To Strive, To Seek, to Find, and max out yields

March 22, 2012 |

Yield unlocks value, and especially feedstock yield. What’s the latest? What feedstocks are reporting yields that could support 1000+ gallons per acre for terrestrial crops?

It was President Kennedy’s favorite poem, Tennyson’s Ulysses, with its stirring coda:

We are not now that strength which in old days 

Moved earth and heaven, that which we are, we are,

One equal temper of heroic hearts, 

Made weak by time and fate, but strong in will 

To strive, to seek, to find, and not to yield.

Of course, in bioenergy, we have to adjust that “not to yield” into a “help me, brother, to max out yield.”

Nothing is more important than yield, in these nefarious emission-loving days that have come upon us in lusty choruses of “drill, baby, drill.” Yield is your Defense Against the Dark Arts.

Yield from the acre, yield from the ton, yield from the dollar. Yield is the to key to parity, survival, finance, glory, profit, all the biggies.

Of course, we have learned to be careful about yield claims. As Algae’s Dr. No, John Benemann writes:

“Unfortunately, [they] are just following the inverse law of knowledge: the less you know the better it looks, and vice-versa.  Now that they understand a little about lignocellulosic ethanol, gosh, it does not looks so good anymore, so let us drop this flame and go on a date with pond scum, that looks really good as we don’t know anything.  One of these days it will dawn on these worthies that neither algae nor ethanol nor whatever will not be THE solution to the oil or climate change or whatever problem, and then we can start doing something rational.”

The feedstock enthusiasm cycle

The five stages of yield and claim could be neatly summarized for many feedstocks, thus:

Stage 1. Eureka! [name your feedstock] could solve everything, if there was more R&D.

Stage 2. Oops! [feedstock] will solve everything in five years, but needs a transitional subsidy.

Stage 3. Shame! [feedstock] will cause deforestation in the Amazon.

Stage 4. Scam! The numbers are inflated. It’s all hype. [feedstock] will solve nothing.

Stage 5. [After a suitable forgetting period, say five years] Return to Stage 1 and repeat forever.

Not all feedstocks fall into this “claim and shame” cycle. There are an increasing number of serious feedstocks developers around – Mendel for miscanthus, Ceres for switchgrass and energy cane, Chromatin for sorghum, SG Biofuels for jatropha, BAL for seaweed, and Agrisoma for carinata, just to name a handful.

Here are some of the latest claims on yield.

Micro-algae,up to 60 tons of biomass containing 3,800 gallons of algal oil per acre per year,” Cellana.

Seaweed. Up to 50 tons per acre, from BAL.

Miscanthus. Up to 12-13 dry tons per acre, from Mendel “”in places like Mississippi and Louisiana”) and LA.

Sorghum. 10-12 dry tons per acre, Chromatin. “Today, our sorghum is expected to have an energy content that is more than 70 percent of coal – roughly equivalent to firewood,” adds Chromatin CEO Daphne Preuss. “Our breeding and crop engineering program is generating new varieties of sorghum that are expected to have an even higher energy content with lower levels of ash and other contaminants. Sure, yield drives value, but you need to have quality.”

Lignin-modified eucalyptus trees, 10 tons per acre, ArborGen

Hybrid switchgrass, 9.4 tons per acre, USDA.

Bioenergy switchgrass, 7.4 tons per acre, USDA.

Shawnee switchgrass, 5 tons per acre, USDA.

Corn stover, 2-3.5 recoverable tons per acre, various producers including POET.

Managed native prairie, 2.5 tons per acre, USDA.

Low-input, high-diversity prairie, 1.75 tons per acre, USDA.

The bottom line.

Yields in the 8+ tons per acre range are impressive indeed. At 100 gallons per ton (conversion rates for best-of-breed cellulosic biofuels projects that do not recapture CO2), those are in the 800 gallons per acre range, comparable to sugarcane and well ahead of, say, corn.

But we will investigate, tomorrow, the impact of the new yields on production costs, as we release our updated 2012 Biofuels Venture Valuation Tool.

Category: Fuels

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