Sunday, September 27, 2009
While we were eating and chatting, we were also had the news on TV in the background and a story caught my attention.
There was a protest going on about the use of diesel locomotives on a rail link between Toronto and the city's airport. The protesters weren't protesting about the new commuter transport facility. They were protesting the use of diesel locomotives, suggesting that electric locomotives might be better for our health.
A noble but misguided thought!
While I'm not a particular fan of fossil fuels, it stuck me, as it has many times before, that protesters are often ill informed, no matter how well intentioned.
Where do these people think electricity comes from?
Most of the electricity in North America is generated by fossil fuels, coal being the predominant source.
Although coal powered generating stations are being phased out in Ontario and other jurisdictions, coal will still account for most of the power generation across North America in the coming years.
Which is the healthier choice, a fossil powered generating station or a few diesel powered locomotives? I don't know the correct answer to that, but I'm pretty sure the power station is the less healthy choice, however until I know the specifics, I'm not going to be lead by the nose.
I think protesters should know the answer to that kind of question. But in my experience most protesters are light on specifics, using emotional arguments to sway public opinion.
Sadly many good projects are prevented from moving forward because emotional arguments have stirred up public opinion against them and we the public don't generally investigate the merits of these arguments to decide who is right. See my post covering the differences between incineration and gasification.
Just because most of us are removed from the source of production, doesn't make electricity as it is produced today, a clean source. Power stations today belch millions of tons of CO2 into the atmosphere every day. Why is electricity produced this way preferable to fossil powered locomotives?
Despite our efforts to generate electricity from clean sources like solar and wind, these two sources will account for less than 10% of our power needs for the foreseeable future.
Protesters; by all means let your feelings be known, but before you do so make sure you are familiar with the facts.
Sunday, September 13, 2009
I tried to explain the difference between incineration and gasification, but she was not having any of it. She told me it was just semantics. Apparently she is a chemist and this gave her superior knowledge about such subjects.
Seeing that I was unable to get her to listen, let me set the record straight about these two issues.
Admittedly there are similarities, but that does not make them the same or the consequences of using them the same.
Incineration is simply burning. Burning requires oxygen either in the air or as a pure feed. When a substance is burnt, it is oxidized. If we burn hydrocarbons like those found in waste we typically get lots of CO2 and some water H2O. Waste is seldom pure and a lot of toxic substances are formed. These toxic substances are released to the atmosphere in smoke if it is not scrubbbed.
I was going to give you my own definition of gasification, but thought an independent 3rd party view might remove any bias that I have. Here's what Wikipedia says:
"Gasification is a process that converts carbonaceous materials, such as coal, petroleum, biofuel, or biomass, into carbon monoxide and hydrogen by reacting the raw material, such as house waste, or compost at high temperatures with a controlled amount of oxygen and/or steam. The resulting gas mixture is called synthesis gas or syngas and is itself a fuel. Gasification is a method for extracting energy from many different types of organic materials.
The advantage of gasification is that using the syngas is potentially more efficient than direct combustion of the original fuel because it can be combusted at higher temperatures or even in fuel cells, so that the thermodynamic upper limit to the efficiency defined by Carnot's rule is higher or not applicable. Syngas may be burned directly in internal combustion engines, used to produce methanol and hydrogen, or converted via the Fischer-Tropsch process into synthetic fuel. Gasification can also begin with materials that are not otherwise useful fuels, such as biomass or organic waste. In addition, the high-temperature combustion refines out corrosive ash elements such as chloride and potassium, allowing clean gas production from otherwise problematic fuels.
Gasification of fossil fuels is currently widely used on industrial scales to generate electricity. However, almost any type of organic material can be used as the raw material for gasification, such as wood, biomass, or even plastic waste."
Plasma gasification runs at about 5,500 degrees Celsius and immediately breaks everything down to its basic molecular structure. The only residue is an inert vitrified slag which can be used to make aggregate for construction.
You can learn more about gasification with this YouTube video.
As you can see the two processes are quite different and gasification offers a number of distinct advantages over incineration.
It is true that gasification does release some CO2, but that is generally less than what is produced by incineration.
Incineration can be used to create heat and steam for the generation of electricity, but the syngas produced by gasification can be used to make a number of value added commodities including liquid fuels like green diesel and ethanol.
Friday, September 4, 2009
Everyday the argument continues and the so called evidence mounts each day for both sides of the argument.
I personally believe that oil is finite and that we've probably reached peak production, but there are a lot of voices from people more qualified than me that might disagree. The announcement last week of BP's deep discovery in the Gulf of Mexico is being used by some to support the theory that there's lots more oil and that modern technology will help us find it and extract it.
That may be true, but as the cost of finding and extracting oil climbs the search for alternatives grows. The problem is that many of the alternatives are not really viable today. Either they cost considerably more than oil, or they are not really scalable and so while contributing to the pool, do little to change the situation.
North America consumes about 8.16 billion barrels of oil per year. Biomass is often touted as the solution. There are about 1.3 billion tons of biomass available in the US to be turned into fuels. Canada probably has more, but i could not find the numbers i needed to confirm this. The problem with Canada is that most of the biomass is in remote areas and the costs of transport and harvesting make it unattractive at the present time.
The truth about biomass everywhere, is that it is expensive to grow, harvest and transport to fuels production facilities. I'm not saying biomass cant work, merely that there are large problems to which we have not found answers. If all of this biomass was converted to liquid fuels, I've estimated we'd create no more than 34% of the fuel needed for North America.
On the other hand waste presents a very interesting set of numbers.
*Municipal solid waste contains about 8000 BTU per pound.
*Each barrel of oil contains about 5.8 million BTUs.
*Each ton of waste converts to 2.7 barrels of liquid fuels
*We dump about a billion tons of waste into landfill each year
This means, using existing technology that we know works, we could produce 2.7 billion barrels of fuel from the MSW we produce and currently spend about $80 billion a year to dump in holes in the ground.
The beauty of converting waste to liquid fuels is that we kill two birds with one stone; we reduce our dependence on landfill and solve a number of the problems that go along with it like the escape of methane into the atmosphere, the leachate that seeps into our ground water and the odors that affect all who are close by.
However more importantly if we were to convert all of this waste we could produce about 37% of North America's fuel needs from a widely distributed energy resource. We go a long way to reducing our dependence on foreign oil and we produce a fuel that is one of the greenest on the planet.
It is unlikely that in the short term there will be the capital available to convert all of our hydrocarbon waste to fuels, but if the governments of the world want to create green jobs, this technology would be a good place to put money.
Fischer Tropsch fuels contain no sulfur, no particulates, no nitrous compounds and no aromatics. Their life cycle greenhouse gases are among the lowest of all fuels and their is a huge carbon offset from the waste diverted from landfill.
What's also important is that these fuels can be produced today, with virtually no technology risk. This technology has been around for over 80 years but only operating at very large scale. With second generation advances it is now possible to build economically viable small scale plants that would provide waste handling solutions to the more than 336 cities around the world with more than 1,000,000 people.
I recently returned from Cleantech Boston where there was much talk of waste to energy, but most were talking about using waste to generate electricity. There's no doubt that this approach works, but it is low value add when compared with fuels. More about this in a later blog.