China has had an affinity with large structures since the olden days. The great wall is a testament to it.
Modern China is no different. When it comes to bridges, roads, buildings, aqueducts, or even telescope, China loves to go big.
That’s why when the world-largest air purifier in China was announced, it didn’t come as a big surprise.
Well, it actually was a big surprise.
World-largest Air Purifier?
Yes, the tower itself is 328 feet (100 meters) tall, roughly as tall as a 20-story building.
The greenhouses at its base cover an area of 27,770 square feet (2,580 square meters). The ones responsible for building this monolith are the scientists at China’s Institute of Earth Environment.
The idea was based on a 2014 paper and first introduced the idea to the Chinese public back in 2016. Construction started in Xian (Shaanxi province) the same year and completed in early 2017.
The main purpose of this building was to fight smog by trapping PM2.5, NOx, and SO2, the three pieces of the puzzle that enables smog to form.
Didn’t China Already Make One in Beijing?
It’s true that this is not China’s first attempt at taking care of smog problems by artificial means.
The 7 meters tall purifier in Beijing, however, is completely dwarfed by the sheer size of the new tower in Xian. That artsy tower in Beijing has also been deemed ineffective in fighting smog.
Why Did China Build it in The First Place?
China has long been burdened by the side effects of its economic growth spurt. The push towards industrialization cost them dearly in the form of stubborn smog that deprives their citizen of the simple views of blue sky, sunrise, and sunset.
Back in 2014, Beijing was using a gigantic LED screen to show the rising and setting sun as the smog was too thick.
To know just how bad smog problem in China is, just watch this time-lapse video showing how quickly smog envelops Beijing.
How Does it Work?
This tower is a Solar-Assisted Large-Scale Cleaning System (SALSCS). The tall tower is working in tandem with the huge greenhouses at its base.
Dirty air is sucked into the greenhouses where it’s heated using solar energy. The hot air rises through the tower where it goes through several layers of filters. Clean air is released from the top part back into surrounding area.
Does it Really Work?
Quite. After the trial run, data gathered from over a dozen of air quality monitoring stations in the nearby area shows promising preliminary results.
It manages to sequester some of the airborne pollutants from the surrounding 10 square kilometers area. The lead researcher, Cao Junji, says it produces more than 10 million cubic meters of clean air in the process.
The data showed that the levels of particulates matter with 2.5 micrometers in diameter or less (a.k.a PM2.5) drops 15% during heavy pollution hours.
The focus on PM2.5 is warranted not just because it’s one of the precursors of smog but also because particles that small can easily get absorbed into human lungs and stay there.
PM2.5 is a major concern in large cities around the globe, not just in China, as it can cause serious health effects.
Locals from nearby neighborhood seem to support the claim that the tower does reduce the amount of pollution in the immediate vicinity.
People on the edge of the 10 square kilometers area, however, notice no difference in air quality when interviewed by the South China Morning Post.
As in any scientific venture, the accountability must base on hard data instead of anecdotal ones.
If that 15% reduction in PM2.5 levels holds any truth, then building more of such tower will have a dramatic effect on the overcoming smog problems in large cities.
Will China Build More of This?
Oh yes. Despite its sheer size, this tower is just a prototype. China plans to build many more in the future. In fact, the initiative to build a structure five times bigger than this one is already set in motion.
The gigantic tower will be 1,640 feet (500 meters) in heights with a diameter of 656 feet (200 meters). The greenhouses at its base will cover an area of 11.6 square miles (30 square kilometers). Truly a colossal project.
Is There a Better Alternative?
Reducing smog in large cities will require the elimination of the sources. Switching to electric vehicles and renewable energy sources are two excellent methods to do just that.
It so happens, China is going in the right direction with the two as they are investing heavily in electric vehicles and solar power. There is no doubt that China will be one of the major players in those two fields within the next decade.
Does the Tower Take Care of CO2 Too?
Sadly it doesn’t. However, should China keep pushing on the shift to renewables, there should be an improvement in that department also.
Still, planting more trees in cities also remains the simplest alternative in fighting rising CO2 levels. Scientists say that the level of CO2 in earth’s atmosphere exceeded 410 ppm in April 2018, the highest in 800,000 years. That means we need to really push the pedal on our effort of reducing the world’s carbon footprint.