新型欧姆加热式反应器强化甲烷蒸汽重整的过程分析和优化

Process analysis and optimization of innovative Ohmic-heating reactor for enhanced steam methane reforming

传统甲烷蒸汽重整(SMR)反应器(cSMR反应器)中容易出现较大的径向温度梯度,增加了催化剂积炭失活的风险。提出了一种新型的含内外管欧姆加热蒸汽重整固定床反应器(eSMR反应器),以欧姆加热替代了传统工业反应器的燃烧供热方式。通过二维拟均相固定床反应器模拟,比较了eSMR与cSMR反应器的性能差异,分析了eSMR反应器结构及操作条件对其性能的影响。结果表明,相比于cSMR,eSMR反应器出口的平均甲烷转化率和平均温度分别高出26.6%和121 K,且径向温度分布更加均匀;eSMR反应器的内外管直径之比为0.589时,其径向温度梯度最小;增加入口温度、加热电压和水碳比均会提高eSMR反应器出口的平均甲烷转化率和平均温度,增加入口压力的影响相反。本研究可为欧姆加热蒸汽重整反应器的开发提供一定的借鉴。

Conventional steam methane reforming(SMR)reactor(cSMR reactor)often exhibit significant radial temperature gradients,increasing the risk of catalyst deactivation due to carbon deposits.A novel design,the Ohmic-heating fixed-bed reactor with inner and outer tubes for steam reformingr(eSMR reactor),has been proposed to replace the conventional combustion-based heating method employed in industrial reactor.Using a two-dimensional quasi-homogeneous fixed-bed reactor simulation,the performance differences between eSMR and cSMR reactor were compared,and the effects of eSMR reactor structure and operating conditions on its performance were analyzed.The results show that compared to cSMR,eSMR reactor exhibits a 26.6%higher outlet average methane conversion rate,a 121 K higher outlet average temperature,and a more uniform radial temperature distribution.When the inner-to-outer tube diameter ratio is 0.589,the radial temperature gradient is minimized in eSMR reactor.Increasing the inlet temperature,heating voltage,and steammethane ratio all enhance the outlet average methane conversion rate and outlet average temperature in eSMR reactor,while the effect of increasing inlet pressure is the opposite.This research can offer valuable insights for the development of Ohmic heating-based steam methane reforming reactors.