Science in the World
Floating in the Air with Naturl Gases
Introduction to Natural Gases
People use natural gas for heating, electrical power, and other purposes. Natural gas produces much less pollution than petroleum, so some people believe it could be an ideal substitute for petroleum and coal in the future. Natural gas is a gaseous hydrocarbon. It is colorless, odorless, and lighter than air. Natural gas is made up of 75 percent methane, 15 percent ethane, and small amounts of other hydrocarbons such as propane and butane.
Advantages and Disadvantages
1. It burns cleanly, producing no by-products except for carbon dioxide and water, so it does not cause the same degree of air pollution as the other fossil fuels.
2. Natural gas cars have no trouble meeting environmental standards because of their low emissions.
3. Natural gas is very safe for the environment; it does not pollute groundwater.
4. If power plants switch to the use of natural gas during summer when demand for natural gas is lowest and smog is highest, they could emit fewer pollutants and improve air quality.
5. Using natural gas instead of other fossil fuels could reduce acid rain and particulate emissions.
6. Natural gas produces 30 percent less carbon dioxide than burning petroleum and 45 percent less carbon dioxide than burning coal to produce the same amount of heat energy.
7. Electrical power plants fueled by natural gas produce far fewer emissions than coal-powered plants.
8. Burning natural gas does not contribute significantly to the formation of smog.
1. Burning natural gas emits carbon dioxide, which is considered a greenhouse gas that contributes to climate change, particularly global warming.
2. Car manufacturers will have to decide that it is cost-effective for them to build natural gas vehicles because consumers will not buy natural gas vehicles until they are convinced that it will be convenient, safe, and inexpensive for them to buy natural gas as fuel.
Article 1: Natural Gas Waits For Its Moment
CARS and trucks powered by natural gas make up a significant portion of the vehicle fleet in many parts of the world. Iran has more than two million natural gas vehicles on the road. As of 2009, Argentina had more than 1.8 million in operation and almost 2,000 natural gas filling stations. Brazil was not far behind. Italy and Germany have substantial natural gas vehicle fleets. Is America next?
With natural gas in plentiful supply at bargain prices in the United States, issues that have limited its use in cars are being rethought, and its market share could increase, perhaps substantially.
According to Energy Department price information from July, natural gas offers economic advantages over gasoline and diesel fuels. If a gasoline-engine vehicle can take you 40 miles on one gallon, the same vehicle running on compressed natural gas can do it for about $1.50 less at today's prices. To that savings add lower maintenance costs. A study of New York City cabs running on natural gas found that oil changes need not be as frequent because of the clean burn of the fuel, and exhaust-system parts last longer because natural gas is less corrosive than other fuels.
Today, those economic benefits are nullified by the initial cost of a natural gas vehicle -- 20 to 30 percent more than a comparable gasoline-engine vehicle. But were production to increase significantly, economies of scale would bring prices down. In an interview by phone, Jon Coleman, fleet sustainability manager at the Ford Motor Company, said that given sufficient volume, the selling price of natural gas vehicles could be comparable to that of conventional vehicles.
It may be years before the economic benefits of natural gas vehicles can be realized, but the environmental benefits appear to be immediate. According to the Energy Department's website, natural gas vehicles have smaller carbon footprints than gasoline or diesel automobiles, even when taking into account the natural gas production process, which releases carbon-rich methane into the atmosphere. Mercedes-Benz says its E200, which can run on either gasoline or natural gas, emits 20 percent less carbon on compressed natural gas than it does on gasoline.
Article 2: Should the US Use Hydraulic Fracturing (Fracking) to Extract Natural Gas?
The US Department of Energy (DOE) wrote in its Aug. 18, 2011 report "Shale Gas Production Subcommittee 90-Day Report" on shalegas.energy.gov:
"Natural gas is a cornerstone of the U.S. economy, providing a quarter of the country’s total energy. Owing to breakthroughs in technology, production from shale formations has gone from a negligible amount just a few years ago to being almost 30 percent of total U.S. natural gas production. This has brought lower prices, domestic jobs, and the prospect of enhanced national security due to the potential of substantial production growth. But the growth has also brought questions about whether both current and future production can be done in an environmentally sound fashion that meets the needs of public trust.
As with all energy use, shale gas must be produced in a manner that prevents, minimizes and mitigates environmental damage and the risk of accidents and protects public health and safety. Public concern and debate about the production of shale gas has grown as shale gas output has expanded.
The Subcommittee identifies four major areas of concern: (1) Possible pollution of drinking water from methane and chemicals used in fracturing fluids; (2) Air pollution; (3) Community disruption during shale gas production; and (4) Cumulative adverse impacts that intensive shale production can have on communities and ecosystems.
There are serious environmental impacts underlying these concerns and these adverse environmental impacts need to be prevented, reduced and, where possible, eliminated as soon as possible. Absent effective control, public opposition will grow, thus putting continued production at risk. Moreover, with anticipated increase in U.S. hydraulically fractured wells, if effective environmental action is not taken today, the potential environmental consequences will grow to a point that the country will be faced a more serious problem. Effective action requires both strong regulation and a shale gas industry in which all participating companies are committed to continuous improvement.
The rapid expansion of production and rapid change in technology and field practice requires federal and state agencies to adapt and evolve their regulations. Industry’s pursuit of more efficient operations often has environmental as well as economic benefits, including waste minimization, greater gas recovery, less water usage, and a reduced operating footprint. So there are many reasons to be optimistic that continuous improvement of shale gas production in reducing existing and potential undesirable impacts can be a cooperative effort among the public, companies in the industry, and regulators."
Aug. 18, 2011 - United States Department of Energy (DOE)