Abstract: This article focuses on the temperature runaway phenomenon that occurred during the loading process of a nickel-based catalyst for full hydrogenation of C4 fractions in the industrial unit of Company G. A statistical analysis of the temperature changes in the catalyst bed during the runaway process was conducted to evaluate the high-temperature exposure profile of the catalyst. A series of catalyst samples were prepared in the laboratory under different atmospheres and temperature conditions. Through characterization methods such as surface property analysis, H2-TPR, and XRD, combined with hydrogenation activity evaluation, recommendations for the subsequent disposal of the catalyst after the temperature runaway were proposed. The results indicate that most of the catalyst in the two reactors of the industrial unit experienced only temperatures below 600 °C under a nitrogen atmosphere. Although catalysts prepared under high-temperature treatment at 500—700 °C in an air atmosphere did not show significant changes in surface properties, they were completely oxidized, making it difficult to properly reduce and activate them under the design conditions of the industrial unit. Catalysts prepared under high-temperature treatment at 600°C in a nitrogen atmosphere exhibited relatively minor changes in surface properties, crystal phase, and reduction performance. After reduction at 300 °C, their hydrogenation activity remained relatively high. It is inferred that the catalyst that experienced temperature runaway in the industrial unit can meet the requirements for use. After activation at 300 °C in the industrial unit, the catalyst was directly put into operation, demonstrating good hydrogenation activity and producing qualified products.

Key words: mixed C4, full hydrogenation, nickel-based catalyst, temperature runaway