Download A Study on Acetylene Reactor Performance with Partial Catalyst Replacement

The effective removal of acetylene in the front end hydrogenation using palladium based chevron Philips E-series catalyst is a challenge to ethylene producer. There are two key parameters to be considered for study of acetylene convertor performance of an olefin cracker: select the right acetylene hydrogenation catalyst and maintain stable operation of reactor. Though, poison can influence the successful operation of catalyst. Since some operational upsets will inevitably occur. The convertor catalyst utilized must be robust enough to manage these changes without degradation of the catalyst performance and unit profitability. United ethane cracker has two acetylene reactor beds in series with intercooler to control the bed inlet temperature. If, the inter cooler has adequate capacity to control the second reactor inlet temperature. Moreover, carbon monoxide (CO) generation from furnaces is optimized. Then, new operation philosophy which is adopted to maximize the acetylene conversion in the top bed and very minimal acetylene conversion is to be maintained in the bottom bed to meet the acetylene specification in ethylene product. It will provide the option to change the partial catalyst after 5-yrs of catalyst life cycle. Therefore, a provision was made to dispose off only the top bed catalyst and re-use bottom bed catalyst in the top bed. A fresh E-series catalyst is to be used in the bottom bed. The above mentioned option has been practiced in UNITED ethane cracker and successfully demonstrated acetylene reactor performance as accepted per study. This paper will present the actual acetylene convertor performance with this option over the entire life of E-series catalyst. It will provide the two fold benefits; firstly it will directly save one bed catalyst cost. Consequently reduce the production cost per ton of ethylene. Secondly it will provide the confidence of longer life cycle of Chevron Philips E-series catalyst with this operation philosophy.