Answer Happy

Problem statement Ethylene oxide, a useful chemical intermediate, is produced through the selective oxidation of ethylene and oxygen over a silver-based catalyst. The reaction is highly exothermic and the selectively is drastically affected by temperature excursions within the reactor. A multitbular reactor configuration is therefore necessary. You are a process engineer employed at a local chemical manufacturing facility. The ethylene oxide reactor unit has recently been taken off-line and charged with a new catalyst. The operators have found that even with changes in feed temperature, coolant flowrate and temperature, the reactor experiences severe temperature increases resulting in localized hot- spots and reduced selectivity to the partial oxidation product. The company is considering two methods for mitigating the reaction exotherm: Option 1: Adding an inert diluent to the feed stream Option 2: Taking the unit offline and adding a solid inert material to the catalyst bed (sizes of available inert material are not uniform and not the same size as the catalyst) The downstream unit managers are concerned about the effects of Option 1, and the company director is concerned that Option 2 will impact significantly on the output from the plant whilst the change is made. Your Task Consider each option and discuss the effect on: - downstream processing (separation of products and reactants) - performance of the reaction system (conversion and selectivity, temperature and concentration profiles) - operability and safety You may present any equations or diagrams to support your discussion. No numerical solutions are required for this problem.