From fredski on Stockhouse

New Material Scrubs Fracking Pollution, Energy Dept Says

May. 22011 - 8:12 am

http://blogs.forbes.com/jeffmcmahon/2011/05/02/fracking-pollution-may-be-solved-doe-says/

An absorbent form of silica can remove nearly allpetro-chemicals from the water produced by hydraulic fracturing inshale-gas wells, Energy Department scientists announced late last week.

After field testing the modified silica, called Osorb, DOE’sNational Energy Technology Laboratory confirmed it can remove more than99 percent of oil and grease from water, and more than 90 percent ofbenzene, toluene, ethylbenzene, and xylenes—also known as BTEX—the volatile compounds that can poison drinking water.

“These tests showed that total petroleum hydrocarbon levels wereslashed from 227 milligrams per liter to 0.1 milligrams per liter,” saidDOE spokesman Jenny Hakun in an April 28 press release that describes Osorb as a “breakthrough technology.”

Hydraulic fracturing of shale has become increasingly important forfreeing vast reserves of natural gas from shale formations in the UnitedStates, such as the Marcellus Shale formation under the AppalachianMountains. But opposition to “fracking” has mounted because waterinjected underground to shatter the shale carries toxic hydrocarbonsback to the surface and could imperil drinking water aquifers.

“Approximately 21 billion barrels of produced water, containing awide variety of hydrocarbons and other chemicals, are generated eachyear in the United States from nearly one million wells,” Hakun said.

This by-product of gas drilling is much more toxic than waterproduced by oil wells, according to a white paper produced for theEnergy Department by the Argonne National Laboratory:

Produced waters from gas production have higher contentsof low molecular-weight aromatic hydrocarbons such as benzene, toluene,ethylbenzene, and xylene (BTEX) than those from oil operations; hencethey are relatively more toxic than produced waters from oil production.Studies indicate that the produced waters discharged fromgas/condensate platforms are about 10 times more toxic than the producedwaters discharged from oil platforms.

via Argonne National Laboratory (pdf)

Image courtesy of ProPublica, Creative Commons License.

Drilling companies also introduce chemicals when they inject waterinto the shale to fracture it and free the gas. The hazards of hydraulicfracturing were highlighted by a recent spill of “fracking fluids” at a shale-gas well in Bradford County, PA.

The produced waterthat emerges from the well—sometimes in much greater volume than gas oroil—is usually treated, recycled, discharged into the environment, or injected back underground.

“A number of existing treatment techniques separate dispersed oilsfrom water, taking advantage of the density difference between oil andwater,” Hakun said. “However, very few technologies effectively addressdissolved hydrocarbons, slicking agents, and polymers that preventflow-back water from being recycled or discharged.”

A mixture of glass and polymer, Osorb rapidly expands when it encounters non-polar liquids,such as hydrocarbons, and captures them in its matrix. But it allowspolar liquids, such as water, to pass unmolested. The capturedhydrocarbons can be removed through heat-evaporation, and the Osorbreused.

Osorb’s absorbent properties were discovered by accident in 2005 by Colleen Burkett, a student at the College of Wooster in Ohio working with associate professor of chemistry Paul Edmiston. Osorb is manufactured in a chemical reactor by Edmiston’s Ohio company, ABSMaterials.

Osorb is one of several small-business technologies that havebenefitted from Department of Energy initiatives to treat producedwater. Earlier this month, DOE’s Energy Lab announcedit had tested a desalination system that successfully treated 77percent of produced water at a Marcellus shale well, producing distilledwater suitable for discharge into the environment.