Kim Ki-Chul, president and CEO of SNenergy

Korea discharges some 13,000 tons of food waste on a nationwide basis daily, of which about 3,000 tons is discharged by Seoul Metropolitan City. Since last year when a ban against throwing food waste into oceans was imposed, costs for treating food waste have increased from 70,000 won-80,000 won to 110,000 won-120,000 won. In 2013, the capital’s bill for treating food waste surged to a whopping 110 billion won. 

In line with this change, voices have been mounting for a need for aggressively introducing alternative solutions to reasonable treatment of food waste to cope with residents and local governments’ rising financial burden stemming from the application of environmentally-friendly treatment methods. 

Responding to the urgency, SNenergy Co. is concentrating on efforts to properly address the treatment of organic municipal solid waste (OMSW) using anaerobic digestion, considered the best treatment system from environmental and economical aspects, which leads the production of biogas for recycling of energy and heat.

To this end, SNenergy conducted a study of European companies that have accumulated extensive operational experiences and selected Austep of Italy to introduce the related equipment. This is owed to the company’s efforts to overcome the environmental problems such as bad odors that existing Korean anaerobic digestion plants experience and economic difficulties related to operations caused by lower efficiency. 

The strong point of Austep’s anaerobic digestion system is that it provides an integrated system of treating food waste thanks to the experience and knowhow it has accumulated through the construction and operation of 108 organic waste treatment plants over 19 years. TORNADO is a system designed and built by Austep for the pretreatment of food waste collection. TORNADO removes inert elements such as plastic bags for packing foods, facilitating the proper grinding to a millimeter size and homogenization of the matrix input to the digester. In this way, the digester is fed with an optimal mixing, excluding inorganic matrices that could disturb the anaerobic digestion, and, consequently the best production of biogas in the course of thermophilic anaerobic fermentation. The concrete slab digester is substantial and excellent in terms of obturation and insulation. Several horizontal mixers working at different heights allow the optimal mixing and maintaining of temperatures for digestion. One of the characteristics showcased by Austep is an outside heating device that makes it easy to maintain the temperatures of the incoming materials and the digester as well as repair & maintenance. 

These strengths are applied to the high-temperature digester, essential for keeping appropriate temperatures on a constant basis, which is combined with the secondary room-temperature digester to produce optimal production of biogas via the production of methane by anaerobic microorganisms. Torino Engineering College’s independant verification of the food waste treatment facility in operation in Italy has proved the efficient production of biogas.  

SNenergy is implementing a project to build an anaerobic digestion plant generating power using agricultural and livestock waste as raw materials on Jeju Island in cooperation with Austep. (photos: SNenergy)

Lastly, Austep, a leader specializing in the construction and management of scores of water treatment plants, has the knowhow to lower nitrogen emissions by 90 percent through the sequencing batch reactor’s treatment of large amounts of ammonia nitrogen, contained in digestate that produces biogas via biological transformation. Waste water, purified in a preliminary treatment, can be reused and released through evaporation using heat created in the course of steam supply and power generation, condensation, and membrane treatment. The concentrated water containing nutrient substances, which is released in the process, is used along with digested solid materials to produce fertilizers, thus offering an optimal cycle of water solutions. 

Austep’s anaerobic digestion system employing a bio filter has solved the problem of bad odors, a long-standing woe that dogged food waste treatment facilities, resulting in criticism and complaints from many people. The proper pretreatment of excluding plastic bags for packing food waste has not only addressed a reduction in efficiency, but also enhanced the value of digested solid matters as the raw materials for fertilizers. Proper temperature maintenance and sufficient residence time in thermophilic digestion tank guarantees an optimal production of biogas in the course of fermentation, thus coping with the vicious cycle of lower biogas productivity and inefficient operation that the existing Korean anaerobic digestion treatment facilities experience.

Optimal preparation of raw materials, proper management of microorganisms, and efficient anaerobic digestion, which is guaranteed by Austep’s system, allows heat supply and power generation around the clock thanks to a combination of its biological considerations and engineering technology. An integration system of linking anaerobic digestion and water treatment systems as a specialized leader prevents inefficiency in the existing food treatment facilities lacking organic linkage.

Austep has strong points: offering an integrated system ranging from design to construction, operation and management in the course of pretreatment, anaerobic digestion, and water treatment. The company’s exclusive technologies offer performances that the existing biogas makers cannot offer, removes worries over inefficiency of the conventional food waste treatment facilities, and guarantees investments. 

SNenergy is seeking to put into operation an anaerobic digestion plant generating power using agricultural and livestock waste as raw materials in cooperation with Austep. A pilot project to introduce Austep’s aforementioned highly-efficient food waste treatment system in Korea has been test-operated. The outcomes of the test-operation, guaranteeing the performances of the real plant, has proved higher biogas production efficiency using food waste in Korea. 

Austep is advancing into several regions of the world by capitalizing on its capabilities to successfully construct and operate biogas facilities. In an effort to supply and proliferate its food waste treatment technologies, the company participated in the 36th ENVEX, the international environment industry technology and green energy exhibition, which took place at COEX in Seoul from June 10-13. Austep became the first European company to introduce its technology at the exhibition and to offer consulting. Korean experts and the CEO of Austep participated in a seminar sponsored by the Ministry of Science, ICT and Future Planning and shared their expertise and experiences on the construction and operation of anaerobic digestion plants.

Given the fact that the existing food waste treatment facilities in operation do not offer integrated and efficient solutions toward food waste treatment, while integrated solutions using Austep’s facilities will become innovative direction guidance for efficient treatment of Korea’s food waste, and this solution will contribute to economic exchanges between Korea and Italy.