A Scale-Up of Fluidized Bed Granulation Process for Calcium–Tryptophan

The importance of tryptophan in both human and animal nutrition continues to drive its demand and market growth. To enhance the usability of tryptophan products, such as flowability, bulk density, and mixing efficiency, the fluidized bed granulation process plays a critical role in the industrial production of tryptophan from microbial fermentation. This process involves a simplified method of evaporation and granulation to efficiently produce commercial granular products. This study conducted a solid flow analysis for scaling up fluidized bed granulators in the manufacturing of calcium–tryptophan granules, focusing on the solid flow characteristics, the flow regime within the granulator, and the granulator's design considerations. The scale-up case for calcium–tryptophan granules revealed that the bubbling fluidization flow regime occurred similarly at both pilot and plant scales. Then, the transport disengaging height to minimize fine particle loss inside the fluidized bed granulator and the entrainment rate to secure the capacity of entrained particle recovery equipment such as cyclones or bag filters were determined to obtain basic design data for scale-up of the fluidized bed granulation process.