Abstract
The objectives of this study are to develope a method for recycling organic matter by using the microwave-thermal air hybrid drying process and to assess the quality and characteristics of RDF(refuse derived fuel) in terms of its 3-component analysis (water content, ash content and combustible content), heating values(high and low heating values), metallic ingredient contents (Hg, Cd, Pb and As), sulfur content and chlorine content based on operating parameters such as mixture ratios with food waste, anthracite coal, waste plastics and sawdust.The experiment using the microwave-thermal air hybrid drying process proved that an optimal mixture ratio was 70% of food waste and 30% of sawdust. The food waste used in this research was pre-treated for better drying efficiency. Also, to improve drying efficiency and heating values of food waste, an experiment was carried out to dry a mixture of powder-type low-quality Ac (Anthracite coal), Wp (Waste plastics) and Sd (Sawdust), all of which were ground to less than 2 mm. This experiment was also carried out in order to achieve less than 10% moisture content. The analysis of the RDF quality as the quality standard was observed the low heating value of 5,663 kcal/kg (2nd-class RDF); the chlorine content of 0.39% (1st-class RDF); the water content of 2.5% (less than RDF class standard of 10%); the combustible content of 2.2% (less than RDF class standard of 20%); and the sulfur content of 0.22% (less than RDF class standard 0.6%). Heavy metals were not detected or found significantly lower than permissible limits.
본 연구는 마이크로파-열풍 융합건조장치를 이용하여 유기성 자원의 활용하기 위해 음식물류 폐기물, 무연탄, 폐플라스틱 및 톱밥의 혼합비율에 따른 RDF(refuse derived fuel)의 품질 및 특성을 평가하고자 하며, 또한 건조물질의 삼성분(수분, 가연분, 회분), 발열량(고위발열량, 저위발열량), 금속 함량(Hg, Cd, Pb, As), 황분 함유량, 염소함유량 등 고형연료로서의 품질특성을 평가하였다. 본 연구에 사용된 음식물 쓰레기는 가연성 물질의 균질 혼합 및 건조효율 향상을 위하여 전처리를 실시하였고. 음식물 쓰레기의 건조효율 향상 및 발열량을 향상시키기 위해 2 mm 이하로 분쇄된 분말 형태의 저품질 무연탄 (Ac ; Anthracite coal), 폐플라스틱 (Wp ; Waste plastics) 및 분말 톱밥 (Sd ; Sawdust)을 혼합하여 건조실험을 실시하였고, 완전건조(함수율 10%)를 기준으로 운전하였다. 마이크로파-열풍 융합건조공정을 이용한 실험결과 최적 혼합비율은 음식물 쓰레기 70%와 톱밥 30%를 혼합하였을 경우이며, 고형연료 품질기준을 분석한 결과 저위발열량은 5,663 kcal/kg (RDF 등급기준 2등급), 염소 함유량은 0.39% (RDF 등급기준 1등급), 수분 2.5% (RDF 등급기준 10% 미만), 회분 2.2% (RDF 등급기준 20% 미만), 황분 0.22% (RDF 등급기준 0.6% 미만)으로 나타났다. 중금속 함유량은 검출되지 않거나 허용한계에 비해 현격하게 낮은 수준으로 함유되어 있었으며, 고형연료 품질기준이 가장 우수한 것으로 나타났다.
