Chemical Engineering Science 60 (2005) 2069 – 2083 www.elsevier.com/locate/ces Modular dynamic simulation for integrated particulate processes by means of tool integration Viatcheslav Kulikov a , Heiko Briesen a , ∗ , Robert Grosch a , Aidong Yang a , Lars von Wedel b , Wolfgang Marquardt a a Lehrstuhl für Prozesstechnik, RWTH Aachen University, Turmstr. 46, D-52064 Aachen, Germany b AixCAPE, Intzestr. 1, D-52072 Aachen, Germany Received 3 August 2004; received in revised form 30 November 2004; accepted 30 November 2004 Abstract In this contribution a sequential modular strategy for the dynamic simulation of particulate process flowsheets is presented and the efficiency of the approach is demonstrated by means of an example process for the crystallization of pentaerythritol. The flowsheet of the process consists of a number of different unit operations, e.g. evaporator, crystallizer, hydrocyclone, and mixer, which are described by mathematical models of largely varying complexity and structure. A key advantage of the presented sequential modular strategy is that specialized tools can be selected for the modelling and solution of each unit operation in the flowsheet. The tools are then coupled together by means of the tool integration framework CHEOPS in order to capture the overall structure of the flowsheet. In a case study, a startup of a crystallization flowsheet is carried out. As a result, detailed information about the dynamic plantwide process behavior is obtained. The practical relevance of the approach is demonstrated by means of a scenario where potential blocking of the filters following the crystallizer has been analyzed.  2004 Elsevier Ltd. All rights reserved. Keywords: Crystallization; Sequential modular approach; Dynamic simulation; Tool integration; Modular algorithm; Population balance 1. Introduction Over the past decades process simulation has become an established tool in industrial applications and academic re- search. However, the tools available for process simulation still show certain limitations. Especially the dynamic sim- ulation of complete process flowsheets of particulate pro- cesses is far from being a resolved issue. Dynamic modelling of any fluid phase unit operation usu- ally leads to the same type of equations: the material and en- ergy balances are augmented by constitutive equations and closing conditions which results in a system of differential and algebraic equations (DAE). When these units are inte- grated into a process flowsheet the system size obviously ∗ Corresponding author. Tel.: +49 241 8094861. E-mail address: briesen@lpt.rwth-aachen.de (H. Briesen). 0009-2509/$ - see front matter  2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ces.2004.11.037 increases but the type of equations remains unchanged. For the solution of the arising possibly large DAE system several powerful algorithms have been developed (e.g. Brenan et al., 1989) which have been implemented in stand-alone solvers like e.g. DASSL (Petzold, 1983) and LIMEX (Deufhardt et al., 1987) as well as integrated into commercial tools (e.g. Pantelides, 1996). This availability of easy-to-use software strongly promoted the widespread use of dynamic process simulation in industrial practice in the last decade. Considering the simulation of processes involving partic- ulate matter, the situation is quite different. The current lack of a versatile flowsheeting tool dealing with particulate mat- ter has several reasons. On the one hand one has to admit that, due to the higher complexity of the processes involved, the knowledge of par- ticulate processes is not as advanced as for fluid phase pro- cesses where standard model libraries are already available. For particulate processes these libraries are not yet at hand,