If all industries could be organized into "food chains," forming their own "ecosystems" in which the waste products of each are used as raw materials by others, this would go a long way towards solving the problem of waste disposal.
When residents of Tainan City's Wanli district used to reclaim metals from electrical scrap, their activities caused serious pollution. But in fact by recovering valuable metals from what would otherwise have just been heaps of refuse, they were already practicing resource recycling.
The Industrial Development Bureau (IDB) has also approached the problem of hazardous industrial waste from the angle of creating commercial opportunities for businesses: in 1987 it set up a "Waste Exchange Center," in which it plays matchmaker by announcing on the Internet the type and quantity of wastes reported by industrial companies, so that they can be purchased by manufacturers needing raw materials or by waste disposal contractors. So far buyers have been found for a number of wastes such as sulfuric acid.
Turning muck into brass
However, to date the exchange center has not been able to balance demand with supply. Lin Chih-sen, a division chief at the IDB, comments that many raw materials derived from waste do not have the same level of purity as original feedstocks, and so do not meet manufacturers' requirements. Hence the proportion of waste materials offered through the exchange center which are actually sold is very low-less than 10%. The IDB is currently encouraging firms to carry out intermediate processing on their waste to improve its salability.
The IDB has also come up with a five-year industrial waste treatment program which singles out many materials which have a resource value, such as waste solvents, plastic-goods-industry wastes and scrap metals. As one item in the program, the government is encouraging trade associations in various industries to set up joint treatment systems to process their industry's waste centrally, thereby saving money and improving efficiency. Today such systems are already up and running in the leather tanning industry, the metal plating industry and the electric steel smelting industry.
For example, the treatment system set up by the leather tanning industry in central and southern Taiwan processes hide offcuts and scrap leather into granules which can be sold to fertilizer makers as a raw material. "It can even be used as compost to grow Oolong tea," says Lin Chih-sen.
A flue dust treatment plant built with funds from 70% of Taiwan's iron and steel manufacturers is also about to enter service, after a four-year planning and construction process. As well as extracting zinc and lead from the flue dust, which contains up to 30% zinc and lead oxides, the plant will also produce iron oxide granules which can be used for road surfacing and for construction.
However, the output of such joint treatment operations has to compete with other products in the marketplace. Lin Chih-sen notes that in the case of leather recycling, many unscrupulous operators fail to properly collect, concentrate and detoxify the chromium-contaminated effluent from the recycling process, so their costs are very low. This enables them to sell their products at rock-bottom prices, undercutting the tanning industry's joint treatment system and making the latter's products very difficult to sell.
Industrial food chains
Many bona fide waste processing organizations are still continuing to work hard at making resources out of waste.
If this is done successfully, "Companies at all stages of industrial processes, upstream, midstream and downstream, can be linked together in a 'food chain.'" Chao Chih-cheng, general manager of environmental programs at the Industrial Technology Research Institute's Energy and Resources Laboratories, uses an ecological metaphor to describe how companies in an industry can be closely interlinked.
Chao explains that creating an "industrial ecosystem" means planning and organizing an industry's activities in such a way as to fully utilize its waste products and by-products by transforming them into resources or energy which can be used by the industry itself or by other industries. Such a system can reduce wastage, reduce the burden on the environment and allow energy and resources to be shared in a system of mutual reliance. Chao likens the users, extractors and converters of resources to the consumers, producers and decomposers within a food chain. If all production processes are conducted within this food chain, no unwanted waste products will be generated.
The world's first "eco-industrial park," located in Denmark, brings together several companies including an oil refinery, a coal-fired power station, a pharmaceuticals factory, a sulfuric acid plant and a cement factory. In order to reduce costs and increase profits they are chained together in an industrial ecosystem which uses energy and resources efficiently, thereby improving the environment.
Towards an ideal
Academics in Taiwan are already studying the feasibility of introducing industrial ecosystems here. Studies focus mainly on technologies, including those needed for energy storage, energy conversion and resource recycling, and for restructuring the links between companies. Progress is still needed in all these areas, and only when the technologies and management skills are in place will it be possible to set up eco-industrial parks.
Objective conditions such as favorable environmental, trade and industrial legislation, and the understanding and support of industry, are also prerequisites to promoting industrial ecosystems.
Under the guidance of the Executive Yuan's National Council for Sustainable Development, various government departments have already begun to promote planning and research work on industrial ecosystems, and the IDB has commissioned a firm of consulting engineers to carry out planning studies for industrial ecosystems for the Tainan Technology Industrial Park and the Changpin Industrial District. Meanwhile the EPA has also begun planning systems based on high-energy-value wastes, toxic sludges and furnace slag. "Setting up an industrial ecosystem is an extremely complex task. It can't be achieved in a single step," says Chao Chih-cheng.
However, the resource recycling and waste reduction currently being promoted in industry, and the technologies and concepts such as waste trading and joint waste processing systems being fostered by the IDB, are the basis for industrial ecosystems. We are off to a good start.
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After being melted down in a furnace, recycled aluminum cans are turned into ingots of usable raw material. This is the technological basis of industrial ecosystems. (photo by Diago Chiu)
After being melted down in a furnace, recycled aluminum cans are turned into ingots of usable raw material. This is the technological basis of industrial ecosystems. （photo by Diago Chiu）
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