Abstract In this paper, the elimination of heavy tar by steam reforming at high temperature was studied with experiments and numerical simulation. The experiments were conducted in a tube reactor with five model compounds at temperatures of 1273–1673 K, steam of 0–40 vol% and sample weight of 3–20 mg with residence time of 2 s. The simulation was performed with the plug flow model in CHEMKIN program based on a kinetic model that consists of >200 chemical species and 2000 elementary step-like reactions. The results of experiments indicate that increasing temperature will accelerate the decomposition of heavy tar; moisture could significantly prompt the decomposition of heavy tars, but not so efficient above 20 vol%; less sample could help the decomposition of heavy tar; longer residence time can slightly increase the decomposition of heavy tar. At high temperature (1573 K or above), the heavy tar is mainly cracked into two parts: the one carbon molecules (CO and CO 2 ) and the soot at the beginning of reactor. Then the soot decomposes into CO, CO 2 and H 2 by steam reforming. The conversion and kinetic data of heavy tar can be divided by two temperature sections. The carbon conversion degrees of different model compounds from 1173 K to1473 K are close with similar trends, which may be represented by a universal kinetic model. Our results provide an insight in the understanding of the heavy tar decomposition and give the necessary information for the designation and operation of the tar cracker to eliminate heavy tar.

中文翻译：

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重焦油蒸汽重整实验研究与建模

摘要 本文通过实验和数值模拟研究了高温蒸汽重整去除重焦油的问题。实验在管式反应器中进行，其中含有五种模型化合物，温度为 1273–1673 K，蒸汽量为 0–40 vol%，样品重量为 3–20 mg，停留时间为 2 秒。模拟是使用 CHEMKIN 程序中的活塞流模型进行的，该模型基于由 >200 种化学物质和 2000 个基本阶跃反应组成的动力学模型。实验结果表明，升高温度会加速重焦油的分解；水分可以显着促进重焦油的分解，但在 20 vol% 以上效率不高；较少的样品有助于重焦油的分解；较长的停留时间可略微增加重焦油的分解。在高温（1573 K或以上）下，重焦油主要裂解为两部分：一个碳分子（CO和CO 2 ）和反应器开始的烟尘。然后烟灰通过蒸汽重整分解成CO、CO 2 和H 2 。重焦油的转化和动力学数据可以分为两个温度段。不同模型化合物的碳转化度从1173 K到1473 K的变化趋势相近，可以用一个通用的动力学模型来表示。我们的结果提供了对重焦油分解的理解，并为焦油裂解装置的指定和操作以消除重焦油提供了必要的信息。然后烟灰通过蒸汽重整分解成CO、CO 2 和H 2 。重焦油的转化和动力学数据可以分为两个温度段。不同模型化合物的碳转化度从1173 K到1473 K的变化趋势相近，可以用一个通用的动力学模型来表示。我们的结果提供了对重焦油分解的理解，并为焦油裂解装置的指定和操作以消除重焦油提供了必要的信息。然后烟灰通过蒸汽重整分解成CO、CO 2 和H 2 。重焦油的转化和动力学数据可以分为两个温度段。不同模型化合物的碳转化度从1173 K到1473 K的变化趋势相近，可以用一个通用的动力学模型来表示。我们的结果提供了对重焦油分解的理解，并为焦油裂解装置的指定和操作以消除重焦油提供了必要的信息。