 43 percent of 2009 energy-related carbon dioxide emissions. and each source of coal has naturally-occurring pollutants that can be released when the coal is burned or stored. more than two-thirds of U. Energy Information Administration. usually along city streets. for centuries.S. but the substance wasn’t considered terribly interesting until the mid 1800s. Humans have known about petroleum. some types of lamps ran on natural gas. natural gas is a popular fuel for heating homes. when it was distilled into kerosene and found to be a good. and . The most direct derivatives of petroleum include diesel and jet fuel. readily mined domestically. Today. and coal fueled steam engines in trains long before the liquid fuel-powered engines of today’s cars were in use. cheap alternative to burning whale oil in oil lamps.S. It’s cheap. petroleum consumption is used for transportation. Coal is the most abundant fossil fuel in the United States. Today. Coal is also the source of countless mining and transportation accidents and steady supply of greenhouse gases. or crude oil. Energy Information Administration. all coal produces carbon dioxide when it is burned.S.Coal has been used as a fuel for hundreds or even thousands of years. cooking. coal quality varies substantially based upon where it is mined. with 18.690. according to the U. petroleum fuel was the single largest source of energy in the United States. During the 19th century. In 2009. Some coals can produce more energy per pound. which mixes gas with air to produce a steady flame for heat or cooking. according to the U. In 1885 Robert Bunsen invented the Bunsen burner.000 barrels per day providing 37 percent of energy. and generated almost half of all electricity in the country in 2009 as well as more than 40 percent of electricity produced globally. Like all fossil and biofuels. including radioactive materials and toxic metals like mercury. and gasoline. However.

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

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

accounting for the diversity in characteristics such as fleet size. station ownership and operation. bus fuel efficiency. 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. and geographic location. Based on a recent 12-month period—and after adjusting for energy content. station maintenance and power costs. (2009-2010) Chapter III Theoretical consideration . and fuel-cost subsidies —the average CNG cost was $1.06 per diesel gallon equivalent. The survey was conducted onsite.experiential data from U. transit agencies with varying degrees of compressed natural gas (CNG) bus and station experience.S. transit agencies that use CNG buses.S. The study found that the average fuel economy in CNG buses is approximately 20% lower than in diesel buses. management system. although there is reason to believe that this gap will be narrower for new CNG and diesel engines. Clean Vehicle Education Foundation (CVEF) staff and subcontractors developed a battery of questions and identified 10 transit agencies to represent all U.

To produce a given amount of electricity. and animals). The type of fossil fuel used to generate electricity will emit different amounts of CO2. and industry. Human activities are altering the carbon cycle—both by adding more CO2 to the atmosphere and by influencing the ability of natural sinks.1 Carbon Dioxide Emission Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. The main sources of CO2emissions in the United States are described below.S. burning coal will produce more CO2than oil or natural gas.S. natural gas. the fuel will be converted to mechanical energy that will let the vehicle move at the driver’s will. CO2emissions and 31% of total U. and oil) for energy and transportation. although certain industrial processes and land-use changes also emit CO2. The byproducts of the combustion process causes pollution. like forests.S. greenhouse gas emissions from human activities. The main human activity that emits CO2 is the combustion of fossil fuels (coal. . The combustion of fossil fuels to generate electricity is the largest single source of CO2 emissions in the nation. business. In 2012.Fuel is the power source of an engine which when burned. Carbon dioxide is naturally present in the atmosphere as part of the Earth's carbon cycle (the natural circulation of carbon among the atmosphere. accounting for about 38% of total U. human-related emissions are responsible for the increase that has occurred in the atmosphere since the industrial revolution. 3. Electricity is a significant source of energy in the United States and is used to power homes. to remove CO2 from the atmosphere. soil. While CO2 emissions come from a variety of natural sources.  Electricity. CO2 accounted for about 82% of all U. oceans. plants. greenhouse gas emissions in 2012.

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

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

1990-2012 . Carbon Dioxide Gas Emissions.2 U.S.Graph 3.

The Table 3. gasoline and kerosene.S.1 shows the CO2 (carbon dioxide) emissions coefficient of natural gas.Note: All emission estimates from the Inventory of U. . there is less emission of CO2. Greenhouse Gas Emissions and Sinks: 1990-2012. It shows that using natural gas.

Chapter IV Methodology 4.1 Flowchart of the Processes The Diagram 4. it is the summary of the research. Basically. Diagram 4.1 . 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.1 is s flowchart that shows the step-by-step process being followed by the researchers.

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

cngnow. Max/Min with Time stamp.000ppm Temperature: -4 to 140°F (-20 to 60°C) Humidity: 10 to 95%RH • Continuous (20. Source: www. Air Quality Tester Measures carbon dioxide (CO2).com/what-is-cng .instrumart. and wet bulb. humidity. temperature. 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 2. and Alarm • Auto Power Off • Easy calibration in fresh air Source: https://www.000 sets) or manual (99 sets) datalogging • Data hold.2 Materials/ Equipment The following are the materials to be used in this research: 1. Features: • Checks for Carbon Dioxide (CO2) concentrations • Maintenance free dual wavelength NDIR (non-dispersive infrared) CO2 sensor • Measurement ranges: CO2: 0 to 6.4. dew point.

3. 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. the engine will automatically switch between CNG and gasoline. These components make CNG the primary fuel for your vehicle with gasoline as the back-up fuel. auto-manufactures have started building cars that either do not need gasoline or rely very little on the product. Due to increased demand for gasoline and crude.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. Once installed. The liquid is highly flammable and evaporates as the engine uses it. Gasoline Crude oil based petroleum product used to power internal combustion engines. Any vehicle running on gasoline and diesel can be converted to CNG. however. CNG storage cylinders will be . 4.

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

 The regulator accepts the CNG and reduces its pressure from 3.  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 leaves the storage cylinders and passes through the master manual shut-off. CNG is fed into the high pressure cylinders through the natural gas receptacle  When the engine needs natural gas.  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.  CNG enters the engine chamber via the stainless steel high pressure line.

References California Energy Commission (2006 . ( Compressed Natural Gas (Cng) As A Transportation Retrieved from http://www.pdf Leanardo Academy Program (2013).d.html Green. Cleaner and Greener.afdc. Retrieved from http://www. Retrieved from http://www. (2004-2011).asp Natural Gas and the Environment.ehow. Compressed Natural Gas (CNG) as a Transportation Fuel. Retrieved from http://dzhingarov. retrieved from http://www. Retrieved from http://www. Clean Alternative Fuels: Compressed Natural Gas. ( (2013.).).2012).html Natural Gas and the Environment.html . (n. Natural Gas Vehicle Safety.d.cleanerandgreener. Retrieved from www. Retrieved from http://www.naturalgas. (n.html Camp.naturalgas. The Importance of CNG Vehicles in Reducing Pollution.). February 6).asp#emission United States Environmental Protection Agency (2002) Compressed Natural Gas. Retrieved from http://www.consumerenergycenter.

nationalgeographic.Brinson. ( http://naturalgas. How much Air Pollution comes from cars? Retrieved from http://auto. http://burnanenergyjournal.).pdf http://education. How Stuffs .