(217d) The Effect of Moisture Content on Mechanical Properties of Alumina Catalysts Tablets

Aluminum oxide, widely known as "Alumina," has extensive use in the chemical and petrochemical industries. Within these sectors, compacted aluminum oxide tablets are commonly used as catalyst support to facilitate efficient chemical processes. These tablets are engineered to meet specified mechanical properties, including hardness, tensile strength, Young’s modulus, and porosity. Manufacturers often need to adjust the compaction load, amount of binder and lubrication to optimize the manufacturing process to produce alumina tablets with optimal mechanical characteristics, ensuring enhanced performance and durability while keeping the cost relatively low.

This work investigates the effect of moisture content on various type of alumina tablets. The moisture content of alumina powders can change due to humidity as well storage and processing conditions. The tablets underwent compaction with differing moisture contents and compaction loads and were subsequently tested 24 hours post-ejection. Elevating the moisture content up to 20% w/w resulted in an increase in both the tensile strength and Young’s modulus of the tablets.

Our hypothesis suggest that the additional liquid acted as a lubricant allowing the particles to move past one another and gas to escape and thus form a denser packing structure. Moreover, drying tablets at 120°C for 24 hours effectively removes most of the water, thereby altering their mechanical properties. Notably, to the best of the authors’ knowledge, there has been a dearth of studies focusing on the effect of moisture on alumina tablets. Our results show that controlling the moisture content is important in order to produce tablets with low variability. In addition, our results show that increasing the moisture content can be used as a strategy to increase the strength of the tablets.