CO2 Capture from Atmospheric Air Necessary to Address Global Warming

Published on July 25, 2012 at 7:42 AM

By Gary Thomas

Researchers from the Georgia Institute of Technology have shown the economic and chemical feasibility for extracting CO₂ directly from air. They utilized new adsorbent materials in the novel method to capture CO₂.

Stephanie Didas, a Georgia Tech Ph.D. candidate, loads an aminosilica sample into a custom-built volumetric adsorption system for measuring adsorption isotherms of different carbon dioxide capture materials. Credit: Gary Meek

The technique may also be used to capture CO₂ from power plant flue gases. The captured CO₂ may be used for improving oil recovery and for producing fuel from algae.
Coal-burning power plants and chemical facilities contribute to less than 50% of the global CO₂ emissions. Transport vehicles such as planes, ships, trucks and buses account for the rest of the emissions and capturing these emissions are comparatively more expensive. According to the researchers, the operating costs involved were approximately $100 per ton when using a large CO₂ removal unit that has the capacity to remove 1000 ton of CO₂ per annum. Removal of CO₂ from flue gas alone will not help address the global CO₂ emissions. Air capture is required.
The atmosphere contains 400 ppm of CO₂ while flue gases contain about 15%. The difference in capture efficiency and economic feasibility can be addressed by establishing CO₂ removal units at sequestration locations.
The Georgia Tech researchers have modeled a batch extraction process that demonstrates economic feasibility. Dry amino-modified silica material is coated onto a ceramic honeycomb structure. The air is blown through the structure and the material captures the gas. Later steam is flown through the structure in order to release the gas.
The researchers have been conducting studies on metal-organic framework materials and have published papers in Journal of the American Chemical Society, ChemSusChem, and Industrial & Engineering Chemistry Research on alternate adsorbent materials.

a chemical that could allow people with degenerative blindness to see again.

WASHINGTON: In a major advance in the field of vision restoration, scientists claimed to have discovered a chemical that could allow people with degenerative blindness to see again.

A team of University of California in collaboration with researchers at the University of Munich and University of Washington are working on an improved compound that temporarily restores some vision to blind mice. The compound called 'AAQ' is less invasive than implanting light-sensitive electronic chips in the eye.

The approach could eventually help those with retinitis pigmentosa, a genetic disease that is the most common inherited form of blindness, as well as age-related macular degeneration, the most common cause of acquired blindness in the developed world. In both diseases, the light sensitive cells in the retina, the rods and cones, die, leaving the eye without functional photoreceptors.

The chemical AAQ acts by making the remaining, normally "blind" cells in the retina sensitive to light, said lead researcher Richard Kramer, UC Berkeley professor of molecular and cell biology.

AAQ is a photoswitch that binds to protein ion channels on the surface of retinal cells.

When switched on by light, AAQ alters the flow of ions through the channels and activates these neurons in the same way rods and cones are activated by light.

"This is similar to the way local anesthetics work: they embed themselves in ion channels and stick around for a long time, so that you stay numb for a long time," Kramer said. "Our molecule is different in that it's light sensitive , so you can turn it on and off and turn on or off neural activity," said Kramer.

Because the chemical eventually wears off, it may offer a safer alternative to other experimental approaches for restoring sight, such as gene or stem cell therapies, which permanently change the retina . "This is a major advance in the field of vision restoration ," said co-author Russell Van Gelder, from the University of Washington. PTI

Now, a cancer drug to flush out dormant HIV

WASHINGTON: A drug used to treat certain types of cancer is able to dislodge hidden virus in patients receiving treatment for HIV, researchers have claimed.

University of North Carolina at Chapel Hill in a study found the existence of persistent reservoirs of dormant HIV in the immune system that are not attacked by anti-AIDS drugs, believed to be a major reason why infection re-emerges once patients stop taking their medication. The disruption of these reservoirs is critical to finding a cure for AIDS.

Researchers at UNC, working in collaboration with scientists from the Harvard School of Public Health, National Cancer Institute and the University of California undertook a series of experiments designed to evaluate the potential of the drug vorinostat . Vorinosta is a deacetylase inhibitor that is used to treat some types of lymphoma, to activate and disrupt the dormant virus.

Laboratory experiments measuring active HIV levels in CD4+T cells, which are specialized white blood cells that the virus uses to replicate, showed that vorinostat unmasked the hidden virus in these cells. Subsequently, vorinostat was administered to eight HIV-infected men who were medically stable on antiretroviral therapy and the levels of active HIV virus were measured and compared to the levels prior to administration.