화학공학소재연구정보센터
Clean Technology, Vol.28, No.3, 203-209, September, 2022
태양광 폐모듈 실리콘을 재활용한 메커니컬 실 제조공정의 환경성평가
Environmental Impact Evaluation of Mechanical Seal Manufacturing Process by Utilizing Recycled Silicon from End-of-Life PV Module
E-mail:
초록
본 연구에서는 태양광 폐모듈 해체과정에서 회수한 실리콘을 재활용하여 기계구조용 메커니컬 실을 제조하는 공정에 대해 전과정평가 방법에 의한 환경성평가를 수행하였다. 재활용 실리콘은 고순도 정제 후 탄소와 반응시켜 β-SiC 입자로 합성하고 압축 성형, 소결 및 열처리를 거쳐 제품을 생산한다. 현장 데이터 수집 및 환경부 LCI DB를 활용하여 각 단계별로 자원고갈, 산성화, 부영양화, 지구온난화, 오존층파괴, 광화학산화물 등 6개 영역의 환경영향을 산정하였다. 영향범주 별 환경영향은 지구온난화 45 kg CO2, 광화학산화물 2.23 kg C2H4으로 크게 나타났으며 가중화 분석결과 광화학산화물, 자원고갈 및 지구온난화에 의한 환경영향이 98.7%로 높은 기여도를 차지하였다. 원료 실리콘과 탄소를 미분쇄 혼합하는 습식공정과 β-SiC 과립화 공정이 주요한 환경영향 유발요인이므로 건식공정으로 전환 및 대기 배출되는 용매는 회수하여 재이용하는 시스템으로 개선이 필요하다. 폐모듈 실리콘의 재활용에 의해 자원고갈의 영향은 53.9%, 지구온난화는 60.7% 감소하며 가중화 결과 전체적인 환경영향이 27% 감소하는 것으로 분석되어 폐모듈 재활용은 자원절약과 탄소중립 실현의 주요 수단이 될 수 있음을 LCA 분석으로 확인하였다.
An environmental evaluation was conducted by employing LCA methodology for a mechanical seal manufacturing process that uses recycled silicon recovered from end-of-cycle PV modules. The recycled silicon was purified and reacted with carbon to synthesize β-SiC particles. Then the particles underwent compression molding, calcination and heat treatment to produce a product. Field data were collected and the potential environmental impacts of each stage were calculated using the LCI DB of the Ministry of Environment. The assessment was based on 6 categories, which were abiotic resource depletion, acidification, eutrophication, global warming, ozone depletion and photochemical oxidant creation. The environmental impacts by category were 45 kg CO2 for global warming and 2.23 kg C2H4 for photochemical oxide creation, and the overall environmental impact by photochemical oxide creation, resource depletion and global warming had a high contribution of 98.7% based on weighted analysis. The wet process of fine grinding and mixing the raw silicon and carbon, and SiC granulation were major factors that caused the environmental impacts. These impacts need to be reduced by converting to a dry process and using a system to recover and reuse the solvent emitted to the atmosphere. It was analyzed that the environmental impacts of resource depletion and global warming decreased by 53.9% and 60.7%, respectively, by recycling silicon from end-of-cycle PV modules. Weighted analysis showed that the overall environmental impact decreased by 27%, and the LCA analysis confirmed that recycling waste modules could be a major means of resource saving and realizing carbon neutrality.
  1. Lee K, Cha J, J. Korean Soc. Miner. Energy Resour. Eng., 56(4), 367 (2019)
  2. Kim TG, Kim KY, KISTEP Tech. Brief, 2021-13 (2021)
  3. Cho JY, Park A, Yun HM, Jun YS, Kim JS, J. Korean Inst. Resources Recycling, 29(4), 15 (2020)
  4. Latunussa CEL, Ardente F, Blengini GA, Mancini L, Sol. Energy Mater. Sol. Cells, 156, 101 (2016)
  5. Kim GM, Jang HK, J. The Korean Solar Energy Society, 41(4), 173 (2021)
  6. Dietzel W, Vasko J, “The Evaluation and Application of Mechanical Seal Face Materials,” 44th Turbomachinery & 31st Pump Symposia, 1-16 (2015).
  7. Bajagain R, Panthi G, An YJ, Jeong SW, J. Korean Soc. Environ Eng., 42(12), 690 (2020)
  8. Kim HJ, Kwon YS, Choi YG, Chung CK, Baek SH, Kim YW, Clean Technol., 15(3), 224 (2009)
  9. Zimmermann AW, Wunderlich J, Langhorst T, Wang Y, Armstrong K, Müller LJ, Buchner GA, “Techno-Economic Assessment & Life Cycle Assessment Guidelines for CO2 Utilization,” Global CO2 Initiative (2020).
  10. Choi JN, An JJ, Park PJ, Lee JJ, Lee GW, Chang BJ, “Development of a Strategic Platform for Carbon Upcycling Technologies,” KICET (2020).
  11. Muteri V, Cellura M, Curto D, Franzitta V, Longo S, Mistretta M, Parisi ML, Energies, 13, 1 (2020)
  12. Lunardi MM, Alvarez-Gaitan JP, Bilbao JI, Corkish R, “A Review of Recycling Processes for Photovoltaic Modules,” Solar Panels and Photovoltaic Materials, Chapter 2, 9-27 (2018).
  13. Lunardi MM, Alvarez-Gaitan JP, Bilbao JI, Corkish R, Appl. Sci., 8, 1 (2018)
  14. https://www.greenproduct.go.kr/epd/epd/total.do (accessed Jan. 2022).
  15. https://www.kncpc.or.kr/resource/lci_pass.asp (accessed Jan. 2022).
  16. https://ecoinvent.org/the-ecoinvent-database/login/ (accessed Jan. 2022).
  17. Lorenz D, Morris D, “How Much Energy Does It Take to Make a Gallon of Ethanol?,” Institute for Local Self-Reliance (1995).
  18. Méndez L, Forniés E, Garrain D, Vázquez AP, Souto A, Vlasenko T, Sci. Total Environ., 789, 1 (2021)