Biofuels - Fuels Generated from Biomass - Biodiesel, ethanol and methane

What is biodiesel?  Biodiesel.org states: "Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics. It is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil. The process leaves behind two products -- methyl esters (the chemical name for biodiesel) and glycerin (a valuable byproduct usually sold to be used in soaps and other products).  Biodiesel is better for the environment because it is made from renewable resources and has lower emissions compared to petroleum diesel. It is less toxic than table salt and biodegrades as fast as sugar. Since it is made in the USA from renewable resources such as soybeans, its use decreases our dependence on foreign oil and contributes to our own economy."

Many in the "do-it-yourselfer" crowd have a love affair with biodiesel, as there is a certain treehugger glamour associated with being able to fill up your fuel tank at your local fast food joint rather than your local gas station.  Online instructions for making your own biodiesel abound, and folks like the Veggie Van travel across the country on "waste" oil.

Although it's a nifty way to keep waste oil out of the landfill and potentially lessen our dependence on foreign oil, biodiesel does have some potential problems.  For "virgin" biodiesel, it's more expensive than regular diesel.  it also may give out more nitrous oxide emissions, depending on how it is blended.  Because of it's viscosity and other traits, biodiesel cannot be transported through pipelines.  This again increases it's cost and environmental impact.  It also starts to gel at low temperatures, significantly more so than standard diesel, which can clog fuel lines and filters.  In addition, because of it's chemical composition, it acts as a solvent in the fuel system.  Standard diesel tends to leave deposits which are dissolved by the biodiesel, which cleans out your engine, which is good, right?  Not exactly.  What usually happens is that it breaks up the chunks where they're not causing a problem and moves them into a narrow passageway (like a fuel line) and plugs it up.  So you can't easily switch back and forth from biodiesel to regular fuel.  This solvent property may also "eat" some seals in older vehicles.  I'm not saying that we shouldn't use biodiesel, I'm just saying that we need to be aware that it's not a simple one for one swap.

On to ethanol...Ethanol.org explains ethanol as "a clean-burning, high-octane fuel that is produced from renewable sources. At its most basic, ethanol is grain alcohol, produced from crops such as corn. Because it is domestically produced, ethanol helps reduce America's dependence upon foreign sources of energy.  Pure, 100% ethanol is not generally used as a motor fuel; instead, a percentage of ethanol is combined with unleaded gasoline. This is beneficial because the ethanol decreases the fuel's cost, increases the fuel's octane rating and decreases gasoline's harmful emissions."

Ethanol has been hailed by many (including the president) as a major piece of the puzzle in breaking our reliance on Middle Eastern oil.  It's lauded far and wide for it's "greenness", and hailed as a great boon to farmers.  I'm more than a little reluctant to buy into the hype.  For one thing, it bothers me that we're putting a potential food source in our gas tanks.  What happens to farmers who buy corn for their livestock when the price goes up due to the demand of the ethanol plants?  What happens to our grocery bill?  Will marginal lands that really should not be under cultivation be put into production with monocropping and heavy use of chemical fertilizers and pesticides to force their production of corn?  Will the increase in ethanol use do more environmental harm than good because of this expansion of resource intensive agribusiness?  I am hopeful that we will see further developments, including projects such as the E3 Biofuels Complex and commercialization of ethanol production from switchgrass or cellulose or other crops less resource intensive to produce than corn grains.

E3 BioFuels Complex Combines Dairy or Beef Cattle, Waste Management, and Ethanol Production - The system incorporates a dairy or feedlot, an ethanol production process, and an anaerobic digester into a self-sustaining, closed-loop system. The manure from the livestock is handled by an on-site waste management facility and turned into biogas. This biogas powers the ethanol production process, eliminating fossil fuel costs. Wet distillers grain – a co-product of the ethanol production process – is fed to the livestock, completing the loop.   In an article in yahoo news, E3 BioFuels chairman Dennis Langley said that "his plants are more cost-efficient than competitors. A traditional ethanol plant requires about 1 British thermal unit (btu) to make 2 to 2.5 btus of ethanol, while Genesis will use 1 btu to make 46.67 btus of ethanol." 

While I am not a fan of feedlot cattle production, if you're going to do it anyway, this is an intelligent way to deal with the waste issue.  On a side track, CowPots are another well thought way to manage excess cow poop.  This product was developed by brothers Matt and Ben Freund of Connecticut.  The process is described as follows on their website:  "Raw manure from the cows is heated and stored in a large tank for 20 days.  The methane gas is collected and burned.  At the end of this process the solids are separated from the liquid. The liquid goes back to the field to grow next year’s crops which feed the cows. The solids continue processing in an in-vessel composter.  It is this composted manure that is weed-seed free, and is used to mold CowPots™."

And a bit about Methane...If you've got lemons, you make lemonade, if you've got cow poop you make methane (and/or CowPots).  How does it work?  The Midwest Renewable Energy Council explains: "Anaerobic digesters convert the energy stored in organic materials present in manure into biogas. Biogas can be fed directly into a gas-fired combustion turbine. The type of turbine most often used for small-scale electricity production is the microturbine. Combustion of biogas converts the energy stored in the bonds of the molecules of the methane contained in the biogas into mechanical energy as it spins a turbine. The mechanical energy produced by biogas combustion in an engine or microturbine spins a turbine that produces a stream of electrons, or, electricity. In addition, waste heat from these engines can provide heating or hot water for use on farm."

I like the potential of this technology.  It seems like a better way to manage manure, producing energy, reducing pathogens and generating by products that can still be used to improve soil fertility.  I've seen enough stories about well contamination from raw manure being spread improperly to have concerns.  If we can compost animal manure for energy, what about people manure (humanure)?  Using a combination of anaerobic decomposition and composting to process waste would kill a very high percentage of pathogens.  It's not 100%, but it's more effective than many treatment systems currently in use.  Although few and far between, some municipal scale humanure composting situations exist, such as the one in Aya Town in Miyazaki Prefecture in Japan. Our current waste disposal may be easier, but as resources become more strained can we really continue to afford to defecate in potable water, flush it away with more potable water, treat it with chemicals and dump the whole mess back into our waterways?  The logistics are challenging, but the potential is enormous.

Methane hydrates are another possible alternative as conventional fossil fuel supplies dwindle, but right now their exploitation is predominantly theoretical.  (Methane hydrates are not biofuels, i.e., fuels generated from biomass, but I thought I would put them in this section because they are and alternative source of methane that didn't fit in anywhere else.)  Getting locked into yet another limited fossil fuel resource doesn't seem to be a logical choice, but our society is what it is and right now it demands carbon based fuels.  If you'd like to learn more, you can view the report from the USGS below or visit the 4th International Workshop on Methane Hydrate R&D.

Links

Wisconsin Ethanol Coalition - The Wisconsin Ethanol Coalition is a collection of organizations working together to promote the the environmental and economic benefits of ethanol to the State of Wisconsin.

Study: Ethanol won't solve energy problems - A report featured in  USA Today that outlines many of the challenges faced by the ethanol industry.

Gas (Methane) Hydrates -- A New Frontier  - A report by the U.S. Geological Survey - Methane trapped in marine sediments as a hydrate represents such an immense carbon reservoir that it must be considered a dominant factor in estimating unconventional energy resources; the role of methane as a 'greenhouse' gas also must be carefully assessed.