Bioethanol ... a drain on water resources?

Article in Science Daily.

The scientists made a new estimate of bioethanol's impact on the water supply using detailed irrigation data from 41 states. They found that bioethanol's water requirements can be as high as 861 billion gallons of water from the corn field to the fuel pump in 2007. And a gallon of ethanol may require up to over 2,100 gallons of water from farm to fuel pump, depending on the regional irrigation practice in growing corn.

If you look at the map, part of the area that is farmed for corn sits on top of the Ogallala Aquifer. Unfortunately, it's a water resource that feeds the nation, and it's beginning to fail. Back in 2007 the non-profit Environmental Defense issued a report on bioethanol and its impact on the Ogallala Aquifer. In the report titled Potential Impacts of Biofuels Expansion on Natural Resources: A Case Study On The Ogallala Aquifer Region (PDF, 18 pages) they state:

In the areas of highest Ogallala Aquifer depletion, new corn ethanol plants currently under construction or planned will increase the region’s ethanol production capacity by 900%. The area currently hosts only five ethanol plants with combined production of 71.5 million gallons per year, but another nine plants, with 639 million gallons per year capacity, are currently under construction. This dramatic expansion of ethanol production has substantial implications for already strained water and grassland resources in the Ogallala Aquifer region.

Water demands associated with individual ethanol plants—due both to ethanol processing and growing corn feedstock—are not exceptionally higher than demands from other industrial or agricultural users, but the construction of new ethanol plants in areas of existing water stress will exacerbate conflicts if water is already scarce. Water demands from new ethanol plants in areas of Ogallala Aquifer depletion may reach 2.6 billion gallons per year for corn-to-fuel processing alone, and between 59 and 120 billion gallons per year for increased water demand if there are local increases in irrigated corn production.

Now, look at those numbers and consider this ... if the above report (at the very top) is true, and water estimates may be 3 times as high as previously considered ... we're talking up to an additional 360 billion gallons of water per year drained out of that aquifer.

Once that water is gone, it's gone. You can't replenish that aquifer any other way that by rainfall, and that's just not going to happen.

Celebrity Death Match - Biodiesel vs Bioethanol (Part II)

When I first came up with the title "Celebrity Death Match" for this series, I was actually referring to a spat in the pages of Trends in Biotechnology, rather than biodiesel versus bioethanol. Specifically, I was speaking about the exchange between Lucas Reijnders and Yusuf Chisti, which I will cover in this blog entry. But hey, the shoe fits, so I'll take credit for the double entendre.

I love these sorts of exchanges. Perhaps the romantic in me believes this is how science discuss was handled in days long gone. Scientists would converge at their respective Academies of Science and debate the pertinent issues of the day. You don't really see that nowadays. Occasionally you'll see a jab or two in a manuscript, but you hardly ever see two scientists butting heads publically. Or, maybe I'm not reading enough of the literature. Given the topic however, this shouldn't come as much of a surprise. Everyone is trying to fill the much needed "new fuel source" niche, so people are going to enter their horse into the fray when they can.

After Yusuf Chisti published the opinion piece mentioned earlier, Lucas Reijnders shot back a letter entitled "Do biofuels from microalgae beat biofuels from terrestrial plants?" to Trends in Biotechnology, the conclusion of which said basically that Chisti was wrong (see Reference #1).

Why?

According to Reijnders, Chisti forgot to consider some "hidden expenses". Reijnders writes:

However, Chisti did not consider fossil fuel inputs during the biofuel life cycle. Fossil fuels are currently used for building the facilities (bioreactor, pond) and for operational activities such as supplying nutrients, maintenance, mixing, the collection of microalgae and biomass processing.

The letter goes on to say that while algae do produce more biomass, they take more fossil fuels to process ...

Empirical data show that, in practie, sugarcane and oil palm yield less biomass than the 100 Mg per hectare per year (dry weight) for Spirulina ... but these terrestrial plants are characterized by lower fossil fuel inputs into the biofuel life cycle for a specified amount of biofuel energy than in the case of the microalgal biofuels studies mentioned before.

Doubt is also raised as to whether reported yields of microalgal biomass will be achievable in practice, and a citation is provided to support the fact that when compared to current commercial facilities, the reported values are well over what has currently been achieved.

Not so fast buddy

To Reijnders comments, Chisti responds back in the same issue in the letter entitled "Response to Reijnders: Do biofuels from microalgae beat biofuels from terrestrial plants?" (see Reference #2).

Chisti takes issue with the two algal reports cited by Reijnders, saying ...

However, both these studies show little understanding of large-scale algae culture and grossly overestimate the fossil energy required in producing algal biofuels.

Chisti in the next couple of paragraphs cites a couple of instances of where the Hirano and Sawayama studies went wrong.

Chisti then takes a moment to point out that ~45% of the fossil energy input into algal biomass is linked to fertilizer. It is then pointed out that most of the added fertilizer re-emerges in the liquid effluent of the anaerobic digesters, which will be reused (remember the figure from Part I). This cuts down on the fertilizer costs by a third.

To close, if microalgal systems were in place, ~11% of cropping land would be needed to supply all US transport fuel needs. For bioethanol to do something similar, ~70% of all US cropping area will be needed.

While the discussion between Chisti and Reijnders may be over for now, this is probably not the end of the issue entirely. We still haven't picked another basket to put some, or all, of our eggs into. Meanwhile the price of food and fuel continue to rise.

References

1. REIJNDERS, L. (2008). Do biofuels from microalgae beat biofuels from terrestrial plants?. Trends in Biotechnology, 26(7), 349-350. DOI: 10.1016/j.tibtech.2008.04.001

2. CHISTI, Y. (2008). Response to Reijnders: Do biofuels from microalgae beat biofuels from terrestrial plants?. Trends in Biotechnology, 26(7), 351-352. DOI: 10.1016/j.tibtech.2008.04.002

Celebrity Death Match - Biodiesel vs. Bioethanol (Part I)

A fight for the ages, and it's being waged through the pages of Trends in Biotechnology!

In 2007, Yusuf Chisti published an opinion piece in Trends in Biotechnology with the title "Biodiesel from microalgae beats bioethanol" (see reference, below). In this article, Dr. Chisti laid out the rationale as to why we should seriously look at biodiesel from microalgae. In the abstract, Chisti states ...

Biodiesel from microalgae seems to be the only renewable biofuel that has the potential to completely displace petroleum-derived transport fuels without adversely affecting supply of food and other crop products.

Say it ain't so! You mean to say, that if we rely on food crops to develop ethanol ... we're going to adversely affect our supply of food? Who would've seen that coming?!?

Let's score it:
Yusuf Chisti: 1
Ethanol Lobby: 0

Figure 1 of the opinion piece lays out a conceptual system (see image below) for producing this microalgal oil for biodiesel. As you can see, not only does the algae have use as an oil source, the remaining byproducts can be used for anaerobic digestion. If you recall my earlier talks, anaerobic digestion produces methane. When this methane is cleansed of contaminants, it is indistinguishable from the natural gas (which is methane) which we use daily to heat our homes, produce electricity, cook our food ... and even some vehicles use as fuel.

And it doesn't stop there. If you use the methane/biogas for power generation (for sale on the grid, and to run the algae production process), you wind up with carbon dioxide. That carbon dioxide can be shuttled back to the algae biomass production area for re-use by the algae in photosynthesis. Very little carbon dioxide will be released into the atmosphere, and very little fossil fuel will be used to run the process. In essence making the system "carbon neutral, as Chisti states:

Ideally, the microalgal biodiesel can be carbon neutral, because all the power needed for producing and processing the algae could potentially come from biodiesel itself and from methane produced by anaerobic digestion of the biomass residue left behind after the oil has been extracted.

Biodiesel kicks bioethanols ass

This section of the opinion piece starts off looking at the algal biodiesel compared to sugarcane bioethanol because "sugarcane bioethanol can be produced at a price comparable to that of gasoline". Simply put, when considering similar levels of energy recovery, sugarcane ethanol produces less than half that recoverable from algal biodiesel (75 metric tons of biomass per hectare for sugarcane versus 158 tons per hectare for microalgal biomass).

So what's stopping us?

In short: economics. The technology, while there in part, is not there in force. However, if the demand were there for microalgal processing equipment, the costs in machinery would eventually come down. Another issue is that of drying technology. Drying (removal of water) is a huge energy cost and additional research into processes which can dry the algae cheaply are needed. Thirdly, further research into the genetics of algae is needed. Increases in production of algal oil metabolism would result in greater yields of oil, resulting in lower production costs per barrel of algal oil.

As Chisti explains:

At this price [$100/barrel], microalgal biomass with an oil content of 55% will need to be produced at less than ~$340/ton to be competitive with petroleum diesel. Literature suggests that, currently, microalgal biomass can be produced for around $3000/ton.

But don't lose heart! Chisti goes on to say:

This analysis disregards possible income from biomass residues. In addition, converting M tons of algal biomass to biodiesel is likely to prove less expensive than converting a barrel of crude petroleum to various fuels. Nevertheless, the assessment given here provides an indication of what needs to be achieved for making algal biodiesel competitive with petrodiesel. A high threshold is placed on competitiveness of microalgal biodiesel by comparing it with petrodiesel: none of the biodiesel being produced commercially from soybean oil in the US and canola oil in Europe can compete with petroleum-derived diesel without the tax credits, carbon credits and other similar subsidies that it receives.

So, we need to get the costs down. I don't think this is an obstacle that cannot be overcome. With the proper infrastructure put in place, to produce and then process large loads of algal biomass, the costs will come down. Further advances in technology will likewise increase oil yields and reduce costs even more. It's not as if the petroleum market dropped into our laps as a full-grown adult, did it? It didn't, and while it currently remains "cheap" and I say "cheap" in comparison to other technologies ... it won't always remain the most economically viable commodity. And that doesn't even begin to address the fact that oil is a matter of national security. The point is ... we need to get these other technologies online NOW, so when the petroleum bubble DOES burst, we have a suitable alternative. Chisti demonstrates that biodiesel from algal biomass can be a basket we can put our eggs into.

Or ... maybe not? [cliffhanger - See Part II)

References

CHISTI, Y. (2008). Biodiesel from microalgae beats bioethanol. Trends in Biotechnology, 26(3), 126-131. DOI: 10.1016/j.tibtech.2007.12.002

Ethanol in the tank ...

Ethanol producers hurting. Big time.

While environmentalists have warned that the rapid growth of ethanol posed a danger to sustainability, the alarm may be somewhat misplaced. Oil has topped $122 a barrel and could be heading to $150. But the ethanol bubble has already popped. The recent poor results from ethanol producers is far more likely to hinder further development than any change in government policy.

Well, it was fun while it lasted, no?

That sure was quick.

Newsflash: Bioethanol Still Bad Idea

According to this article at least.

Indeed, many livestock operations are getting hit with a double whammy. First, they’re paying more for each ton of corn-derived feed. At least as importantly, a new study finds, the corn product that’s they're feeding to their animals can be anticipated to carry triple the normal load of fungal toxins.

Because those fungal poisons — or mycotoxins — threaten the health of animals, farmers can look for reduced livestock growth, especially in swine.

The new analysis conservatively estimates the current cost to U.S. hog producers from just one of those toxins, fumonisin, at about $9 million a year.