Nantou is one of six counties and municipalities in Taiwan without an incineration facility. The Caotun Landfill is a headache for Lee Yi-shu, director of the Nantou Environmental Protection Bureau.

Over 70,000 tons of rubbish spill over the outer walls of a temporary landfill depot, reaching nearly four stories high.

Two years ago, methane produced by the Caotun garbage mountain caused a major fire that took two weeks to extinguish. In the effort to prevent spontaneous combustion, the Environmental Protection Bureau installed infrared sensors to measure the temperature of the garbage and trigger sprinklers when necessary to cool it down.

(Source: Chien-Ying Chiu)

But this is just the tip of the iceberg, as Nantou has piled up 190,000 tons of garbage. “It will be overflowing in another year or two,” Lee says anxiously.

Nantou County does not have an incinerator. Prior to 2015, with support from incinerators in Chiayi, Taichung, Miaoli, and Kaohsiung, Nantou achieved a 100-percent proper garbage processing rate.

Since 2016, the issue of aging incinerators has worsened around Taiwan, as treatment capacity has been greatly diminished. This has led cities and counties to shift their priority to processing residential garbage.

Nantou’s proper garbage processing rate has dropped to 60 percent, the worst in the country, as the volume of untreated garbage piled up within the county has risen from 30,000 to 40,000 tons over the course of one year.

The solution Lee has come up with is to emulate Europe, turning waste into Solid Recovered Fuel (SRF) in place of industrial coal-fed boilers.

Turning garbage mountains into thermal energy

Turning waste into energy has become common practice in waste treatment around the world. After collection and transport, combustible waste is separated and processed into fuel. Properly separated, the thermal energy produced by SRF approaches that of coal, with around one-third the CO2 output that burning coal produces.

In March, two waste processing machines imported from Austria and Sweden were installed in Caotun. The machines are capable of sorting and separating out plastic waste, compressing the fluffy plastic and wrapping it in white film.

Bags of garbage weighing one ton each and standing about a meter tall are stacked high in Caotun, waiting to be opened until Nantou has set up an SRF processing facility. After undergoing around a dozen steps, including selection, pulverization, cleaning, and formation into pellets, they would be turned into fuel rods with a stable heat value before being burned in an industrial boiler.

This is the waste processing method long implemented in a lot of European countries. Around 55 percent of the municipal waste produced in Nantou is plastic, 96 percent of which is plastic suitable for burning that can provide increased thermal energy.

The remaining 45 percent of rubbish, including toilet paper, bamboo chopsticks, and kitchen compost, must be transported for incineration due to its low heat value. Over the short term, this can lighten the incineration load by around half.

Lee is currently searching for an industrial boiler that can take Nantou’s waste fuel rods. Among the candidates are paper mills, electrical power plants and cement plants. In Yunlin, some of the boilers in the Formosa Plastics Mailiao Industrial Zone are using SRF made with municipal waste from the Yunlin region.

Nantou also looks forward to building an SRF power plant in the future, which could sell electricity while also solving its garbage issue.

In Lee’s estimation, if this model proves operational, Nantou could even exchange waste with other municipalities, thereby helping extend the incinerators’ lives.

SRF: From stagnation to high demand

Practically every major coal-fired power plant has set its sights on SRF. The “Path to Net Zero Emissions by 2050”, issued by the National Development Council in March, made special mention of expanded SRF utilization among cement factories and paper mills.

Further, the Bureau of Energy has defined SRF power generation as renewable energy. And with a feed-in-tariff rate (FIT) approaching NT$4.0, the Hsinwu facility owned by YFY Paper produces SRF from paper, and completed construction in 2020 of Taiwan’s first coal-free heat and power cogeneration (CHP) system.

Taiwan could produce around 150,000 tons of SRF annually. If additional production volume from plants currently under development is factored in, this can be increased to roughly 400,000 tons. Yet this is still not enough.

Long-Shun Green Energy Technology Ltd. (隆順綠能科技), established in Tainan five years ago, is the single SRF production facility in Taiwan with the largest production volume as of now. Here, second-hand clothing and plastic waste are turned into fuel, and their top customer is a paper mill.

(Source: Chien-Tong Wang)

Chen Chun-hao, Long-Shun’s marketing director, observes that two years ago, the company was grappling with who to sell its products to, but “starting last August, supply has been unable to keep up with the demand, and will probably not be enough for the next year or two,” he reports.

Chen relates that global brand customers’ demand for ESG and the trend toward emissions reduction has greatly increased factories’ willingness to employ SRF over the past two years, adding that “production lines can’t even stop for a single day now.”

(Source: Chien-Tong Wang)

“SRF is an industry chain that touches upon multiple factors,” observes Jim Tai, general manager of Remondis Taiwan, Germany’s largest waste management group. 

Europe, where the recycling rate is lower than that of Taiwan, began intense research into making fuel out of waste two decades ago. From the origins of SRF, to manufacturing specifications, certification agencies, to back end elimination, re-use of dregs, to energy production CO2 audits, clear policies have been put in place.

Although the investment cost is heavy, as it can reduce CO2 emissions and replace coal burning; as long as the boiler burns at over 900 degrees, the SRF can burn cleaner and will not cause new air pollution issues.

Cement kilns that burn at around 1,300 degrees are an ideal downstream use case for SRF. In Europe, nearly half of coal burning has been replaced by alternative fuels, with some facilities achieving total decoupling from coal.

However, extensive reform is still necessary for Taiwan’s garbage treatment system.

The most critical issue is that sorting facilities require a large piece of land and a huge financial investment.

The SRF sorting plant planned for Nantou will be a BOT (build-operate-transfer) project requiring an investment of at least NT$1 billion. However, the entire economic development project budget for Nantou County is only a little over NT$4 billion.

Local governments that have established SRF systems, like Yunlin County, have done so only on a small scale. Comparatively speaking, Europe’s SRF facilities are large and generate high volume to produce synergy.

In addition, whoever burns SRF must also conduct surveys. Chia-chi Chang, senior researcher at the Taiwan Bio-energy Technology Development Association, asserts frankly that SRF manufacturing planning is “user priority.” In other words, it is necessary to determine the degree of customization at the upstream SRF facility starting with the boiler design. Otherwise, “If it won’t fit inside the boiler, it is just waste.”

And SRF has its limitations. Garbage can be turned into fuel, but it doesn’t mean we can get rid of incinerators and landfills entirely.

“For instance, there are two SRF plants in Barcelona, as well as a methane-powered electrical power plant, incinerator, and landfill,” relates Chang, illustrating that energy from waste and incineration must be conducted in tandem.

(Source: Chien-Ying Chiu)

For incinerators, there is very little that can be changed in the effort to reach net zero targets.

“You can’t reduce waste treatment volume in order to reduce emissions,” asserts Liao Chun-chi, chairman of Ecove, one of Taiwan’s top incinerator operators.

Following the announcement of the path to net zero, Ecove has considered how to incorporate chimney carbon capture, but it has not found any answers as for how to eliminate the carbon dioxide once it is captured.

Central gov’t must direct incinerator planning

Modern incinerators all come with power generation systems. The most direct method of reducing emissions is to raise efficiency.

Taking the example of Ecove’s Miaoli incinerator, the on-site system was upgraded, reducing overall electricity consumption by 14 percent; the outdated facilities at the Gangshan plant were updated and processing volume increased by 15 percent, so that electric power savings of approximately 16 percent have been achieved per ton of garbage treatment, while the volume of electric power produced has increased by more than 20 percent.

This took maximum effort. “Overseas, incinerator overhauls consist of getting a new boiler,” says Liao.” Meanwhile, the overhauls of Taiwan’s several incinerators just updated non-core equipment, not including boilers or generators, and thus making it especially difficult to make any breakthrough improvements.

Garbage volume keeps growing around Taiwan. Last year, residential garbage set a new record at over 10 million tons, and industrial waste output has also reached a high of around 20 million tons.

As Taiwan enters a new era of waste management, whether it is a threat or an opportunity will depend on how much willingness there is to invest.

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Translated by David Toman
Edited by TC Lin
Uploaded by Penny Chiang