STUDY OF THE PSEUDO-STEADY-STATE KINETICS OF CO2 HYDRATE FORMATION AND STABILITY

被引:41
作者
LUND, PC
SHINDO, Y
FUJIOKA, Y
KOMIYAMA, H
机构
[1] NATL INST MAT & CHEM RES,DEPT CHEM SYST,TSUKUBA,IBARAKI 305,JAPAN
[2] MITSUBISHI HEAVY IND CO LTD,NAGASAKI RES & DEV CTR,NAGASAKI 85103,JAPAN
[3] UNIV TOKYO,DEPT CHEM ENGN,BUNKYO KU,TOKYO 113,JAPAN
关键词
D O I
10.1002/kin.550260207
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
article describes a dynamic model for formation and stability of CO2-hydrate on the interface of liquid CO2(LCO2) and ocean water at large depths. Experimental results indicate that a thin film of hydrate naturally forms on the interfaces between LCO2 and water, and inhibits diffusion between the two phases. Experiments further shows that the flux of CO2 through the hydrate film is dependent of the CO2-concentration in the ambient sea water. The model proposed here explains these phenomena by introducing four major mechanisms; diffusion of water to the LCO2-phase, formation of hydrate in the LCO2-hydrate interface, decay of hydrate in the water-hydrate interface, and diffusion of CO2 through the water phase. The model explains the CO2 flux not by diffusion through the hydrate film, but suggest a mechanism of continuous hydrate formation and decay. The overall effect is a ''moving,'' pseudo-steady-state hydrate film due to transport of CO2 through the film. The film velocity is dependent of liquid-liquid diffusivity parameters and reaction constant, and lacking experimental values of these parameters, an order-of-magnitude analysis is done by fitting the model to experimentally obtained data for the overall film velocity. The motivation for this work is to elucidate options for CO2 depositions in deep oceans, of which liquid CO2 sequestration is believed to be one of the most feasible. Spreading of CO2 from a liquid CO2-lake and associated lowering of pH in the ecosystem surrounding the lake is of large concern. The work presented here concludes that diffusion of CO2 in the ocean is largely reduced by the hydrate film and suggests that hydrate formation may alleviate some of the environmental concerns regarding deep ocean sequestration of liquid CO2. (C) 1994 John Wiley & Sons, Inc.
引用
收藏
页码:289 / 297
页数:9
相关论文
共 12 条
[1]   DEPOSITION OF CO2 ON THE SEABED IN THE FORM OF HYDRATES [J].
AUSTVIK, T ;
LOKEN, KP .
ENERGY CONVERSION AND MANAGEMENT, 1992, 33 (5-8) :659-666
[2]  
AYA I, 1992, ASME HTD, V125, P17
[3]  
DRANGE H, 1992, NEERGY CONVERS MGMT, V33, P698
[4]  
FUJIOKA Y, UNPUB INT J ENERGY R
[5]   THE FATE OF CO2 SEQUESTERED IN THE DEEP OCEAN [J].
GOLOMB, DS ;
ZEMBA, SG ;
DACEY, JWH ;
MICHAELS, AF .
ENERGY CONVERSION AND MANAGEMENT, 1992, 33 (5-8) :675-683
[6]   FEASIBILITY, MODELING AND ECONOMICS OF SEQUESTERING POWER-PLANT CO2 EMISSIONS IN THE DEEP OCEAN [J].
HERZOG, H ;
GOLOMB, D ;
ZEMBA, S .
ENVIRONMENTAL PROGRESS, 1991, 10 (01) :64-74
[7]  
LUND PC, UNPUB ENERGY CONVERS
[8]   CO2 CLATHRATE FORMATION AND ITS PROPERTIES IN THE SIMULATED DEEP OCEAN [J].
NISHIKAWA, N ;
MORISHITA, M ;
UCHIYAMA, M ;
YAMAGUCHI, F ;
OHTSUBO, K ;
KIMURO, H ;
HIRAOKA, R .
ENERGY CONVERSION AND MANAGEMENT, 1992, 33 (5-8) :651-657
[9]  
OHSUMI T, 1993, P IEA CARBON DIOXIDE
[10]  
SAKAI H, 1990, SCIENCE, V248, P933