Jim Lane

“To Carthage then I came
Burning burning burning burning”
T.S. Eliot, The Waste Land

Recently, among the list of countries in which Biofuels Digest readers reside, appeared a new addition: the Vatican City. I cannot shake the improbable hope that the Pope has taken an interest in bioenergy. He certainly has taken a deep interest in climate change.

“Perhaps reluctantly we come to acknowledge,” Pope Benedict wrote last March, “that there are also scars which mark the surface of our earth: erosion, deforestation, the squandering of the world’s mineral and ocean resources in order to fuel an insatiable consumption”

Of all the developments in bioenergy, I figure Pope Benedict as a fan of waste-to-energy. What better way to use the modern symbol of western excess — the landfill — than to convert it to fuels that can power everything from African cookstoves to the Pope’s own Mercedes M-Class SUV?

For that reason, as well as persuasive economics, I haven’t been able lately to get through an entire day without thinking about the promise of companies, such as BlueFire Ethanol and Agresti Biofuels, that are on the verge of a revolution in waste-to-fuel production.

Neither of the two is as well known as they should be, although BlueFire has probably received more coverage for its Arkenol process for converting municipal solid waste to ethanol, winning a $40 million DOE grant to build a demonstration-scale cellulosic ethanol plant. BlueFire’s technology is a sulphuric acid hydrolysis, which converts cellulose to a fermentable sugar without the use of expensive designer enzymes.

Some background on acid hydrolysis

It’s based on the acid hydrolysis method first developed in Germany in 1898; by 1932 German researchers had been able to generate up to 50 gallons of ethanol per ton of dry wood biomass using the techniques.

Agresti also uses weak acid hydrolysis, although they have a unique approach. They use a gravity pressure vessel, that draws the biomass down into a 2000-foot deep borehole, using gravity and heat to provide an energy source that, when oxygen is introduced at the bottom burns off the lignin, converts the cellulose to sugars which can be fermented into ethanol, and melts the lignin away.

Sulphur and oxygen - literally the stuff of fire and brimstone. Scientists call it oxidation, but  the man in the street calls it burning, albeit a slow kind that doesn’t result in a fire. Burn, baby, burn. That’s an answer to last summer’s “drill, baby, drill”, and to a burning question.

The tale of the tape

Enough science. What is important to know about the process is that it produces up to 50 gallons of ethanol per ton of municipal solid waste in a commercially viable manner.

I can’t quite get it out of my head because, in solid waste, we have a large and replenishing source of biomass that no one uses, people pay to get rid of, and for which we already have an aggregation system in place. Around five pounds of garbage per person, per day, aggregated on a city or county-wide basis not by hard-pressed bioenergy producers but by municipal order. No need to harvest switchgrass, corn stover or cobs.

There are more than 180 municipalities with populations of 250,000 or more in the United States - right now, the viability point for these systems, but they hold 75 percent of the US population and presumably three-quarters of the garbage. Actually, since the archives of the Grocers Manufacturing Associations’ jihad against biofuels are located in an urban area, the garbage percentage is probably even higher than three-quarters.

That’s about 200 million tons of municipal solid waste, or enough to generate 10 billion gallons of ethanol at 50 gallons per ton. The capital cost is around $200 million per 1600 ton per day facility on a 12-18 acre footprint, according to Agresti, and around $320 million for a 3200 ton per day facility that produces 58 Mgy of ethanol per year. That’s a high capital cost, compared to other advanced biofuels, but the ethanol production cost is well below $1 per gallon and the control over future feedstock price swings is absolute.

According to my back of the envelope calculations, a community that opts for this model will produce ethanol at a retail price of around $1.10, which is equivalent (on a fuel economy basis) to $1.46 gasoline. That’s about a 50 cent discount today to the retail price of gasoline, even at oil prices that are 60 percent down from last summer. Plus, no need for a $1.00 per gallon advanced biofuels subsidy or the ethanol tariff. That’s a total savings to the taxpayer of $1.50 per gallon in today’s economics, and much more if the price of oil skyrockets again. It adds up to a $44 million return on 29 million gallons of fuel per $200 million plant, or around a 4-year payback on the cost of building out the biorefinery.

The math looks good to me, and the emissions benefits are excellent, because it would be a hard-hearted biofuels hater who would not see that the direct and indirect land-use impact is practically nil, and waste-to-ethanol presents a strong carbon emissions opportunity compared to crop-based biofuels, or gasoline.

The financing problem

Capital is a problem, but municipalities can help themselves by guaranteeing the project debt or issuing bonds, which shifts the risk from project to the town, reducing the cost of financing and giving buyers of municipal bonds something to crow about. 

Even better would be for the United States to guarantee the debt through the Treasury, making it possible to offer investors the safety of US Treasuries combined with the higher yields of commercial paper. 

A $70 billion investment would pay back in five years, march us 10 billion gallons towards energy independence or about 6% of US gasoline demand, tariff-free, subsidy-free, with a great emissions story.

Acid hydrolysis is so old a process that it seems too old-fashioned to capture our imagination like the real-time scientific endeavor of making algae into energy. For acid hydrolysis and waste-to-energy, it has been a long time coming; a long, slow burn indeed.

Feel the Burn

Like a burn, it itches, and compels attention, and it should. For what are we burning but the excess slop of a western lifestyle that, were it adopted by the whole of the brotherhood of man, would be utterly unsustainable?

It’s garbage worth burning, for it is a vanity, and waste-to-energy is a bonfire of the vanities.

As St. Augustine wrote in the Confessions: “What innumerable toys…far exceeding all necessary and moderate use and all pious meaning, have men added to tempt their own eyes withal”. 

I can imagine even the Pope being delighted with a process that, sustainably and economically, converts the refuse from our ‘innumerable toys’ into useful, clean and affordable energy.

“Feel the burn,” say our personal trainers, urging us to fight, and fight more to work off the fat. In waste-to-energy, we have a burn that is worth feeling, and worth fighting for.