Mass transfer study of electrochemical processes with gas production
Mass transfer study of electrochemical processes with gas production
复制标题
DOI：
10.1016/j.cep.2009.08.006
复制
发表时间：
2009-09-01
影响因子：
4.3
通讯作者：
Vilar, E. O.
中科院分区：
文献类型：
--
作者：
Albuquerque, I. L. T.;Cavalcanti, E. B.;Vilar, E. O.
众所周知，由于特定电极几何形状上形成的气泡的影响，涉及气体生产的电解过程可能具有低产额能量。这些附着在电极表面的气泡增加了其覆盖面积，可能会影响平均传质系数，从而影响电池电位和屈服过程。本文测定了扩散控制下K3Fe(CN)(6)在碱性溶液中电还原制氢的综合平均传质系数。就像生产电解氯碱的反应器一样，电解槽由由石棉隔膜隔开的阳极室和阴极室组成。研究了电解液渗流速度和阴极几何形状(穿孔板和金属网)的影响。结果表明，对于网状结构，杆上的综合平均传质系数k(D)*随着电解液通过隔膜的平均渗流速度的增加而增大。对于穿孔钢板，观察到了相反的趋势。平均渗流速度在3.5x10(-5)m以下时，S(-1)。穿孔板上的(k(D)*)值高于网格几何形状。对于所研究的情况，给出了著名的无量纲方程Sh=Are(B)Sc(1/3)的常数a和b。爱思唯尔出版公司(Elsevier B.V.)
It is known that electrolytic processes involving the production of gas may have a low yield energetic due to the influence of the bubbles formed on specific electrode geometry. These bubbles adhering the electrode surface increases its area of coverage may affect the average mass transfer coefficient and hence the cell potential and the yield process. In the present work, the combined average mass transfer coefficient was determined for the hydrogen production from the electroreduction of K3Fe(CN)(6) in alkaline solution under diffusional control. Like a reactor to produce electrolytic chlorine-soda, the electrolytic cell was formed by anodic and cathode compartments separated by an asbestos diaphragm. The effects of electrolyte percolation velocity and cathode geometry (perforated plate and metal mesh) were studied. The results showed that for the mesh geometry, the combined average mass transfer coefficient (k(d)*) over bar increased with the average electrolyte percolation velocity through the diaphragm. A contradictory trend was observed for the perforated plate. For average percolation velocities below 3.5 x 10(-5) m s(-1). the perforated plate showed higher values of (k(d)*) over bar than the mesh geometry. The constants a and b of the well-known dimensionless equation Sh = aRe(b)Sc(1/3) were presented for the cases studied. Published by Elsevier B.V.