Fossil fuels haven't been winning any popularity contests. A lot of that's because approximately 80 percent of greenhouse gases consist of carbon dioxide that is generated, in part, by burning fossil fuels [source: Gardner]. So today, it's wind, water and solar energy that are all the rage. Keep in mind that alternative energies aren't without their faults, though they're the lesser of the evils for sure. But the fact is that wide-scale use of green power is years away, so fossil fuels are still by far the largest producers of energy in the United States.
The good news is there are new technologies emerging that attempt to handle the mining and processing of fossil fuels in more environmentally friendly ways. From harvesting gases trapped for millions of years in ice cages to cars powered by hydrogen extracted from coal, these non-renewable power sources may yet be able to help address one of the biggest global issues of our day: our rampant consumption of energy. While the ultimate solution to fossil fuel emissions will be to one day reduce our dependence on oil, coal and other fossil fuels, steps are being taken to make those out there a little cleaner.
Read on to learn about five future fossil technologies on the rise.
5. Carbon Capture and Sequestration
The idea of clean coal sounds like an oxymoron because we know the facts. Coal mining destroys mountains and is the leading contributor to global warming [source: Union of Concerned Scientists]. But here's another fact: Coal is cheap and plentiful. And that's where
CCS separates the C02 from the general emissions stream in one of three ways: post-combustion carbon capture, which occurs immediately after fossil fuels are burned; pre-combustion carbon capture, which occurs before fossil fuels are burned; and oxu-fuel combustion carbon capture, which burns oxygen with the fossil fuel before separating the C02.
Now for the second step in CCS: dealing with the leftover toxins. The most basic explanation is that the C02 is compressed and then transported via long pipelines to geologic or oceanic "storage facilities." There, it's injected deep into the Earth, where it remains for years.
CCS reduces the number of toxins being spewed into the atmosphere. As we will see in a bit, hydrogen, a by-product of CCS, can be used as a zero-emissions source of energy. One of the major downsides of CCS is energy consumption. All three processes require a tremendous amount of energy and are extremely expensive.
Up next, we'll take a look at extracting hydrogen from coal.
4. Hydrogen from Coal
Hydrogen is one of the cleanest forms of energy out there. It's efficient, renewable and has zero-emissions. The Department of Energy's National Energy Technology Laboratory (NETYL) is working two technologies, Central Hydrogen Production and Alternate Hydrogen Production, which extract pure hydrogen from gasified coal syngas (synthesis gas). Syngas is a combination of hydrogen, carbon monoxide and carbon dioxide. A chemical process is used to boost its hydrogen content while removing all other components, resulting in a stream of hydrogen.
Central Hydrogen Production is a promising "co-production" technology. The goal is to produce electricity and hydrogen by burning clean syngas in gas turbines, and the byproducts are then converted into pure hydrogen. Central Hydrogen Production is looking toward membrane technologies (microporous, metallic or ceramic) to eliminate steps and reduce costs associated with hydrogen from coal extraction while achieving a hydrogen purity of 99.9 percent [source: NETL].
Alternate Hydrogen Production uses a technology known as Fischer-Tropsch to convert clean syngas to liquid hydrocarbon carries, alcohol or methane that have high concentrations of hydrogen. These products can help address the issues of distributing hydrogen on a large-scale, as they can be transported through our current fuel distribution channels. This addresses a current issue with hydrogen: the need to build new infrastructure to transport it to fueling stations [source: NETL].
Now let's take a look at hydrogen-powered fuel-cell cars that are taking the automobile industry by storm.
3. Fuel-Cell Cars
Fuel-cell vehicles are part of the clean car revolution. Why are they getting so much play in the world of alternative-energy transportation? In a word: hydrogen. Fuel-cell vehicles are propelled by a chemical reaction that is clean as a spring morning on an uninhabited island. And they have zero emissions [source: U.S. Department of Energy].
Fuel-cell cars look like any standard model you might see on the roads. But their inner-workings are a bit out of the ordinary. They contain fuel-cell stacks, where hydrogen gas and oxygen are converted into electricity, which, in turn, sends juice to their electric motors. And who doesn't love electric motors for their efficiency and quiet ride? Fuel-cell cars give themselves a boost with their onboard regenerative braking system, which improves overall efficiency by up to 20 percent. If saving some bucks and driving cleaner isn't enough incentive, here's another reason for parking one of these in your garage: Qualified fuel-cell vehicles, which are those powered by one or more fuel-cells converting hydrogen to electricity, receive a tax credit from the IRS [source: IRS].
As with any new technology, though, fuel-cell cars aren't perfect. They're expensive because very few are produced, and most of the country's hydrogen fueling stations are in California. That said, fuel-cell cars hold great potential for the future of clean transportation. Look for them on a road near you.
Next we'll discuss methane hydrates, a most curious fossil fuel.
2. Methane Hydrates
Methane hydrates are unusual. To the naked eye, they appear to be big chunks of muddy ice, but in reality, what you're looking at is biogenic methane produced by deep-sea bacteria. These methane hydrate chunks are found in gigantic deposits deep in oceans around the world. In fact, it's believed that trillions and trillions of cubic feet of methane hydrates are tucked neatly beneath the ocean's floor. As world consumption of fossil fuels continues to rise -- and deplete existing stores of natural gas and oil -- it's no wonder that methane hydrates are receiving serious attention as a potential source of energy. Figuring out how to tap into methane hydrates safely and sustainably has become a global effort. The United States, India, Korea and Japan have joined forces to form mining research programs.
So what are the drawbacks? First, getting methane hydrates is dangerous work. Some scientists fear mining them will leak methane into the atmosphere, potentially increasing the rate of global warming. Still others believe methane hydrates play a vital role in stabilizing ocean floors. Start drilling and we could create the risk of a landslide on the continental slope. Another huge factor is cost, not to mention current technologies are limited and make extraction financially impractical. Significant research remains to be done to see if methane hydrates are even an option. If they prove to be stable and sustainable, they could be a solid alternative to natural gas and oil.
Finally, let's take a look at natural gas, the fossil fuel often billed as the clean alternative to oil.
1. Natural Gas Vehicles
Natural gas vehicles (NGV) are emerging on the green transportation scene. As of 2010, in fact, there were an estimated 11 million NGVs on the road [source: Nijboer]. NGVs aren't so different than cars that run on gasoline; the difference is in how the engine works. Natural gas is mixed with oxygen and then ignited with a spark plug that moves the piston up and down. NGVs are efficient and clean, and also less costly to drive, and gassing them up is convenient. Currently, there are more natural gas fueling stations than there are hydrogen cars, and NGV owners can even tap into their homes' natural gas lines. Plus natural gas burns pretty clean, which means little engine wear, and relatively easy and low-cost maintenance over the long haul.
But, historically the acquisition of natural gas has been a problem. There was a time when the industry relied on explosive seismology to find stores deep within the Earth. The environmental consequences of this type of process go without saying. By-in-large, the seismic vibrator truck has now replaced controlled dynamiting. Injecting low-frequency vibrations under the surface of the Earth, data is collected about the Earth's layers. This field data allows digital landscapes of subsurface areas, and enables more precise predictions of natural gas locations.
Suffice it to say, we have a long way to go on most of these technologies. But the good news is there are new technologies out there. For more information on energy and fossil fuels, check out the links on the following page.
Lots More Information
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- Renewable Energy Puzzles
- Department of Energy. "Hydrogen Production." Oct. 2006. (Dec. 15, 2010) http://www.hydrogen.energy.gov/pdfs/doe_h2_production.pdf
- Gardner, Timothy. "U.S. Carbon Emissions to Rise Next 2 Years-EIA." Jan. 12, 2010. (Dec. 15, 2010) http://www.reuters.com/article/idUSTRE60B4TW20100112
- IRS. "Qualified Fuel-Cell Vehicles." March 31, 2010. (Nov. 17, 2010). http://www.irs.gov/businesses/corporations/article/0,,id=203908,00.html
- Mercer, David. "FutureGen Secures $1 billion in Stimulus Money from Energy Department for Clean-Coal." The Huffington Post. Sep. 28, 2010. (Nov. 17, 2010) http://www.huffingtonpost.com/2010/09/29/futuregen-secures-1-billi_n_743008.html
- NETL. "Technologies: Hydrogen and Clean Fossil Fuels." (Nov. 20, 2010). http://www.netl.doe.gov/technologies/hydrogen_clean_fuels/index.html
- Nijboer, Michael. "The Contribution of Natural Gas Vehicles to Sustainable Transport." International Energy Agency. 2010. (Nov. 19, 2010). http://www.iea.org/papers/2010/natural_gas_vehicles.pdf
- Popular Mechanics. "Methane Hydrates-Energy Source of the Future?" Oct. 1, 2009. (Nov. 18, 2010). http://www.popularmechanics.com/science/environment/2558946
- Shogren, Elizabeth. "Turning Dirty Coal into Clean Energy." April 2006. (Nov. 18, 2010). http://www.npr.org/templates/story/story.php?storyId=5356683
- Union of Concerned Scientists. "How Coal Works." 2009. (Nov. 17, 2010 http://www.ucsusa.org/clean_energy/coalvswind/brief_coal.html
- U.S. Department of Energy. "Carbon Capture and Storage R&D Overview." Aug. 23, 2010. (Nov. 20, 2010) http://fossil.energy.gov/sequestration/overview.html
- U.S. Department of Energy. "Fuel Cell Vehicles." Nov. 19, 2010. (Nov. 19, 2010) http://www.fueleconomy.gov/feg/fuelcell.shtml
- U.S. Department of Energy. "Methane Hydrates." 2000. (Nov. 17, 2010). http://www.ornl.gov/info/reporter/no16/methane.htm
- U.S. Department of Energy. "Natural Gas." (Nov. 18, 2010). http://www.energy.gov/energysources/naturalgas.htm
- Walton, Marsha. "Algae: 'The Ultimate in Renewable Energy." CNN. April 1, 2008. (Nov. 18, 2010 http://articles.cnn.com/2008-04-01/tech/algae.oil_1_algae-research-fossil-fuels-nrel?_s=PM:TECH