The coking tendency under steam cracking conditions of CoatAlloy, a newly developed multilayered Al barrier coating deposited on a commercial 25/35 Cr–Ni base alloy and aimed at reducing the coke formation under hydrocarbon atmosphere at >1100 K temperatures was investigated. It was benchmarked to the uncoated commercial 25/35 Cr–Ni base alloy with a known low coking tendency in ethane steam cracking in a pilot plant. The influence of process conditions, such as coil outlet temperature, presulfidation, continuous sulfur addition and aging was evaluated. The applied coating resulted in a reduced coking tendency as well as reduced yields of both CO and CO₂ compared to the uncoated coil. The surface of both tested reactor materials was studied by means of SEM and EDX analysis. Further scale up was assessed by simulations of an industrial ethane cracker. All the findings show that the CoatAlloy barrier coating is capable of reducing coke formation and maintains its anticoking activity over multiple cracking–decoking cycles.

中文翻译：

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用于减少蒸汽裂化反应器中焦炭形成的CoatAlloy阻隔涂层：实验验证和模拟

研究了CoatAlloy（一种新开发的多层Al阻挡涂层）在蒸汽裂化条件下的焦化趋势，该涂层沉积在商品化的25/35 Cr-Ni基合金上，旨在减少在1100 K以上的碳氢化合物气氛下形成焦炭。它以未涂覆的商用25/35 Cr-Ni基合金为基准，该合金在中试工厂的乙烷蒸汽裂解中具有较低的焦化趋势。评估了工艺条件的影响，例如盘管出口温度，预硫化，连续添加硫和老化。所施加的涂层导致降低的焦化趋势以及降低的CO和CO ₂收率与未镀膜的线圈相比。通过SEM和EDX分析研究了两种测试的反应器材料的表面。通过工业乙烷裂解装置的模拟评估了进一步扩大规模。所有发现均表明，CoatAlloy防渗涂层能够减少焦炭形成，并在多个裂化-焦化循环中保持其抗焦化活性。