Put a little oink in the tank?

Put a little oink in the tank?
U. of I. researchers learn to extract crude oil from pig manure
By Miriah Meyer
Copyright © 2006, Chicago Tribune
Published August 13, 2006

URBANA -- Yuanhui Zhang has smelled the future of oil, and it stinks.

The pungent, earthy scent emanates from swine pens that professor Zhang's graduate students visit regularly at the University of Illinois. Holding spades in gloved hands, they collect buckets of moist pig poop and carefully drive it to a lab on the edge of campus.

Inside a white metal building nestled among corn and soybean fields, the students pressure-cook the messy muck until it becomes thick, black, energy-dense crude oil remarkably similar to the stuff pumped from deep within the earth.

As oil and gas prices continue their steep climb, the dedicated crew of engineering researchers at the U. of I. is refining an economical process to transform smelly hog droppings into piggy petroleum that can be refined into industrial fuel.

Although experts say the oily end product is not likely to make a big dent in the U.S. energy shortage, the process may help relieve the odor and pollution problems that plague high-density animal farming by providing a use for porcine poop produced in vast quantities.

It's a promising technology, if sloppy and unpleasant at times.

"I have no choice," said graduate student Rong Dong of his waste-shoveling duties. "It's a part of my job; it's a part of my thesis."

Zhang had the idea 10 years ago of combating the mounting manure problems of dense hog farms with a technique called thermochemical conversion.

Updating Mother Nature

The process is a test-tube version of Mother Nature's recipe for crude oil, substituting pig manure for the prehistoric plant and animal substances that are the raw ingredients of petroleum, and a small metal reactor for nature's pressure-cooker of the planet's deep layers.

During the last decade Zhang's group perfected the process, finding they could break down the organic material into shorter petroleum molecules in less than an hour--a feat that naturally takes millions of years.

Although the technology can be modified to break down any type of organic material, the researchers focused on refining their method for the specific composition of swine manure.

"We wanted to take care of the waste material and take care of some of the environmental problems, and we found we can create some useful energy," said Zhang.

His work is just one of a growing number of experiments in renewable sources of power. Experts say President Bush's statement on America's "addiction to oil," along with the price hike of oil to more than $70 a barrel, has dramatically increased interest by investors in technologies that convert everything from corn to human waste into fuel.

At the U. of I., the accelerated version of the Earth's oil production pipeline begins with a machine that looks like a giant malt mixer, which blends the chunky raw swine manure into a thick brown slurry. The appliance sits on a table surrounded by rolls of toilet paper used to clean up any unfortunate messes, the remnants of which are splattered on the wall behind.

"We have to make sure there are no big chunks," said Dong, wearing a white lab coat smeared with dark brown stains.

The smooth slurry is carefully poured into an eight-gallon cylindrical tank and then creeps through metal pipes at a pace of just two tablespoons a minute. The mixture is pressurized to 100 times the normal atmospheric pressure before slowly draining into a reactor where it is heated to a broiling 575 degrees Fahrenheit.

The researchers were able to determine the precise balance between a temperature hot enough to break down the manure's molecular bonds and a pressure high enough to keep the super hot poop from turning into a gas. These conditions allow the pig excrement to emerge less than an hour later as thick, black, sludgy oil.

Along the way the product is stripped of its telltale scent--it smells like wet coffee grounds--and is only slightly less pure than the natural stuff, Zhang said. The only byproducts are a small puff of carbon dioxide, a few dribbles of water and a tiny bit of dirt.

"What's fascinating is that it's a relatively simple process," said Ted Funk, a researcher in Zhang's group. "Even though the process has complex chemistry, it's relatively short, requires almost no extra materials, and you get a nice energy output."

In fact, the researchers have found the sludge contains three times the energy used to produce it. This energy ratio, combined with a technical breakthrough earlier this year that allows continuous feeding of the system with fecal matter, has been noticed by entrepreneurs.

Zhang is "the only researcher that's been able to use animal waste and get oil in an economic way," said Otis Jessee, co-owner of Worldwide BioEnergy, a company based in Jefferson City, Mo., that has licensed the technology from the university.

"When oil was at $25 and $30 a barrel this was an economically feasible thing to do. Now with oil more than $70 a barrel, it's even more so," he said.

Jessee's company has sublicensed the technology to two engineering firms that are developing pilot plants. According to Jessee, both firms plan to be churning out barrels of crude oil within two months--one using swine manure processed in a mobile plant, the other using sewage in a Houston suburb.

With 43 million hogs in the Midwest, pig-based petroleum could eliminate 10 percent of the region's foreign oil imports, according to Zhang's estimates of the average hog's poop production. But experts say that swine manure is not likely to quench the nation's thirst for foreign fossil fuel any time soon.

At Changing World Technologies, a company in Carthage, Mo., that converts turkey offal into petroleum, Chief Executive Officer Brian Appel said getting renewable crude oil into the mainstream market is tough, in part because the nation's refineries aren't set up to accept the product.

Even if bio-fuel producers refine their crude oil into fuels that can be readily used to produce electricity in generators, getting the energy into the power system is a challenge, say experts in renewable energy.

Helping out hog farms

"One of the problems we have [with] producing electricity is that utilities are not standing there and saying, `Let me have your electricity,'" said William Holmberg, chair of the biomass committee at the American Council on Renewable Energy.

Illinois is among the majority of states that pay customers for self-generated power, although currently the state accepts only solar and wind electricity.

For Zhang, though, thermochemical conversion was never about the alchemy of black gold. It was an unconventional idea for easing the odor and water pollution problems associated with hog farms.

That idea smells sweet to pork producers like Chris Borrowman, whose western Illinois farm is slated to receive an oil-producing pilot plant this fall.

Most of the manure scents that waft over to his neighbors come from a gigantic lagoon that stores enough putrid pig poop to fill 23 swimming pools. Nearly every spring, an Environmental Protection Agency inspector pays a visit in response to the neighbors' complaints.

"When I first heard about [the technology], I was very excited," said Borrowman. "Reducing the odor coming off of our lagoons is a huge plus for us farmers." He speculated that neighboring grain farmers could benefit from using his cheap crude to run large diesel-guzzling equipment.

And that's good news for Zhang, who has green dreams of pig power being produced on sustainable swine farms.

"I see each swine farmer having a little plant," he said. "We could then raise the animal, produce the feed and process the waste locally. And then in the end, we can have a useful product. That would be a perfect world."