Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
권호 표지
DOI QR코드

DOI QR Code

Enrichment of Indole by n-Hexane Re-extraction of Extract Phase Recovered with Formamide Extraction of Crude Methylnaphthalene Oil

조제 메틸나프탈렌유의 포름아미드 추출에 의해 회수한 추출상의 노말 헥산 역 추출에 의한 인돌의 농축

  • Su Jin Kim (Department of Chemical & Biological Engineering, Chungwoon University)
  • 김수진 (청운대학교 화학생명공학과)
  • Received : 2024.08.05
  • Accepted : 2024.08.09
  • Published : 2024.10.10
Download PDF
⟨ Previous Next ⟩

Abstract

For high-purity purification of indole (IN) contained in crude methylnaphthalene oil (CMNO), this study was reviewed by adopting the re-extraction method using n-hexane as an enrichment method of IN contained in the extract phase recovered from equilibrium extraction of CMNO and formamide aqueous solution. The raw material (extract phase) contained three types of nitrogen-containing compounds (NCCs): quinoline (QU), isoquinoline (IQU), and IN; and four types of bicyclic aromatic compounds (BACs): naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, and biphenyl (BP). The distribution coefficient and selectivity of IN showed almost constant values regardless of the change in the initial volume fraction of the re-extraction solvent to the raw material. Compared to the distribution coefficient of IN, those of two types NCCs excluding IN and three types BACs excluding BP, respectively, are about 4~7 times and 190~394 times higher. In addition, the concentration of IN in the raffinate oil recovered through equilibrium n-hexane re-extraction run of the batch co-current five-stage under constant re-extraction was 54.6%, which was approximately 2.5 times higher than that of the raw material. From the excellent IN enrichment efficiency of this study, the re-extraction method using n-hexane was expected to be a new IN enrichment method that can be an alternative to the distillation method.

조제 메틸나프탈렌유(CMNO)에 함유된 인돌(IN)의 고순도 정제를 위하여, 본 연구는 CMNO와 포름아미드 수용액의 평형추출로부터 회수한 추출상에 함유된 IN의 농축법으로서 노말 헥산을 사용한 역 추출법을 채택하여 검토했다. 원료(추출상) 중에는 3종의 함질소 화합물(NCCs)인 퀴놀린(QU), 이소퀴놀린(IQU), IN과 4종의 2환 방향족화합물(BACs)인 나프탈렌(NA), 2-메틸나프탈렌(2MNA), 1-메틸나프탈렌(1MNA), 비페닐(BP)이 함유되어 있었다. IN의 분배계수와 선택도는 초기 원료에 대한 역 추출의 체적분율(E0/R0)의 변화와 무관하게 거의 일정한 값을 보였다. IN의 분배계수에 비해 2종의 NCCs (QU, IQU)와 BP를 제외한 3종의 BACs의 분배계수는 각각 약 4~7배, 197~394배 높았다. 또한 일정한 역 추출 조건하의 회분 병류 5단 평형 역 추출에 의해 회수된 추잔유 중의 IN 농도는 54.6%로 21.7%의 역 추출 원료에 비해 약 2.5배 높았다. 본 연구의 우수한 IN 농축효율로부터 노말 헥산을 이용한 역 추출법은 증류법을 대체할 수 있는 하나의 새로운 IN 농축법으로 기대되었다.

Keywords

Acknowledgement

본 논문은 2020년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(No. 2020R1I1A3061492).

References

  1. K. Sakanishi, H. Obata, I. Mochida, and T. Sakaki, Removal and recovery of quinoline bases from methylnaphthalene oil in a semi-coninuous supercritical CO2 separation apparatus with a fixed bed of supported aluminum sulfate, Ind. Eng. Chem. Res., 34, 4118-4124 (1995).  https://doi.org/10.1021/ie00038a056
  2. D. V. Lobovich, I. V. Zinoeva, N. A. Milevskii, A. E. Kostanyan, Y. A. Zakhodyaeva, and A. A. Voshkin, Extraction kinetics of pyridine, quinoline, and indole from the organic phase with natural deep eutectic solvents and separation study using a centrifugal extractor. Processes, 12, 488 (2024). 
  3. S. J. Kim, Upgrading of wash oil through reduction of nitrogen-containing compounds, Processes, 9, 1869 (2021). 
  4. S. J. Kim, Study on removal of nitrogen-containing heterocyclic compounds contained in crude methylnaphthalene oil by formamide extraction, Processes, 12, 1550 (2024). 
  5. H. C. Kang and S. J. Kim, Experimental study on reduction of nitrogen-containing compounds contained in crude methylnaphthalene oil by solvent extraction (II), Appl. Chem. Eng., 33, 477-481 (2022). 
  6. S. J. Kim, Effect of experimental factors on reduction of nitrogen compounds contained in crude methylnaphthalene oil by formamide extraction, Appl. Chem. Eng., 34, 665-669 (2023). 
  7. K. Ukegawa, A. Matsumura, Y. Kodera, T. Kondo, T. Nakayama, H. Tanabe, S. Yoshida, and Y. Mito, Solvent extraction of nitrogen compounds from a coal tar fraction. (Part 1). Effect of extraction conditions on the extraction rate and the selectivities of nitrogen compounds. J. Jpn. Pet. Inst., 33, 250-254 (1990).  https://doi.org/10.1627/jpi1958.33.250
  8. S. J. Kim, and Y. J. Chun, Separation of nitrogen heterocyclic compounds from model coal tar fraction by solvent extraction, Sep. Sci. Technol., 40, 2095-2109 (2005).  https://doi.org/10.1081/SS-200068488
  9. S. J. Kim, H. C. Kang, Y. S. Kim, and H. J. Jeong, Liquid membrane permeation of nitrogen heterocyclic compounds contained in model coal tar fraction, Bull. Korean Chem. Soc., 31, 1143-1148 (2010).  https://doi.org/10.5012/bkcs.2010.31.5.1143
  10. Y. Kodera, K. Ukegawa, Y. Mito, M. Komoto, E. Ishikawa, and T. Nagayama, Solvent extraction of nitrogen compounds from coal liquids, Fuel, 70, 765-769 (1991).  https://doi.org/10.1016/0016-2361(91)90076-M
  11. S. J. Kim, Purification of indole contained in wash oil by combination of extraction and crystallization (Part 1: Recovery and concentration of indole contained in wash oil by solvent extraction), Molecules, 27, 5331 (2022). 
  12. K. Sakanishi, H. Obata, I. Mochida, and T. Sakaki, Capture and recovery of indole from methylnaphthalene oil in a continuous supercritical CO2 extraction apparatus over a fixed bed of anion-exchange resin, Ind. Eng. Chem. Res., 35, 335-337 (1996).  https://doi.org/10.1021/ie950284+
  13. Y. Mamoru and K. Tomonori, Separation and purification of indole from coal tar by supercritical fluid extraction, J. Chem. Eng. Jpn. 26, 153-158 (1993).  https://doi.org/10.1252/jcej.26.153
  14. Y. Ji, Y. Hou, S. Ren, and W. Wu, Highly efficient separation of indole from model wash oil using tetraethyl ammonium amino acid ionic liquids, Sep. Purif. Technol., 258, 117997 (2021). 
  15. D. Xu, M. Zhang, J. Gao, L. Zhang, S. Zhou, and Y. Wang, Separation of heterocyclic nitrogen compounds from coal tar fractions via ionic liquids: COSMO-SAC screening and experimental study, Chem. Eng. Commun., 206, 1199-1217 (2019).  https://doi.org/10.1080/00986445.2018.1552855
  16. P. Gao, J. Zhang, Z. Guo, J. Gao, D. Xu, Y. Ma, L. Zhang, and Y. Wang, Experimental and quantum chemical calculations investigations of morpholine-based ionic liquids as extractants for efficient extraction of nitrogen heterocyclic neutral compounds, Fuel, 333, 126446 (2023). 
  17. Q. Liu, T. Zhang, P. Gao, J. Gao, D. Xu, P. Zhao, L. Zhang, and Y. Wang, Separation of indole by designed ionic liquids with dual functional chemical sites: Mechanism exploration and experimental validation, J. Environ. Chem. Eng., 9, 105971 (2021). 
  18. L. Zhang, D. Xu, J. Gao, S. Zhou, L. Zhao, and Z. Zhang, Extraction and mechanism for the separation of neutral N-compounds from coal tar by ionic liquids, Fuel, 194, 27-35 (2017).  https://doi.org/10.1016/j.fuel.2016.12.095
  19. I. Mochida, Y. Q. Fei, and K. Sakanishi, Capture and recovery of basic nitrogen species in coal tar pitch, using nickel sulfate as adsorbent, Chem. Lett., 19, 515-518 (1990).  https://doi.org/10.1246/cl.1990.515
  20. S. J. Kim, Separation and purification of indole in model coal tar fraction of 9 compounds system, Polycycl. Aromat. Compd., 39, 60-72 (2019).  https://doi.org/10.1080/10406638.2016.1259170