HANGZHOU, China — In one of this nation’s most popular tourist cities, famed for the beauty of its surrounding mountains, willow trees, lotus blossoms and ancient stone-arch bridges, a new sightseeing attraction is making its debut: the local landfill.
With its so-called “trash tour,” the landfill has attracted more than 10,000 visitors since it launched last year. There, tourists visit its trash-to-gas power plant, play environmental video games and hike in an eco-park the size of 10 football fields. Underneath that lush green park is a mountain of trash generated by the city’s 3 million residents more than a decade ago.
To Hangzhou Environmental Group, which operates the landfill, this is just a small piece of a bigger plan to generate value from trash in a sustainable way. The company is already leading China’s move to deal with methane, a climate-harming byproduct of decaying trash, by turning it into clean energy. Now it aims to speed up the methane production cycle from years to a matter of days at the same time as cutting the need for more land to bury garbage.
Garbage is a rising threat to China’s environment. As Chinese get wealthier and buy more modern products, many cities are finding themselves drowning in trash. The problem became so serious that it caught the eyes of no less than Prime Minister Wen Jiabao.
Shortly after Wen addressed China’s trash problem in March, a national campaign rolled out, urging cities to reduce their waste as well as to find ways to create value out of it. In the past, though, many such efforts have flopped.
In recent years, Chinese cities have tried to build waste incinerators, aiming to burn the trash while producing electricity. The practice, while popular in Europe, isn’t welcomed by the Chinese public. Rising concerns about possible cancer-causing emissions led to protests against planned incinerators in many cities, including Beijing.
Meanwhile, according to environmentalists, efforts to educate the public to produce less trash and separate it properly, aiming to recycle more, could take years to bear fruit. But landfill companies like Hangzhou Environmental Group see this as more of an opportunity.
“The company is now transforming its business from simply burying trash to a one-stop solution provider that taps into every possible way of reusing it'” explained Li Yujun, a waste management expert at Chinese Academy of Social Sciences, a leading think tank in Beijing.
The model here is expected to spread across China, added Li, who has already witnessed other landfill companies following suit.
Following the footsteps of Marco Polo
Back in the 1990s, the company already demonstrated the then state-of-the-art waste treatment in China, for the first time shielding soil and water from pollution. But it failed to protect the air.
Everyday, the decaying trash releases large quantities of a climate-harming gas cocktail. More than half of the landfill gas is methane, which warms the planet 20 times faster than carbon dioxide. But with a low awareness at that time of its environmental hazards, the company did nothing except simply let it into the atmosphere.
Methane has a tendency to explode, which soon made this an urgent matter. There were accidents in other landfills, which made for hazardous operations. Engineers were sent to seek solutions abroad and came back with the idea of processing the landfill gas into clean energy.
This idea isn’t exactly new in China. Italian traveler Macro Polo recorded how Chinese peasants captured methane from covered sewage tanks to power their huts some 700 years ago. But nowadays in urban landfills, the enormous quantities of gas produced make dealing with it beyond the average citizen’s reach.
Thus, the company decided to partner with an American firm, Waste Management Inc., for China’s first industrial landfill gas power plant. Through their cooperation, the American firm, and France’s Veolia, which later acquired the plant, walked away with more than $1 million of annual revenue. And, in return, the company’s engineers satisfied their thirst for technical know-how.
What started out as a learning project for its own engineers, according to the company, soon became China’s study center for landfill gas use. The technology that inhales the dangerous gas and exhales clean energy has impressed Chinese leaders. They asked the landfill team to author national guidelines that were disseminated throughout China.
Feeding clean energy to an electricity-starved city
Last year, the company decided to expand the capacity of its landfill gas power plant, aiming to tap into the increasing amounts of trash. Instead of relying on foreign technicians, this time it opted for a self-designed plant.
The plant, built next to the landfill, stretches tentacles composed of hundreds of pipelines that are woven through the layers of trash. It catches the bubbling landfill gas and shoots it into highly sophisticated machinery to clean it. Then the processed gas is burned to generate electricity — enough to meet the daily demands of 8,000 families.
Feeding electricity into the power grid has never been more welcomed by the local utility. Due to recent droughts, hydro power plants — a major energy supplier here — could not respond to growing demand, leaving the city with a severe electricity shortage. The city began limiting air-conditioner use in commercial sites like office buildings in order to save energy.
But the landfill company is determined not to give up any creature comforts. Engineers here hope to recycle energy waste from the power plant and use it for heating and cooling their own five-floor office building.
In addition to that, they plan to heat up water with the recycled energy, aiming to provide free hot showers to the nearby district that is home to many of the company’s workers.
Speeding up the process to save land
While such moves help extend local energy supplies, they can’t help in another challenge. With mountains of new trash arriving weekly, the landfill is expected to reach its storage limit 12 years earlier than planned. Worse yet, the landfill company, like many of its peers in China, found it difficult to bargain for a new site, bumping up against the limits of increasingly scarce land resources.
The company has been scrambling for ways to handle more trash while occupying less space. Later this year, it will build an advanced facility in which trash will enter decay and produce methane in days, instead of lying underground for years to wait for the process to happen naturally.
Still, there’s a problem: It is hard to collect enough kitchen waste — a key raw material for the upcoming facility — despite the fact that half of urban waste comes from the kitchen.
Currently, the city is estimated to generate nearly 3,000 tons of kitchen waste per day, but less than 200 tons of that goes to the designated trash bin. The rest is a trash salad containing all types of non-degradable materials from soda bottles to diapers, as most citizens hardly bother to separate it properly.
And re-separating trash on the site, which the company plans to do, is viewed by waste management experts as, well, a waste, since this will vastly push up the operating costs. The engineers, realizing they need more help, saw another opportunity.
In an exhibition center, part of the company’s “trash tour,” visitors are now playing a new video game. They must drop trash correctly into different bins in order to win.
Photo courtesy of the Hangzhou Environmental Group