化学链干重整联合制氢热力学分析及实验

提出了一种化学链甲烷干重整联合制氢工艺。该工艺由还原反应器、干重整反应器、蒸汽反应器和空气反应器组成,在实现制氢的同时获得可变H₂/CO比的合成气。借助ASPEN plus软件和小型流化床实验台,在等温条件下,温度900℃,采用Fe₂O₃/Al₂O₃载氧体,对该工艺进行热力学分析和实验验证。结果显示,当铁氧化物被还原至FeO/Fe时,干重整反应器内甲烷转化率可以达到98%,CO产率可以达到94%。干重整反应器中同时发生甲烷干重整和部分氧化反应,载氧体内部晶格氧可以有效降低积炭并提高合成气H₂/CO比。积炭发生于晶格氧消耗殆尽时。积炭进入蒸汽反应器,发生气化反应,降低氢气纯度。

Thermodynamic and experimental analysis of chemical looping dry reforming with hydrogen production system

A chemical chain methane dry reforming combined hydrogen production process was proposed. The process consists of a reduction reactor, a dry reforming reactor, a steam reactor and an air reactor to obtain a synthesis gas having a variable H₂/CO ratio while achieving hydrogen production. In this study, thermodynamic validation was carried out at 900℃ and 1.01×10⁵ Pa, and experiments were performed to verify the feasibility of the process in a fluidized-bed reactor using Fe₂O₃/Al₂O₃ oxygen carrier. It was found that a high conversion of CO₂ and CH₄ to syngas can be achieved on the reduced iron oxygen carrier. When the reduction extent of the oxygen carrier was 33%, the CH₄ conversion and CO yield over 98% and 94%, respectively. During the dry reforming stage, the ratio of CH₄/CO₂ was variable. Partial oxidation of excess CH₄ by active lattice oxygen increased H₂/CO molar ratio of syngas and reduced the carbon deposition. Carbon deposition formed since the active lattice oxygen has been depleted, which would react with steam in the next steam oxidizer and causing the hydrogen purity reduced.