Converting food waste is not a rubbish idea

SHEEPS wander amid mountains of rubbish as collectors dump garbage from carts. Dogs yelp when outsiders approach stoves where used cooking oil simmers.

Those are scenes in "Besieged by Waste", a documentary made by artist Wang Jiuliang, who spent two years shooting landfills surrounding Beijing.

As the city expands so does its volume of waste. Beijing's 20 million residents generate 11,000 tonnes of cooking waste every day.

Is there anything useful in all this garbage?

Not all of it ends up in landfills. Some becomes feed for livestock. Some is processed and used again in restaurants. With food safety dominating headlines, government agencies vowed to check sources of cooking oil and work on quality standards.

Meanwhile, entrepreneurs see opportunity in the table scraps and orange rinds, bones and congealed oil you see - and smell - late at night along Guijie, the city's most popular street for gourmets.

"The treatment of food waste is a flourishing industry," said Ren Lianhai, a scholar with Beijing Technology and Business University.

Some companies are working on technologies to generate electricity with rubbish. Others plan to turn food scraps into fertiliser or animal feed.

In Gao'antun, northeast of Beijing, barrels of food waste are delivered to treatment facilities. The waste is fed into a machine with an enzyme, is heated to 75-80 degrees Celsius for 10 hours, and emerges as a brownish powder that can be used in soil as fertiliser. A few bones and toothpicks might remain, but the gutter smell is gone.

Beijing Goldenway Bio-Tech operates about 10 such facilities as it tries to tap into the field of rubbish treatment. When put into full operation, the company says, this one factory could deal with 400 tons of waste a day.

The company sees those millions of bits of food as raw material for organic fertilisers. "They are actually raw materials of abundant supply and extremely low cost," said Yu Jiayi, Goldenway's CEO.

The company was founded eight years ago, before food safety and rubbish treatment grew into the issues they are today, but Yu saw the potential. She had studied animal nutrition in China, had headed State-owned agriculture companies, and then had studied international commerce and globalisation in the United Kingdom.

Natural balance

Yu, 49, sees the world as a constant recycling of chemical elements. Nature works through the interaction of animals, plants and microbes, she said. Ideally, the three work consistently and reach a natural balance.

But the natural process has been disrupted in China by the expanding gap between urban and rural areas, she said.

Consumption by urban dwellers increases rapidly as cities expand. Trash treatment facilities can't keep pace, so rubbish is transferred to outlying areas. As a result, huge cities are surrounded by rubbish landfills, as Wang's documentary shows.

But it's not just a useless mess. Yu said about 70 per cent of China's urban trash is rich in organic compounds. The challenge is to distill the nutritious elements from them and put them to use.

The abundance of rich garbage material in urban areas contrasts with the poor soil in some rural areas, where peasants turn to chemical fertilisers to boost agricultural production. Such fertilisers can increase output in the short term; in the long term, they damage the soil and make it more barren.

Further, too much of certain elements in those synthetic fertilisers, such as nitrogen, enters the water supplies and becomes a source of pollution in the ecosystem.

Some chemicals also can go into the vegetables and fruits, making them decay easily and harming people's health.

For Yu, the solution is to reconnect the ecological chain. The company collects the garbage in urban areas, processes it, makes it into organic fertilisers and sells them to the rural areas.

In addition to the goodwill factor, Yu's business plan has the potential of producing profits. China generates about 1 billion tonnes of rubbish a year, 10 million tonnes of it cooking waste. The most common ways of disposal are to burn it or bury it. Neither way creates any business value.

Many rubbish treatment companies depend on government subsidies as their main source of income. Goldenway says it can ask for fewer subsidies because it can realize income through the sale of its fertilisers.

And the company obtains the raw materials almost for free, providing a competitive edge. Goldenway sells fertiliser through big state-owned companies, such as Sinochem Group, and directly to the government, which distributes it to rural areas.

Unlike most fertilisers used in China, Goldenway's fertiliser is organic, which can make the soil healthier. Zhang Hailiang works a strawberry field on a farm in Changping, northwest of Beijing. When he started, he said, the soil was almost barren. "It was so hard that our tools broke when we tried to turn the area into a strawberry field."

After three years, the soil has recovered its quality and now produces strawberries. "The farmers all know that the organic fertilizer is useful," Zhang said. "Some even fight for it."

Investors interested

Goldenway has just started to turn a profit, and financiers have seen its potential. The company received 167 million yuan (US$26.4 million) from investors including Goldman Sachs in 2007. Tsing Capital, a venture capital firm that specialises in clean technology, invested US$11.7 million two years later. Goldenway is preparing to seek a stock market listing next year.

Yu sees her company as doing well by doing good: By turning food waste into fertilisers, it will also cut the supply of oil processed from cooking waste.

Some people collect the waste, distill oil from it, and sell the oil to restaurants - hence, it is called waste oil.Sorting out waste is another problem. The classification of rubbish, a common practice in developed countries, is far from widespread in China.

The government started experimenting in some key cities in 2000. In Beijing, for instance, some neighborhoods have barrels colored and labelled green for kitchen waste, blue for recyclables and black for other waste. But many households still put all their waste in the same plastic bag and throw it away.

Sanitary workers put kitchen waste into a special garbage tank in a residential community in Beijing. "I know someone who said they just don't have enough space for so many barrels," Mo said.

He said some companies try to generate electricity by burning waste, but when everything is mixed together, they sometimes cannot manage to burn.

China Daily/ANN