Journal of the Korean Wood Science and Technology

The Korean Society of Wood Science & Technology (한국목재공학회)
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Effect of Bark and Drying Waste Liquor of Larix kaempferi Used as An Additive on The Fuel Characteristics of Wood Pellet Fabricated with Rigida Pine and Quercus mongolica Sawdust

첨가제로서 낙엽송의 수피 및 건조폐액이 리기다소나무 및 신갈나무 펠릿의 연료적 특성에 미치는 영향

  • Yang, In (Department of Wood and Paper Science, College of Agriculture, Life & Environments Sciences, Chungbuk National University) ;
  • Chae, Hyun-Gyu (SYEnergy Co., Ltd.) ;
  • Han, Gyu-Seong (Department of Wood and Paper Science, College of Agriculture, Life & Environments Sciences, Chungbuk National University)
  • 양인 (충북대학교 농업생명환경대학 목재종이과학과) ;
  • 채현규 (SY에너지(주)) ;
  • 한규성 (충북대학교 농업생명환경대학 목재종이과학과)
  • Received : 2017.01.24
  • Accepted : 2017.03.01
  • Published : 2017.05.25
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Abstract

In this study, pitch pine (Pinus rigida, PIR) and Mongolian oak (Quercus mongolica, QUM) pellets were fabricated with bark or/and drying waste liquor (DWL) of larch (Larix kaempferi, LAK) as an additive. Based on the results of fuel characteristics of the pellets, optimal conditions for producing the high-quality pellets were provided. In the analysis of chemical composition, bark contained holocelluose and lignin of 90% and over. DWL had 0.1% solid assumed to sugars which are generated from the oven-drying of LAK logs. QUM showed high ash content (2.2%) by containing of bark in the sawdust. Bark and DWL of LAK had high ash content of 4% and over. Calorific values of all specimens and additives were higher than that of the $1^{st}$-grade standard of wood pellets designated by NIFOS (18.0 MJ/kg). PIR and QUM pellets were fabricated with additive of 2 wt% based on the solid weight of oven-dried sawdust using a piston-type flat-die pelletizer, and thus ash content and calorific value of the pellets did not affect by the use of additive. Durability of the pellets increased with the use of additive. Durabilties of pellets, which were fabricated with bark as an additive and DWL as a controller of moisture content for sawdust, did not differ from those of pellets without additives and were lower than those of pellets either with bark or DWL. However, use of both bark and DWL for the production of wood pellets might be favorable because it can make a profit from the collection process of DWL. Based on the results of fuel characteristics of the pellets, QUM and PIR pellets were produced by a flat-die pelletizer. Moisture content (MC), bulk density and durability of the pellets improved with the use of additive. Particularly, sawdust MC of 10% and the addition of bark or DWL for PIR as well as sawdust MC of 12% and the addition of bark for QUM might be optimal conditions for the production of high-quality pellets. Except for the ash content of QUM pellets, other properties of PIR and QUM pellets exceeded the $1^{st}$-grade wood pellets standards of NIFOS.

리기다소나무와 신갈나무 목분에 낙엽송 수피 또는/그리고 인공건조시 발생하는 폐액을 첨가제로 사용하여 펠릿을 제조하고, 이에 대한 연료적 특성의 분석을 통하여 고등급 목재펠릿 제조를 위한 원료 및 제조조건을 제공하고자 본 연구를 수행하였다. 첨가제에 대한 화학적 조성을 조사한 결과, 수피는 90% 이상의 전섬유소와 리그닌으로 구성되어 있었으며, 건조폐액은 대부분 당 성분이라 추정되는 0.1%의 고형분을 가지고 있었다. 신갈나무 목분은 수피의 포함으로 회분 함량(2.2%)이 높았으며, 수피와 건조폐액도 4% 이상의 회분을 가진 것으로 조사되었다. 목분 및 첨가제의 발열량은 모두 국립산림과학원(NIFOS)에서 고시한 "목재제품의 규격과 품질기준"의 목재펠릿 1급 기준(18.0 MJ/kg) 보다 높았다. 피스톤형 펠릿성형기로 제조한 펠릿은 첨가제의 양이 2 wt%인 관계로 회분함량과 발열량에 영향을 미치지 않았다. 내구성의 경우, 대부분의 제조 조건에서 첨가제의 사용에 의하여 증가하였다. 한편 첨가제로 수피 그리고 목분의 함수율 조절을 위하여 건조폐액을 함께 첨가하여 제조한 펠릿의 내구성은 첨가제없이 제조한 펠릿과 차이가 없었으며, 수피 또는 건조폐액을 각각 첨가제로 사용하여 제조한 펠릿보다 낮았다. 그러나 펠릿 제조비용 측면에서 건조폐액은 폐수처리에 따른 수익이 가능한 관계로 수피와 건조폐액을 공동으로 펠릿 제조에 사용하는 것이 유리할 것으로 생각한다. 피스톤형 펠릿성형기로 제조한 펠릿의 연료적 특성 측정 결과를 토대로 파일럿 규모의 평다이펠릿성형기로 리기다소나무 및 신갈나무 펠릿을 제조하였다. 제조된 펠릿의 함수율은 목분 및 첨가제의 사용과 상관없이 NIFOS 1급 기준($${\leq_-}$$10%)을 모두 만족하였다. 이에 대한 겉보기밀도와 내구성 측정결과를 종합하면, 첨가제의 사용은 리기다소나무의 경우 목분 함수율을 10%로 조절하고 수피나 건조폐액을 사용하는 것이 그리고 신갈나무의 경우 12%의 목분 함수율에 수피를 사용하는 것이 각각의 최적 목재펠릿 제조 조건이라 생각한다. 신갈나무 펠릿의 회분 함량을 제외하고 이 조건에서 제조한 목재펠릿의 품질은 NIFOS 목재펠릿 1급 기준을 크게 상회하는 것으로 나타났다.

Keywords

References

  1. Ahn, B.J., Chang, H.S., Cho, S.T., Han, G.S., Yang, I. 2013. Effect of the addition of binders on the fuel characteristics of wood pellet. Journal of The Korean Wood Science and Technology 41(6): 475-489. https://doi.org/10.5658/WOOD.2013.41.6.475
  2. Ahn, B.J., Lee, S.M., Choi, S.H., Cho, S.T., Choi, D.H. 2013. Preparation of standards and quality standard for the implementation of wood fuel labeling. 2013 Proceedings of The Korean Society of Wood Science and Technology Annual Meeting: 114-115.
  3. Ahn, B.J., Chang, H.S., Lee, S.M., Choi, D.H., Cho, S.T., Han, G.S., Yang, I. 2014. Effect of binders on the durability of wood pellets fabricated from Larix kaempferi C. and Liridendron tulipifera L. sawdust. Renewable Energy 62: 18-23. https://doi.org/10.1016/j.renene.2013.06.038
  4. Bergstrom, D., Israelsson, S., Ohman, M., Dahlqvist, S., Gref, R., Boman, C., Wasterlund, I. 2008. Effects of raw material particle size distribution on the characteristics of Scots pine sawdust fuel pellets. Fuel processing Technology 89: 1324-1329. https://doi.org/10.1016/j.fuproc.2008.06.001
  5. Briggs, J.L., D.E. Maier, B.A. Watkins, and K.C. Behnke. 1999. Effects of ingredients and processing parameters on pellet quality. Poultry Science 78: 1464-1471. https://doi.org/10.1093/ps/78.10.1464
  6. Han, G.S., Yang, I., Sagong, M. 2012. Investigation of the basic properties of agriculture residues as a raw material for the production of agropellets and the evaluation of their fuel characteristics. Journal of Korea Society of Waste Management 29(2): 169-179.
  7. Jeong, G.S., Park, B.S. 2007. Wood properties of the useful tree species grown in Korea. Korea Forest Research Institute, Seoul, Republic of Korea.
  8. Kim, H., Lu, G., Li, T., Sadakata, M. 2002. Binding and desulfurization characteristics of pulp black liquor in biocoalbriquettes. Environment Science and Technology. 36: 1607-1612. https://doi.org/10.1021/es0105921
  9. Kim, S.H., Jeong, S.K., No, S.G., Kim, M.Y., Han, G.S. 2013. Comparison of wood pellets distributed domestically. 2013 Proceedings of The Korean Society of Wood Science and Technology Annual Meeting: 118-119.
  10. Kim, S.H., Yang, I., Han, G.S. 2015. Effect of sawdust moisture content and particle size on the fuel characteristics of wood pellets fabricated with Quercus mongolica, Pinus densiflora and Larix kaempferi sawdust. Journal of The Korean Wood Science and Technology 43(6): 757-767. https://doi.org/10.5658/WOOD.2015.43.6.757
  11. Kim, S.H., Yang, I., Han, G.S. 2015. Effect of moisture content and particle size of sawdust and operation time of flat-die pelletizer on the fuel characteristics of wood pellets fabricated with Mongolian oak and rigida pine sawdust. New & Renewable Energy 11(3): 1-10.
  12. Korea Energy Agency. 2015. New & Renewable Energy Statistics 2014. KEA, Yongin, Republic of Korea.
  13. Korea Association of Pellet. 2016. Korea Forest Service-Statistical data of wood pellet. http://www.koreapellet.org/ [accessed Dec 30, 2016].
  14. Kwon, G.J., Kwon, S.M., Cha, D.S., Kim, N.H. 2010. Characteristics of pellet prepared from sawdust and wood-tar. Journal of The Korean Wood Science and Technology 38(1): 36-42. https://doi.org/10.5658/WOOD.2010.38.1.36
  15. Lee, S.M., Choi, D.H., Cho, S.T., Nam, T.H., Han, G.S., Yang, I. 2011. Effects of various factors on the durability of pellets fabricated with Larix kaempferi C. and Liridendron tulipifera L. sawdust. Journal of The Korean Wood Science and Technology 39(3): 258-268. https://doi.org/10.5658/WOOD.2011.39.3.258
  16. Lee, S.M., Ahn, B.J., Choi, D.H., Han, G.S., Jeong, H.S., Ahn, S.H., Yang, I. 2013, Effects of densification variables on the durability of wood pellets fabricated with Larix kaempferi C. and Liriodendron tulipifera L. sawdust. Biomass and Bioenergy 48: 1-9. https://doi.org/10.1016/j.biombioe.2012.10.015
  17. Lehtikangas, P. 2001. Quality properties of pelletised sawdust, logging residues and bark. Biomass and Bioenergy 20: 351-360. https://doi.org/10.1016/S0961-9534(00)00092-1
  18. Li, Y. and H. Liu. 2000. High-pressure densification of wood residues to form an upgraded fuel. Biomass and Bioenergy 19: 177-186. https://doi.org/10.1016/S0961-9534(00)00026-X
  19. Mani, S., Tabil, L.G., Sokhansanj, S. 2006. Effects of compressive force, particle size and moisture content on mechanical properties of biomass pellets from grasses. Biomass and Bioenergy 20: 648-654.
  20. Ministry of Environment. 2016. New Paris Climate Agreement. https://www.me.go.kr/home/file/readDownloadFile.do?fileId=130470&fileSeq=1&openYn=Y [accessed Jan 18, 2017].
  21. National Institute of Forest Science. 2016. Standard and quality grades for wood-based products: Wood pellets, NIFOS No. 2016-6, Seoul, Republic of Korea.
  22. Obernberger, I., Thek, G. 2004. Physical characterization and chemical composition of densified biomass fuels with regard to their combustion behavior. Biomass and Bioenergy 27: 653-669. https://doi.org/10.1016/j.biombioe.2003.07.006
  23. Ryu, J.Y., Kang, C.Y., Lee, E.S., Seo, J.W., Lee, H.J., Park, H. 2010. The study on the characteristics of pellets manufactured with morphologically different domestic Larix kaempferi C. sawdust. Journal of The Korean Wood Science and Technology 38(1): 49-55. https://doi.org/10.5658/WOOD.2010.38.1.49
  24. Stakl, M., Granstrom, K., Berghel, J., Renstorm, R. 2004. Industrial process for biomass drying and their effects on the quality properties of wood pellets. Biomass and Bioenergy 27: 621-628. https://doi.org/10.1016/j.biombioe.2003.08.019