Composting in China: RIP?
China composted household waste for decades, probably millennia. An agricultural manual dating all the way back to 1149 AD includes written record of composting practice in China. Between the late 1970s and the mid-90s, when the waste stream included little non-organic material and modern waste treatment techniques had not yet entered China, composting was an encouraged and, with the exception of open dumping or burning, dominant method of treating household waste. Not only was composting economically efficient, but it also helped enrich agricultural soils and prevent pollution from waste.
Fast forward twenty years, and much has changed in China. As recently as 2001, nearly 20% of treated municipal solid waste (MSW) was composted, while incineration was used to treat only one or two percent. Now, those figures have flipped, and composting has been all but eliminated as an MSW treatment method in China.
So, what happened?
Did the composition of waste change so dramatically – economic development and rising consumerism typically usher in higher volumes of plastic, paper and uncompostable composites of these two – that composting no longer made sense? Not quite. According to recent statistics, organic material still comprises roughly half of the urban waste stream in China, and in many cities as much as 65%. In Beijing, the amount of compostable waste in the overall stream exceeds 70%.
Has the sector developed so dramatically that sanitary landfills and modern incineration plants have displaced the need for composting? Not exactly. Though alternative waste treatment methods are much more common than they used to be, with each sector growing at a rapid clip, officials from China’s most booming cities admit that they cannot tackle a growing waste problem strictly using landfills and incineration technologies.
Has public approval of other treatment methods or scientific evidence against the utility of composting diffused political support for it? At least half that statement is correct.
Waning Political Support for Composting in China
According to international environmental best practice standards on waste management, composting continues to hold its place as a better treatment method than landfilling or incineration, and is the most preferable option where waste reduction and recycling are not feasible.
And, as far as public opinion goes, China’s urban residents have become increasingly vocal in recent years in their opposition to incineration and even landfilling, citing health concerns owing to the odors and dangerous emissions produced by these facilities.
So, really, the decline of composting in China – a somewhat sad story – owes much to waning political support for composting. This is made all the more noticeable when contrasted with recent, concerted political efforts to promote landfilling and incineration uptake.
Before continuing, it is only fair to point out some of the problems associated with composting in China, both historically and currently.
The Flotsam and Jetsam of China’s Municipal Solid Waste Stream
Previously, composting in Chinese cities occurred at the household or community level, making it far more manageable. The initiation of more formal municipal waste management in the late-90s in China effectively ended the micro-management of waste and introduced larger scale handling.
Unlike the relatively straightforward process of household composting, centralized MSW composting is much more complex. For one, the composition of feedstock – or the raw material supplied to fuel the composting proces – is harder to control. To be effective, centralized composting relies heavily on household-level sorting. This is because mixed waste is more likely to contain trace metals and other hazardous substances (like batteries) that – when present on their own or when reacting chemically – contaminate the waste and make it unsuitable for compost.
In China, as in many developing countries, household-level waste separation is uncommon, and the extra cost of centralized sorting presents an untenable burden. Though some cities have made progress in the area of household-level separation, city infrastructure used for collection and transportation is still inadequate. For example, garbage trucks in Chinese cities do not have compartmentalized hauling capacity. This means that even effectively source-separated waste will get mixed up in the end.
In the 1990s, many Chinese cities began to promote centralized composting. Though well-meaning, initial efforts were hampered by high concentrations of heavy metals that severely limited the market potential of composting facilities’ output. Since then, the quality of compost improved to some degree, though technical challenges remain. The stigma associated with the product still lingers with the same potency. As a result, farmers are reluctant to buy compost from MSW. Lacking profitability potential, the market for composting from MSW has failed to attract sizable private investment in recent years.
In addition to relying on separated and carefully managed waste, efficient composting requires land, trained personnel and time. These three factors are often in short supply in the Chinese cities beset by rising volumes of MSW. Whereas composting experts attest that anywhere from 8-12 weeks is needed to create a stable, market-viable product, many Chinese cities that compost MSW allow only a month. They cite waste storage capacity constraints for the rapid cycle requirement.
On the other hand, government officials in Chinese cities that do not compost will tell you that there is no room for composting facilities. Land scarcity is a big part of the reason incineration has largely replaced composting and landfilling. In addition, limited market viability is sometimes attributed to the cost of sophisticated composting equipment.
Addressing Misperceptions about Composting
Based on this information, it would seem that land constraints paired with rising volumes of waste, and comparative cost-effectiveness, are the reasons behind the scaling up of incineration in China.
In fact, common perceptions about composting, even those held by waste management decision makers, are often erroneous.
Cost-wise, incinerators are nearly always the most capital-intensive solid waste management option (http://grn.com/library/5myths.htm). The up front investment required for incinerating facilities exceeds even that of sophisticated composting facilities, like anaerobic digestors. According to a Swiss study, composting facilities comparable to incineration plants (in terms of capacity) need just one-half or one-third the investment of incineration facilities.
Operation costs are also much higher for incineration than composting. The UK-based non-profit advocacy group Waste & Resources Action Programme’s 2011 Gate Fees Report reveals that operating costs for incineration facilities are two to three times that of composters, even before you include any of the taxes oft levied on incinerators. Though these fees are based on UK data, they are consistent with assessments of waste treatment costs in other countries, and assume environmental compliance costs not significantly higher than those in China.
Composting in China Flounders, Incineration Uptake Surges
So, it seems pretty clear that composting is the best MSW management option from both an economic and environmental perspective. Why, then, has composing lost out to incineration in China in recent years?
Simply, the Chinese Central government has made concerted efforts in the last seven or so years to promote incineration over composting. Deploying the full suite of policy tools: regulations, targets and financial incentives such as tax breaks and preferential lending, government promotion of incineration in recent years has made it a market-viable option, with composting less competitive by comparison.
In addition, the Central government has classified the electricity co-generated in the incineration process as a renewable energy. This enables waste-to-energy facility owners to sell electricity to the grid at a price roughly 80% above conventional energy per kilowatt hour. Nevermind that, often, well over 20% of the feedstock in waste-to-energy plant loads is coal, added because of the low combustability of Chinese MSW. Taking advantage of this subsidy, and contractually-agreed upon per-ton tipping, or treatment, fees, WtE facilities enjoy two revenue streams and turn a profit more quickly than composters.
By comparison, no specific political strategies have been proposed to promote the scaling of composting in China, or to address some of the existing barriers and associated risks. The 12th Five-Year Plan includes vague encouragement of composting, as well as biological pre-treatment and other alternative waste treatment methods; but so far the government has not released any targets or implementation directives.
In light of all this, one cannot help but suspect the prospect of increased composting in China is dim, at best. I wish to argue, and hope to believe, that that is not the case.
Though MSW management in China has developed considerably in recent years, it is still an immature industry. Not only will the sector continue to grow as Chinese cities begin to take a more comprehensive approach to waste management planning, but the sheer volume of MSW in China – already the largest single waste stream in the world, growing 10% annually – will necessitate the utilization of all kinds of waste treatment options. As is the case with energy, where demand currently outstrips demand and is forecasted to continue growing, China is investing heavily in various means of power generation, from fossil fuel-based to renewable energy and nuclear power. Thus, it is reasonable to expect that there will eventually be strong demand for composting not because the political climate favors its environmental or cost advantage, but rather, because China will need all the waste management tools it can get.
In the meantime, what can be done to make the conditions more favorable for composting?
Looking Ahead
The key to increasing the uptake of composting as a waste treatment method is raising the quality of the feedstock; and the best way to achieve this is separate collection of waste at the household level.
As mentioned above, waste separation programs are already underway in many major Chinese cities. Beijing, for example, has set a goal to achieve 65% separation of MSW by 2020. Under the framework of the 12th Five-Year Plan, 50% of cities should introduce kitchen waste sorting programs by 2015. Though an efficient household separation system comparable to that in Korea, Japan or Germany is still years, if not decades off, current efforts to move towards that goal are encouraging.
However, effective separation at the household level is not enough. Because waste is subjected to considerable transport and processing before reaching its final disposal or treatment site, both capital and labor investment as well as effective planning are essential inputs. For composting to become viable in China, compatible infrastructure and equipment for separated waste treatment streams need to be better developed.
Finally, if you search hard enough, you will find pilot composting schemes in China making use of just about every technology. Experts and waste management officials openly point to composting as part of “the next stage” of the sector’s development. This, too, is a promising trend.
Though Chinese MSW does not currently make a very suitable candidate for composting, do not give up hope just yet. In time, composting is bound to rise from the dead.