The design for treatment processes of chlorine and hydrogen in the caustic soda industry
ABSTRACT
With wide industrial applications, chlorine and hydrogen are the most common industrial gases and very important chemical raw materials. They are usually fabricated by electrolysising the saturated salt water in industry. However, the fabricated hydrogen and chlorine generally have the higher temperature, and mix a lot of water vapor, which would seriously affect the purity of the product. The design is about the solution of chlorine, hydrogen dryness, and contain two parts, which deal with the material and energy calculation during the process, major equipment design and selection, parameters calculation, plant design and design layout of the chlorine and hydrogen, seperately. Taking into account the problem of temperature and corrosive in chlorine, the method of cool dry firstly, and then the sulfuric acid dry was used in this design. While for the hydrogen, ordinary cooler was used during the process because of its corrosion resistance property.
Indirect cooling method was used in during the chlorine treatment process, with acid cycle drying process in packed tower contected with series blister tower drying process. The water content in chlorine was design to less than 0.05% through the process calculation and equipment design. To simplify the process and reduce the investment, the direct method in the hydrogen treatment process was used. With two scrubber for cooling, the purity of hydrogen can finally reach to 98%.
Key words: chlorine hydrogen temperature drying corrosive