Challenges in multiscale modelling and its application to granulation systems

Since the mid 1990s there has been an increasing recognition of chemical engineering's multiscale nature. Multiscale modelling attempts to create flexible and efficient models by linking two or more partial models that describe phenomena at different characteristic length and time scales. In the first part of this paper, we briefly review multiscale modelling in chemical engineering. Three key tasks used in multiscale modelling are identified, and the current practices and unresolved issues in each are discussed. The second part of the paper examines the modelling of a wet granulation circuit from a multiscale perspective. A 'scale map' for drum granulation is proposed to assist in visualising the multiscale nature of the system. The three multiscale modelling tasks are considered in turn and some suggestions for modelling are proposed. Through this paper we are seeking to promote discussion on multiscale modelling and to receive feedback on its application to granulation