We must find alternatives to carbon-based fuels

Todd Whitcombe

As I See It

In the "Upside of Down," Thomas Homer-Dixon points out that at the height of construction of the Roman Coliseum, 5.5 acres of virgin forest was being cut down every day to provide the wood for the fires needed to heat the limestone to make cement, to provide warmth for the workers engaged in construction, and to provided cooking fuel.

We have depended on wood as a primary source of fuel for a very long time. Indeed, our dependence upon wood goes back somewhere close to a million years. Controlling fire was one of the first steps in the development of modern humans and our present civilization.

Modern civilization dates back 12,000 years and wood has been the dominant - if not sole - source of fuel for about 11,800 of those years.

Forests all over the world have been sacrificed for the sake of industrialization and creature comforts. But the combustion of wood is not a very clean process, as it results in a large amount of ash, smoke, and soot.

Wood is a dirty fuel.

A little over 200 years ago, coal became the fuel of choice, as it provided more energy, in an easier form, and wood was running out. Many of the forests of Europe were in a state of crisis as wood was being burned faster than it could grow. Coal was the natural and most convenient alternative.

Of course, coal produces large amounts of ash, smoke, and soot during combustion.

Coal is a dirty fuel.

In 1858, the first oil wells were drilled in Pennsylvania and petroleum became our major source of energy with all of its smoke and soot. Not a lot of ash, though, and that is important for our modern lifestyle.

Still, oil is a dirty fuel.

Interestingly, of the carbon based fuels, the only one that isn't a dirty fuel is methane. It is a relatively clean burning fuel with little in the way of by-products. No ash, soot, nor smoke. Methane, as a fuel source, almost makes sense, particularly because there are renewable resources that can be used to make methane. It does not have to be a "fossil fuel."

In the end though, burning carbon is generally a messy business with inherent problems above and beyond the simple production of carbon dioxide. And while we have developed progressively cleaner methods of burning carbon, carbon is intrinsically dirty.

Without question, the dirtiest of all the combustion processes for carbon-based fuels is the burning of wood. Anyone who has lived in Prince George for a long time knows this.

The pulp mills and saw mills used to burn wood with little in the way of environmental controls. Nobody thought much about the particulate being produced in those days. It was just part of the process of making money.

However, bee hive burners, for example, were notorious for their emissions. Particulates, such as PM10s and PM2.5s, compromised the health of the ecosystem and the people living within it.

Industry can control these emission to a large extent. Electrostatic precipitators, cyclones, and other technologies can be applied to trap almost all of the dirty emissions. These technologies are expensive, though, and only really work well on large scale applications like a pulp mill.

This is why I find bio-energy such a strange "alternative" fuel. Yes, for a district heating system or a large-scale operation, combusting wood might make sense and certainly might help with carbon credits.

But on a small scale, such as a household heating system, where an electrostatic precipitator is just not practical nor affordable, burning wood leads to many hazardous emissions - in the form of ash, smoke, and soot. Bioenergy, in the form of burning wood, just doesn't make a lot of sense from an environmental point of view.

Consider further there are some 1.8 million households in British Columbia consuming an average of 106 gigajoules per year for heating purposes.

If each of these was to switch to wood-based heating, that would require about 11 million cubic metres of wood per year, which is a significant portion of our annual allowable cut.

More to the point, maybe, is that about two per cent of that volume would remain as ash. That is 220,000 cubic metres of metal ions, caustic material, and pyrolyzed organic compounds that would need to be treated and disposed of.

That is a lot of waste.

What it really comes back to is that burning any form of carbon for energy is a dirty business. We need to use our intellectual capacity to get past carbon-based fuels and develop fuels that don't have such a detrimental footprint.