烃类蒸汽转化法是目前工业产氢的主要工艺,而高能耗和高碳排放是制约这一工艺发展的瓶颈因素.采用(火用)分析方法对烃类蒸汽重整工艺进行了系统的考察.对天然气蒸汽重整制氢(SMR)过程考察了重整反应转化温度和水/碳摩尔比对系统(火用)效率和单位H2碳排放的影响,确定了在考察的范围内最佳的操作条件.比较了3种制氢原料在各自典型操作条件下的系统(火用)效率及单位H2碳排放量.系统(火用)效率由大到小的原料依次为天然气(0.676)、液化气(0.638)和石脑油(0.635),而单位H2碳排放由大到小的顺序与之相反.基于相对(火用)负荷的概念,推导了系统(火用)效率与子单元(火用)效率的关联式,并以此为基础在子单元的层面上分析了系统(火用)效率变化的根本原因,给出了具体的调优策略.%Steam reforming of hydrocarbons is the main process of industrial hydrogen production, however, the process is strongly limited by its high energy consumption and carbon emission. Systematic evaluation of the process was performed by using exergy analysis. For steam methane reforming, the exergy efficiencies and carbon emission for unit H2 production were evaluated with variation of reformer temperature and steam to carbon molar ratio. The optimal operation conditions were identified in the investigation range. The steam reforming processes with natural gas, naphtha and liquefied petroleum gas (LPG) as raw materials, respectively, were compared. The system exergy efficiency for natural gas, LPG, naphtha were 0.676, 0.638 and 0.635, respectively. An analytical expression for the relationship between efficiencies of subunits and system exergy efficiency was obtained and used to investigate the steam reforming process on the sub-unit level, by which the strategies were proposed to improve the system exergy efficiency.
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