What is Natural Gas?
Natural gas is a mixture of hydrocarbons, primarily methane which is a relatively unreactive hydrocarbon. Natural gas delivered through the pipeline also contains ethane and propane (hydrocarbons) and other gases (i.e., nitrogen, helium, carbon dioxide, hydrogen sulfide, and water vapor). Natural gas can be produced from gas wells or as a result of crude oil production. Because of the gaseous nature of natural gas, it must be stored onboard a vehicle in either a compressed gaseous state (CNG) or a in a liquefied state (LNG). End users for natural gas include all economic sectors: residential, commercial, industrial, and transportation.
How is Natural Gas Made?
Most natural gas used in the U.S. is domestically produced. Gas streams produced from reservoirs contain natural gas, liquids, and other materials. Processing is required to separate the gas from petroleum liquids and to remove contaminants. In addition, natural gas (methane) can also come from landfill gas and water/sewage treatment.
First, the gas is separated from free liquids such as crude oil, hydrocarbon condensate, water, and entrained solids. The separated gas is further processed to meet specified requirements. For example, natural gas for transmission companies must generally meet certain pipeline quality specifications with respect to water content, hydrocarbon dewpoint, heating value, and hydrogen-sulfide content.
A dehydration plant controls water content; a gas processing plant removes certain hydrocarbon components to hydrocarbon dewpoint specifications; and a gas sweetening plant removes hydrogen sulfide and other sulfur compounds (when present).
Natural Gas Fuel Market
Natural gas is distributed throughout the United States in extensive pipeline systems that extend from the wellhead to the end user. Every continental state has access to natural gas through pipelines. The pipeline system consists of long-distance transmission systems, followed by local distribution systems.
Natural gas vehicles can easily be fueled at public stations or on-site refueling can be built. Individual home compressors use a slow-fill system for overnight refueling. A small compressor would usually be located in a home’s garage area and would be connected directly to the natural gas supply in the house. In heavy-duty applications, the cost of a high capacity fast-fill private or public station could be anywhere from $200K to as much as $3 million.
The future holds great potential for natural gas because it can potentially be used in fuel cell vehicles to make hydrogen. Researchers found that fuel cell vehicles using hydrogen produced from natural gas could present an attractive solution for cutting greenhouse gas emissions.
What are the Benefits of Natural Gas?
Natural gas is one of the cleanest burning alternative fuels available and offers a number of advantages over gasoline. In light-duty applications, air exhaust emissions from natural gas vehicles are much lower than those from gasoline-powered vehicles. In addition, smog-producing gases, such as carbon monoxide and nitrogen oxides, are reduced by more than 90% and 60%, respectively and carbon dioxide, a greenhouse gas, is reduced by 30%-40%.
For heavy-duty and medium-duty applications, natural gas engines have demonstrated more than 90% reduction of CO and particulate matter and more than 50% reduction of NOx relative to commercial diesel engines.
How Do I Convert My Car to Compressed Natural Gas – SAFELY?
As gasoline and diesel prices continue to rise, many people are considering converting their car or light truck to run on compressed natural gas (CNG). But conversion frmo gasoline to CNG should not be done by unqualified technicians, using unapproved conversion kits or unsafe high-pressure gas cylinders.
Please download the NGVAmerica and Clean Vehicle Education Foundation press release discussing safe conversion of vehicles to compressed natural gas.
The information above was obtained from the Alternative Fuels Data Center, which is a great technical resource on all alternative fuels and vehicles. Source link: http://www.eere.energy.gov/afdc/altfuel/natural_gas.html.
Current Clean Cities Natural Gas Projects
Brian Daniels, Daimler Trucks North America
John Bono, Navistar
Joseph Annotti, Environmental Protection Agency
Cliff Gladstein, Gladstein, Neandross, and Associates
Arlington County CNG
Virginia Clean Cities awarded Arlington County Public Schools with State Energy Program Special Projects funding to purchase OEM compressed natural gas school buses.
Charlottesville CNG School Bus Project
Funding for Charlottesville Public Schools to purchase 2 CNG school buses was provided by Virginia Clean Cities through a State Energy Program Special Projects award. Funding also allowed for the purchase of a time-fill CNG refueling system manufactured by Fuelmaker which has the capability of refueling four buses simultaneously.
National Airport CNG Transit Bus Project
Virginia Clean Cities provided Ronald Reagan National Airport funding to help defray the incremental cost of purchasing CNG transit buses and purchase the CNG station from Washington Gas on Clark Street in Northern Virginia.
Natural Gas Toolkit
Virginia Clean Cities worked with the East Tennessee Clean Cities Coalition to create the Natural Gas Toolkit http://www.ngtoolkit.net. This toolkit allows you to find and utilize two primary numbers, the fuel price difference and your vehicle cost difference, to calculate a simple payback period. Perhaps more importantly, it helps you get basic pieces of information in one place to prepare for potential funding opportunities in the future. What you need to know is that this is just a starting point for looking at natural gas for your fleet. Clean Cities coalitions, NGVAmerica, and other resources are out there to help you find the other numbers you need, so use the resources page to find those as you need them. Simply go to the “calculator” page and all you need is provided there. An overview of what you will do in the spreadsheet is there, as is a list of the outside information you will need to get payback numbers for your chosen vehicles.