Credit: Nigel Buchanan
It is the worst stuff in the world. Eighteen tonnes of turkey offal – rotting heads, gnarled feet, slimy intestines and lungs swollen with putrid gasses – slides down a dump truck bed and sloshes into an 24-metre-long hopper with a sickening glorp. The smell is worse than the sight: an assertive mélange of midsummer corpse with fried liver overtones and a distinct faecal note.
But two hours later, sterile as you please, an oil truck pulls up behind this Thermal Conversion Process plant in the small American Midwest town of Carthage, Missouri, and the driver attaches a hose from a nearby stationary tank to the truck's intake valve. One hundred and fifty barrels of fuel oil (23,800 L), worth US$12,300, gush into the truck's tank, and off it goes to an oil company that will blend it with heavier fossil-fuel oil to upgrade the stock.
Three such trucks arrive here daily, loading up with the day's production of 500 barrels of oil made from 270 tonnes of turkey guts and 20 tonnes of pork fat. Most of what can't be made into oil becomes high-grade fertiliser; and the rest is water clean enough to discharge into a municipal wastewater system.
"This is a real plant," says Brian Appel, chief executive of Changing World Technologies, the company behind the offal-to-oil alchemy. "This is the first commercial biorefinery in the world that can make oil from a variety of waste streams."
He nods towards the US$42 million facility, which resembles a generic industrial plant from a James Bond movie's climactic shootout: A collection of tanks, pipes, pumps, grinders, boilers and catwalks inside a corrugated steel building. It is perched some 90 metres from ConAgra Foods Corporation's Butterball plant, where 35,000 turkeys die daily and surrender their viscera to Appel's operation; the pork fat comes from four other Midwestern ConAgra slaughterhouses.
"To anybody who thinks this can't work on an industrial scale, I say, 'Come here and look,'" says Appel with a grin.
Forget about straw into gold. The Thermal Conversion Process can take stuff that's far worse than straw – slaughterhouse waste, municipal sewage, old tyres, mixed plastics... virtually all the wretched, varied, voluminous detritus of modern life – and make from it something the world needs much more than gold: high-quality oil.
"This is a solution to three of the biggest problems facing mankind," says Appel. "This process can deal with the world's waste; it can supplement our dwindling supplies of oil; and it can slow global warming."
Pardon me, says a reporter, but that sounds too good to be true.
"Everybody says that," says Appel. No wonder. Unlike other solid-to-liquid-fuel processes such as cornstarch into ethanol, company officials say this one will accept almost any carbon-based material.
If a 79 kg man fell into one end, he would come out the other end as 17 kg of oil, 3 kg of gas, and 3 kg of minerals and 56 kg of sterilised water. And while no one plans to put people into a Thermal Conversion machine, an intimate human creation could certainly become a prime feedstock.
"There is no reason why we can't turn sewage, including human excrement, into a glorious oil," says Terry Adams, Changing World Technologies' chief technology officer. So the city of Philadelphia, Pennsylvania, is in discussion with Appel's company to begin doing exactly that.
Appel's is far from the only voice lauding the Thermal Conversion Process. "This is not an incremental change. This is a big, new step," says Alf Andreassen, a venture capitalist and a former Bell Laboratories director.
"I'm impressed," adds Gabriel Miller, a New York University chemistry professor and a consultant to Keyspan Energy Corporation, an electric supplier that serves New York City.
"The fuel that comes out is better than crude, and you don't need a refinery to use it. I think they can bring it deep into commercialisation." Miller recommended that Keyspan burn the oil in its generators. Keyspan is running tests now, with an eye to investing in its own Thermal Conversion Process plant in New York State. In the meantime, Appel sells the plant's oil to a "large oil blender" whose name he is contractually bound not to reveal.
"The technology is sound and the science really works," says Michael Walter, ConAgra Foods' senior vice-president responsible for commodity procurement.
But the fact that a process works chemically is no guarantee it makes sense economically. Renewable Environmental Solutions, the joint venture of ConAgra Foods and Changing World Technologies that runs the Carthage plant was expected to have become profitable (just) in January 2006 – after three years of losses. Poor contractor workmanship, political snafus and odour-pollution problems have all driven up production costs.
In 2003, Appel predicted the Carthage plant would make oil for about US$15 a barrel. But the actual production cost turned out to be US$80; meaning for most of the plant's working life, he has lost up to US$40 a barrel at the contracted price. As recently as April 2006, he fretted that the operation might collapse.
"There have definitely been growing pains," he concedes. "We have made mistakes. We were too aggressive in our earlier projections."
But today, after nearly US$100 million in private funding and some US$17 million in government grants, several hurdles have tumbled. The Carthage plant is in continuous production. A tax credit has levelled the playing field with other renewable fuels such as biodiesel and ethanol. The odour issues with the authorities have stopped.
Appel is a former basketball star for Hofstra, a university in northern New York State, and a ticket-sales marketing executive who taught himself organic chemistry. He leans his 196-cm frame against a bench in the company's lab and rubs his face. The road to profitability has been longer and more costly than he had planned, but he is undaunted, and is planning for the worldwide rollout.
Officials in Europe are especially interested, and ultimately, Appel says, Australia is a logical candidate. "The Australians are large meat producers," he says, adding that any country that is agriculture-rich, oil-poor and environmentally responsible would likely welcome the technology.
In fact, the ultimate irony is that this process, developed in America by Americans, will probably spread more quickly overseas than in its native land.
Appel has Shepperd development of the Thermal Conversion Process (previously known as the Thermal Depolymerisation Process; he changed the unwieldy moniker last year) since 1997, building on organicsolids- into-oil research stretching back nearly a century. By 1999, he had lined up investors, hired engineering staff and had a pilot plant processing seven tonnes of waste daily.
Early in 2003, company officials predicted their first industrial-sized plant would be working around the clock in Carthage by that summer; but poor workmanship pushed that back by about 18 months (Appel has since sued the contractor). Continuous production still didn't start until February 2005.
Which is surprising, because at first blush, the Thermal Conversion Process seems quite straightforward. A pressurised pipe pushes raw material into a brawny grinder that chews it into pea-sized bits. Dry raw materials such as tyres and plastics require extra water at this stage, but offal is wet enough.
A first-stage reactor uses heat and pressure to break down the material, after which the pressure rapidly drops, flashing off excess water and minerals. In turkeys, minerals come largely from bones, and are shunted to a storage bin to be dried into a high-calcium fertiliser.
The remaining concentrated organic soup moves to a second reaction tank where it is heated to 260°C. and pressurised to 42 kg/cm2. In just 15 minutes, the process can shorten complex long-chain molecules of hydrogen and carbon into rather shorter and lighter molecules of oil.
Next, the pressure and temperature drop and the soup swirls through a centrifuge that separates the remaining water from the oil. The water, which in the case of slaughterhouse waste is laden with nitrogen and amino acids, is stored to be sold as a high-potency liquid fertiliser. Meanwhile, the oil goes into the storage tank to await the next truck.
The whole process is efficient, says Terry Adams, the company's chief technology officer: only 15 per cent of the potential energy in the feedstock is used to power the operation; 85 per cent is embodied in the output of oil and other products.
There is no magic in the process; in fact, making oil and gas from hydrocarbon-based waste is a trick that Earth mastered long ago. Most crude oil is from single-celled plants and animals that died, settled to ocean floors, decomposed, and were mashed by layers of sediment that settled on top. Under pressure and heat, the dead creatures' long chains of hydrogen, oxygen, and carbon-bearing molecules, known as polymers, decomposed into short-chain petroleum hydrocarbons.
However, Earth takes its own sweet time doing this – generally, thousands or millions of years – because subterranean heat and pressure changes are chaotic. Thermal Conversion turbocharges the process by raising heat and pressure precisely to levels that break the feedstock's molecular bonds.
The oil meets specification D975, a type widely used to power electrical generators. The oil can be sold to utilities as is, or further distilled into vehicle-grade diesel, gasoline, or even steam-reformed into hydrogen.
Depending on the feedstock and cooking times, the process can be tweaked to make other specialty chemicals that may be even more profitable than oil. Turkey offal, forexample, can be used to produce fatty acids for soap, tyres, paints, and lubricants.
Polyvinyl chloride, or PVC – a widely used plastic and popular building material used for cladding and water/waste pipes – yields hydrochloric acid, an industrially valuable chemical used to make cleaners and solvents.
"That's what's so great about making water a friend," says Appel. "The hydrogen in water combines with the chlorine in PVC to make it safe. If you burn PVC [in a waste incinerator], you get dioxin – very toxic."
But if it's so easy, why hasn't anyone done it before? In fact, many scientists have converted organic solids to liquid fuel using waste products with some success, but the drawbacks have been legion.
"The problem with most of these methods was that they tried to do the transformation in one step; to superheat the material to drive off the water, and simultaneously break down the molecules," says Appel.
That leads to profligate energy use and makes it possible for hazardous substances to pollute the final product. Very wet waste – and much waste is wet – is particularly difficult to process efficiently because driving off the water requires so much energy. Usually, the kilojoules trapped in the resulting oil or gas barely exceeds the amount needed to make the stuff.
By using water to limit the chemical reactions and heat the material, then separating out the water via centrifuges and rapid depressurisation rather than boiling it away, "we get great efficiencies," says Appel.
Still, the development process, which Appel has worked on for over a decade, has been far from simple. First, the process needed tweaking. Each variable – temperature, pressure, volume, tank-residence time – needs to match the raw material precisely… which proved to be no mean trick at an industrial scale.
"The really difficult thing has been to find the sweet spot in the process parameters," says Appel. "This isn't a laboratory. We have to respond to the real world of varying supply. If I get two truckloads in a row of feathers, I need to deal with that high-protein peak; if I get too much blood at once, the result is too much water."
Solution: careful management of a feedstock holding tank, which blends the disparate truckloads into a consistent mix.
"Fat, fibre, protein, moisture, ash – getting those right, that's our mantra," says James Freiss, vice president of engineering. "Now, we are able to nail the same quality every day."
Freiss says he and fellow engineers Adams and William Lange, "have learned so much that I am very confident we can build a second plant that's optimised from the start."
But chemistry was far from the only challenge. Since 2004, the Bush government has subsidised biodiesel, usually made from soybeans, to the tune of US$1 a gallon (3.79 L) – but gave nothing for the fuel produced by Appel's plant.
"It was very hard to believe that a competitor could get a dollar a gallon while we were excluded," grouses Appel.
To his relief, that hole was plugged in August: the fuel he makes, known officially as renewable diesel, received a subsidy of US$1 per gallon in the 2005 Energy Bill, which took effect in January 2006. That boosted the company's income by US$42 a barrel. So while Renewable Environmental Solutions makes oil for a lofty cost of US$80 a barrel, it can now sell it for US$82 per barrel, making a slim profit.
Appel offers no apologies for needing government largesse to make money.
"All oil, even fossil fuel oil, gets government subsidies in the form of tax breaks and other incentives," he says. He cites a 1998 study by the International Centre for Technology Assessment (a non-profit research centre in Washington D.C.) showing that unsubsidised conventional petrol would cost consumers as much as US$15 a gallon (about A$3.96 a litre, NZ$4.71 a litre or £1.65 a litre).
"Before we got this, I had the only oil in the world that didn't get a subsidy."
Another hurdle: the plant reeked, and within six months had been hit by as many notices of emissions violation by the Missouri Department of Natural Resources and a lawsuit from the City of Carthage. "It was like rotting flesh. It would sort of get stuck in your nostrils," recalls Mayor Kenneth Johnson. "It was getting bad all the way through town."
Renewable Environmental Solutions spent US$2 million on biofilters, scrubbers and other odour squelchers, and by late September 2005 complaints had dwindled from 20 in a day to "three or four a week" says Mark Rader, who runs the department's southwest regional office. If things go on this way, Rader anticipates no further citations.
"It's much better," says Johnson. "Appel was really committed to fixing it. We want it to work, too. There's about 30 jobs out there now, and we're not talking about minimum wage."
"The smell issue is over," says Appel. "But that was a hard, expensive lesson."
Other barriers still loom. The Thermal Conversion Process is probably the only practical, large-scale method of dismantling prions, the rogue proteins that cause bovine spongiform encephalopathy, or mad cow disease.
The process has never been specifically tested on prions, but Jefferson Tester, a professor of chemical engineering at the Massachusetts Institute of Technology, says he's confident that the proteins would not survive such extreme temperatures and pressures. "Large molecules like that really don't like that kind of environment," he says.
The problem: the disease is thought to spread via the practice – common in the U.S. but banned in many other places – of feeding rendered animal parts back to animals. Appel planned his business on the expectation that the U.S. would comprehensively ban such feeds, creating a huge demand for his machine.
In 1997, the U.S. government banned feeding cattle parts to cattle; but turkey and chicken are still fair game for farm-animal cannibalism, meaning the birds' guts are still valuable to traditional renderers.
"We thought we would get US$24 a tonne for taking the waste," says Appel. "Instead, we are paying US$30 a tonne." That alone raises his production cost by 13 U.S. cents per litre, or nearly US$22 a barrel.
Which brings us to Europe. While the U.S. crawls towards food-safe legislation, Europe is sprinting, eager to stem mad cow disease, staunch global warming and promote renewable energy. Result: major incentives for Thermal Conversion. In July and August of 2005, Appel gave presentations to rapturous government officials and private investors in Ireland, Wales and Germany, and the company is planning projects in Italy and Spain.
Meanwhile, Europeans are making the pilgrimage to America's heartland. In May, Renewable Environmental Solutions ran 360 tonnes of beef waste through the Carthage plant for a group from Irish Food Processors, the biggest beef operation in the British Isles. The Irish Sunday Tribune wrote that chief executive Larry Goodman "is understood to be planning a biofuel facility" and that he hoped to complete it in 2006.
Given the possible profits, this transatlantic love fest is no wonder. In Ireland, Changing World Technologies would get an impressive US$60 per tonne to haul slaughterhouse waste away, another US$30 per tonne in carbon dioxide emissions reduction credits, a guaranteed price of up to US$92 per barrel – and a 20-year price guarantee. "In a 500-tonne per day plant, our production costs would be under US$30 a barrel, and we could sell for US$100 a barrel," Appel says. "It's amazing."
So what about the United States? Appel sighs. Only three states – California, Virginia and Pennsylvania – have incentives that could make the process financially worthwhile, he says.
But he is encouraged by a study commissioned by a car-makers' consortium showing that the Thermal Conversion Process could be a near-miraculous solution to one of the U.S.'s most vexing solid waste problems: the unholy mix of plastics and other leftovers from automobile metals recycling. "If we do build a plant for that, it will likely be based in Michigan," Appel says.
Back in Carthage, process technician Stacy Dennison watches as the last bloody dollop of poultry carnage drains from the hopper. Twelve trucks dump their smelly loads here daily, and the whole process has become routine. But in the early days, she says, "there were yucky moments". The feed lines would clog, requiring her to stand in containment dykes on the plant's floor, open valves, and "let the turkey spooge just flow. Twice, it got up to my elbows. I had to sort of swim out."
Swimming through difficult circumstances is an apt metaphor for Appel's journey as well, but he is sure he is no longer sinking. Indeed, he says he hit the turning point in the middle of 2005, and now feels success is inevitable. "I was actually developing a 'leave-behind strategy' for us as a company, and planning to set up in Europe only."
Though he still thinks most new-plant construction for the foreseeable future will take place overseas, he believes there will likely be some ongoing construction in the U.S. as well.
"I am so happy to be making oil," he says. "I want this technology everywhere."
OIL FROM CARS
AMERICAN RECYCLERS deftly pluck nearly all of the metal from the 15 million cars the U.S. junks each year, but up to 4.5 million tonnes of residual debris goes straight to landfills. This residue is an unrecyclable mix of at least 36 kinds of plastic, treated fabrics, rubber and nylon. In May 2005, representatives of USCAR – a research consortium made up of Daimler Chrysler, Ford and General Motors and the American Plastics Council – arranged a test in which Changing World Technologies ran 1,360 kilograms of the problematic stuff through its Philadelphia pilot plant.
"The CWT process is brilliant," says Candace Wheeler, a General Motors research scientist. "There are substances of concern in shredder residue, and incineration of chlorinated plastics can make dioxins." But, she says, preliminary results show that the hydrolysis at the heart of the Thermal Conversion Proces degrades the chlorinated plastics (PCBs) and converts the chlorine to hydrochloric acid. "No PCBs. No dioxins. No emissions," says Wheeler, noting that the principal output was a 'light oil' that could be used at an electricity-generation facility. "It looks good," she says. "We think it has great potential." — Brad Lemley
CARBON TRAP
IF THERMAL CONVERSION works as claimed, it will clean up waste and generate new sources of energy. But its backers contend it could also stem global warming, which sounds very questionable. After all, burning oil contributes to the problem of global warming, right?
Carbon is among the major chemical constituents of most organic matter – plants take it in; animals eat plants, die, and decompose; and plants take it back in, ad infinitum. Since the industrial revolution, human beings burning fossil fuels have boosted concentrations of atmospheric carbon more than 30 per cent, disrupting the ancient cycle. According to global warming theory, as carbon in the form of carbon dioxide accumulates in the atmosphere, it traps solar radiation, which warms the atmosphere – and, many say, disrupts the planet's ecosystems.
But if there were a global shift to Thermal Conversion technologies, belowground carbon would remain there. The accoutrements of the civilised world – domestic animals and plants, buildings, artificial objects of all kinds – would then be regarded as temporary carbon sinks. At the end of their useful lives, they would be converted in Thermal Conversion facilities into short-chain fuels, fertilisers, and industrial raw materials, ready for plants or people to convert them back into long chains again. So the only carbon used would be that which already existed above the surface; it could no longer dangerously accumulate in the atmosphere. — Brad Lemley
THERMOFUEL
THE AMERICANS are not the only alchemists turning waste into oil. Australian company Ozmotech has a technology called Thermofuel which breaks down waste plastic to produce high-grade diesel.
Marc Middleton, marketing manager for Ozmotech, proudly points out that with each plant "6,800 tonnes of plastics a year will be diverted away from landfill".
The Thermofuel process begins when shredded plastics are melted at temperatures just under 260°C. The scalding goop then drains into a chamber that contains no oxygen, allowing the contents to break down without the contaminating effects of O2. The chamber is heated to 420°C, and the resulting gases are then piped to a catalytic converter. There, the molecular bonds of the long carbon chains are broken down into the shorter ones found in diesel.
From the catalytic converter the fuel gases flow through to a distillation column where they are separated according to the size of the carbon chains they contain. The gases containing molecules of the length typical of those found in diesel are cooled, condensed and flow through to the main fuel line. Any remaining contaminants and impurities are removed and the fuel, now pure, is sent to a tank where the last of the checks are made. What results is an exceptionally clean fuel, low in sulphur (a major cause of acid rain), readily useable in all diesel engines, and compliant with every worldwide regulatory standard.
It all sounds too good to be true, but the Thermofuel plants speak for themselves. Worldwide, 10 to 20 tonnes of plastics pass through Ozmotech's systems on a daily basis, producing between 9,000 and 18,000 litres of diesel. However none of Australia's annual 800,000 tonnes of plastic packaging is reprocessed using a Thermofuel system. Backers pulled out of a planned project late in 2005 when the Australian Federal Government announced a proposed tax on the fuel produced in the Ozmotech manner.
"They have put an environmentally sound process in jeopardy" says Middleton. "If an excise is introduced, the fuel will be sold abroad to the detriment of Australia and the Australian environment." — Choechoe Brereton
POWERFUL FERTILISER
EVERY ORGANIC GARDENER knows the pang of watching a neighbour blithely squirt chemical fertiliser on his vegetable garden. Sure, the idiot has no respect for the nature's elegant cycles; but holy cats, look at those zucchinis!
Now, however, synthetic-chemical envy may become history. Along with oil, the Thermal Conversion Process makes fertiliser that "works a great deal like some of instant-gratification fertilisers," says Jim Friess, vice-president of engineering for Changing World Technologies and a former fertiliser industry executive. With nine per cent nitrogen, one per cent phosphorus, two per cent potash and 19 amino acids, it is, in essence, what he calls "an organic Miracle-Gro," (a popular American plant food). "In the organic industry, these kinds of nutrient concentrations are unheard of. The best that's out there is on the order of six per cent nitrogen."
Tests on tomato and pepper plants conducted by Joseph Kloepper, professor of entomology and plant pathology at Auburn University in Alabama, confirmed the liquid fertiliser's unique potency. "In my experience," he wrote in a summary paper, "it is rare to fi nd a biological product that demonstrates such a consistent promotion of overall plant growth and root growth on two crops in two different field soils."
Fertiliser industry officials are just as enthusiastic. "Because it has been through high temperatures, there is no coliform bacteria or any of the other problems often associated with organic fertilisers such as manures," says Raj Mehta, president of Organica Biotech, a manufacturer of non-synthetic fertilisers and pesticides in Norristown, Pennsylvania. "I'm convinced there will be a large market for this." — Brad Lemley
MAKING COAL CLEANER
ONE MIGHT EXPECT fossil-fuel companies to fight Thermal Conversion. If the process can make oil out of waste, why would anyone bother to get it out of the ground? But switching to an energy economy based entirely on reformed waste will be a long process, requiring the construction of thousands of Thermal Conversion plants.
In the meantime, Thermal Conversion can make the petroleum industry itself leaner and more profitable, says John Riordan, president and chief executive of the Gas Technology Institute, an industry research and training organisation. Experiments at the Philadelphia Thermal Conversion plant have converted heavy crude oil, shale, and tar sands into light oils, gases, and graphite-type carbon.
"When you refine petroleum, you end up with a heavy solid-waste product that's a big problem," Riordan says. "This technology will convert these waste materials into natural gas, oil, and carbon. It will fit right into the existing infrastructure."
Appel says a modified version of Thermal Conversion could be used to inject steam into underground tar-sand deposits and then refine them into light oils at the surface, making this abundant, difficult-to-access resource far more available. But the coal industry may become Thermal Conversion's biggest fossil-fuel beneficiary. "We can clean up coal dramatically," says Appel.
So far, experiments show the process can extract sulphur, mercury, naphtha, and olefins – all saleable commodities – from coal, making it burn hotter and cleaner. Pre-treating with Thermal Conversion also makes coal more friable, so less energy is needed to crush it before combustion in electricity-generating plants. — Brad Lemley
Brad Lemley is a science writer in Arizona and a contributing editor of Discover magazine.
