열화학 황-요오드 수소 생산 공정의 요오드 결정화기 설계를 위한 결정 침강 모델링

박병흥; 정성욱; 강정원; Byung Heung Park; Seong-Uk Jeong; Jeong Won Kang

Korean Chemical Engineering Research, Vol.52, No.6, 768-774, December, 2014

Export Citation

열화학 황-요오드 수소 생산 공정의 요오드 결정화기 설계를 위한 결정 침강 모델링

Crystal Sinking Modeling for Designing Iodine Crystallizer in Thermochemical Sulfur-Iodine Hydrogen Production Process

박병흥^†, 정성욱¹, 강정원 ²

한국교통대학교 화공생물공학과, 380-702 충청북도 충주시 대학로 50
¹한국에너지기술연구원 수소연구실, 305-343 대전시 유성구 가정로 152
²고려대학교 화공생명공학과, 136-701 서울특별시 성북구 안암로 145

Byung Heung Park^†, Seong-Uk Jeong¹, and Jeong Won Kang²

Department of Chemical and Biological Engineering, Korea National University of Transportation, 50 Daehak-ro, Chungju-si, Chungbuk 380-702, Korea
¹Hydrogen Laboratory, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon, 305-343, Korea
²Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-701, Korea

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초록

황-요오드(Sulfur-Iodine, SI) 공정은 물을 분해시켜 수소를 생산하는 열화학 공정으로 공정에 사용되는 황과 요오드는 재순환된다. SI 공정 중 요오드가 분리 순환되는 Section III에서는 공정 효율 개선을 위해 다양한 방법이 개발되고 있다. EED(electro-electrodialysis)를 이용한 방법은 추가적인 화합물이 필요하지 않는 공정으로 Section III의 효율을 높일 수 있으나 공정 흐름에 포함된 요오드에 의해 상당한 부하가 걸리게 된다. 이를 해결하기 위해 EED 앞에 요오드제거 공정으로 결정화 방법이 고려되고 있다. 본 연구에서는 요오드 결정화 반응기 설계를 위한 기초 자료 확보를 위해 I2 포화 HIx 용액에서 요오드 결정의 침강 속도를 모델링 하였다. HIx 용액 조성은 열역학 모델인 UVa를 이용하여 결정하였으며 용액 물성은 순수한 물성들과 상관관계식을 활용하여 추산하였다. Multiphysics 전산툴을 이용하여 침강에 따른 속도 변화를 계산하였으며 요오드 직경과 온도에 따른 변화를 추산하였다. 직경(1.0~2.5 mm)과 온도(10~50 ℃) 범위에서 요오드는 0.5 m/s 내외의 종말 속도를 보이며 이 속도는 용액의 점도 보다 밀도에 더 크게 영향을 받는 것으로 나타났다.

SI process is a thermochemical process producing hydrogen by decomposing water while recycling sulfur and iodine. Various technologies have been developed to improve the efficiency on Section III of SI process, where iodine is separated and recycled. EED(electro-electrodialysis) could increase the efficiency of Section III without additional chemical compounds but a substantial amount of I2 from a process stream is loaded on EED. In order to reduce the load, a crystallization technology prior to EED is considered as an I2 removal process. In this work, I2 particle sinking behavior was modeled to secure basic data for designing an I2 crystallizer applied to I2-saturated HIx solutions. The composition of HIx solution was determined by thermodynamic UVa model and correlation equations and pure properties were used to evaluate the solution properties. A multiphysics computational tool was utilized to calculate particle sinking velocity changes with respect to I2 particle radius and temperature. The terminal velocity of an I2 particle was estimated around 0.5 m/s under considered radius (1.0 to 2.5 mm) and temperature (10 to 50 ℃) ranges and it was analyzed that the velocity is more dependent on the solution density than the solution viscosity.

Keywords:Hydrogen Production;SI Process;Crystallizer;Iodine;Terminal Velocity

[References]

IAEA-TECDOC-1085, “Hydrogen as an Energy Carrier and Its Production by Nuclear Power,” IAEA (1999)
Funk JE, Int. J. Hydrog. Energy, 26(3), 185 (2001)
Brown LC, Besenbruch GE, Lentsch RD, Schultz KR, Funk JF, Pickard PS, Marshall AC, Showalter SK, “High Efficiency Generation of Hydrogen Fuels using Nuclear Power,” GA-A24285 (2003)
Norman JH, Besenbruch GE, O’Keefe DR, “Thermochemical Water-Splitting for Hydrogen Generation,” GRI-80/0105 (1981)
Roth M, Knoche KF, Int. J. Hydrog. Energy, 14, 545 (1989)
Berndhaeuser C, Knoche KF, Int. J. Hydrog. Energy, 19, 239 (1994)
Norman JH, Besenbruch GE, Brown LC, O’Keefe DR, Allen CL, “Thermochemical Water-Splitting Cycle, Bench-Scale Investigations, and Process Engineering,” GA-A16713 (1982)
Hwang GJ, Onuki K, Nomura M, Kasahara S, Kim JW, J. Membr. Sci., 220(1-2), 129 (2003)
Murphy JE, O'Connell JP, Fluid Phase Equilib., 288(1-2), 99 (2010)
Parsly LF, “Design Considerations of Reactor Containment Spray Systems - Part IV. Calculation of Iodine-Water Partitioning Coefficients,” ORNL-TM- 2412, Part IV (1970)
Yaws CL, Thermophysical Properties of Chemicals and Hydrocarbons, William Andrew (2008)
Lide DR, CRC Handbook of Chemistry and Physics, 87th ed., CRC Press (2006)
http://www.cheric.org/research/kdb/.
Poling BE, Prausnitz JM, O’Connell JP, The Properties of Gases and Liquids, 5th ed. McGraw-Hill (2001)

[Related Articles]

[1] IAEA-TECDOC-1085, “Hydrogen as an Energy Carrier and Its Production by Nuclear Power,” IAEA (1999)

[2] Funk JE, Int. J. Hydrog. Energy, 26(3), 185 (2001)

[3] Brown LC, Besenbruch GE, Lentsch RD, Schultz KR, Funk JF, Pickard PS, Marshall AC, Showalter SK, “High Efficiency Generation of Hydrogen Fuels using Nuclear Power,” GA-A24285 (2003)

[4] Norman JH, Besenbruch GE, O’Keefe DR, “Thermochemical Water-Splitting for Hydrogen Generation,” GRI-80/0105 (1981)

[5] Roth M, Knoche KF, Int. J. Hydrog. Energy, 14, 545 (1989)

[6] Berndhaeuser C, Knoche KF, Int. J. Hydrog. Energy, 19, 239 (1994)

[7] Norman JH, Besenbruch GE, Brown LC, O’Keefe DR, Allen CL, “Thermochemical Water-Splitting Cycle, Bench-Scale Investigations, and Process Engineering,” GA-A16713 (1982)

[8] Hwang GJ, Onuki K, Nomura M, Kasahara S, Kim JW, J. Membr. Sci., 220(1-2), 129 (2003)

[9] Murphy JE, O'Connell JP, Fluid Phase Equilib., 288(1-2), 99 (2010)

[10] Parsly LF, “Design Considerations of Reactor Containment Spray Systems - Part IV. Calculation of Iodine-Water Partitioning Coefficients,” ORNL-TM- 2412, Part IV (1970)

[11] Yaws CL, Thermophysical Properties of Chemicals and Hydrocarbons, William Andrew (2008)

[12] Lide DR, CRC Handbook of Chemistry and Physics, 87th ed., CRC Press (2006)

[13] http://www.cheric.org/research/kdb/.

[14] Poling BE, Prausnitz JM, O’Connell JP, The Properties of Gases and Liquids, 5th ed. McGraw-Hill (2001)