China pollution

From ionising towers to bicycles, Dutchman’s smog-removing inventions stand to clear the air in polluted China

Daan Roosegaarde’s Smog Free Towers in Beijing and Tianjin parks use ionisers to suck in pollutants and pump out clean air; now he wants to do the same for individuals riding bicycles by harnessing their pedal power

PUBLISHED : Saturday, 10 June, 2017, 7:47am
UPDATED : Monday, 12 June, 2017, 2:14pm

The sky is blue and Dutch innovator and designer Daan Roosegaarde is sitting in the outdoor lounge at Shanghai’s Puli hotel, holding a beer in one hand and a small, clear plastic zip bag filled with a black powder in the other.

He’s just back from installing one of his seven-metre-tall Smog Free Towers in a park in the northern Chinese city of Tianjin, after successfully setting up a similar structure last year in Beijing’s 798 Art District.

“This is Beijing smog,” he says, holding up the bag, “the stuff we’re sucking up from the skies with our tower … It’s actually a lot of pollution from the factories, coal factories, cars, a lot of rubber from tyres. Every city has a different mix. We wanted to do something with this stuff we’re collecting from the tower, as we think that waste should not exist.”

“Forty-two per cent of this black pollution powder we collect is carbon; and carbon under high pressure is of course diamond, so we made Smog Free Jewellery,” Roosegaarde says, pulling out a small, stainless steel ring with a black cube inside a larger one made of clear resin, while the waiter nearby arches a curious eyebrow.

“By buying a ring, you donate 1,000 cubic metres of clean air. It’s redefining luxury. Luxury is not necessarily about an LV bag or a Ferrari; it’s about clean air.”

Roosegaarde’s innovations combine the quirky and symbolic with the grand and powerful. The Smog Free Towers (the largest air purifiers in the world) create around them a “bubble” of clean air, and use only about 1,100 watts of energy, a similar amount to an electric kettle. He’s now developing one powered by solar panels.

The exact technology behind these outdoor air-cleaning structures is patented by Roosegaarde’s studio but, simply put, they suck in and ionise the surrounding air, extracting pollutants, and blow out clean air. There were similar air ionising systems in hospitals before the invention of the Smog Free Tower, but the large-scale outdoor system is an advance on the technology.

Although it’s perhaps impractical to solve air pollution by populating cities with the towers, certain areas, such as parks or the polluted 798 Art District, can benefit. “It’s really about showing the beauty of a new future,” Roosegaarde says.

Now working with China’s central government, the artist and innovator and his Studio Roosegaarde will be installing more of the towers around the country. Beyond China, the Indian capital, New Delhi, will get one in November, and after that there will be projects in Mexico and also Medellin, Colombia. It’s no coincidence that these cities are listed among the world’s most polluted.

Roosegaarde has just released a smaller-scale application for the technology – the Smog Free Bicycle, currently in its first phase of development; they’re working on a prototype. The idea came from a workshop the studio hosted in Beijing, and Roosegaarde says he “just fell in love with it”.

The concept is that a unit fitted around the handlebars will suck in polluted air and eject clean air around the bike and cyclist as they pedal, the parameters of which will be affected by wind and velocity.

Whereas America is going backwards, China is really stepping up and owning the conversation [about sustainable energy and battling climate change] … That’s powerful, I want to be part of that
Daan Roosegaarde

“It’s using the same kind of technology and principles of the Smog Free Tower. In a way it’s all about the dream of clean air – it’s using design to improve life,” he says. “We’ve just announced the project online, and already bike-sharing schemes have been in touch. I just got an e-mail from a Chinese company literally an hour ago saying, ‘We can collaborate and help you build this.’”

The feasibility, cost and scalability of millions of people using Smog Free Bicycles is yet to be worked out, but there’s undoubtedly a powerful symbolism to the idea. China and Roosegaarde’s native Netherlands both have a long tradition of public bicycle use, and recent times have seen a revival of interest. The huge expansion of bike-sharing projects in China hints at the idea’s potential and, of course, bikes also relieve traffic congestion and promote healthy exercise.

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“There’s the cultural icon and connection of the bicycle shared between China and the Netherlands, but it got killed because of the cars,” Roosegaarde says. “It’s of course fascinating to bring back this culture.”

In the past few years, China has been a huge part of the Smog Free Project. Roosegaarde’s invention went from a Kickstarter project (including the sale of smog rings and cufflinks to fund the tower) to being supported by the Chinese government, which is trying to flex its muscles in sustainable energy and technologies.

“Now they are investing,” he says. “We’re working on the plan to produce more of the towers with a local Chinese partner. We’re setting up shop, doing quality checks, and that’s going to grow … At the same time, my job is to focus on new designs, like the Smog Free Bicycle, and see where that takes us.”

With the Smog Free Project focusing on public parks, Studio Roosegaarde is talking to cities around the world to propose installing 30 to 40 of its towers in a single park. It also has an engagement programme with links to student workshops, NGOs and clean power programmes connected to governments.

Roosegaarde hopes to spend more time in China, for both personal and professional reasons. He likes the eagerness of the country and how future cities are being built, but also the attitude of the people. “I connect with here. I don’t know why, I just do.”

He adds that China is making significant movements in terms of investing in sustainable energy and technology, battling pollution, and addressing climate change. “Whereas America is going backwards, China is really stepping up and owning the conversation … and if we were having this conversation three or five years ago, we would have never thought it would be this situation. That’s powerful, I want to part of that.”

Roosegaarde's previous work hasn’t always been so environmentally focused – he has a background in fine art, maths and architecture – but he has always been big on bright ideas. His portfolio includes a dress made from smart e-foils that become more transparent in response to the wearer’s quickening heart rate; a glow-in-the-dark bicycle path powered by the sun; a sustainable dance floor that generates electricity when danced on; and wind turbine light installations.

“I want to make things which trigger people,” he says. “Now, we always make things that connect nature [and] sustainable energy with poetry.”

Roosegaarde clearly values the currency of ideas, but relies on the team of engineers, designers and project managers at his Rotterdam-based studio.

His Smog Free Project was conceived more than three years ago as he looked out of a 32nd floor window on a polluted day in Beijing. Now, after tireless promotion, its expansion is rapid, fuelled by powerful government backing.

The ideas are being spread, too, with the intention to encourage designers from all over to come up with their own Smog Free solutions. Roosegaarde hopes that his invention will ultimately spawn more clean technology innovations.

“The dream is really to have cities where [such innovations] are not necessary any more,” he says. “If we become meaningless – that’s the dream. Until then we still have work to do.”

Inside a Smog Free Tower

The Smog Free Tower uses environmentally friendly, patented positive ionisation technology that cleans 30,000 cubic metres of air per hour, making the direct area around the tower 55 to 70 per cent cleaner than the rest of the city. Each tower runs on green wind energy and about 1,100 watts of electrical energy – about the same as an electric kettle.

“[When] you have a plastic balloon and you polish it with your hands to make static, and dust particles or your hair stick to it – that process is called ionisation,” Roosegaarde explains. “It’s always used indoors in hospitals, but we just teamed up with the experts to build a larger one for outdoors.

“[The tower] charges the air with positive ions; small particles stick to the inside of the tower and clean air comes out. That’s the only way to clean really large volumes in a safe, low energy way.”

What exactly is causing China’s toxic smog?

The tower captures and removes up to 70 per cent of PM10 (particulate matter 10 micrometres or less in diameter) and up to 50 per cent of PM2.5. Polluted air is sucked in through the top of tower, with the purified air blown out through vents on its four sides.

There has been some recent debate about how effective the tower really is. The Chinese Forum of Environmental Journalists (CFEJ) published a report in November last year (link in Chinese) stating that over 50 days of testing at the tower, removal of PM2.5 was less than claimed. The report concluded that ultimately the tower is limited in scope and its effect on PM2.5 levels “was unstable and the effective range was very much limited to its immediate surroundings”.

Roosegaarde explains a tower’s effective range can vary. “The parameters of air space it affects depends on factors such wind and whether the area is enclosed or semi-enclosed,” he says. “It’s a minimal 20 to 50 metres radius around each seven-metre tower.”

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The towers’ effect, he adds, were validated this year by field data results and numerical simulations using computational fluid dynamics compiled by the Eindhoven University of Technology.