Procedures for extracting or refining sensitive substances using dense gases have been developed for numerous purposes. Dense carbon dioxide is already being used industrially for decaffeination of coffee and extraction of hops. Further possible applications have been tested on the laboratory or pilot plant scales and shown to be mostly economical. Uses as varied as the non-aggressive extraction of spice, extraction of polymers, refining of spent oil, pyrolysis/extraction of wood and liquefaction of coal show the extremely wide range of application. The book comprehensively reviews the present state of development and features examples of application of this new technique.

The book treats the C -hydrocarbons and their secondary products as a contribution 4 to chemical engineering economics, applying this field of teaching and research to the technical processes for making and processing this group of products, so important to the chemical industry. As early as tpe 1950s the then director of the Institute for Technical Chemistry of the Berlin Technical University, Professor Herbert Kolbel, took the' initiative in the domain of Chemical Engineering Economics and began systematic studies of Project Engineering and Cost Estimation in connection with chemical plants. He also started a course on technical chemical processes in 1966. Properties, production procedures, plant equipment, and also the uses of technically interesting products are the central features of Chemical Technology. The information is to be found in the large encyclopedias of Technical Chemistry. On the other hand, Chemical Engineering Economics deals with all the economic conditions of usage of the raw materials, possibilities of utilizing co-products, and the integration of these products into definite production programmes, from the stand point of the chemical and technical fundamentals of the processes. Further important viewpoints are the costs of the products, taking into consideration important and variable influences on these costs, the situation and development of the market for the products and, of increasing significance, also the ecological global conditions for procuring raw materials and the production and marketing of the particular products."