In the vein of using Buffalo chips as fuel to cook your dinner while treking along the Oregon Trail, what things that are now going into land fills and hazardous waste disposal sites, would you be willing to use in incinerators as a heat source to fire Steam turbine generator site?
Used tires?
Newspapers?
Old furniture?
Industrial Waste chemicals?
Sewer sludge?
Let’s not do anything. We don’t really have an immediate problems with energy supplies per se.
If you want to be forward thinking, it would be a good time to start building nuclear plants. We can fuel them with environmentalists. Well, maybe not (not too radioactive).
I am an expert on this, and can probably give you some answers, but I’m not quite sure if I understand your question. Can you clarify it a bit perhaps?
Not to put words into the OP’s mouth, but I took it to mean “is there anything we’re throwing out that we should be using as an energy source on a consistant basis”. And now I’ve gotten curious. Enlightenment, please, Anthracite. BTW, is it true we’re gonna be using fuel cells for cell phones and computers before we use them for cars and homes?
Exactlly Q.t.M! What is it that we now discard with nearly reckless abandon, that we could be using to produce a useful energy such as Electricity?
Yes Ms. Anthracite, enlightenment please!
This is a complex question. The short answer is sure, there are a lot of things we throw away that can be burned for energy. But several things prevent this from happening.
The main reason more of these so-called “opportunity fuels” are not utilized is due to air pollution legislation. Overall, although environmentalists would never admit it, coal, gas, and oil are pretty benign substances to burn. They produce emissions that are realtively easy to control, and are not normally anything really seriously hazardous, unpleasant, or troublesome. When one gets into burning industrial waste, animal waste, plastics, tires, diapers, etc. you start to run into a whole host of potential compounds that can be emitted. Heavy metals can be very problematic in industrial and municipal waste. Burning plastics can emit all sorts of unpleasant aromatic comounds which require additional emissions controls to keep the neighbors happy.
Some of these opportunity fuels require processing to burn properly. For an example of some of the pitfalls and benefits of burning tires, see my last post in this thread,
Energy from waste coal?. Biomass fuels, including sewage sludge, require extensive processing at times. Municipal waste can require significant sorting and classification before combustion is possible.
Another factor to consider is supply - how much of the opportunity fuel is available. For example, waste cardboard boxes may be a good thing to think of burning. But where do you get a concentrated source of the fuel? Even if you are looking at tires, wood scrap, newsprint - a power plant that produces any significant amount of power needs a lot of fuel that is readily and consistantly available. To produce enough power to supply 250,000 residential homes you may need a continuous feed of as much as 85-100 tons per hour of processed tires. Or perhaps 300 tons per hour of dry newsprint. Or 500 tons per hour of sewage sludge. That’s a lot of fuel to power a small city. Landfill methane gas is another good example - a great way to make some power for nearly free, but there just isn’t enough quantity available to make a significant dent in the power problem. (for some more info on landfill methane and its issues, see my post in this thread, Energy Question for Anthracite).
And of course, there is the political and social impact involved. People simply do not want waste burning plants near their houses, in their cities, or sometimes anywhere at all. Tell the populace that you are building an 80 MW plant that runs off of hog farm sludge, and see how many death threats you get in a 24-hour period. The main way in which these opportunity fuels are used is by the producer themselves (such as ADM using corn and grain waste to heat and power their plants in Decatur - and yes, I know they also have a 200 MW coal plant on site as well), or by coal plants that are blending in these waste fuels at ratios from 1% - 20% of their heat input. This is the only real way that it is being used here. In other countries, you can find many plants that run off of opportunity fuels. Sugar cane waste, or bagasse, is a great source of energy and is used for power generation in such areas as the Caribbean and Madagascar. Danish plants are burning high levels of straw from their marshlands. A German plant or two is firing dried sewage sludge.
Hundreds of things have been considered for use as opportunity fuels. Ones I have seen used or know have been used in real life include:
Tires and tire-derived fuel
Municipal waste and residential waste
Dried sewage slude
Petroleum coke
Oil refinery sludge (BACA)
Sawdust
Particle board chips
Black liquor
Bagasse
Railroad ties and old wooden electrical poles
Automobile plastic waste (bumpers, interior parts, etc - called “fluff”)
Diapers (no, I am not joking)
Olive stones
Coconut oil
Alfalfa stems
Rice hulls
and many, many other biomass sources (miscanthus straw, switchgrass, hybrid willows and poplars) too numerous to count.
If you are interested in any one particular fuel, I can be much more specific on problems and potentials. But this field is very wide - too wide to provide specifics on everything.
My best guess is that it’s going to take a lot to get that first product to market. So much in fact that I am uncertain if that will be the case. I rather think cars will be the first use of fuel cells. But I am not an expert on these items.
I got an idea for an “alternative fuel” last night cutting the grass.
See, when you feed a cow, the bacteria in its gut makes a lot of methane as it breaks down the fodder. So we could take all the grass clippings from suburban lawns and feed them to cows and collect the methane for fuel. Pure genius.
But we don’t need the cows. Just a big tank full of the “fart bacteria” that we could dump the grass into. That way we don’t have to hook the cow up to a “recovery device” for the gas. (Like the hoses they hook your car up to when they work on them in a garage. Only different)
That’s when I started having trouble with the valve thingy in the fuel line and the lawn mower kept choking out. By the time I got that fixed, my cow thought was de-railed. By then I was thinking of the Garter Snake Mating Balls in Canada. (We have Garter Snakes in the backyard and the mower was Cluster Fu… Charlie Foxtrotted…it was a natural progression at the time)
Not really pertinent to the OP, but it kinda relates. “Fuels from waste” and all. Don’t bother telling me how un-workable the plan is. My mind tends to wander when I have to cut the grass.