富氧条件下对二甲苯氧化反应器的氧浓度分布

<title>ofile of Oxygen Concentration in p -Xylene Oxidation Reactor under Oxygen-Enriched Process Conditions

采用轴向分散模型模拟计算了工业对二甲苯氧化反应器内的气液相氧浓度分布,考察了富氧进气(进气中氧的摩尔分数为21％-27％)对于该分布的影响。结果表明,反应器内气相氧的浓度分布存在一定的梯度,其值沿塔高单调递减;空气进气时,气相氧摩尔分数最大值为最小值的1.64倍;若保持尾气氧含量不变,则采用富氧进气后,气、液相氧含量有所降低。气相氧含量的降低说明操作安全性不受影响,而液相氧含量的降低则导致反应结果恶化。

<abstract>mathematical model accounting for gas-liquid exothermic reaction and axial dispersion in both gas and liquid phases was employed to study the effect of feed oxygen concent ranging from 21% to 27% in an industrial bubble column reactor. Computational results showed that there was remarkable oxygen concent gradients in the gas phase in the reactor: the oxygen mole fraction in the gas phase decreased along the column, and the maxium at the bottom was 1.64 times of the minium at the top. In the oxygen-enriched process whose feed oxygen concent was higher than the value in air,i.e.21% ,the oxygen pressure in the gas phase and balance oxygen pressure in the liquid phase all decreased. The former meant that the safety of operation was unaffected and the latter meant that decrease in dissolved oxygen concent in the liquid phase led to poor reaction result.