DOI QR코드

DOI QR Code

Pretreatment of Corn Stover for Improved Enzymatic Saccharification using Ammonia Circulation Reactor (ACR)

순환식 암모니아 반응기(Ammonia Circulation Reactor (ACR))를 이용한 옥수수대의 전처리 및 효소 당화율 향상

  • Shrestha, Rubee Koju (Department of Environmental Engineering, Kongju National University) ;
  • Hur, Onsook (RDA-Genebank Information Center, Rural Development Administration (RDA)) ;
  • Kim, Tae Hyun (Department of Environmental Engineering, Kongju National University)
  • ;
  • 허온숙 (국립농업과학원 농업유전자원센터) ;
  • 김태현 (국립공주대학교 환경공학과)
  • Received : 2013.03.12
  • Accepted : 2013.04.10
  • Published : 2013.06.01

Abstract

Ammonia circulation reactor (ACR) was devised for the effective pretreatment of corn stover. This method is designed to circulate aqueous ammonia continuously so that it can reduce the chemical and water consumption during pretreatment. In this study, ammonia pretreatment with various reaction conditions such as reaction time (4~12 hour), temperature ($60{\sim}80^{\circ}C$), and solid:liquid ratio (1:3~1:8) was tested. Chemical compositions including solid remaining after reaction, lignin and carbohydrates were analyzed and enzymatic digestibility was also measured. It was observed that as reaction conditions become more severe, lignin removal was significantly affected, which was in the range of 47.6~70.6%. On the other hands, glucan and xylan losses were not substantial as compared to that of lignin. At all tested conditions, the glucan loss was not changed substantially, which was between 4.7% and 15.2%, while the xylan loss varied, which was between 7.4% and 25.8%. With (15 FPU-GC220+30 CBU)/g-glucan of enzyme loading, corn stover treated using ammonia circulation reactor for 8~12 hours resulted in 90.1~94.5% of 72-h glucan digestibility, which was higher than 92.7% of $Avicel^{(R)}$-101. In addition, initial hydrolysis rate (at 24 hour) of this treated corn stover was 73.0~79.4%, which was shown to be much faster than 69.5% of $Avicel^{(R)}$-101. As reaction time increased, more lignin removal and it was assumed that the enhanced enzymatic digestibility of treated biomass was attributed to the lignin removal.

목질계 바이오매스인 옥수수대 전처리를 위하여 고안된 순환식 암모니아 전처리 반응기(Ammonia Circulation Reactor (ACR))를 이용하여 연구하였다. 이 전처리 방법은 적은 양의 액체를 사용하도록 고안되었으며 이 연구에선 기존의 전처리 공정보다 낮은 전처리 온도($60{\sim}80^{\circ}C$), 반응시간(4~12 hour) 그리고 고체:액체 비율(1:3~1:8) 등의 공정 조건을 실험 하여 효과를 비교하였다. 즉 여러 공정 조건에서 전처리 후 고형물의 잔류 고체량, 당, Lignin 함량, 그리고 효소당 화율 등을 측정하였다. 여러 실험 조건에서 공통적으로 관찰된 것은 전처리 조건이 더 가혹해 지면 Lignin의 제거율이 가장 큰 영향을 받았으며, 47.6~70.6% 범위로 나타났다. 반면 다른 당(Glucan, Xylan)은 손실이 비교적 작게 나타났다. 모든 실험 조건에서, 전처리된 고형물의 Glucan 손실율은 4.7~15.2% 범위로 변화가 크지 않았으며 Xylan 손실율은 여러 조건의 변화에 따라 7.4~25.8% 정도 범위로 나타났다. 암모니아 순환 전처리로 8~12 hour 동안 처리된 옥수수대는 90.1~94.5%의 높은 72-h Glucan 당화율을 (15 FPU-GC220+30 CBU)/g-glucan의 효소 투입으로 나타냈으며 순수 Cellulose인 Avicel의 당화율(92.7%)과 비슷하거나 높았다. 또한 8~12 hour 처리된 옥수수대의 초기 24-h Glucan 당화속도는 73.0~79.4%로 Avicel의 같은 시간 당화율인 69.5% 보다 높게 나타났다. 반응시간을 증가는 보다 많은 Lignin을 제거하였으며 따라서 효소 당화율 증가에 기인한 것으로 보인다.

Keywords

References

  1. Kamm, B., Gruber, P. R. Kamm, M., "Biorefineries - Industrial Processes and Products," Wiley-VCH Weinheim(2007).
  2. 2013 Ethanol Industry Outlook, RFA (Renewable Fuels Association) Washington, DC. USA(2013).
  3. Kim, S. D. and Dale, B. E., "Global Potential Bioethanol Production from Wasted Crops and Crop Residures," Biomass Bioenerg., 26, 361-375(2004). https://doi.org/10.1016/j.biombioe.2003.08.002
  4. Mosier, N., Wyman, C. E., Dale, B. E., Elander, R, Lee, Y. Y., Holtzapple, M., "Features of Promising Technologies for Pretreatment of Lignocellulosic Biomass," Bioresour. Technol., 96, 673-686(2005). https://doi.org/10.1016/j.biortech.2004.06.025
  5. Kim, T. H. and Lee, Y. Y., "Fractionation of Corn Stover by Hot water and Aqueous Ammonia Treatment," Bioresour. Technol., 97(2), 224-232(2006). https://doi.org/10.1016/j.biortech.2005.02.040
  6. Kim, T. H., Kim, J. S., Sunwoo, C. S. and Lee, Y. Y., "Pretreatment of Corn Stover by Aqueous Ammonia," Bioresour. Technol., 90, 39-47(2003). https://doi.org/10.1016/S0960-8524(03)00097-X
  7. Yoo, C. G., Lee, C. W. and Kim, T. H., "Optimization of Two-Stage Fractionation Process for Lignocellulosic Biomass using Response Surface Methodology (RSM)," Biomass Bioenerg., 35, 4901-4909(2011). https://doi.org/10.1016/j.biombioe.2011.10.015
  8. Zheng, Y., Lin, H. M., and Tsao, G. T., "Pretreatment for Cellulose Hydrolysis by Carbon Dioxide Explosion," Biotechnol. Prog., 14, 890-896(2008).
  9. Mosier, N., Wyman, C., Dale, B., Elander, R., Lee, Y. and Holtzapple, M., "Features of Promising Technologies for Pretreatment of Lignocellulosic Biomass," Bioresour. Technol., 96, 673-686(2005). https://doi.org/10.1016/j.biortech.2004.06.025
  10. Li, X., Kim, T. H. and Nghiem, N. P., "Bioethanol Production from Corn Stover using Aqueous Ammonia Pretreatment and Twophase Simultaneous Saccharification and Fermentation (TPSSF)," Bioresour. Technol., 101, 5910-5916(2010). https://doi.org/10.1016/j.biortech.2010.03.015
  11. Kootstra, A. M. J., Beeftink, H. H., Scott, E. L. and Sanders, J. P., "Optimization of the Dilute Maleic Acid Pretreatment of Wheat Straw," Biotechnology for Biofuels, 2, 31(2009). https://doi.org/10.1186/1754-6834-2-31
  12. Sun, Y. and Cheng, J. J., "Dilute Acid Pretreatment of Rye Straw and Bermudagrass for Ethanol Production," Bioresour. Technol., 96, 1599-1606(2005). https://doi.org/10.1016/j.biortech.2004.12.022
  13. Par, C. and Kim, J. S., "Enzymatic Hydrolysis Characteristics of Pretreated Rice Straw By Aqueous Ammonia for Bioethanol Production," Korean Chem. Eng. Res.(HWAHAK KONGHAK), 49(4), 470-474(2011). https://doi.org/10.9713/kcer.2011.49.4.470
  14. Kim, T. H., "Sequential Hydrolysis of Hemicellulose and lignin in Lignocellulosic Biomass by Two-stage Percolation using Dilute Sulfuric Acid and Ammonium Hydroxide," Korean J. Chem. Eng., 28(11), 2156-2162(2011). https://doi.org/10.1007/s11814-011-0093-6
  15. Yoo, C. G., Nghiem, N. P., Hicks, K. B. and Kim T. H., "Pretreatment of Corn Stover using Low-Moisture Anhydrous Ammonia (LMAA) Process," Bioresour. Technol., 102, 10028-10034(2011). https://doi.org/10.1016/j.biortech.2011.08.057
  16. Berlin, A., Balakshin, M., Gilkes, N., Kadla, J., Maximenko, V., and Kubo, S., "Inhibition of Cellulase, Xylanase and $\beta$-glucosidase Activities by Softwood Lignin Preparations," J. Biotechnol., 125, 198-209(2006). https://doi.org/10.1016/j.jbiotec.2006.02.021
  17. Ghosh, T. K., "Measurement of Cellulase Activities," Pure Appl. Chem., 59(2), 257-268(1987). https://doi.org/10.1351/pac198759020257
  18. National Renewable Energy Laboratory, "Standard Biomass Analytical Procedures," http://www.nrel.gov/biomass/analytical_procedures.html.
  19. Kim, T. H. and Lee, Y. Y., "Pretreatment of Corn Stover by Soaking in Aqueous Ammonia at Moderate Temperature," Appl. Biochem. Biotechnol., 136-140, 81-92(2007).
  20. Kim, T. H., Taylor, F. and Hicks, K. B., "Bioethanol Production from Barley Hull Using SAA (soaking in aqueous ammonia) Pretreatment," Bioresour. Technol., 99, 5694-5702(2008). https://doi.org/10.1016/j.biortech.2007.10.055

Cited by

  1. Pretreatment of Kenaf Core by Combined Electron Beam Irradiation and Water Steam for Enhanced Hydrolysis vol.52, pp.1, 2014, https://doi.org/10.9713/kcer.2014.52.1.113
  2. Bioconversion Strategy in Conversion of Lignocellulosic Biomass upon Various Pretreatment Methods using Sulfuric Acid and Aqueous Ammonia vol.52, pp.1, 2014, https://doi.org/10.9713/kcer.2014.52.1.45
  3. Recovery of Xylo-oligomer and Lignin Liquors from Rice Straw by Two 2-step Processes Using Aqueous Ammonia Followed by Hot-water or Sulfuric Acid vol.53, pp.6, 2013, https://doi.org/10.9713/kcer.2015.53.6.682
  4. 열수전처리를 이용한 탈지미세조류로부터 발효당 생산 공정 개발 vol.54, pp.4, 2013, https://doi.org/10.9713/kcer.2016.54.4.443
  5. Pretreatment and enzymatic saccharification process of rapeseed straw for production of bioethanol vol.43, pp.4, 2016, https://doi.org/10.7744/kjoas.20160067