FRANZ TRACHSEL¹*, ANDREAS KELLER², RALF PROPLESCH²
*Corresponding author
1. DSM Nutritional Products Ldt., P.O. Box 2676,
CH-4002 Basel, Switzerland
2. DSM Nutritional Products AG,
Zweigniederlassung Werk Sisseln, Hauptstrasse 4,
CH-4334 Sisseln, Switzerland

Abstract

Applying an integrated process development methodology based  on modelling and experiment it was demonstrated that a continuous operation mode leads to significant product and process advantages compared to an existing batch operation. The applied methodology consists of the steps deriving physico-chemical properties, simulation and sensitivity studies and experimental verification in scaled down, continuously operated Miniplant equipment. Efficient execution was achieved by applying experimental short cut estimation methods for VLE’s. For final product characteristics like odor and color, which often cannot be assessed from simulation, high quality experimental facilities which show production plant like characteristics are required.

The comparison with an existing batch purification plant shows a significant intensification by changing to the continuous process. Due to lower thermal stress on the product the yield is increased by 10%. By choosing the optimal split sequence a superior product quality could be achieved in terms of number and amount of by-products, color and odor causing compounds. Because of reduced recycled volumes and no need for inefficient heat up and cool down of equipment, energy consumption for similar product quality can be reduced by 50%.

INTRODUCTION

The here presented case study is the process improvement of an industrial scale distillation as a final purification step. Business demand required a capacity increase in a batch distillati ... ...