Taiwan Today

Taipei is working on a system that turns food waste into useful raw materials.

In the showroom of the F2E & F124 Project at the Neihu Refuse Incineration Plant in Taipei City, technicians feed food waste into a machine. Some hours and a few additional machines later, the waste has been converted into bioethanol. “This is a 75-percent pure ethanol concentration, which can be used for sterilization,” says Wu Wen-yuan (吳文園), general manager of the plant. “It can then be purified for use in making biodiesel or as a key ingredient for manufacturing plastic No. 1, 2 and 4.” With Wu’s explanation, the project’s name begins to make sense, as it contains the abbreviations for food waste to energy (F2E) and food waste to industrial plastics No. 1, 2 and 4 (F124).

Thanks to Taipei’s implementation of a comprehensive waste recycling system in the early 2000s, the project has plenty of free raw materials to work with. A few decades ago, however, the situation was very different. In fact, garbage treatment was the public’s No. 1 environmental concern in the late 1980s, as many of Taiwan’s landfills were nearing capacity. Environmentalists and the central and local governments began actively investigating methods of managing the growing volume of trash in the 1990s.

In 2000, the Taipei City Government implemented a novel system in which residents are required to purchase specific bags for disposal of non-recyclable garbage. Enforcement is handled by collection crews, who only accept such garbage in the paid bags. Recyclable products, on the other hand, are collected free of charge, which encourages people to recycle and reduces the amount of waste that must be disposed of. “More recyclables means less garbage to be incinerated or buried,” says Wu Sheng-chung (吳盛忠), commissioner of Taipei City’s Department of Environmental Protection. “It takes people some extra time to separate garbage from recyclables, but it saves money and helps the environment.”

Taipei residents have shown great support for the policy, as the amount of non-recyclable garbage Taipei now collects is only about a third of the amount in 2000, the commissioner says. It is difficult to determine how much of the reduction is due to the desire of households to save money by minimizing purchases of the special plastic bags, and how much is attributable to increasing environmental awareness, but there is no arguing with the results.

With the advent of the paid garbage bag system in Taipei, households began separating ordinary trash from recyclable items made from glass, metal, paper and plastics, but food waste—leftover meals, fruit and vegetable peels, food scraps and the like—continued to be a problem, as such waste accounted for between 20 and 30 percent of the garbage produced by an average household. Farming families could dispose of their food waste by dumping it directly into pig troughs, but kitchen scraps produced by urban households continued going into incinerators and landfills. Both methods for disposing of food waste remained problematic, however, as they caused unpleasant odors and produced different types of pollution. Incineration was particularly troublesome, as the high moisture and salt content of some food waste made burning it difficult. Meanwhile, Taiwan’s lack of space and a growing not-in-my-back-yard mentality also precluded opening new landfills and building more incinerators.

In light of such difficulties, the Environmental Protection Agency (EPA) proposed a system that required food waste to be collected separately and sorted according to whether it was cooked or uncooked, as the former can be used for pig feed after high-temperature sterilization, while the latter can be used for organic fertilizer after composting. Taipei became one of the first cities to implement a system for recycling food waste by launching small-scale demonstration projects in 2000 and implementing city-wide recycling in 2003.

In 2006, the separation of recyclables—including food waste—became mandatory nationwide. According to statistics from the EPA, Taiwan recycled 835,541 tons of food waste in 2012, with about 70 percent of that amount processed into pig feed. Just as with operators of incinerators and landfills, however, composting businesses often face protests from local residents. “Making compost is basically a process of allowing food waste to rot and ferment,” Wu Wen-yuan says. “Nobody wants that unpleasant odor in their backyard.” Some composters have managed to cut deals that compensate area residents, while others have been forced to close or relocate to remoter areas.

Taipei City currently recycles about 200 tons of food waste each day. The city diverges from Taiwan’s norm, however, as about 90 percent of the city’s kitchen waste is recycled into compost, according to Wu Sheng-chung. He explains that the disparity is the result of urban dietary habits. “Taipei people seldom cook at home, which means they produce little cooked kitchen waste,” he says. “But they do seem to eat fruit at home, as there are a lot more fruit peelings in Taipei’s compost waste.” The city’s small portion of cooked food waste is collected and then sold directly to pig farms, which brings the city an annual income of about NT$6 million (US$200,000). Meanwhile, Taipei pays nearly NT$100 million a year (US$3.3 million) to private companies to compost uncooked food waste.

A New Possibility

Wu Sheng-chung, who holds a master’s degree in chemistry, was not satisfied with merely composting uncooked food waste. Eventually he realized that such waste can contain a large percentage of sugar, and he knew that bioethanol was made mostly from sugar or starch-rich crops such as sugarcane or corn. When he put those two factors together, he began to contemplate the possibility of a new way of dealing with Taipei’s food waste. “Directly processing food crops into bioethanol doesn’t seem right for me, but I thought it’d be totally acceptable if we could use food waste, which contains sugar, as the raw material,” he says.

The commissioner, however, was not sure if or how processing recycled food waste into bioethanol could be done on a commercial basis. He called private companies and research institutions for help, and received an answer from the Atomic Energy Council’s Institute of Nuclear Energy Research (INER). In addition to nuclear power, the institute conducts research on renewable energy sources. As part of that effort, the INER established an experimental bioethanol factory in Taoyuan County, northern Taiwan in 2009.

In April 2013, the institute’s factory started experimenting with food waste provided by Taipei City and, after a few months, told Wu Sheng-chung that the process was viable. In August 2013, the INER loaned the required equipment to the Neihu Refuse Incineration Plant and began training personnel in its use. Setting up the bioethanol equipment at the incinerator was a logical step, as the food waste was already being transported to the plant and the electricity needed to run the machinery was generated during the incineration process. Even better, the bioethanol produced could be used to make biodiesel to fuel some of the city’s garbage trucks.

Making bioethanol involves dehydrating food waste and adding enzymes to convert sugar in the extracted liquid into the final product. In the trial phase, the plant processes about 100 kilograms of food waste to produce 10 to 15 liters of bioethanol each day. At full capacity, the equipment is expected to handle 20 tons of food waste daily.

While the raw material and power are free, the machinery and the enzymes needed to convert uncooked food waste into bioethanol are expensive, and Wu Sheng-chung says that the city has not yet calculated the F2E & F124 Project’s economies of scale. Nevertheless, he believes it is very likely that the scheme will be expanded to all three of Taipei City’s incinerators. “Money is not always the main concern in waste management,” he says. “The key issue here is to find the most environmentally friendly solution to the problem.”

Wu Wen-yuan notes that certain types of food waste—fruit peels, for example—contain more sugar than others. Thus, he says that if the project is to be expanded citywide, households will not only need to separate cooked and uncooked food waste, but also separate uncooked food waste according to its sugar content. To introduce the bioethanol scheme to more residents, the city government is working with Miniwiz Sustainable Energy Development Ltd., a Taipei-based company dedicated to “upcycling” consumer trash and industrial waste to create versatile, high performance materials suitable for use in everything from buildings to consumer products. Miniwiz is best known for its conception and design of the EcoArk, a facility constructed from 1.5 million recycled plastic bottles for the 2010 Taipei International Flora Expo.

At the Neihu Refuse Incineration Plant, Miniwiz used the same technique to build the F2E & F124 Project’s showroom, which showcases bioethanol-based sample products. Arthur Huang (黃謙智), founder and managing director of Miniwiz, notes that it is easier to convert food waste into fuel in Taiwan than it is in many other countries. For one thing, Taiwan has established a waste management system that can supply the necessary raw material. “Few countries recycle food waste, and I’ve never seen residents in other countries wait patiently on the roadside for garbage trucks so that they could dump their separated food waste,” he says. Huang also believes Taiwan still has the industrial capacity to manufacture bioethanol-based products, whereas most other developed countries have shed that capability.

According to Wu Sheng-chung, the F2E & F124 Project is as much about design as it is about protecting the environment. In November 2013, he explains, Taipei was selected as the 2016 World Design Capital (WDC) by the Canada-based International Council of Societies of Industrial Design. The WDC designation was established in 2008 and is conferred biennially on the city that makes the best use of design in its effort to revitalize and reinvent its urban environment. The theme for Taipei’s WDC tenure will be Adaptive City—Design in Motion, and the bioethanol scheme provides solid evidence of the city’s adaptability. “It’s not just about product design using bioethanol-related materials,” Wu Sheng-chung says. “It’s also about designing a solution to deal with a waste management issue.”

Although the WDC event is two years away and the F2E & F124 Project is still at an early stage, Taipei City’s bioethanol production has already garnered international attention. The Neihu facility, for example, was featured in MegaStructures, a documentary television series aired by the National Geographic Channel. Meanwhile, environmentalists and officials from Hong Kong, where food waste management is also a problem, showed interest in the scheme when they learned about it during an inter-city forum held in Taipei in June 2013. It seems that the trick of turning kitchen waste into useful materials while minimizing the impact on the environment is catching on, and Taipei is leading the way.

Write to Jim Hwang at cyhuang03@mofa.gov.tw