Bio Fuel Con?

[Broomstick]

Mind, it might be possible that there's something special about tropical rainforests that would make them hard to regrow (given enough time for the trees to get that big, of course), but I'd be at a loss to say what it would be if it's actually the case.

Thin topsoil (in a tropical rainforest most of the organics are in the plants, anything that decomposes into nutrients is sucked up almost immediately unlike temperate or boreal forests) combined with erosion from plentiful rainfall once the ground cover is removed. The result is eroded, gullied subsoil of low fertility that can no longer support the prior level of vegetation. Other forms of ground cover have to grow up and slowly restore the topsoil, and that takes at least decades and probably centuries.

[Rogue 9]

If the topsoil is that bad, you'd think you wouldn't get much of anywhere with cutting it down for farmland, because crop plants don't like that kind of soil any more than trees do. Actually, they like it less.

[Broomstick]

Typically, in the tropics the locals would cut down a section of forest, burn the vegetation (returning some nutrients to the soil), then get one or two crops out of the land before needing to move on. If you have small groups of people at low population densities doing this the rainforest can recover but it is nowhere near sustainable with modern populations. You can add fertilizer to the cleared area, but you have to do it every season. And you still have erosion problems.

[Mayabird]

What Broomstick is talking about is slash-and-burn agriculture. It's gone on in the rain forests for centuries, but populations were once not large enough to cause any problems - the only halfway sorta densely-populated places in the Amazon rain forest before the European diseases arrived was along the Amazon River itself, and they could live on the plentiful fish as well.

So yeah, people come in, cut down the trees, burn them, get a couple years worth of crops out the ground - maybe - before they run out of nutrients/rain leeches out the nutrients and then go to burn some other land. Open patches in the forest can quickly recover - there are plenty of seeds falling from elsewhere, and the surrounding vegetation shields the ground from erosion, neither of which are available as increasingly large tracts of land get burned.

In addition, the forest helps maintain its own climate through evapotranspiration. As plants get CO2, they release water accidentally, but the huge amount of biomass means that a lot of water in total gets back into the atmosphere, which then falls back down. Something like 50% of the rain in the Amazon basin is produced by this process. Destroying the forest in vast regions breaks that cycle, making it even harder to recover.

[Flagg]

Bio-fuels are being pushed hard for one reason, and one reason alone: the political power of farmers.

To be fair, that's not the only reason. The other big reason is because you have to do very little in the way of modifications for our current motorpool to run on it.

[Flagg]

What pisses me off about this biofuel (and hydrogen) nonsense is that it's always very pie in the sky and just around the corner. So we just have to wait for this technology to become available. Well, waiting isn;t a fucking option anymore. I'm not even convinced that changing is even an option at this point.

We would be far better off if we switched to electric vehicles using our current coal based power infrastructure than waiting around for hydrogen or starting to use biodiesel. And then there's this big nuclear=evil mindset on the left which I just cannot fathom. I don't think nuclear is the best option for the longterm simply due to the waste produced, but it's far better than pumping co2 into the air while waiting around for some miracle to save us all. And it's a perfect short term solution until shit like hydrogen, solar, and tidal (and eventually fusion) become viable options.

[Zablorg]

By the time nuclear power becomes a valid choice to polititians will it be too late to do anything about it? How expensive are nuclear plants to build?

[Flagg]

By the time nuclear power becomes a valid choice to polititians will it be too late to do anything about it? How expensive are nuclear plants to build?

I don't think it will ever be a valid choice for politicians. One of the few things Bush wanted that Democrats managed to kill was a push to build more nuke plants. I imagine they are pretty expensive to build, but considering how cheap they are to keep running, it's offset alot. The 2 main impediments are the lack of a place to store the waste (having it sitting outside of the plants isn't exactly safe and makes it a good target for terrorism) and public opposition.

[Sikon]

If managed sustainably in a tree plantation that stays the same size over time with new trees planted as some are cut down annually, the effect is carbon just going in a loop.

How far will that go if there is money to be made? greed does wonders for motivating people.

Sometimes the economic motivation is to replant trees or to cut only a sustainable number countered by forest regrowth, in order to stay in business, like a farmer replanting his crop. And there can be the effect of government supervision, especially in regard to logging on public lands.

The degree to which forests are managed sustainably varies by location, and there was vast devastation to original old-growth forests in the past.

But the overall trend for the U.S. in the past century is total forest coverage staying about the same. Specifically, U.S. forest area was 307 million hectares in 1907, then ninety years later was about 302 million hectares in 1997.

[Sikon]

I've regarded bio-fuel as an attempt to have one's cake and eat it it, too - to continue our current ways without having to cut back, conserve, or change our habits.

We would be far better off if we switched to electric vehicles using our current coal based power infrastructure than waiting around for hydrogen or starting to use biodiesel.

Whatever the particular percentage of energy conservation, there's still some practical need for liquid fuel. To take an extreme example, nobody's going to be flying fighter-bombers on electric batteries. Likewise there's little reason not to continue having ships running on combustible fuel, particularly since large ships use only on average around 0.2 MJ per ton-mile of cargo transported, 150 times more efficient than the average truck.

While more usage of electric vehicles is possible, desirable, and starting to occur, especially as their performance increases, treating this as an either/or situation is unrealistic. Real world engineering uses multiple technologies as appropriate in different applications, something very understandable particularly with the J/kg energy density difference between batteries and liquid hydrocarbons.

Even for automobiles, hybrids which travel most daily short commutes on a small inexpensive set of electric batteries but fulfill consumer desires for several-hundred-mile range capability with an onboard engine have much potential.

The one situation where biofuel wouldn't be needed at all would be all-abiotic synthesis of synthetic liquid fuel, e.g. a nuclear-powered FT process using CO2 extracted from air and water like that discussed in another post today here. But as much as such has potential, it isn't commercially implemented so far, while biofuels are getting enough support for increasing current production.

In practice, in the real world, opposing biofuels would just mean more usage of fossil fuels instead. More renewable fuels are desirable.

Instead of "sequestering" organics in landfills you're going to burn them? That won't reduce CO2.

In practice, most paper garbage ends up in landfill, where it does not decompose and release CO2. You can still clearly read headlines on newspapers dredged up from 30 years ago in landfills.

While there are some cases of old garbage remaining intact, a lot of it still decomposes over the years and decades. It emits both CO2 and what is about 23 times worse for global warming per unit mass: methane. Landfill gas is around half and half a mixture of CO2 and CH4.

With the percentage decomposition, up to on the order of 100 kg of methane per ton of average solid waste is released eventually, though the rate changes over time, e.g.:



Such is up to a couple tons of CO2-equivalent radiative forcing per ton of waste from that alone. That's merely part of the additional effect on global warming; there would also be the CO2 emissions from the extra fossil fuel used to meet needs because of the lack of biofuel.

In contrast, conversion to biofuel and combustion causes CO2 to go in a cycle but does not cause those large methane emissions.

It's better for reduction of global warming to have suitable waste converted into biofuel than to use more fossil fuel in its place and just dump it in a landfill.

While, technically, if landfills were designed to be sealed and the landfill gas emissions collected, such could be used for carbon sequesterization without the emissions of the average current landfill, there's more direct benefit and economic incentive in replacing a portion of petroleum consumption anyway.

Indeed, really, the U.S. government is supporting renewable fuel more to reduce future dependence on foreign oil and strengthen the domestic economy than because of environmental benefits, though both are good reasons.

[Sikon]

(When the goal is net decrease in CO2, as opposed to simply preventing the amount of increase if fossil fuels were used instead, that requires methods such as producing biomass and then collecting and sequestering some, not burning it and not letting all of it decompose either, partially stopping the cycle).

Oh, you mean like burying organics like paper and food and yard waste in a landfill rather than allowing it to decompose?

... not in a landfill, unless making a different design from the average real-world landfill, making it instead sealed airtight, then processing the gas emissions from decomposition.

Other choices have potential, such as oceanic fertilization indirectly sending some carbon to the ocean floor and underground CO2 sequestration.

Really, though, net decrease in atmospheric CO2 levels isn't going to happen unless there is first a switch to renewables and nuclear energy, to eliminate new emissions from fossil fuels. By default, that will be a long process since some fossil fuels remain economically affordable and available for a while, some potentially lasting to a substantial degree beyond even this century (although the right combination of technology and politics could possibly cause a faster switch than physical limits alone force). Once it eventually happens, though, then removing a little CO2 annually would become not too hard.

But the primary near-term concern is switching away from oil, for multiple reasons including the problems with dependence on limited supplies and the Middle East, while reducing the rate of increase in CO2. More biofuels having their carbon just go in a cycle help there.

Meanwhile, you're looking for something else to fertilize your crops... Without petroleum derived fertilizers organic compost is what you have to keep agriculture productive. Or we take some of the land out of production, letting it lie fallow or planting nitrogen-fixing crops to plow under as fertilizer, but that will result in a net drop in production at some point.

You really either haven't read other threads or haven't comprehended them...

Fertilizer isn't primarily petroleum-derived.

Nitrogen fertilizer production is based on natural gas and coal rather than petroleum (though the Haber-Bosch process also works on any other hydrogen and energy generation method like nuclear and renewables too). That's been shown in multiple past threads, with references, most recently in this thread (not that those references are even needed for proof if one understood the process of N2 + 3H2 -> 2NH3).

Even if we could increase forested areas/biomass without reducing the world population it still wouldn't work - there are just too damn many people.

The world is going to have no less than around its current population or a bit greater even at the start of the 22nd century according to typical projections, since in the near-term the population declines in developed nations are countered by increases in developing nations. There's a tendency towards potential eventual net population decline even for the world as a whole, due to how drastically average fertility rates drop after nations industrialize with the accompanying societal changes. But such population change is a slow process.

However, there is the potential to switch the dominant energy and liquid fuel source, particularly since decline in crude oil and to a degree other fossil fuels during this century help enforce that.

Such is discussed in more detail in part of the next post, below.

We are already seeing a competition between crops-as-food and crops-as-fuel. Is there enough arable land for both needs?

Ethanol from corn and sugarcane isn't the only method. The primary potential of biofuel is from the expanding cellulosic and gasification methods, which can sustainably consume some of the vast amounts of non-food biomass one sees when flying over the U.S. An example is the earlier USDA study; out of the 1 billion tons per year, it included an estimate that 90 million tons of extra grain could be produced by U.S. production but the other 90% wasn't food.

[Sikon]

Area previously covered with peat or rainforests is hardly typical, making it particularly obvious that they carefully selected these atypical studies to find a couple much supporting their desired argument.

Is it not the case that wide-scale deforestation is occurring across the globe, and that agricultural requirements are a large cause of that? Of course, human overpopulation is the other cause.

[...]

Is it practical to reforest areas that have been deforested? Or does the process create such changes in the soil that this would be very difficult?

Rainforests are an exceptional concentration of biomass. They cover only around 6% of earth's land area but are the most valuable ecosystem in terms of concentrated life and diversity. Rainforests are around 50 kg/m^2 average carbon content, illustrating their biomass, while, for example, grassland can be 2 kg-carbon/m^2 of above-ground vegetation mass. Burning down rainforests is among the worst things to do to the environment.

Some countries have wide-scale rapid deforestation. As an extreme example, at least one of the top several countries in the world in deforestation rate relative to area, Zambia lost about 14% of its forest area between 1990 and 2005 with continuing rapid decrease.

But for this discussion of biofuels, let's look at the world's top two energy consumers, the U.S. and China, which consumed 100 quadrillion Btu and 60 quadrillion Btu annually respectively in 2004. In some ways, China is in not too bad of a situation in regard to liquid fuel: While 40% of total U.S. energy consumption is from petroleum, the figure for China is only 20%. (That's not surprising since public mass transit and trains are more common in China with personal cars not as prevalent).

The fairly constant total U.S. forest area over the past century is discussed in one of today's posts above, from 307 million hectares in 1907 to about 302 million hectares in 1997.

Although China is justifiably known for environmental problems in many regards, their area covered by forests has mostly experienced net increase in the past several decades, partially with the help of this:

Over the past two decades, people from all walks of life have participated in tree-planting since China set March 12 as a National Tree Planting Day in 1979 and launched the national voluntary tree-planting campaign in earlier 1980s.

According to the 1981 resolution by China's top legislature on the campaign, every healthy Chinese citizen older than 11 has a duty of planting three to five trees each year without pay.

Last year, nearly 560 million people planted more than 2.5 billion trees throughout China. The accumulated efforts of volunteers reached 8.8 billion with more than 42 billion trees planted during the 1982-2003 period, NAC's statistics indicate. [...]

Most places provide free planting kits, and people can buy different kinds of saplings there for 20 to 40 yuan (US$2.40 to US$4.80) each for a little bit more. [...]

As a result, the national forest cover rate has been raised from less than 12 per cent years ago to the present 16.5.

From here.

China's forest coverage:



There would be some local regions within China where there was major net deforestation, but the preceding is the overall trend of net increase.

Such was while meanwhile Chinese population and agricultural production much increased, as illustrated by wheat production tripling from 40 million tons in 1975 to 120 million tons in 1997, while rice production went up by about 50%.

World forest cover decreased at a 0.2% average annual rate, by 3% between 1990 and 2005, going from around 4.077 billion hectares to 3.952 billion hectares. But, more precisely, the trend utterly varies by region. Outside of Africa and South America, it was 2.49 billion hectares in 1990 and actually still 2.49 billion hectares in 2005, while the main decrease occurred on those two continents.

The amount of the world's land area converted to cropland by humans is significant but, still, it is a few percent of the total, though more is used as pasture. Combined with much increasing yields per unit area, the situation is not quite so bad as most people probably assume.

Human activities emit 6 + 1.5 = 7.5 Gton of carbon every year, and yet the levels of CO2 in the atmosphere are only increasing at a rate of about 3 Gton of carbon each year. Where does the missing carbon go?

Part of the CO2 resulting from fossil fuels is taken up by new forests growing in the Northern Hemisphere. [...]

It appears that existing forests are growing faster today than they were before. The [precise details of the] exact cause is unknown but could involve the higher levels of atmospheric CO2, and/or possible fertilization effect from man-made nitrogen compounds [...] This fertilization effect could account for an additional carbon sink of 2 Gton C/year. [...]

Another important player in the carbon cycle is the ocean. CO2 can dissolve in the oceans, and today they take up about 2 Gtons of carbon each year.

From here

To use some figures from a few years ago, there was about 6 Gt-C/yr of CO2 emissions from fossil fuels plus another 1.5 Gt-C/yr from deforestation for 7.5 Gt-C/yr increase ... except the actual measured increase in atmospheric CO2 was less than half as much as the preceding alone would suggest, because ~ 2.5 Gt-C/yr was absorbed by extra growth of new biomass plus another ~ 2 Gt-C/yr by the oceans. Another description of the preceding is here in the starting section on the IPCC assessment of the carbon cycle.

As illustrated, there's a net increase in world biomass currently, on the order of a gigaton of carbon per year. That's despite the unfortunate deforestation in some areas of the world because there is meanwhile an increase of forests and other biomass in other regions.

For example, U.S. forests are increasing in biomass per unit area, while their total area is staying almost constant.

There is deforestation in some places in the world, but it's a much more complex (and better) situation than the common popular assumption of worldwide deforestation.

How much gasoline would that make? [...]

If managed sustainably in a tree plantation that stays the same size over time with new trees planted as some are cut down annually, the effect is carbon just going in a loop.

That makes sense. The biggest problem is the sheer quantity required to replace our current oil usage.

The relatively near-term situation with expanding biofuel production is heading towards changing the U.S. liquid fuel supply to being tens of percent from biofuels, tens of percent from substitution of other fossil fuels for conventional crude oil (CTL, NGL, oil sands, oil shale), and only a limited fraction from conventional crude oil.

Such would vastly enchance energy security, a goal of the U.S. government.

The amount produced from biofuels depends on whether there is much change to land usage.

Without major change to land usage, that study has estimated that their goal of 30% of U.S. petroleum consumption could be substituted, which is a lower limit rather than an upper limit.

Since the real world doesn't consist of pursuing a single method to the exclusion of the rest, that's a substantial amount when combined with other fuel synthesis, increased substitution of electric transportation, etc. Renewable methods will continue to be supplemented by usage of other fossil fuels (coal to liquids, oil sands, etc) in the near-term future of the next few decades.

In the longer term, more major changes to land usage have the potential of allowing biofuel production up to as much or more than current petroleum consumption if desired. It has been estimated that on the order of 15000 square miles of algae biofuel farms could produce as much liquid fuel as current U.S. petroleum usage. While there's some percent uncertainty in the particular figure, the important aspect is the order of magnitude. Such may superficially seem like a lot, but actually it is only around 0.4% as much as total U.S. land area (3.5 million square miles).

Of course, a nuclear power plant is far more concentrated energy generation per unit area than any farm, and the ultimate in scalability for greater production is not biofuels but an option like that described in this segment of an ORNL paper:

Liquid fuels can be made from hydrogen and CO2 extracted from (1) the atmosphere or (2) the ocean. A modified Fischer-Tropsch synthesis process is used. The hydrogen is used (1) as a feedstock to make the liquid fuels and (2) as an internal energy source to drive the process of producing the fuel.

Because the CO2 is recovered from the atmosphere or seawater, no greenhouse impacts occur. About 80% of the total energy input required to produce the liquid fuel is used to produce the hydrogen. Carbon dioxide extraction from air or water is not the primary energy cost.

The direct production of liquid fuels from air and water is the ultimate option for liquid-fuel production. This option (Forsberg 2005) has been studied for both commercial liquid-fuel production and military fuel production

From here.

As described in more detail and estimated in another post of today here, the future production cost for such could be several dollars per gallon of gasoline.

However, like the military saying that you go to war with the army you have, not the one you desire, methods in current commercial production do not include the above yet. Biofuels are the most environmentally-friendly liquid fuel source in commercial operation today, and their expanding production increases survivability to disruptions in the crude oil supply, helping the U.S. government's goal of greater energy security.

[Sikon]

What pisses me off about this biofuel (and hydrogen) nonsense is that it's always very pie in the sky and just around the corner. So we just have to wait for this technology to become available.

It is available, with production increasing over time. Hydrogen fuel cells are not appropriate to put in the same category as biofuels. A handful to zero hydrogen fuel-cell vehicles have ever been sold commercially, due to excessive expense and major infrastructure change requirements (a situation which could possibly change someday as some predict but with that uncertain in the context of alternatives).

In contrast, biofuel is already a dominant fuel for millions of vehicles in Brazil, for example. Expanding production of the cellulosic and gasification methods has much potential, especially now that the conventional gasoline competition is expensive enough instead of being just $1/gallon a few years ago.

While not the sole source of fuel now or necessarily ever, expanding biofuel production is worth it to reduce oil dependence bit by bit.

I don't think nuclear is the best option for the longterm simply due to the waste produced, but it's far better than pumping co2 into the air while waiting around for some miracle to save us all.

Yes, it's a lot better than the environmental problems and other disadvantages of fossil fuels.

The waste isn't too bad relatively if cost versus benefits are evaluated quantitatively. For example, although any rare incident of someone dying in a radiation accident at a nuclear power plant can make headline news, nuclear waste doesn't kill many tens of thousands of people worldwide per decade like the accident rate of coal mining, which has 6000 to 7000 deaths annually in China alone.

With radioactivity inversely proportional to half-life, proportional to the number of atoms decaying per unit time, in the long-term the radioactivity of the waste decreases by orders of magnitude as eventually only the long half-life radioisotopes are left. For perspective regarding nuclear waste disposal deep underground, there are literally trillions of tons of long half-life uranium, thorium, and potassium-40 natural radiosotopes in earth's crust, dispersed at low concentration among the many quadrillions of tons of rock.

[Sikon]

By the time nuclear power becomes a valid choice to polititians will it be too late to do anything about it? How expensive are nuclear plants to build?

In some cases, nuclear power has been the very cheapest generation method in price per kilowatt-hour, the net result after amortized capital cost plus operating, maintenance, and (small) fuel cost. In other cases, it is a few percent more than coal, but it is relatively close even then, not multiple times more expensive or anything excessive.

Nuclear is doing better in some other countries than the U.S. at the moment. But unless everything is done with non-nuclear renewables alone --unlikely--, more nuclear power is simply inevitable eventually. For example, the 22nd century can't and hence won't just run on oil.

[montypython]

Algae tanks can also be constructed alongside carbon-emitting powerplants, so that the CO2 emissions can be absorbed by the algae for more fuel.

[MKSheppard]

Burning the rainforest is the best thing that happened for it. It's just a giant cesspool of really nasty things that want to kill you. Kill 'em before they get a chance with cleansing fire, and then build a house on the remains.

[Darth Wong]

Burning the rainforest is the best thing that happened for it. It's just a giant cesspool of really nasty things that want to kill you. Kill 'em before they get a chance with cleansing fire, and then build a house on the remains.

Are you trying to win some sort of award for "most useless and stupid post" or something?

[Flagg]

Burning the rainforest is the best thing that happened for it. It's just a giant cesspool of really nasty things that want to kill you. Kill 'em before they get a chance with cleansing fire, and then build a house on the remains.

Are you trying to win some sort of award for "most useless and stupid post" or something?

Sounds like the South Park school of bullshit to me. "The Rainforest Sucks" is the name of the episode, IIRC.

[Admiral Valdemar]

Stuart Staniford of TOD did a good piece recently on the trends regarding corn ethanol and food production here which gives some insight into how fast this sector is growing and how it can hurt many people in the long run (I am certainly not an advocate of bio-fuels from food crops). It is vital that we change our attitudes and move towards perfecting cellulosic ethanol reactors that use feedstock that doesn't subtract from the global food supply and further boost food price inflation. Incidentally, another post on the effect on freshwater supplies in CONUS is interesting reading, whether we use bio-fuels en masse or not. Water shortages are a predicted and imminent threat as stated in the IPCC papers and various other assessments.


GTL is a big alternative here as well, along with the future potential of nuclear energy producing hydrocarbon liquid fuels should we have the capital and time to implement them effectively

On the rainforest, if we don't raze it, then nature will. The drying out of vast swathes of the Amazon that led to the truly epic firestorms of last year are only going to become more common. There were times where the actual river could not be used for transport as the water level was too low for boats, and so helicopter support was needed.