Self-Cleaning Buildings to Fight Smog

bryan8m writes "Using technology already available for self-cleaning windows and bathroom tiles, scientists hope to paint up cities with materials that dissolve and wash away pollutants when exposed to sun and rain. The idea: UV rays hitting the titanium dioxide coated cement and concrete trigger a catalytic reaction that destroys the molecules of pollutants, including nitrogen oxides."

Comments

Re:Effective?

[Graymalkin]

Keyword here is catalytic reaction. A catalyst is a substance that initiates a chemical reaction but is not consumed itself in the reaction. The catalyst in the paint would stay in existence, it would simply break down pollutants when they came in contact with the material when UV radiation was hitting it. As long as the pollutants were reduced to innocuous materials there wouldn't be an issue with toxic waste disposal.

That's the point

[myukew]

It's not about cleaner houses, it's about cleaner air!
They try to make a house work like a tree to actively reduce the amount of pollution in the air. That the house stays clean is just a nice side-effect

Re:Now, can we put DC on the transmission lines?

[Anonymous Coward]

Now, that high power solid-state switches ( hence, power converters ) are becoming do-able, is there any way we can start putting high-voltage DC on our power grids?

DC is horribly inefficient at delivering power. Besides, high voltage is high voltage. Power lines run just under the voltage needed to ionize the air. Once you ionize the air, then you set up currents, and those currents are sucking power, power that isn't being delivered, and could have been charged for.

Titanium dioxide has other problems

[domefreak]

The article explains that the smog-busting coating for buildings will contain titanium dioxide. They note that this compound is already prevalent in paints, but presumably this process requires a higher concentration than that. I searched GreenSpec for any existing paints that use this effect, and instead found this interesting fact:

The production of pigments can be a highly polluting process. When titanium dioxide is extracted from sand, large quantities of by-products are produced that have historically been disposed of by ocean dumping and/or deep-well injection. The process of refining titanium dioxide is also very energy intensive, with significant releases of carbon dioxide and sulfur oxides. The European Community considers these problems associated with titanium dioxide so serious that they have established limits on the amount of white pigment allowed, and limits on allowable emissions from pigment manufacture, for paints under consideration for the European Eco Label.

(from Environmental Building News, February 1999)

Re:Solar?

[falconwolf]

Wouldn't it be smarter to cover the buildings with solar panels, use that to power half the building and cut down of the amount of smog created by the power plants instead? Your car puts out NOTHING compared to a 250Mw coal plant.

Actually from what I read, I think one place might of been in HomePower mag and/or Solar Today mag , was that vehicles are the single biggest contributers to manmade greenhouse gases. A simple remedy for this though is Biodiesel . Without modification diesel engines can run on biodiesel. Actually Rudolph Diesel the designer of the diesel engine designed it to run on most any vegetable oil. And because the plants used to make the oil soak up carbon dioxide they are carbon neutral. It's not so much how much one vehicle puts out as it is the total of all vehicles.

However more building should include solar power in their design, active and passive. One way as you've stated is pv panels. Another way is a thin film that's being developed that can be applied to windows and the sides of building to generate solar power. Another method of power generation are wind genies, wind generators.

Falcon

Re:Tarffic is the primary cause of pollution

[Firethorn]

I know that they have at least three running into Detroit.

The trick was that they replaced nine undereground power lines, that were already oil-cooled. Basically, the continuing cost for the LN2 is less than the pumps needed to circulate the oil.

The three new cables contain only 250 pounds of superconductor, yet they will be able to carry just as much current as the 18,000 pounds of copper in the nine cables they replace.

The trick is, you don't need to pump the LN2, as it just boils off, you just have to keep it 'topped off'. The cables are heavily insulated, so the boil off rate is actually low, as the cables don't produce any heat, whereas the copper lines did.

I remember reading that they actually made money on the replacement, as 18,000 pounds of copper is quite a chunck of change.

A source, the rest I'm working off of remembered articles that aren't easily found on the internet today.

I'll admit, it's going to be a while before they bother running a superconducting line to your neighborhood, but for the main trunks out of power stations, into cities, or other major distibution centers, it makes sense.