Engineering Aspects of Electrochemical Plant Design

摘要

Over the years there have been some excellent summaries of electrochemical cell design highlighting trends and design features. Examples are references 1 and 2. These have focussed largely on understanding and modeling of the cells themselves and the unique features which electrochemistry brings to the table. Following the 14th conference and through subsequent work with various electrochemists it became apparent that there was often a wide gap between the electrochemists who conduct fundamental research into electrode processes, and engineers who implement cell concepts into working chemical plants. While conferences such as the International Forum bring chemists and cell engineers together, the cell is often not considered in the context of a broader and more expansive chemical plant. A useful point of reference is that in a large chloralkali plant (500 t/d NaOH) the cell cost may amount to approximately 20% of the total installed capital of the plant; in a small 30 t/d plant, it may be no more than 10%. Figure 1 puts the cellhouse in the context of the broader plant for a chlorate facility; Figure 2 is a photograph of a chloralkali plant identifying the cell area. In this paper we will try and explain some of the key items which are considered by process, mechanical and electrical engineers who design the balance of the plant around an electrochemical cell. The focus will be on hydraulics, some issues pertinent to scale up, materials Most commercial electrochemical processes routinely operate with points in the circuit that exceed 70 V; therefore, accessible bus systems and electrolyzers must be designed to eliminate the possibility of electric shock through electrical isolation of walkways and structures and/or shielding and/or use of personal protective equipment such as dielectric boots and gloves. A combination of these strategies is recommended.