Extraktion von Hexanol aus Fermentationsbrühen und Lösungsmittelrückgewinnung
Extraction of hexanol from fermentation broths and solvents recovery
Fermentation has played a major role in Alcohol production for decades from renewable sources such as plant biomass material and agricultural wastes that have been sitting and intensifying for a long period of time. These biomass materials can also be used as a renewable source of energy to produce gasoline and diesel. Since the recovery of alcohols from fermentation broths is an expensive process, several research groups have been trying to find an inexpensive way. One of the possibilities for recovery seemed to be liquid extraction. The necessary data have been worked out all over the world. Liquid-Liquid Extraction is one of the most significant unit operations used widely in the chemical industry for the separation of liquid-liquid mixture with the aid of an extracting solvent. The Liquid-Liquid Extraction finds applications in the petroleum industry, hydrometallurgy, biotechnology, nu-clear technology, waste management, and other areas. There are many different types of extraction apparatus, tools and devices which differ in internals, geometry, energy input and construction materials. Stirred extractors are also known as extracting agent. The and one of the most important stirred extractors is the so-called stirred cell extractor, which is very heavily used in the petroleum engineering industry in general. The stirred cell extractor will be used in this thesis. Research in this field are also focused on the so-called extractive fermentation. This process allows the recovery of alcohols by solvent extraction from fermentation broths during alcohol formation. Because, when alcohols are produced by a biotechnological process, the product con-centration is usually low due to product inhibition. For example, the ethanol concentration in the fermentation broth is always low, usually from about 5 to l0%.Of these alcohols, the primary metabolites ethanol, butanol and hexanol are of main practical interest. In the chemical industry, these alcohols are petrochemical products. They are formed in high concentrations and purified by means of fractional distillation. This paper deals with the extraction of hexanol from fermentation broths and solvents recovery. This will be done, using the special extractor stirred cell column and for the solvent's recovery simulation with packed rectification column will be done. In order to design the functioning pilot plant in this thesis, five different tasks are studied from the laboratory stage to the large plant. The tasks will be done as follows:- Setup of a test plant for continuous extraction and rectification, - Experiments with simulated fermentation broth (mixtures of pure substances according to the project partner's specifications), - Possibly, experiments with real fermentation broths without cell constituent parts, - Development of a concept for coupling the pressure fermenter of the project partners with the continuous extraction and rectification (extractive fermentation), - Production-scale cost estimation.
Münster, FH, Master Thesis, 2020