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H2/CO 기체 분리 PSA 공정의 연속/이산 혼합변수 상세 동적 모사
Combined Continuous/Discrete Variable Rigorous Dynamic Simulation of H2/CO Separation PSA Process
HWAHAK KONGHAK, April 1998, 36(2), 151-158(8), NONE
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Abstract
PSA공정의 설계와 운전 기반을 마련하기 위하여 H2/CO(70:30) 혼합기체 분리공정을 대상으로 상세한 동적 모사를 수행하였다. 흡착시 물질전달 표현으로 LDF 모형을, 평형흡착 등온식으로 LRC식을 사용하였으며, 이에 대한 각 파라미터들은 문헌치를 참고하였다. 또한 탑내의 압력 변화를 고려하기 위하여 Ergun식을, 탑 양끝의 압력과 유속의 변화를 계산하기 위하여 밸브 모델을 도입하였다. 연속/이산 혼합변수를 동시에 고려한 본 연구는 급속한 유속, 압력, 농도, 온도 등의 변화를 용이하게 계산할 수 있는 수치적 방법으로 탑의 길이를 10개의 요소로 나눈 3차의 OCFEM을 사용하였다. 이러한 모델링을 통하여 초기 운전부터 100주기까지의 연속 동적 모사를 통해 초기 비정상상태의 변화들을 살펴보았으며, 주기적 정상상태에서는 밸브 개폐에 의한 순간적 압력 증감과, 가압, 향류감압, 압력평형 단계에서 시간에 따른 압력 변화를 표현할 수 있었다. 또한 주기적 정상상태에서 H2의 순도와 회수율은 각각 99.99%와 86.73%로써 문헌치보다 약간 높은 경향을 나타내었다. 본 연구를 통해 상세 PSA 공정 모델을 개발함으로써 효과적인 공정 설계와 운전의 기반을 마련하였다.
A rigorous dynamic simulation is performed in binary gas mixture H2/CO(70:30 vol%) to improve design and operation technology of PSA(Pressure Swing Adsorption) processes. As rigorous models of PSA processes include combined continuous/discrete variables and some PDEs essentially, it is difficult to treat those heterogeneous variables and solve PDEs exactly. Through the use of the State-Task-Network concept and special numerical techniques such as OCFEM, those combined PDEs can be solved efficiently in this study. A rigorous dynamic model for a PSA process contains a LRC model for equilibrium adsorption isotherms, an Ergun equation for expressing the pressure drop in a bed, and valve equations to compute the boundary pressure change of the bed. As the result of the continuous dynamic simulation of 100 operating cycles, the unsteady-state appears in the early period and the cyclic steady-state come out about 11-l3th cycle. As time goes by, valve equations change the pressure at each end of the bed in pressurization, countercurrunt-depressurization and pressure equalization steps. The H2 purity and the recovery is 99.99% and 86.73% respectively, which is slightly higher than the experimental data. Main contribution of this study includes supplying fundamental technologies of handling combined variable PSA processes by developing rigorous models.
References
Crittenden BD, Guan J, Ng WN, Thomas WJ, Chem. Eng. Sci., 49, 2662 (1994)
Cen PL, Yang RT, Sep. Sci. Technol., 21, 851 (1986)
Cen PL, Yang RT, Ind. Eng. Chem. Fundam., 25, 759 (1986)
Yang RT, Doong SJ, AIChE J., 31, 1832 (1985)
Chou CT, Huang WC, Ind. Eng. Chem. Res., 33(5), 1250 (1994)
Chou CT, Huang WC, Chem. Eng. Sci., 49(1), 75 (1994)
Oh M, Ph.D. Dissertation, Imperial College, London, United Kingdom (1995)
Huang WC, Chou CT, Comput. Chem. Eng., 21(3), 301 (1997)
Kaczmarski K, Mazzotti M, Storti G, Morbidelli M, Comput. Chem. Eng., 21(6), 641 (1997)
Han S, Yang J, Lee CH, Lee H, HWAHAK KONGHAK, 34(3), 277 (1996)
Park SY, Oh M, Moon I, HWAHAK KONGHAK, 34(5), 585 (1996)
Cen PL, Yang RT, Sep. Sci. Technol., 21, 851 (1986)
Cen PL, Yang RT, Ind. Eng. Chem. Fundam., 25, 759 (1986)
Yang RT, Doong SJ, AIChE J., 31, 1832 (1985)
Chou CT, Huang WC, Ind. Eng. Chem. Res., 33(5), 1250 (1994)
Chou CT, Huang WC, Chem. Eng. Sci., 49(1), 75 (1994)
Oh M, Ph.D. Dissertation, Imperial College, London, United Kingdom (1995)
Huang WC, Chou CT, Comput. Chem. Eng., 21(3), 301 (1997)
Kaczmarski K, Mazzotti M, Storti G, Morbidelli M, Comput. Chem. Eng., 21(6), 641 (1997)
Han S, Yang J, Lee CH, Lee H, HWAHAK KONGHAK, 34(3), 277 (1996)
Park SY, Oh M, Moon I, HWAHAK KONGHAK, 34(5), 585 (1996)
