Effect of feed nozzle configuration on n-butane to maleic anhydride yield: From lab scale to commercial Original Research Article

In the process to produce maleic anhydride via the partial oxidation of n-butane, selectivity is sensitive to feed gas configuration of both oxygen and n-butane. Based on laboratory scale fluidized bed experiments, selectivity was superior when the n-butane was co-fed together with oxygen. When the oxygen and n-butane were fed separately through a distributor and a sparger, selectivity was highest when the sparger was closest to the distributor (independent of whether the n-butane was fed through the sparger and the oxygen through the distributor or vice versa). Various feed gas configurations were tested in a 4.2 m diameter commercial circulating fluidized bed reactor equipped with 926 spargers at three different levels. Maleic acid production rate increased by about 15% when oxygen was fed to a lower sparger 0.45 m above the distributor compared to when it was fed at a height of 1.9 m. These observations indicate that maintaining the catalyst in an atmosphere containing oxygen is important for overall n-butane conversion and maleic anhydride selectivity.