Biofuels and nitrous oxide


in Economics, Law, Politics, Science, The environment

In theory, biofuels are an appealing climate change solution. They derive the carbon inside them from atmospheric CO2 and their energy from the sun. They can be used in existing vehicles and generators, and store a lot of energy per unit of volume or weight. The raw materials can be grown in many places, without massive capital investment. Of course, recent history has given scientists and policymakers an increasingly clear understanding of the many problems with biofuels. A report (PDF) from Scientific Committee on Problems of the Environment (SCOPE) of the International Council for Science (ICSU) concludes that, so far, biofuel production has actually produced more emissions than using fossil fuels would have. Partly, this is on account of the nitrous oxide emissions associated with the use of artificial fertilizers in agriculture. Over a 100 year period, one tonne of nitrous oxide causes as much warming as 310 tonnes of carbon dioxide. Corn produces especially large amounts of nitrous oxide, because it has a shallow root system and only takes in nitrogen for a few months each year.

It is possible that better feedstocks, agricultural techniques, and biofuel production processes will eventually make these fuels ecologically viable. Not all transportation can be electrified, and there will probably always be industrial processes that require petroleum-like feedstocks. Nonetheless, it must be recognized that the world has been going about biofuel production in the wrong way. That is something that should be borne in mind particularly by the citizens of states that are lavishing government support on them, both in the form of subsidies and by mandating that they comprise a certain proportion of transportation fuels.

{ 5 comments… read them below or add one }

BuddyRich April 25, 2009 at 8:48 am

I was going to comment something like:

“Then they should move to organic production if the fertilizer is the problem…”

Then I thought, if the NO2 is emitted during growth, is it the creation of the synthetic fertilizer or the mere use of it that is the source of emission? What I am getting at is, would a natural fertilizer (manure, etc.) release as much NO2 as a synthetic one? I would think it would release some but would it be a lessor amount to tip the scales in ethanol’s favour?

Tangentially, I have heard that because of the predominant use of corn in their construction, the plastic-like biodegradable bags many stores are turning to as an alternative to the regular plastic bag (rather than going cloth) are worse from a CO2 standpoint than plastic, though at least they biodegrade. So this doesn’t surprise me.

I think its disingenuous to lump all bio-fuels together. I think algae-based bio-diesel is where its at in the medium term (though diesel in general is not as good in our cold climate), however food-based ethanol is wrong on many different levels.

I added the food-based in their because I have read some stuff on cellulosic ethanol and there have been many promising breakthroughs, such as the one by researchers at the University of Georgia that use grass or other waste based sources to create ethanol. Ff you can use grass rather than corn then you are much more carbon neutral, as this study conducted by researchers at the University of Illinois showed.

. April 26, 2009 at 6:26 pm

The environment

Apr 8th 2009
From The Economist print edition
Farming biofuels produces nitrous oxide. This is bad for climate change

“The ICSU report concludes that, so far, the production of biofuels has aggravated rather than ameliorated global warming. In particular, it supports some controversial findings published in 2007 by Paul Crutzen of the Max Planck Institute for Chemistry in Mainz, Germany. Dr Crutzen concluded that most analyses had underestimated the importance to global warming of a gas called nitrous oxide (N2O) by a factor of between three and five. The amount of this gas released by farming biofuel crops such as maize and rape probably negates by itself any advantage offered by reduced emissions of CO2.

N2O is made by bacteria that live in soil and water and, these days, their raw material is often the nitrogen-rich fertiliser that modern farming requires. Since the 1960s the amount of fertiliser used by farmers has increased sixfold, and not all of that extra nitrogen ends up in their crops. Maize, in particular, is described by experts in the field as a “nitrogen-leaky” plant because it has shallow roots and takes up nitrogen for only a few months of the year. This would make maize (which is one of the main sources of biofuel) a particularly bad contributor to global N2O emissions.”

. May 19, 2009 at 4:29 pm

GreenFuel Bites the Dust

By Robert Rapier

I have written several articles over the past couple of years that argued that there is a low probability that any of the would-be algal biodiesel manufacturers are going to make it. These essays included:

More Reality Checks for Algal Biodiesel

The Prospects for Algal Biodiesel Dim

In both essays, I mentioned GreenFuel Technologies, which arose out of research done at MIT, and was the highest-profile (and well-funded) company working on algal biodiesel.

. May 19, 2009 at 4:30 pm

“Based on first principles of solar insolation falling on a square meter of land, the maximum algal biodiesel yield you could expect to get is around 1 gallon/square meter/yr. Not only do photobioreactors cost over $100/square meter (so you are paying $100 capital to produce 1 gallon per year), but GreenFuel was claiming that they could get 11 gallons/square meter/yr.

Well, the laws of thermodynamics have now caught up with them”

. June 5, 2009 at 3:55 pm

Book Review: Green Algae Strategy
By Robert Rapier

I love to read. I particularly enjoy books about energy, sustainability, and the environment. One of the benefits of reviewing books is that I end up getting a lot of free books on these topics. One thing about getting free books, though, is that I have to be careful that it doesn’t impact my objectivity. After all, the publisher or author was nice enough to send me this free book. How do I then approach the matter if I sharply disagree with some aspects of the book?

I am on record as being very skeptical about the ability of algal biodiesel to scale up and contribute significantly toward liquid energy supplies. Mark Edwards, a Professor of Strategic Marketing and Sustainability at Arizona State University recently saw one of my essays, and said that while he agreed with my points that many algal producers have been overly optimistic, he also felt like I had glossed over algae’s potential. He offered to send me a copy of his book Green Algae Strategy: End Oil Imports And Engineer Sustainable Food And Fuel.

The first thing I thought when I saw that title is “Either Mark Edwards is dead wrong, or I am dead wrong.” But I believe it is important to read and understand a wide range of viewpoints, because I just might change my mind. Maybe I am dead wrong. This book won the 2009 IPPY award for the best science book, so there are definitely those who think Mark makes a good case.

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