Monday, August 17, 2009

What the Big Waste Companies Dont Want You To Know About Landfill?

I don't know anyone who thinks landfill is a good idea, yet it is one of the most widely used ways of disposing of waste. Every city in the world seems to have one. I'm sure there are a few places that don't and would definitely be interested to find out where these cities are and what they do instead.

Yet despite this common dislike, very few people understand the perils beyond; "They stink!" or "I don't want to live near one!". They don't want to live near one, probably because they stink and maybe because of all the trucks taking garbage to the dump.

Most of the big companies that operate them definitely don't want the public to know the problems associated with them. Some of them are multi-billion dollar corporations and their business models would be irreparably damaged if they were not allowed to landfill, which is what would happen if people really understood the truth about landfills. However some of the more enlightened ones are looking at alternatives. Most of the alternatives involve incineration and using the heat to drive turbines to generate electricity. Incineration has its own set of problems and destroys the resource molecules so they are lost forever.

The first thing you should know is that even where there is rigorous recycling, more than 30% of what we throw out ends up in landfill. More likely its closer to 60%. These numbers rise when commodity prices are low, like now, and it becomes too costly to recycle much of what is collected.

All cities could do a better job of recycling, but we need to change their paradigm about recycling and what it is. See my blog What is Recycling at the Molecular Level? This way resource molecules can be reused many times over.

The reason why landfill smells is largely because of the bacteria in waste that cause decomposition. We all know what rotting food smells like and its only one of the components. These smells are carried into the air with the gas that escapes from landfill. This decomposition is slowed by the lack of oxygen in the landfill and it results in a combination of biological processes, physical processes and chemical process that may take more than 150 years to break down all the materials in a landfill. Until that happens gas builds up and leaks out of even the best managed landfills.

There is a lot of talk these days and some action around tapping landfills for the methane gas they produce. The idea is to capture it and use it to produce electricity or to use as a natural gas substitute. This definitely works, but is one of those ideas that work better in theory than in practice. Landfills by their nature are not completely gas tight, so as much as 50% of the methane produced simply escapes into the atmosphere. This is a big problem if you are a believer in the climate changing effects of green house gases (GHG)from landfill. Methane is 21 times more powerful than CO2 as a GHG. Methane is light and rapidly dissipates into the atmosphere.

Municipal waste is the most non-homogeneous substance known to man. The problem is that we throw anything undesirable into the garbage. Apart from plastic, paper glass and metals, we throw rotting food, dirty diapers, dog poop, soiled tampons, paper towel used to clear up everything from gravy spills to vomit etc. I could go on, but you get the point.

Much of this stuff is laden with bacteria. The bacteria spreads and grows in the warm moist environment,further breaking down whatever it can thrive on. This in turn generates liquids, some of which can be very toxic and they can leak out as leachate. Leachate can contaminate the ground water and must be monitored on a very regular basis with wells in the nearby country side. We've got better at preventing ground water contamination, but why take the chance.

In some countries landfill fires are a problem. These fires fill the air with toxic smoke and the ash may also mix with the leachate, causing further problems if it is toxic. This doesn't often happen in North America, but it doesn't mean it cant.

We need to begin to push back against new landfills and embrace emerging technologies that offer the promise of zero landfill. The big companies that operate landfills make a fortune from this archaic and unpleasant practice and it is not in their best interests to change their business model.

Monday, August 3, 2009

Checklist for Alternative Fuel Viability

I was at a party last night and at one time the discussion topic was the next big breakthrough in alternative fuels to power vehicles. One young woman was excitedly extolling the virtues of the "Hydrogen Economy" and bio fuels. One or two others at the party were convinced that the future lies in electric cars, forgetting that today most electricity is generated using fossil sources.

I personally doubt that any single approach is going to save us from the problems of a diminishing oil supply and the concurrent rise in oil prices. I believe there are a number of viable alternatives and we need to consider them all. The problem is that many will prove not to be viable in the long run.

We also need to remember that fuels that are fine for cars may not be suitable for trucks and aviation. Ethanol and methanol may be suitable for cars, but have not found a place in trucking or aviation.

The question is; What criteria determine if a fuel will be a viable alternative?

I believe that in order to succeed a fuel must offer positive answers to the following 8 questions:

1. Is it sustainable?

How long will supply last? There are a number of fuels that can be considered, but many are in short supply. Bio-diesel is a prime example, there just isn't enough to supply all the demand for diesel. Biomass; crops that have to be grown and converted to liquid fuels are less sustainable because although it's theoretically possible to have an unlimited supply, practical reasons like space and soil productivity suggest this may not be the case over the long term.

Right now solar, wind, hydro-electricity, geothermal and garbage look like they are truly sustainable and to all intents and purposes unlimited, but most of these are not suitable for powering vehicles and planes.

2. Can it be produced in sufficient volume?

The volume of liquid fuels consumed is enormous at close to 100 million barrels per day during peak demand periods. It has been estimated that if every acre of arable land in the USA was converted to growing corn for fuel and not one ear of corn was used for food, we'd probably only be able to provide about 10% of the US's liquid fuels, so bio fuels are unlikely to be the long term solution, but may well provide part of the answer.
With regard to waste, my own estimates show that we dump enough raw material into our landfills each year to produce nearly a billion barrels of oil.The capital costs of doing this may prove challenging, but this solution is viable.

3. Can it be utilized with existing infrastructure?

To change the infrastructure to accommodate a new fuel is incredibly expensive. Imagine the costs of changing all of the engines in all of the vehicles on the road, updating fueling stations and transport systems to get it to the fueling station and the cost of changing support systems to support and entirely new type of fuel system. If this ever happens, it will happen gradually, probably over 20-30 years or more, otherwise it is unlikely to be affordable even to countries as rich as the US and Canada.
What is more likely is a fuel that can be used in all parts of the existing infrastructure with no or minimal cost. Fischer Tropsch fuels are attractive for that reason as they are chemically identical to fossil fuels and because they are so much cleaner burning.

4 Are the environmentally sound?

Today the watchword is green. If a fuel isn't green, its unlikely to pass the smell test.The question what is "green"? Is is something that burns clean? Is it something that has a low GHG profile when all parts of its life cycle are considered? Is it something produced from sustainable sources? All these issues are still unclear, but what is clear, is that the public want fuels that are clean burning, sustainable and reasonably priced.

5. Can it provide a constant supply?

What happens when the wind stops blowing, crops fail or the sun doesn't shine for a few days. At present we don't have commercially viable answers to these problems. The only thing that might stop the supply of garbage for a waste to liquids plant, is a garbage strike like we just had in Toronto or competition for the raw material by other waste to energy businesses.

6. Is it competitively priced?

Oil price is the yardstick by which the price of all alternative fuels are measured. If the cost to produce a fuel is way out of line with the price of oil, people will simply stick with fossil derived fuels. As the price of oil rises, this will make other alternative fuels more attractive, but to truly compete, the cost to produce an alternative fuel needs to be pretty close to that of oil if it is to be competitive with oil.

7.How much energy is used to create the fuel?
In fuel circles there is a term that covers this; its Energy Return on Energy Invested (EROEI.) Simply stated if it takes less than 1 barrel of oil to make one barrel of oil the energy return is positive. If it takes more then it is negative and you go bankrupt. Government incentives help, but no alternative energy should be dependent on them for the long term.
Over the years the EROEI for oil has gradually fallen from an average of 100 barrels produced for every one in inputs, down to 3 for every one of input, but it is still positive. Many peak oil theorists believe that we are not so much running out of oil as we are coming to the point where the EROEI is negative. For a lot of alternative fuels, the EROEI is negative. This is true of cellulosic ethanol and for hydrogen. Because garbage is essentially free it remains an attractive feedstock for waste to liquids projects and the EROEI is positive.

8. Scarce materials
Some alternative energy sources require the use of scarce materials. Lithium for use in batteries may be relatively plentiful now, but if we are successful in producing batteries that can store enough current to sustain longer journeys in electric powered vehicles and the public begins to embrace electric powered cars, how long will it be before the world's lithium supplies become depleted and we enter "Peak Lithium"?

For the above reasons we need to be developing multiple alternatives and over time public opinion and price will determine the winners. As I see it waste to liquids from Fischer Tropsch comes very close to meeting all of these criteria and deserves a close look. There is probably no single solution that will meet all of our liquid fuel needs so let's commit before its too late to finding ones that will work and provide us with the fuels we need for transportation and for the quality of life to which we've become accustomed.