Extraction of dried sage and coriander seed was carried out using near critical carbon dioxide to obtain oleoresin, non-volatile oil and essential oil extracts. Extractions were carried out in both a 4 litre and 75 litre extraction plant, to determine the effects of the particle size, carbon dioxide flow rate, bulk density and extraction temperature and pressure on the yield and extraction time. The rate of extraction of oleoresin from sage depended only on the particle diameter, and was limited by intra-particle diffusion. The rate of extraction of non-volatile oil from coriander seed was limited both by its solubility in carbon dioxide, and intra-particle diffusion. The results were satisfactorily correlated with a mathematical model. Scale-up calculations were performed to enable the economics of the extraction process to be evaluated.

Supercritical CO2 extraction of oleoresin from portuguese rosemary (Rosmarinus officinalis L.) was carried out with a flow apparatus at temperatures of 35 and 40 degrees C and pressures of 100, 125 and 200 bar. The highest fraction of volatile compounds (oil) in the oleoresin was obtained at 100 bar and 40 degrees C. An unsteady mathematical model was able to give good representation of the supercritical extraction curves and a mass transfer coefficient was determined using the successive quadratic programming method. Values of this coefficient ranged between 4.49 and 15.07 kg/m3s and the shift to a diffusion-controlled regime occurred when 44% of the total oil was extracted.

In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method is presented. SFA aims at providing the relevant information for a country’s overall management strategy regarding single substances or coherent groups of substances. This article is dedicated to the presentation of a threestep general framework for SFA-type studies, and elaborates on its first step the systems definition. Attention is given to the definition of the external and internal system boundaries, the categorization of the system’s elements, aspects of materials choice, time, and space, and how these depend on the aim of the conducted study. Moreover, a broader discussion is started on the need for standardization of materials flow studies in general.In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method and its software tool SFINX are presented. SFA aims at providing the relevant information for a country’s overall management strategy regarding single substances or coherent groups of substances. Three modelling techniques and their possibilities and limitations are discussed: Bookkeeping, static modelling, and dynamic modelling. The computer program SFINX can be used for varoius purposes: (1) to obtain an overview of stocks and flows of a substance in, out and through a nation’s economy and environment for a specific year, (2) to trace the origins of specific pollution problems, and (3) to estimate the effectiveness of certain abatement measures. Each application has its own requirements with regard to data and modelling.