Turning 2,700 Tons of Food Waste into Green Power via Anaerobic Digestion, Instead of Pig Farms

Central News Agency

Food Waste Challenge Under the Table 5 (CNA reporter He Xiuling, Taoyuan, 12th) Stepping into the Taoyuan Guishan Water Resources Recovery Center, one does not smell the typical odor of a food waste processing plant. On the contrary, several egrets can be seen gracefully resting and foraging by the stream next to the facility. Amidst this eco-friendly atmosphere, it is hard to imagine that the plant, just tens of meters away, processes dozens of tons of household food waste every day.

This is the biogas power generation system launched by YFY Group's subsidiary, Feng Chuan Green Energy Technology, in Guishan, Taoyuan, last October. It turns food waste into energy. With the 2027 ban on using food waste as pig feed approaching, this processing model has recently become a focus for local governments.

Unexpected Hurdle from Pig Feed Ban Brings Energy Recovery Needs to the Forefront

After being crushed and homogenized, the food waste is fed into a fully enclosed anaerobic system. It can be converted into biogas for power generation in as little as 18 hours, producing 6.4 million kWh of electricity annually, enough to power 1,600 households for a year. The organic matter in the food waste is ultimately transformed into energy and effluent water that meets discharge standards.

"Food waste has truly become an unexpected hurdle," said Li Genghuan, plant manager of the Guishan Water Resources Treatment Plant, with a wry smile during an interview with CNA. The facility was originally prioritized for treating food processing wastewater like milk and beer, as well as septage. However, after Taiwan's first domestic case of African Swine Fever (ASF) at the end of last October, the busiest task over the past six months has become receiving household food waste from across the country.

"We calculated that if all 1 million tons of food waste in Taiwan were crushed and slurried, and processed through an anaerobic system, it could generate about 260 million kWh of green electricity," Li said.

However, the Guishan plant's water resources recovery center can currently only process 30 to 40 tons of food waste per day. Combined with YFY's Xinwu plant, which houses one of Taiwan's largest anaerobic biological treatment systems, the total daily processing capacity is about 100 tons. This is still a significant gap compared to the national demand. He admitted that if regional processing capacities are not established early, the pressure to dispose of food waste will rapidly emerge once the full feed ban policy takes effect in 2027.

Incineration, Composting, and Black Soldier Flies Have Limitations; Anaerobic Digestion Emerges as an Alternative

Current methods for food waste disposal include incineration, composting, black soldier flies, and anaerobic digestion. Li believes each has its pros and cons, but from the perspectives of processing efficiency, carbon reduction, and energy recovery, anaerobic digestion holds certain advantages.

He pointed out that incineration is the fastest, completing the process in as little as 2 hours. However, many counties and cities already have strained incinerator capacities. Adding large amounts of food waste would squeeze the space for general waste treatment, and the combustion process also results in significant carbon emissions.

Composting has lower costs but requires large areas and about two months for maturation. The process generates odors and greenhouse gases like methane, and the final product still relies on farmland for application. The black soldier fly model, a recent trend, uses insects to decompose organic matter. It also requires sufficient space and faces challenges in pest management.

In comparison, the Guishan plant uses anaerobic digestion technology to "turn waste into energy," offering another option for disposal.

Li noted that anaerobic systems involve facilities like anaerobic tanks, desulfurization equipment, and generator sets, requiring high investment and technical expertise. For example, the Guishan plant involved an initial investment of approximately NT$210 million (approx. US$6.5 million) and took years of construction and commissioning to achieve stable operation, creating a technological barrier.

Microbes Also Fear Irregular Feeding; Stable Feedstock is Key to Power Generation

Currently, the Guishan Water Resources Treatment Plant prioritizes household food waste but also accepts a small amount of commercial food waste. Li said that if they expand to accept more commercial food waste in the future, they will prioritize food businesses that are large-scale and can provide a stable supply, focusing on cooked food waste. "Because microbes also fear irregular feeding," Li explained. Unstable feedstock supply affects the activity of anaerobic bacteria and the volume of biogas generated.

Even with the technology and equipment in place, Li stated that one of the biggest current challenges is coordinating the collection and transportation model with local governments and food waste processors. Previously, food waste in some counties and cities was collected centrally at night and delivered to pig farms in the early morning. With the introduction of energy recovery processing, the related collection, transportation, and pre-treatment processes need to be adjusted to improve subsequent transport and processing efficiency.

Countdown to the Ban; YFY Evaluates Regional Energy Centers in Taichung, Hualien, and Taitung

Once the 2027 pig feed ban is officially implemented, Li believes Taiwan will inevitably need more regional energy centers. "Facilities like this should be established in the north, center, south, and east," he said. Therefore, Feng Chuan Green Energy Technology is evaluating potential locations including Taichung, Hualien, and Taitung, in addition to Taoyuan. He argued that the transport distance for food waste should not be too long. Transporting it from the east to the west would not only increase costs but also reduce processing efficiency, making localized processing capacity in each region crucial.

Beyond investing in and building its own plants, YFY also aims to play a role in technology export and consultation in the future. Li revealed that a large corporation has recently approached them, seeking an evaluation for building an anaerobic digestion system within its own factory premises.

As the 2027 ban on using food waste as pig feed approaches, Taiwan's waste management system is facing new challenges. When over 2,700 tons of food waste daily no longer flows to pig farms, establishing sufficient and stable disposal capacity will not only be crucial for environmental governance and waste management but will also test Taiwan's ability to advance its circular economy and green energy development. (Editor: Chang Liang-chih, Lin Shu-yuan) 1150612