Iron chloride and iron naphthenate has been used as targeted iron contamination sources to simulate the industrial iron-poisoned catalysts, and these catalysts have been investigated in details. The study of catalysts contaminated with different iron sources shows that the iron content singly can’t count for its influence on the catalyst, whereas its distribution on catalyst is the key factor, which is determined by the iron source species. Small iron species such as iron chloride could penetrate particles and lead to uniform iron distribution on catalyst, resulting in less influence on unit performance. Differently, iron contamination caused by large molecular like iron naphthenate leads to local enriched iron deposition on the surface of catalyst particles. Accordingly the total acid amount of catalyst decreased significantly, which is adverse to the catalytic activity. Furthermore, the reductive temperature is therefore lowered, causing the dry gas yield increased. In addition, it’s worth noting that the same conclusions as above-mentioned can be drawn by analyzing the industrial equilibrium catalysts from different instruments.
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