Summary and a View to the Future

Melt crystallization, with all the mentioned advantages, has not found the place it deserves among the unit operations in chemical engineering today. Research efforts conducted by industry during the last few years, however, are a good beginning in the efforts to change this. 

A second, new approach uses the aforementioned Sandvik conveyer to produce pastilles from an impure melt by a drop formation process which are then fed to a wash column thus improving the fluid dynamical behavior of the plant (DE 1995). Inside the wash column the impurities are removed from the pastilles. The dependence of the pastille properties on the production parameters and their influence on the purification potential of the pastilles was intensively investigated and is described in Biilau (1997). 

An optimization of all three purification steps is needed for all types of melt crystallization processes in order to make melt crystallization more economically competitive. For such an optimization, a mathematical description of the phenomena is necessary. When such a description becomes reality, a great deal of progress for the unit operation melt crystallization will be made. Research in the field continues, therefore this technique is likely to have a bright future. 

Arkenbout, G.J. (1995). Melt Crystallization Technology, TECHNOMIC Publishing Company, Inc., Lancaster, U.S.A. 

Beilstein (1987). Beilsteins Handbook of Organic Chemistry, Springer-Verlag, Berlin, Germany. 

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