Cheap coal: This demonstration plant in Wilsonville, AL, uses a transport gasifier to turn two tons of cheap, low-quality coal per hour into a clean-burning gas. A plant based on similar technology is scheduled for China.
KBR
A novel gasification process for low-quality coal heads to China.
The industrial boomtown of Dongguan in southeast China's Pearl River Delta could soon host one of the country's most sophisticated power plants, one that uses an unconventional coal-gasification technology to make the dirtiest coal behave like clean-burning natural gas. Its developers, Atlanta-based utility Southern Company and Houston-based engineering firm KBR, announced the licensing deal with Dongguan Power and Chemical Company this month.
Dongguan Power plans to implement the gasification scheme at an existing 120-megawatt natural-gas-fired power plant, turning it into an integrated gasification combined cycle (IGCC) plant that uses cheap, moisture-laden lignite coal. The retrofit should be operating in 2011. That will provide its developers with a demonstration to determine whether technology will work in larger IGCC plants and whether it is a process suitable to integrate carbon capture and storage technology, according to John Thompson, director of the Coal Transition Program for the Clean Air Task Force, a nonprofit environmental consulting firm based in Boston. "They want to show that this works," says Thompson.
Southern and KBR's gasification design can use dirty coal because, compared to other gasification reactors, it uses a relatively slow, low-temperature process. Conventional gasifiers, such as General Electric's and Shell's, rely on temperatures around 1,500 ºC to turn finely ground coal into a combustible mixture of carbon monoxide and hydrogen known as syngas. Unfortunately, such temperatures melt ash and other mineral contaminants in the coal, forming a glassy slag that eventually eats through the ceramic tiles that protect the reactors' steel walls. Even reactors using high-quality coal have to be taken out of service for installation of new tiles at least every three years. They are thus ill-adapted for lower-quality coals that would produce several times more slag.
Dongguan's gasifier will sidestep those issues by operating at just 925 ºC to 980 ºC, below the contaminant melting temperature, explains Randall Rush, Southern Company's general manager for gasification systems. Coal nevertheless gasifies completely at these lower temperatures because it spends twice as long in Southern and KBR's process.
The technology is an adaptation of the fluidized catalytic cracking employed in refineries since the 1940s, which processes petroleum by "transporting" it around a loop along with solid catalyst particles. In the gasification reactor, the incoming feed of fresh coal is transported with a looping flow of solid coal contaminants, primarily ash. The hot mass drives off most of the coal's energy content as syngas. The solids left over simply join the flow.
Southern and KBR began designing the technology in 1988 and, with support from the U.S. Department of Energy, started up a demonstration reactor at Wilsonville, AL, in 1996 that can gasify two tons of coal per hour. Four years ago they redesigned it, incorporating what they'd learned at Wilsonville. Rush says the result will be a comparatively reliable and affordable IGCC design. In the absence of slag, a reactor's ceramic lining should last 10 to 20 years, says Rush.
The technology is attractive to Dongguan Power because it can use coal that is cheaper and less desirable. Presentations by the firm note that a doubling in fuel costs between 2004 and 2006 eliminated the company's profit margin. And while Dongguan Power initially commissioned a reactor from the Chinese Academy of Sciences' Institute of Engineering Thermophysics, which built a demonstration-scale transport gasifier last year, the firm has now opted for KBR and Southern's design.
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Eli, you had me until your last paragraph. I'm no fan of coal, but the transport of synthetic fuels to fueling stations all over the country is much less efficient than pushing electricity over transmission lines to electric vehicles. (granted, they are still a futuristic item). The habit of transporting tons of liquid fuel to our vehicles via fueling stations is rarely sustainable even if said liquid approaches a neutral footprint.
Sufficient transition to/expansion of nuclear and wind power will take many years/decades. Without a stopgap of cleaner coal, is the transition to wind and nuclear economically viable (it is certainly not palatable)? Meanwhile, let's not add more momentum to the fuel transport industry by shipping synfuel all over the country.
I am with you all the way on evaluating the full-life cycle costs.
I agree on the fact that liquid fuels have several drawbacks, but with current technology I fail to see any reasonable alternative to susbtitute them. This is mainly for two facts: 1) they have higher energy density than any current or conceivable battery or other means for storing electricity and 2) they are liquid at room temperature, thus they can be transported and stored in a relatively safe and convenient way (see this Wikipedia graph). By comparison, hydrogen has a much a higher energy per mass unit (yet lower per volume unit) than most liquid fuels, but is much more difficult and hazardous to store.
In truth, one must account for the fact that an electric motor has a higher efficiency than any thermal (fuel burning) engine due to the laws of thermodynamics (Carnot's principle), thus electric motors are much more efficient in using the energy of batteries (they can even be used for regenerative braking).
Transportation is not just about urban cars. For this purpose you can use an electric vehicle (with several shortcomings), but for other uses there is just no alternative to known liquid fuels now and in the foreseeable future. Could you ever imagine a truck or a Jumbo going on batteries?
Might want to checkout www.hybridpwr.com
Hybrid marriage of coal gasification, combined-cycle and nuclear gas reactor technologies that drastically reduces greenhouse gas emissions without any particular need for sequestrating of CO2.
Carbon sequestration is a bad idea
I think carbon dioxide sequestration is a bad idea. If all carbon dioxide currently released into the atmosphere by humanity were sequestered, the oxygen in the air would last for less than 200,000 years; the calculation for this can be easily performed by the data given at http://en.wikipedia.org/wiki/Carbon_dioxide_in_the_Earth%27s_atmosphere. Using up just 1/20th of the oxygen would probably cause serious trouble for humanity, and this would take less than 10,000 years. Currently, whatever carbon dioxide is released is at least partly recycled by plants into oxygen.
But then again, there is no future in oil, nuclear, hydro-electric, geothermal, wind, solar, tidal, and other forms of energy production either. Why? Because a new, unlimited and clean energy source will soon appear on the world stage. Here is why:
A reevaluation of our understanding of the causality of motion leads to the inevitable conclusion that we are immersed in an immense lattice of energetic particles. This realization will unleash an age of bountiful energy and extremely fast transportation. Soon, we’ll have vehicles that will go almost anywhere at tremendous speeds, negotiate right angle turns without slowing down and without incurring any damage as a result of inertial effects. Floating cities, earth to Mars in hours, New York to Beijing in minutes. That's the future of energy and travel.
You don't understand motion even if you think you do:
http://rebelscience.blogspot.com/2009/09/physics-problem-with-motion-part-i.html
Coal as an energy source will not be around in 10 years. We will all be using totally green energy sources that are virtually free.
It is definitely encouraging that the coal power plants are being retrofitted with some sort of scrubbing technology. However, what would be really interesting is to have large scale production of biomethane (natural gas via anerobic digestion of wastes and energy crops). That would not only help reduce landfills, but also, avoid issues associated with coal mining!
...just like "peacetime" nuclear power or rocketry. They were born out of a war-mongering era, and the "fruit" of it is still waging war on the environment.
A parasite is able to stay alive because it changes its form to adapt to its host, so as to remain undetected. (enter "Operation Paper Clip")
It is all about the love of money, and the desire for control over others, that keeps it alive.
The answer is to be found, not in some exotic "free energy" system, that keeps the masses hooked into some centralized source. And mainly this is just for their basic survival needs of daily having food, water, shelter and clothing.
Isn't this what it's really all about? To empower the individual with already tried-and-tested WIND and SOLAR technology...to live simply, so that others may simply live?
Not some promise of a "pie in the sky" perpetuating 'pipe dream' of some exotic, high-tech "free energy" gizmo, that's supposedly coming down the pike to us at some "future date". How often have we heard that one before?
And even if it IS true this time around, what is the point? To continue on in our bland, "free energy"-run day-to-day, narcissistic automaton-way of existence? Is the goal to maintain the atmosphere of "business as usual"?
Or, is the true aim of coming here to planet Earth, to become eligible to eventually be called OUT of this age of death and horrors, and back into the eternal age, where we originally came from. The point being that we will have been greatly enhanced by the entire process?
A cosmic "Wizard of Oz", no less!
I say "back", because we have really forgotten that this is truly one heck of a bad dream, that we ALL desperately need to awaken from!
And we are presently doing this, one-by-one, people are being called out of this vegetable universe. And there is no one who will fail.
We've either played a part, or we have yet to play a part. I believe that where we originally came from can be likened to the difference between a shadow, to that of the actual item.
And how do I believe that ascension this lifetime could be accomplished? By simply taking on the qualities said about the patternman JESUS! One day, everything said of him will be said of each one of us. And no one can fail. Not even Hitler.
There's nothing wrong with anyone, that a little restoration to a brand-new body, in another terrestrial world won't take care of!
Yea, I know, you're probably now thinking that I'm some kind of religious nut.
Yet, no matter how many band-aid "free energy" fixes that we think can be made on this miscarriage called 'modern industrialism', keep in mind that the most important life accomplishment that one can make, is to "set the captives free".
There are many examples of already-working "free energy" devices, (solar and wind) that empower the individual to do it all by themselves.
Why not work on promoting the obvious solutions that are already offered for this 'synthetic' problem?
Do this instead of 'beating the dead horse' of some supposed new-and-improved "clean coal" technique!
Isn't it better to light a candle, than to keep stumbling around in the cave of educated darkness?
http://www.huffingtonpost.com/josh-dorner/brian-williams-clean-coal_b_144764.html
Burning coal will unavoidably produce CO2 so there is no such thing as "clean coal".
Yet 50% of US electricity is produced with coal and alternatives to replace it are maybe 20 years ahead not necessarily due lack of technology but because of the huge amount of new construction needed.
For intermediate solution to reduce emissions and buying more time I propose modifying existing conventional stations to hybrid geothermal-coal power stations. EGS`s that provide energy to heat processed water going to boilers are first step and ones that provide high enough temperature to actually make steam are second step. A lot more work needs to be done to make this technology a reality. The DOE got 350 million in May to advance geothermal projects. Since the coal burning stations ones who could profit from this tech they should pitch in financially and by providing pilot plants.
Hybrid geothermal-coal power stations have huge potential in reducing CO2 emissions so the matter should not be overlooked.
the US has really focuseed on mining and burning clean coal. Same with oil. If you have ever heard the term "light, sweet crude" used in describing oil it refers to the cleanest grade of oil, which is what the US and most developed nations prefer. The problem is that the crap still has to go somewhere so it goes to developing nations. This helps our local air quality but does nothing for the global problem.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
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eliraul
4 Comments
A future for coal?
One should assess the environmental footprint of coal looking at the fuel cycle as a whole, not only at the fact of having a more or less "clean" powerplant to burn it.
Coal mining alone is very aggressive for the environment, using such destructive techniques as the Mountain top removal.
A conventional (not supercritical, no CO2 capture) 1 Gigawatt pulverized coal plant (same power as a medium nuclear plant for today's standards) burns 416 metric tons of coal per hour and generates more than 127 metric tons per hour of solid and liquid wastes (see the MIT report The Future of Coal , Appendix 3.B).
From the same source we learn that a 1 GW IGCC plant would consume 370 metric tons of coal per hour, mainly because a combined cycle has higher efficiency than a single stage Rankine (steam turbine) cycle. It would also generate 55 metric tons of wastes. These are better figures, but the cost of an IGCC plant is much higher than that of a conventional plant.
In my opinion is a nonsense to burn coal in order to produce electric energy when one can obtain it from other sources (i.e. nuclear and renewables); I believe it is much wiser to keep coal as a raw material for making synthetic gasoline and other fuels (via gasification and Fischer-Tropsch or similar process) when fossil fuels will be exhausted.
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rbernie
1 Comment
Re: A future for coal?
I agree the long term goal should be zero emission energy but we are not there yet and countries who do have a lot of coal or tar sands are going to be inclined to use it and sell it. There is technology now in Australia from IgniteEnergy that turns lignite into oil and black coal which brings the CO2 emissions down 60% less than current two step methods. This means that you can burn brown coal with the same level as natural gas, plus the biomass technology can burn algae and water and organic fertiliser is provided.
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