Implications of sensor location in steam reformer temperature control

Hydrogen can be produced via steam reformation of many feedstocks. External heat sources provide the thermal energy required by the endothermic steam reformation reactions. Temperature control of the steam reformation reactor is critical to reactor performance and catalyst life. Closed-loop control systems are typically used to modulate the heat input rate based on a comparison between a set point temperature and a temperature measurement. The location of the temperature sensor relative to the heat input location is a choice made during reactor design that can have significant impact on reactor temperature control.     

Comparison of steam and autothermal reforming of methanol using a packed-bed low-cost copper catalyst

Small-scale reformers for hydrogen production via steam and autothermal reforming of hydrocarbon feedstocks can be a solution to the lack of hydrogen distribution infrastructure. A packed-bed reactor is one possible design for such purpose. However, the two reforming processes of steam and autothermal methods have different characteristics, thus they have different and often opposite design requirements. In implementing control strategy for small-scale reformers, understanding the overall chemical reactions and the reactor physical properties becomes essential. This paper presents some inherent features of a packed-bed reactor that can both improve and/or degrade the performance of a packed-bed reactor with both reforming modes.The high thermal resistance of the packed bed is disadvantageous to steam reforming (SR), but it is beneficial to the autothermal reforming (ATR) mode with appropriate reactor geometry. The low catalyst utilization in steam reforming can help to prevent the unconverted fuel leaving the reactor during transient by allowing briefly for higher reactant fuel flow rates. In this study, experiments were performed using three reactor geometries to illustrate these properties and a discussion is presented on how to take advantages of these properties in reactor design.     

延安炼油厂高标号汽油生产平衡方案研究

在对国内汽油质量标准发展过程分析的基础上,以延安炼油厂现有装置生产的成品汽油产量、组分及质量为依据,结合延安炼油厂即将投产的120万t/a重整装置油品的产量、组成等设计数据,以生产高标号汽油为目标,研究设计了两种汽油产品生产的技术方案。通过对两种方案销售收益的横向对比,确定了一种理想的油品加工方案。研究结果可为延安炼油厂高标号汽油质量升级方案的规划提供重要的依据。     

二段炉加过量空气节能方案研究与分析

二段炉加过量空气，一段炉转化负荷相应降低，可节省一段炉燃气用量，提高转化系统的有效能利用率，达到节能的效果，在低负荷下增加二段炉的过量空气，增产节能效果更为明显，加过量空气后工艺参数作适当的调整，生产装置可以稳定运行。     

试论钢结构拱顶在二段转化炉中的应用

四川天华股份有限公司布朗型合成氨装置二段转化炉操作温度高达870℃,其下部的重要构件拱顶由耐高温的刚玉砖制作。该文将从理论和实践的角度对出现突发意外情况下,又无刚玉砖备件时,可否用钢拱顶代替刚玉砖拱顶加以论述。     

一段炉高压蒸汽过热盘管翅片脱落分析与改造

通过对一段炉高压蒸汽过热盘管翅片脱落原因及风险的分析,研究与探讨新的解决方法,消除设备安全隐患,确保装置长周期运行。     

特殊条件下的一段炉升降温方法

中原化肥厂合成氨装置由于修复过渡段保温材料，在过渡段降温及一段炉升温方法上采取了特殊措施，特别是一段炉升温采取了先点火的升温方法。