Greenhouse gas scrubbers almost ready for worldwide production

Posted by Rick C. Hodgin

Calgary (AB) - It's like something out of The Arrival staring Charlie Sheen, only this one happens to be good for the environment. Researchers at the University of Calgary (pronounced "Cal Gary") have developed a CO2 greenhouse gas scrubber that's nearly ready for global production. The massive towers draw in regular atmospheric air, which includes the reported growing concentrations of CO2. After safely removing the carbon content, it then release pure oxygen back into the environment. So, is this the answer?

Can it really be that simple? Can man fix his own carbon problem with a bunch of big gas scrubbin' towers placed all around the globe? The experts say "Yes."

The process they have developed is very straight-forward: It's a type of continuous chemical bath for the air. A dissolved liquid of sodium hydroxide (lye) and water is sprayed at high intensity across an air flow (5 liters per second). Sodium hydroxide is a very strong chemical base typically used in the manufacture of paper and soaps. Yet it is this strong base which extracts the carbon.

A steady, continuous steam of very small droplets shows the most promising conversion efficiency. But, those small droplets have proven difficult for the team to achieve in a sustainable way. The longest period of continuous operation has only been about 8 hrs on their prototype scrubber.

Even so, in laboratory tests their tower was able to reduce concentrations in continuous air flows from 375 ppm to 150 ppm using the spray of 5 liter/s. This equates to a unit efficiency of 60% and a theoretical maximum capture rate of 15 tons of CO2 per square meter per year if used continuously

The team has shown that 150 units distributed worldwide would effectively reduce manmade CO2 greenhouse gas emissions to one-fifth of their current levels.

 

 

Big CO2 emitters

The 150 largest coal burning power plants produce 10% of greenhouse gas emissions. The next 1000 largest "point sources" contribute 30%, with the next 7000 accounting for an additional 15%, bringing the total to 55%. The remaining 45% comes from distributed and mobile sources (cars, coal fireplaces, etc.).

Big SO2 emitters

Let's also consider sulfur dioxide production for a moment. Worldwide, normal volcanic activity contributes about 15 million tons of sulfur dioxide per year. Human activities produce about 200 million tons per year. Volcanos aren't the huge contributors that many believe they are.

During the famous 1980 eruption of Mt. St. Helens, which sent out a massive mud-slide, ashen rain like gray snow, and leveled forests, homes and everything in its way for miles, an estimated 1 million tons of sulfur dioxide was released. Another 1 million tons was released in the days following the initial eruption.

In 1991, an eruption of Mount Pinatubo lasted more than 9 hours. It belched out an estimated 1 cubic mile of solid and liquid rock up from the Earth. That huge eruption, the largest of the century, released an estimated 20 million tons of sulfur dioxide in one go, still only about 1/10th the amount man generates every year.

The effects of those eruptions were significant, however. Due to the creation of aerosols in the Earth's upper atmosphere, a portion of the sun's radiation was reflected back into space. The Earth's temperature actually cooled by 1.3 degrees F in the three years immediately following the eruption - before climbing upward again.

Many volcanologists believe that were it not for the effects of volcanos "masking" the increases in temperature due to the side-effects of their massive eruptions, things would be far hotter on Earth than they are today.