Biomass – Now It’s Renewable

Image: E-ON UK

For a long time, people equated wood and peat with coal – burning all three released a lot of carbon dioxide (CO₂) into the atmosphere. And that is bad.

But, on sober second thought, wise people realized that coal has been buried for millions of years, and as long as it remains buried and isn’t on fire, it doesn’t emit CO₂. On the other hand, trees and peat are growing plants that trap CO₂ when they are alive. When they die, the trapped CO₂ is released. And, here’s the important part, the same amount of CO₂ is released whether the material decomposes naturally or whether it’s burned. Consequently, wood and peat and other biodegradable substances are carbon neutral. And that is good.

Burning carbon neutral material for fuel is better than burning something that will emit new CO₂ into the atmosphere, or if not new CO₂, CO₂ that’s been out of circulation for millions of years.

Most of the wood burned in Canada is fuel for space heating and is burned in residential woodstoves and fireplaces. However, Canada has a large forestry industry that harvests trees for wood and pulp and paper products. Many forestry companies collect the wood residue from harvesting trees and from sawmills and paper mills and burn it to provide electricity for their operations. And many of these generate more electricity than they need, so they sell it back to the grid.

In fact, the Canadian Industrial Energy End-Use Data and Analysis Centre estimates that the energy capacity of wood residue in Canada is 1.4 megawatts for electricity and 3.6 megawatts for heat, and in 2008, biomass fueled generation of 9,829 gigawatt-hours of electricity.

Canada also has the largest peat reserves in the world, roughly 45 per cent of global supply. Peat bogs are found in every province and territory, with the majority being in Northwest Territories, Ontario and Manitoba. However, Canada does not use peat as biomass fuel for commercial generation of electricity.

Maybe it’s time we did.

Not All Coal is the Same

It’s all a function of heat and pressure. Coal began as plant remains that accumulated in a moist environment like a swamp or bog. As the bog filled in with sediment, the plant remains were buried. As more sediment accumulated, the depth of burial increased, as did the temperature and pressure. High temperature and pressure reduce the moisture content of the plant remains and increase its carbon content, turning it first into peat, then into lignite or brown coal, then sub-bituminous coal, bituminous coal and anthracite, the highest grade or rank of coal in terms of both carbon content and heating value.

Coal Rank	Carbon Content (per cent)	Heating Value (megajoules/kilogram)	Per cent of World Reserves
Anthracite	86 to 97	Up to 35	1
Bituminous	45 to 86	24 to 33	52
Sub-bituminous	35 to 45	19 to 26	30
Lignite	25 to 35	15 to 17	17

Although anthracite is found in British Columbia and Yukon, it is not mined in Canada.

Bituminous coal is found and mined in British Columbia, Alberta and Nova Scotia, and was mined in New Brunswick until 2009, when the last mine closed. Bituminous coal is used in steel making and in electricity generation. In 2009, about 27.9 million tonnes of bituminous coal were mined in Canada.

Sub-bituminous coal is mined only in Alberta, which produced 24.6 million tonnes in 2009, most of which was used to generate electricity.

Saskatchewan is the only province to mine lignite. In 2009, the province produced 10.6 million tonnes for electricity generation.

Until recently, peat was considered by the Intergovernmental Panel on Climate Change, an organization operating under the auspices of the United Nations, to be a fossil fuel. However, peat bogs contain living, growing plant life, and if harvested properly, are sustaining. As well, peat is carbon-neutral, meaning that the carbon dioxide bound up in the plant while it is growing is released to the atmosphere whether the plant decays naturally or is burned as fuel. Consequently, the IPCC now classifies peat in its own category and as a “slowly renewable fuel.”

If It’s So Green, Why Does It Burn Blue?

We’ve all been told that natural gas is the greenest of the fossil fuels. Greener than coal and greener than petroleum products. So why is this?

It’s all a matter of carbon, or hydrogen depending on how you look at it. Natural gas is primarily methane with lesser amounts of ethane, propane, butane, pentane and heavier hydrocarbons, nitrogen, water vapour, sulphur and carbon dioxide. Processing removes most of these other components so by the time the natural gas is actually heating our homes, it’s almost totally methane.

Methane is composed of  four hydrogen atoms surrounding one carbon atom – CH₄ – which means there’s four times as much hydrogen as there is carbon.

Other fossil fuels are made of more complex carbon and hydrogen molecules. Gasoline, for example, is made of molecules containing from five to 12 carbon atoms, arranged in linear chains, branched chains and rings. As more carbon atoms are added, the relative proportion of hydrogen decreases. The chemical formula for ethane, the two-carbon molecule, is C₂H_6, giving a hydrogen to carbon ratio of 3:1. In a 12-carbon chain, C₁₂H₂₆, the hydrogen to carbon ratio is 2.4:1.

Carbon dioxide is a by-product of burning fossil fuels. It is also a greenhouse gas which has been linked to climate change. The less carbon there is in a substance, the less carbon dioxide it produces when burned. Natural gas, being mostly methane, has the least carbon of all the fossil fuels.

On average, natural gas emits 53.06 kilograms of CO₂ per million British thermal units (kg CO₂ per MMBtu). Gasoline emits 71.62 kg CO₂ per MMBtu and diesel emits 73.15 kg CO₂ per MMBtu. Bituminous coal emits 93.28 kg CO₂ per MMBtu.

Because of its relative greenness, natural gas has been replacing coal as fuel for heat and power generation in both Canada and the United States.

And to answer the question: natural gas burns with a blue flame when well oxygenated. This results in more complete combustion.

Laying it on thick

So, you’ve heard about oil sands in a documentary or on the news. You’ve heard, perhaps, in conversation or classroom debates, about its impact on the environment. Perhaps you even know some people who have packed their bags and headed to Alberta to get their own nugget of black gold and share in the wealth. But this Texas, er…Alberta tea doesn’t come up from the ground like a bubbling crude as Jed observed in the famous classic, Beverly Hillbillies.

Instead, it comes in the form of bitumen… gummy, gooey and thicker than molasses in January. To make matters worse, it’s mixed right in with the sand, presenting a grueling challenge for industry. How to separate such an unruly brew from the ground is for another story, but this is a tale about the origins of bitumen’s thick skin and how we toil to tame this intractable taffy of the turf.

Thicker than peanut butter, but not quite as tasty, Athabasca bitumen has a viscosity, or resistance to flow, of more than 500,000 centipoise (cP) at room temperature.

Now, with every story you have some sort of conflict, a rising action, a climax and a conclusion. The conflict here is bitumen’s high viscosity, and the implications it has on this resource’s means of production and impact on the environment.

That’s a heavy story man

A penetrating glimpse inside the molecular structure of bitumen reveals the cause behind its thickness. Are you ready for it? Bitumen is thick because… (insert drum roll)… it is heavy.

You may have heard the term “heavy oil” before, but few people know what this actually means. What makes heavy oil heavy? What makes oil sands heavier than conventional oil or methane?

Essentially, when we say a certain oil is heavy, what we’re really saying is that it is carbon heavy, meaning that type of oil has longer and more complex carbon chains than other types of oil. Light crude oil, such as conventional Alberta crude, contains many small, hydrogen-rich hydrocarbon molecules whereas heavy crude oil contains many large carbon-rich hydrocarbon molecules.

As you can see, the antagonist in this particular story is the carbon molecules.

So, in order to bring bitumen to a viscosity that refiners can actually work with, you have to upgrade the bitumen, which essentially means, getting rid of some of the carbon, resulting in a product that is less thick. In fact, when you consider the extra process bitumen has to go through in order to get rid of all that heavy carbon, you can see where the environmental conflict lies. Additional energy is required to separate bitumen from the sands and upgrade it. As well, heavy crude oil requires more refining to transform it into transportation fuels. And of course, more energy equals more greenhouse gas emissions if the energy being used to power the extraction, upgrading and refining processes is natural gas.

So the rising action in this story has everything to do with the rising demand for cheap energy around the world, the important role of oil sands in meeting that demand and the unrelenting challenge of reducing greenhouse gases. The plot starts to thicken as the bitumen thins because at each stage of carbon removal, the viscosity of the bitumen becomes less and less, making it easier to work with. But the overall energy used becomes more and more. It’s really annoying.

Technology is starting to change all that. Scientists are exploring ways to reduce the energy used in oil sands extraction and upgrading. One approach in the pipes is adding bacteria to bitumen deep underground, converting it into methane, which is easier and less energy intensive to extract. Another in-situ approach of extraction is Toe to Heel Air Injection (THAI) which involves injecting air into the ground, causing combustion. As the bitumen heats it becomes less viscous allowing it to flow towards the well. As it flows it leaves some of the heavy carbon behind in a process called “coking”. Coking usually happens above ground as part of the upgrading process but doing it underground results in a lighter product that can be transported through pipelines, is partially upgraded and results in fewer lifecycle greenhouse gas emissions.

Of course, another approach is to use renewable energy to power any or all of these processes. The challenge here is that renewable energy is not as cheap and bountiful. But as society and governments evolve towards increased sustainability, that could soon change.

Although renewables are rapidly being embraced across the globe, it is important to recognize the degree to which we depend on oil, even as we make the transition to greener alternatives. Sure we can heat our homes with solar and earth energy, and derive electricity from nuclear, wind and hydro, but there remains a conundrum surrounding our cars. Solar, nuclear, wind and hydro-powered cars are still a long way off. Sure we have hybrids, but for the most part they still run on gasoline and electric cars have very limited ranges and low speeds. As well, a lot of electricity used to power them is coal or natural gas fired thermal electricity.

Now, every good story must have at least a few literary devices, and the most delicious of them is irony. We labour to make bitumen and the resulting crude products less viscous right from the extraction phase (especially with in-situ extracting techniques) through to the upgrading and then refining phase. The most premium petroleum products are the highly refined and less viscous transportation fuels such as jet fuel and gasoline. Ironically, lubricating oil, which is a highly refined product, needs to be more viscous so as not to ruin the engine. So after all this work to make it less viscous, additives are put in to make sure it retains its viscosity.

Because the oil sands and its continually evolving technologies are a work in progress, this story is too. There are yet so many variables that could affect the outcome, such as the direction of the economy, incentive to invest in research and development and carbon pricing laws. While the U.S. is introducing a tough stance on carbon emissions through its Green Energy and Security Act, Canada is waiting to see what happens before coming up with anything definitive.

But the rest of the world isn’t holding its breath. Already the wheels are in motion to come up with a global carbon pricing scheme in an effort to reduce world greenhouse gas emissions and to ensure an even playing field for renewable energy to compete in the global energy market. It may be safe to predict that the outcome of the upcoming conference of world leaders in Copenhagen this December could serve as a climax for this story.

Most importantly, however, is the conclusion and that rests in the hands of energy consumers as well. Mitigating climate change is a heavy topic and while many remain thick headed towards a potentially warming planet, many more are working towards a positive conclusion for the planet – one where energy, the economy, the environment and its inhabitants live happily ever after.

Fuelling irony and the cost of knowledge

Consider the irony of rising fuel costs making research to distant locations like Antarctica more expensive.

Climate change recently offered a resounding reminder of its presence when a gigantic, four-square-kilometre arctic shelf broke away in the Canadian North. It seems cruelly poetic, then, that missions to study the effects of climate changes largely brought about by our use of greenhouse gas-emitting fossil fuels require the same fuels to make their trips. It’s a catch-22 that draws out one of the central dilemmas of any climate change argument, namely that no matter what we do, whether it’s researching melting polar shelves or walking to the corner store for milk, our activities have measurable effects on our environment.

The rising cost of fuel coupled with the increased price of doing business also demonstrates that if there’s any recurring theme in energy and climate change it’s of unintended consequences (or, sometimes, benefits). From biofuels increasing the price of food to kidney stones as a result of warmer climates, the unpredictability of climate and business makes for a frustrating combination.

It’s a complex, interconnected system of energy, costs and benefits, but if we’re going to be analyzing it any further we’d better hope the answers aren’t too far away. We can’t afford the trip.

Bulls, babies and bacteria

When it comes to energy, we’re usually speaking in the figurative when we talk about “clean” energy, or “dirty” power. But for some alternative fuel sources, those labels become far more literal. After all, while holding a chunk of coal might leave you brushing off some carbon residue, a fistful of manure is definitely going to require a thorough wash afterward.

Nobody’s saying we shouldn’t make better use of the waste we produce. Alternative fuel sources like landfill gas and the methane produced from manure are proving that conservation makes economic, as well as environmental sense. Years ago, for instance, disposing of fryer grease was a chore that franchise restaurants had to pay others to do for them. Now, the grease is not only disposed of, it’s become so valuable that profiteering “pirates” are actively stealing it from fast food grease traps.

Still, it’s a messy business turning dung into dollars.

There’s a distinct correlation between the “ick” factor of a waste product and its eventual use as a fuel source. And it goes beyond the fact that people are probably more inclined to handle something as appealing as corn over something as repulsive as trash heaps.

Methane, one of the six primary greenhouse gases identified under the Kyoto Protocol, derives from fermenting organic materials, which means that while the gas itself may be odourless, its companions rarely are. Diapers, for example, produce methane (in addition to offering the recyclable materials of the diaper itself), and the drive toward manure as a fuel source comes with growing recognition of the greenhouse gas emissions from industrial-scale feedlots. Whether they’re babies or bulls, the result is the same — metric tonnes worth of poop that’s sending greenhouse gases to high heaven.

And the stinky correlation isn’t confined to methane. Researchers in the UK recently unveiled a process that turns food waste into hydrogen, one of the most promising alternative fuel sources. In a bioreactor, “biohydrogen” is created by the same bacteria whose fermentative processes turn waste materials into the smelly substances we otherwise avoid. In the absence of oxygen, they create hydrogen, which in turn can be used to produce an emission-free reaction in a hydrogen fuel cell. Not bad for table scraps.

Whether they release methane or hydrogen, waste products carry more than the smells that keep most of us at bay. Beyond the backyard composting that keeps our garden healthy, recycling waste is reaching an industrial scale that will change the way we generate power, “clean” or otherwise. So, as sources of alternative power become increasingly appealing in the face of rising fuel prices, holding our noses will just become that much easier.

Mo money, mo carbon

The why’s of rising gasoline prices have never concerned Canadians as much as their practical consequences — higher prices at the pumps and less money to be spent on life’s essentials. But while we all have to deal with the consequences of more expensive fuel, the distribution of those consequences isn’t necessarily equal.

As reported by the Victoria Times Colonist, a report by B.C.’s provincial government found 18 per cent of the province’s residents are living in “energy poverty.” With 17 per cent of their income diverted to energy costs, these low-income Canadians stand to be harmed disproportionately by increasing fuel prices.

But if the provincial government’s findings seem to indicate that lower-income Canadians are liable to trim their energy use in light of soaring costs, another report by the Canadian Centre for Policy Alternatives (CCPA) cautions that even low income Canadians have carbon footprints many times as large as those found in developing nations. Just as a select percentage of Canadians are being affected by rising fuel costs, though, another segment is using more than their fare share.

In that same report, the CCPA revealed that the richest 10 per cent of Canadians have carbon footprints a full 66 per cent higher than average Canadians (12.4 hectares per capita). With the lowest 60 per cent below the Canadian average of 7.5 hectares per capita, the highest 10 per cent enlarge their footprint in mobility, goods and services (55 per cent of their footprint), compared with lower-income Canadians’ emphasis on necessities like food and housing (70 per cent).

The two reports show that while Canadians may be unified in their distaste for paying more for a commodity we want to buy, the impact of those prices and the ways we use our increasingly expensive fuel are anything but universal.