Optimizing the recovery of residues in the production of polyurethane: learn how we process hazardous and toxic distillation residues and recover the valuable TDI monomer.

The increase in the amounts of paint and lacquer sludges from industrial processes combined with more stringent legislation, reduction in available land-fills, escalating costs, and the increasing pressure for residues to be processed at the point of origin has created a tremendous incentive for the development of new and economic concepts and techniques for their minimisation.

Consistent with the diversity of chemical-process-industries materials that undergo drying, a wide variety of contact dryers have been brought to the marketplace. However, there is a common set of principles for their process design, and for specifying them.

Bei der Aufbereitung von Industrierückständen, Schlämmen und Sonderabfällen müssen nicht nur gesetzliche Vorschriften beachtet werden. Sinnvoll ist es, die Aufbereitung am Entstehungsort vorzunehmen; darüber hinaus sollte eine maximale Rückgewinnung an Wertstoffen sowie ein Minimum an unvermeidbaren Reststoffen gewährleistet sein.

Over time, different types of reacotrs have been developed in order to improve the stability of the polymerization process. This article Reviews those reactors designed for heterogeneous and homogeneous polymerization. It then explorres the production of solid polymer granules directly in a kneader reactor under evaporative cooling, which is seen as an efficient and reliable polymerization Technology.

In the mid seventies, LIST developed and industrialized a continuous process for the recovery of toluene diisocyanate (further TDI) from distillation residue. The process, which will be highlighted in this document, ensures the Maximum recovery of TDI. The final residue is transformed into a non-toxic (neutral) and easy to handle solid/granular material.

Grossvolumige Knettrockner ermöglichen es, Prozessschritte zu kombinieren und damit Vorteile hinsichtlich Wirtschaftlichkeit und Produktqualität zu erzielen, speziell dann, wenn zähpastöse oder krustende Zustände zu bewältigen sind.

This paper elaborates on the constraints of the drying process of industrial sludges and distillation residues, such as, closed design and product containment, processing of sticky, crusting, or fouling intermediate phases, versatility, low energy demand, and single step drying. It then presents the mechanical, thermal and processing features as well as the operating principles of specialised single-shaft, DISCOTHERM B CONTI/BATCH, and twin-shaft, ORP (Opposite-Rotating Processor) CONTI, kneadersdryers.

Trocknen und Reagieren kombiniert – Die Verbesserung von Produktionsabläufen konzentriert sich heute weniger auf die Optimierung einzelner Verfahrensschritte, als vielmehr auf eine Vereinfachung des Verfahrensablaufs als Ganzes.

This lecture concisely reviews the development and evolution of specialised contact kneaders-dryers, presents the field of their application, defines the selection criteria, describes a basic design procedure, and closes with a list of parameters, that helps one to decide between the implementation of a batch or a continuous operating dryer.