Even though 2015 saw the biggest decline in coal usage around the world on record according to Greenpeace, the use of the material is still thriving globally. In fact, according to the US Energy Information Administration, global coal consumption was at about eight billion short tons in 2012 (around 7.2 billion tonnes), the most recent year for which the agency provides statistics. So if coal isn't going away any time soon, what is there to do about the fuel source that is often blamed for pollution and global warming due to carbon emissions? Make it more efficient. And that's exactly what a new hybrid energy system out of MIT could do.
According to MIT News, conventional coal-burning power plants only convert 30 percent of the energy contained in coal to electricity. That's a pretty low efficiency rate. A new system that combines two existing technologies — coal gasification and fuel cells — could up that rate to between 55 and 60 percent, in effect halving the amount of carbon dioxide produced for producing the same amount of energy using today's methods.
Both of these methods are currently used to create energy in today's world, but stacking them together in one system could be the key to greater efficiency, says MIT doctoral student Katherine Ong and professor Ahmed Ghoniem, who reported their theory in the Journal of Power Sources.
The system would start with coal gassification, a process where coal is crushed to a powder and heated in a flow of hot steam that releases the gases it contains — primarily carbon monoxide and hydrogen.
After those gases are freed, Ong and Ghoniem suggest funneling them through a fuel cell where a membrane splits off the carbon monoxide and hydrogen from oxygen, thus creating electricity. Such fuel cells were announced in 2011 by a team from Geogia Tech. The fuel cell would, in turn, create heat that could generate more steam to continue the gasification process. This would eliminate the need to burn some of the coal to generate the higher temps at which gasification occur.
Because nothing is actually burned in this system, the researchers say that there would be less ash and other pollutants from a plant employing this method which, thus far, has only been tested using computer simulations. And while carbon dioxide would be a byproduct of the process, it wouldn't be mixed with air, as is the case in traditional factories, which would make it easier to capture and sequester.
To test out the real-world application of the hybrid theory, Ong says a small pilot plant should be built which, she adds, could happen relatively quickly. "This system requires no new technologies," she says. "It's just a matter of coupling these existing technologies together well."
Late last year a process that uses algae and the coal dust usually wasted from mining operations to produce burnable bricks was created by researchers at the Nelson Mandela Metropolitan University (NMMU) in South Africa. That process, along with with MIT's hybrid system, could certainly help coal shake off its reputation as a dirty fuel source and help the world get more efficient power from the material for years to come.
Source: MIT News
it is amazing how much green ideology/religion creates a faith in the god of 'renewables' and casts coal as evil satan.
instead of using their rational brains that god gave them, the green faithful simply follow the prayers set out of them.
why is this? let us examine the obvious. the future of a green world is one where the entire electricity grid is used to transport our energy , rather than pipelines and tubes and fuel carrying rail and truck. why? because 1)electricity is efficient to move compared to fuel itself. 2) any revolution in energy STORAGE must utilitze the grid to be efficient at transporting energy from where it is created to where it is stored and to where it is consumed. the complex benefits realized from 'grid batteries' located at production facilities or on your roof, can only be realized through a better funcitoning electricity grid.
THEREFOR. improving the 'low hanging fruit' of the dirtiest energy on the grid will make the GRID itself far more efficient at transporting what is now green electricity.
natural gas is burned so cleanly and efficiently in turbines that it cannot be improved much. solar and wind are great but they are not the be all and end all. they are both relatively clean already and , more importantly , marginal improvements in them don't make a huge difference as they both still only account for a small % of grid electricity produciton.
COAL is super dirty. cleaning up coal and making it more efficient would yield in tremendous gains as it already accounts for 30+% of electricity.
with a more effecitve grid that produces MORE AND CHEAPER ELECTRICITY electric cars and grid powered transportation becomes more attractive to the already dominant petroleum fueled supply network to the transportation network of internal combustion engines on the road. and petroleum is already very cheap. so without increases in aggregate of electricity production , electricity cannot compete with petroleum. a green future relies on cleaner coal. Anyone who would rather sabotage the grid by eliminating coal simply wants to increase electricity prices which guarantee the dominance of petroleum for transportation . which diminishes demand for electricity, which DETRACTING from the possiblity of getting off petroleum in the next 100 years. therefore the grid is our salvation as a means of t
Important to appreciate that coal plants are not efficient uses of capital as you need capacity to meet peak demand even if that demand exists only for a few months during the year or a few hours on a summer day. Same lack of economic efficiency with nuclear power plants which is why every single one requires a $8 billion dollar subsidy by the taxpayers and utility customers.
Solar panels when used with smart string inverters can smooth out fluctuations in the power running over the grid and greatly reduce the odds of a rippling brownout that cascades into a regional or even national blackout. Single large production sources only make the grid more vulnerable to failures of this type.