Renewable Fuels 2: Biomass

From the NRDC website: “Biomass power comes from plants — crop and forest residues, corn kernels and stalks, energy crops, perennial grasses, and fast-growing trees like poplars, to name a few. It can be used to make liquid biofuels that serve as alternatives to oil, or to produce heat or electricity to power our homes. Biomass power accounts for roughly half of all the renewable energy produced in the United States, and we use more of it than any other country in the world.” Given Brazil’s heavy use of ethanol made from sugar cane, that’s saying something. U.S. ethanol made from corn is probably the reason.

Here’s how biomass looks in the U.S. It produces roughly 3% of America’s energy.

renewablesources

The NRDC adds the useful caveat: “Most of the biomass energy we use today comes from unsustainable sources that are not an improvement over fossil fuels: ethanol, made by fermenting food crops like corn and sugarcane, which require large amounts of land, water and chemicals to grow; and wood or even whole trees from forests, which are often “co-fired” with coal in power plants, increasing global warming pollution and threatening our forests as well.

Focusing on food crops like corn or soybeans as sources of biofuels can have unintended economic and environmental consequences. Harvesting these crops for biofuels could raise the price of feed for livestock and possibly food as well. Because these crops are grown using large amounts of fertilizer, land, and water, water quality and availability could suffer, due to soil erosion and pollution from fertilizer runoff. All in all, the production of corn ethanol creates more carbon pollution than the oil it is supposed to replace.

Wood can also be a problematic source of biofuels, if it’s not sustainably harvested. Demand for wood pellets is expected to increase significantly over the next few years, as European countries strive to meet renewable energy goals of 20 percent by 2020.[1] Pellet manufacturers in the southeastern United States are gearing up to satisfy this growing market, as European suppliers will not be able to meet this demand — unfortunately, they are increasingly looking to whole trees for energy.

Burning a whole tree not only releases stored carbon — it takes away the tree’s ability to absorb more carbon in the future. Harvesting whole trees for energy increases carbon pollution and degrades our forests, one of our best defenses against global warming. Furthermore, forests in the southern United States already produce more wood and paper products than anywhere else in the world, so increased demand from the bioenergy market could put even more pressure on these overworked ecosystems.”

Worldwide, biomass is a major source of energy, about 12% of all energy consumed worldwide.

Total_World_Energy_Consumption_by_Source_2010

It is used especially in the developing world. Sadly, the biomass is really just branches and dung and is burned over simple stoves for cooking, contributing to or directly causing about 4 million deaths a year.

Europe is a big fan of biomass, especially when it is not their biomass being used. They import large quantities of U.S. wood pellets for use in power generation, usually alongside coal.

Given the very real negative impacts of biomass on the health of those in the developing world and the negligible benefits to the climate from most uses, the rush to biomass seen over the past 15 years seems misguided.

Indeed, I would say that every ton of biomass not burned (with some exceptions, such as Brazilian ethanol) is perhaps of more benefit to humanity than an equivalent number of negawatts.

Biomass as it stands today—not efficient, not useful, camouflaging the damage done to the developing world–seems like a modern example of the idiot’s solution: ‘We must do something. This is something. We must do this.’

12 responses to “Renewable Fuels 2: Biomass

  1. When speaking of ethanol, it is important to talk about how it is used. E10 is a blend that uses 10% ethanol as an octane booster and oxegenator for gasoline. It does for modern fuel what lead did back in the bad old days. E85 (and other variants), on the other hand, use ethanol as the primary fuel.

    There is a lot of discussion about how ethanol does not contain as much energy as gasoline and how it takes as much energy to produce as it provides, while this criticism may be valid for E85, it is not valid for E10 which is used to get more energy (work) out of gasoline by making it burn more efficiently. This efficiency factor is rarely credited to the energy budget of ethanol studies.

    As for the claim that growing corn consumes a great deal of water and nitrogen – that is certainly true, but it is most problematic out west where the corn is used to feed cattle, not as feedstock for ethanol plants.

    As one might tell by the “Iowa” in my name, I live in corn country and thus get a different perspective on farming issues than one gets in other places.

    • Almost Iowa,

      I do not believe that E10 burns any more efficiently than non-ethanol containing gasoline. Ethanol is one of many octane boosters. The only thing that could plausibly be credited to ethanol would be the energy required to make a different octane enhancer. I think that is typically small.

      Tom has nailed this one.

      • “I do not believe that E10 burns any more efficiently than non-ethanol containing gasoline.”

        But it does.

        We have known for well over a hundred years that straight gasoline does not burn well in a car engine. It has a low octane rating and there are problems with pre-ignition (knock). In the bad old days, Tetraethyllead (lead) was added to address this problem. We all know the result of that.

        For a while, refineries added Methyl tert-butyl ether (MTBE) but found that ethanol achieved the same result without persisting in the environment and containmenting ground water like MTBE does.

        To properly credit the ethanol energy budget, one must measure the “work” achieved with straight gasoline compared to what is achieved using E10.

        For instance, straight gasoline contains 114,000 BTU’s. E10 contains 111,836 BTU’s. So one can say in all honesty that straight gasoline contains 2,164 more BTU’s than E10.

        But this only represents potential. A car engine is very inefficient, thus anything that raises its efficiency will produce more work – even if it contains less energy.

        The measure of fuel efficiency is Gasoline gallon equivalent (GGE). A straight gallon of gasoline has a GGE of 1.000. E10 has a GGE of 1.0190

      • Almost Iowa,

        You wrote: “To properly credit the ethanol energy budget, one must measure the “work” achieved with straight gasoline compared to what is achieved using E10.”

        Nonsense. You must compare E10 to what would be used otherwise. I am pretty sure that you have never purchased a gallon of what you call “straight gasoline”; I certainly never have. And I suspect that you, like me, would have no idea of how to go about purchasing “straight gasoline”.

        You wrote: “The measure of fuel efficiency is Gasoline gallon equivalent (GGE). A straight gallon of gasoline has a GGE of 1.000. E10 has a GGE of 1.0190”.

        I don’t think that GGE has anything to do with efficiency of combustion, it is only a measure of energy content. See https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent. And how is it a good thing that it takes 1.0190 gallons of E10 to equal 1.000 gallon of gasoline?

      • BTU’s are the measure of energy content. GGE is the measure of efficiency. Let’s call it energy put to work rather than blown out the exhaust tube which is where the majority of BTU’s go. 1.0190 is more than 1.0000.

      • Almost Iowa,

        “GGE is the measure of efficiency.”

        Do you have any evidence of that claim? The Wikipedia article I cited above says otherwise. So does this
        http://alternativefuels.about.com/od/resources/a/gge.htm
        and every other source I have found.

        “1.0190 is more than 1.0000”

        Of course it is. But this is like golf, the bigger number is worse. See the above sources.

      • Mike M,
        Wiki states this:
        “Ethanol and fuels like E85

        1.5 gallons of ethanol has the same energy content as 1.0 gallon of gasoline.

        The energy content of 1.0 US gallon of ethanol is 76,100 BTU, compared to 114,100 BTU for gasoline. (see chart above)

        A flex-fuel vehicle will experience about 76% of the fuel mileage MPG when using E85 (85% ethanol) products as compared to 100% gasoline. Simple calculations of the BTU values of the ethanol and the gasoline indicate the reduced heat values available to the internal combustion engine. Pure ethanol provides 2/3 of the heat value available in pure gasoline.”
        https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent#Ethanol_and_fuels_like_E85

        Ethanol, like nearly any policy the so-called “greens” impose on energy and climate, is about funding “green” insiders at the expense of the tax payer and the environment.

      • Mike, I was wrong, you were right. GGE is a alternate method of measuring energy. I used the wrong measure to make a point.

        The point I was attempting to make is simple. You get more power from gas with octane additives than you do from gas without – because the gas burns more efficiently. The “energy” tables are thus deceptive. There is no “energy” in Tetraethyllead but when it is mixed with gas the engine is able to utilize more of the energy contained in gasoline.

        The same is true for E10.

      • AI,
        What implications do you see in the post I provided showing the actual impacts of Ethanol on fuel mileage?

      • Almost Iowa,

        Being able to admit it when you are wrong is a mark of character. I respect you for it.

        “You get more power from gas with octane additives than you do from gas without – because the gas burns more efficiently.”

        Actually, the way octane enhancers work is by reducing pre-ignition (knocking) and thus making it possible to use a higher compression ratio, which improves the efficiency of converting heat into work. Since it is the compression ratio that matters and that is designed into the physical dimensions of the engine, there is no advantage to using gasoline with a higher octane rating than the car was designed for. So there is no advantage to using premium fuel in a car designed for regular. And if the gas is 87 octane, it does not matter if that is achieved by adding ethanol or MBTE or aromatics, etc.

        “The “energy” tables are thus deceptive.”

        No, they aren’t. In comparing two fuels with the same octane rating it is energy that is by far the most important property.

        Some people claim that E10 gives better gas mileage than you would expect from the energy content. So far as I know, that has no explanation that stands up to scientific scrutiny. There are also people who claim that you get much worse mileage with E10. So far as I know, the claims on both sides are purely anecdotal, with no solid scientific studies to back either side. I suspect that the results either way are the result of measurement error combined with confirmation bias.

  2. Bjorn Lomborg recently posted this soundless video on Germany’s energy:

    Among all the other damning stuff, note the growth on the graph of the “green” hydro and biomass band. I found another graph which shows that it was not hydro that was growing:

    http://www.triplepundit.com/2014/04/german-renewable-electricity-consumption-hits-record-high-25-4-percent-2013/

    • Canman,
      Yet again we see that the “greens” are deceptive with the data, and that implementing green policies does not result in meeting their stated goals.

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