본 연구에서는 고온고압 건식탈황장치를 이용하여 고체순환량과 탈황반응기 내의 공극률에 대한 수력학적특성을 파악하고, 아연계 탈황제의 고온고압 조건에서 탈황반응온도에 대한 반응특성 및 연속운전을 통한 탈황 효율을 분석하였다. 실험에 사용된 고온고압건식탈황장치는 고속유동층 형태의 탈황반응기(내경: 0.015 m, 높이: 6.2 m), 기포유동층 형태의 재생반응기(내경: 0.053 m, 높이: 1.6 m), 가스의 역흐름을 방지하는 loop-seal, 두 반응기 후단에 압력컨트롤밸브로 구성되어있다. 수력학 특성으로는 고체순환밸브 개구비, 탈황반응기 가스 유속, 탈황반응기 온도 변화에 따른 고체순환량과 각 조건에서의 고속유동층 형태의 탈황반응기 높이에 따른 공극률 분포를 알아보았다. 고체순환량은 동일한 유속조건, 동일한 고체순환밸브 개구비에서 탈황반응기 온도가 상온일 때보다 300 ℃와 550 ℃일 때 감소하였으며 300 ℃와 550 ℃ 조건에서는 큰 차이가 없었다. 탈황반응기내의 공극률은 고체순환밸브 개구비가 10~20%로 고체순환량이 적은 경우 고속유동층 형태의 공극률 분포를 보이고, 30~40%로 고체순환량이 많아지는 경우 탈황반응기 하부에서 turbulent 형태의 공극률의 분포를 나타냈다. 아연계 탈황제의 탈황반응온도에 따른 반응특성은 시스템 압력 20 atm, 연속 반응 조건에서 탈황온도를 변화시키면서 살펴보았다. 일정한 고체순환 조건에서 탈황온도 450 ℃ 이하에서 탈황 효율 저하가 시작되는 것을 확인하였으며, 높은 탈황 효율을 유지시키기 위하여 10시간 연속운전에서는 탈황 반응 온도를 500 ℃로 설정하여 실험하였다. 실험 결과, 10시간 연속운전을 통해, 유입 H2S 농도 5,000 ppmv 조건에서 탈황반응기 후단 H2S 농도는 UV분석기(Radas2)와 검지관(GASTEC)의 검출한계인 1 ppmv 이하를 유지하여 H2S 제거 효율 99.99% 이상을 달성하였다.

In this study, hydrodynamics such as solid circulation rate and voidage in the desulfurizer and the reaction characteristics of Zn-based solid sorbents were investigated using lab-scale high pressure and high temperature desulfurization process. The continuous HGD (Hot Gas Desulfurization) process consist of a fast fluidized bed type desulfurizer (6.2 m tall pipe of 0.015 m i.d), a bubbling fluidized bed type regenerator (1.6 m tall bed of 0.053 m i.d), a loop-seal_x000D_ and the pressure control valves. The solid circulation rate was measured by varying the slide-gate opening positions, the gas velocities and temperatures of the desulfurizer and the voidage in the desulfurizer was derived by the same way. At the same gas velocities and the same opening positions of the slide gate, the solid circulation rate, which was similar at the temperature of 300 ℃ and 550 ℃, was low at those temperatures compared with a room temperature. The voidage in_x000D_ the desulfurizer showed a fast fluidized bed type when the opening positions of the slide gate were 10~20% while that showed a turbulent fluidized bed type when those of slide gate were 30~40%. The reaction characteristics of Zn-based solid sorbent were investigated by different desulfurization temperatures at 20 atm in the continuous operation. The H2S removal efficiency tended to decrease below the desulfurization temperature of 450 ℃. Thus, the 10 hour continuous_x000D_ operation has been performed at the desulfurization temperature of 500 ℃ in order to maintain the high H2S removal efficiency. During 10 hour continuous operation, the H2S removal efficiency was above 99.99% because the H2S concentration after desulfurization was not detected at the inlet H2S concentration of 5,000 ppmv condition using UV analyzers (Radas2) and the detector tube (GASTEC) which lower detection limit is 1 ppmv.

Desulfurization Hydrodynamics Reaction Characteristics Zn-based Sorbent Continuous Process

Lee TJ, Park NK, Kim JH, Kim KS, Park YW, Yi CK, HWAHAK KONGHAK, 34(4), 435 (1996)
Kang SH, Rhee YW, Kang Y, Han KH, Lee CK, Jin GT, HWAHAK KONGHAK, 35(5), 642 (1997)
Na JI, Park SJ, Wi YH, Yi CK, Lee TJ, HWAHAK KONGHAK, 37(4), 499 (1999)
Yi CK, Park J, Cho SH, Jin GT, Son JE, HWAHAK KONGHAK, 37(1), 81 (1999)
Gupta R, Turk B, Lesemann M, Schlather J, Denton D, “Status of RTI/Eastman Warm Gas Clean-up Technology and Commercialization Plans,” Gasification Technologies Conference, October, Washington, DC (2008)
Gupta Ret al., RTI/Eastman warm syngas clean-up technology: Intergration with carbon capture, Gasification Technologies Conference, October (2009)
Jo SH, Lee BH, Lee JB, Ryu CK, Jin GT, Yi CK, HWAHAK KONGHAK, 40(2), 231 (2002)
Park EH, Hong SS, Jo SH, Yi CK, Jin GT, HWAHAK KONGHAK., 33(3), 333 (2001)
Luyben WL, Yi CK, Ind. Eng. Chem. Res., 40(4), 1157 (2001)
Choi JH, Moon YS, Ryu HJ, Yi CK, Son JE, Kim SD, Ind. Eng. Chem. Res., 43(18), 5770 (2004)
Jo SH, Lee BH, Lee JB, Ryu CK, Jin GT, Yi CK, HWAHAK KONGHAK, 40(2), 231 (2002)
Yi CK, Cho SH, Kwon HS, Kim KB, Chae HK, Jin GT, Son JE, HWAHAK KONGHAK, 40(2), 246 (2002)
Yi CK, Son JE, Adv. Powder Technol., 21(2), 119 (2010)
Yi CK, Bae DH, Shun D, Jin GT, Son JE, HWAHAK KONGHAK, 37(4), 604 (1999)
Kuni D, Levenspiel O, Fluidization Engineering, 2nd ed., Butterworth-Heinemann, Boston, 200 (1991)