Retired MU professor develops a brand new brick

Sunday, December 23, 2007 | 5:09 p.m. CST; updated 3:07 a.m. CDT, Friday, July 18, 2008
Henry Liu has developed a brick made solely from fly ash.

COLUMBIA — Out of the group of 25 products Popular Science magazine selected this year as nominees for the 2007 invention awards, many conjure up images of super heroes. There’s the electrified telescoping neuroscrambler (an electrified billy club of sorts) and the powered rope ascender, which looks like it came out of Batman’s utility belt.

Henry Liu’s nomination was for a comparatively simple device — a “green” brick.

This brick, developed by Liu’s Freight Pipeline Co. in Columbia, impressed the judges for several reasons. The brick is made of fly ash, a powdery waste product from coal-fired power plants. The fly ash is mixed with water and compacted. Because it isn’t heated with natural gas, like clay bricks, the fly ash brick factories are predicted by Liu to be zero emissions factories. Liu predicts that lack of heating will reduce the cost of bricks by an estimated 2 cents apiece. And recent tests show that Liu’s brick actually takes in mercury, a pollutant, from the surrounding air.

All the pieces to bring the product to commercial use are falling into place. An MU student has developed plans for the brick factory. Several utilities and a brick company have proposed locations. Venture capitalists are showing interest in investing in Liu’s company or licensing the product.

Testing on the brick is nearing completion, and Liu said his product meets federal safety standards and is set to go.

“Even as it is now, it’s good enough to be used in buildings,” he said.

Liu started his company in 2000 after retiring from MU as a professor of civil engineering. The company originally planned on using Liu’s knowledge of pipeline technology in the commercial world. The brick, he said, was a secondary idea developed during his time at MU, but it took off quickly when he began focusing on how to make the product work.

Liu said his company has always focused on energy, though the focus has shifted in some ways away from his idea to transport coal in fluidized pipelines. He said the criteria for the energy technology his company has strived to develop has always been the same — the technology must save energy, benefit the environment and be cost-effective.

Nick Peckham, a Columbia architect and president of the Heartland Chapter of the U.S. Green Building council, is on the advisory board of Liu’s company. He said the brick is not necessarily revolutionary in itself but for the way it makes use of waste. According to the American Coal Ash Association, 71.1 tons of coal ash were created in 2005 and less than half of that was reused.

“The brick is more evolutionary than revolutionary,” he said. “Using the fly ash from coal-burning plants is a step in the direction of creating public awareness of a problem in a non-confrontational way.”

Greg Borchelt, vice president of engineering and research for the Brick Industry Association, said the clay brick industry isn’t worried.

“We’ve got a whole different approach,” he said. “We use a widely abundant material available all over the world. We see this product as another masonry product, and the masonry industry is plenty big to welcome this type of product.”

Liu initially tested his idea for a brick made entirely out of fly ash during his time at MU. There were problems, though. The brick was strong, but in tests measuring how the brick could stand up to cycles of freezing and thawing the original brick could only last through eight cycles before falling apart. In order to pass industry safety standards, a brick must be able to withstand at least 50 freeze-thaw cycles in a laboratory.

Liu went to the National Science Foundation with nine proposals on how to make the brick survive the freeze-thaw tests, and the foundation supplied Liu with a grant to begin experimenting with options to make the brick less brittle.

The option that worked involves putting a drop of a chemical air entrainment agent into the fly ash material, which creates millions of air bubbles inside the brick. The brick can now stand up to more than 100 freeze-thaw cycles, but there’s no clear scientific explanation of why the process works.

“It’s still in the early stage of knowledge,” Liu said. “...It will be years of people studying in the future to find out why putting this little bit of air bubbles worked.”

Over the years, people have raised concerns about fly ash because of its mercury content. State highway departments have allowed the mixing of fly ash into concrete for decades, with no known environmental or human health impact. But because the brick is composed entirely of fly ash, Liu conducted tests to ensure his brick doesn’t leach mercury into the air.

The test results, he said, were surprising: The brick actually takes in mercury from the air.

At first, Liu’s team doubted the findings and went back to check the data.

“This was another important finding favorable to fly ash,” he said “It not only saves energy, but the brick itself has come with some environmental benefits.”

Liu said solving the freeze-thaw problem brought him a Phase 2 grant from the National Science Foundation, which in turn brought him publicity. That publicity, he said, earned one of 10 2007 Invention Awards from Popular Science and was named one of the best environmental inventions of 2007 by Time Magazine. That, in turn, brought more publicity, with more than 300 calls in the past few months from companies all over the world that want to license his product or invest in Liu’s company.

Liu said his brick innovation is tangible, and he finds satisfaction in knowing his product will provide something useful to society. He said he’s proud of what he accomplished as a professor, including his work with students and papers accepted for publication, but the brick offers something different.

“Now I get the satisfaction of seeing that something I invented or developed made into a commercial product that people will use,” he said. “That’s the ultimate end of research, isn’t it? To apply the results, to use the results? The purpose of research is not for research’s sake; it’s for doing something good that others can benefit from.”

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