(109b) Scale-up Effects On Plant-Material Extraction In the Standardised Laboratory Apparatus

The extraction of plant materials is a subfield of solid-liquid extraction. It deals with the task of attaining substances from herbal materials. Industrial processes for the extraction of these natural products have been based mostly on empirical methods so far. The scientific design of extraction equipment is being complicated by the inherent complexity of plant material.

To enable the systematic research on solid extraction of various components under different conditions, a standardized laboratory-scale apparatus for the extraction of natural raw material has been developed. With this apparatus the study of the kinetics and equilibrium of the extraction process is possible under defined conditions. To detect the influence of scale-up on the extraction process experiments were carried out on a larger scale.

The experiments were performed in a tube extractor and a stirred tank reactor, using water and water ethanol mixtures as solvent. For the solid phase melissa leafs (melissa officinalis) and valerian roots (valeriana officinalis) were used. The influence of the solvent flow rate on the extraction behaviour will be presented in several examples. The effect of flow-rate variation on the saturation of the solvent will be discussed. In addition the effect of the flow direction will be demonstrated.

The experimental data gained from the extractors will be compared to alternative models. To optimize the experimental conditions, the model-based experimental design (MEXA) was used. Performing experiments at optimized conditions will maximize the information obtained from every experiment. So the overall experimental effort will be reduced typically by a factor of at least three while maintaining accuracy of the results.