Every autumn, after the harvest ends, agricultural Busan waste such as rice straw, rice husks, and outer leaves and peels of vegetables floods farmlands. The industry estimates that the annual generation of agricultural Busan waste reaches approximately 14 million tons. A significant portion is burned in fields or buried in the ground; burning causes wildfires and fine dust, while buried Busan waste emits greenhouse gases as it decomposes.
Greenefl, a faculty-founded startup from Korea National University of Science and Technology (KENTECH), is developing “dry anaerobic digestion (ADOS)” technology that produces biogas usable for electricity, heat, and hydrogen from this dry Busan waste. The technology enables Misaeng materials that conduct electricity to directly exchange electrons with one another, producing methane faster and in greater quantities.
Anaerobic digestion for producing biogas from waste resources has traditionally focused on “wet” methods that handle moisture-rich raw materials such as food waste and livestock manure. Although the Biogas Act mandates producing biogas from a certain proportion of waste resources, actual facility expansion has been slow due to wastewater and odor generated after processing. An even bigger problem was productivity. Biogas production volumes were not high enough to yield significant profits for facilities. It was a technology closer to waste disposal than energy production.
Greenefl is boosting energy output to shift anaerobic digestion technology from the “waste disposal” domain to “energy production.” Lee Hyeong-sool, CEO of Greenefl, stated, “Biogas production per ton is 230–250 N㎥, which is four times more energy than existing wet methods,” adding, “There is no wastewater or odor, so installation and operating costs are much lower.” He further noted, “Unlike solar and wind power, it can produce energy consistently without being affected by weather, which is also a strength.”
The utility as waste disposal is also greater than with existing methods. By using agricultural Busan waste, which previously lacked proper treatment methods, as the main raw material, it solves burning and landfilling problems. It can also treat livestock manure and other materials used as raw materials in existing technologies by mixing them with agricultural Busan waste.
Lee (CEO) said, “Agricultural Busan waste does not stand out like food waste or livestock manure, so it has received relatively little attention.” He added, “However, it has the potential to cause significant problems, and accordingly, the Biogas Act also recognizes plant and animal residues, such as agricultural and forestry Busan waste, as raw materials.”
Greenefl completed a 10㎥-scale pilot demonstration in Gangjin County, South Jeolla Province, and began constructing a 0.1MW-class modular demonstration plant at the KEPCO New Business Technology Research Institute in Naju starting last July. It is also pursuing overseas expansion to countries such as Indonesia. As its business viability has been recognized, it has raised a cumulative investment of 2.2 billion won from Future Science and Technology Holdings, Soop Ventures, Blue Point Partners, and others.
Meanwhile, Greenefl will compete in the finals of the “5th K-Deep Tech Startup King of the Kings ,” a special side event of “Smart Energy Plus (SEP) 2026” held at Seoul COEX on the 30th of this month, representing KENTECH faculty-founded startups. At the competition, it will face off against faculty-founded startups from KAIST, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Ulsan National Institute of Science and Technology (UNIST), Gwangju Institute of Science and Technology (GIST), and POSTECH (formerly Pohang University of Science and Technology).
Now in its fifth year, this King of the Kings competition is hosted by MoneyToday’s startup-specialized media platform “Unicorn Factory” and organized by six national science and technology specialized universities with the support of the Ministry of Science and ICT. KENTECH joined this year. It was established to support the promotion of R&D (research and development) technology transfer and commercialization, the growth of promising deep tech startups, and the construction of a regional innovation ecosystem.
A total of 12 teams advanced to the finals, consisting of six faculty-founded and six student-founded startups each from the six major science and technology specialized universities. Executives from Samsung Electronics C-Lab, GS Vendors, L&S Venture Capital, Ecopro Partners, LB Investment, Blue Point Partners, CNTech, Series Ventures, Korea Science and Technology Holdings, and the R&D Special Zone Promotion Foundation will participate as judges.
Among faculty- and student-founded startups, one team each in the grand prize category will receive the Vice Prime Minister’s Award (Ministerial Award from the Ministry of Science and ICT) and a prize money of 3 million won. Grand prize teams will also receive additional support, including △linkage for follow-on investment recruitment and △recommendation for TIPS. Two teams each in the excellence award and encouragement award categories will be awarded prizes along with prize money of 1 million won and 500,000 won, respectively.
<Application to observe the 5th K-Deep Tech Startup King of the Kings >
-Date: October 30 (Fri) 9:30–17:00
-Location: Seoul COEX Hall B PLUS STAGE
-Target: Deep tech field startups and investment VC reviewers
-Organizers: KAIST, DGIST, UNIST, GIST, POSTECH, KENTECH, MoneyToday Unicorn Factory
-Application: https://forms.gle/McNBqdiBts8RJazVA
[MoneyToday startup media platform Unicorn Factory]
in FUTURE
