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Zusammenfassung (Englisch)

At this moment in time the chemical and pharmaceutical industry relies heavily on fossil fuels. About 90 % of all produced goods are made out of or with fossil fuels. Also 97 % of the used fossil fuels get burned to generate energy for the established technical processes. This state of the industry can’t be preserved in the long run, since the fossil fuels will ultimately run out. But before that their price has to rise to compensate for the increasing difficulty in extracting fossil fuels from the environment. This will lead to increasing prices for the produced goods by the chemical and pharmaceutical industry which will result in dropping sales figures. To avoid this substitutes for fossil fuels need to be found. An attractive alternative for fossil fuels are renewable resources. Some even have the potential to substitute fossil fuels completely. One of those renewable resources is lignin. It is a component of wood and the only biopolymer which includes aromatic structures, just like crude oil. Modified lignins are byproducts of the paper industry und the biorefinery. The dominant process to produce paper is called kraft pulping in which kraft lignin is generated as a by-product. At this time it is only getting burned to produce energy. The organosolv lignin needs to find applications to add value and furthermore increase the ecologically and economically potential of biorefineries. To capitalize on the natural lignin synthesis and the added modification of the aforementioned processes an application in the production of phenolic resins offers an interesting and promising approach to generate a multitude of valuable products. To achieve this, the technical lignins need to fit certain requirements. They need to have little to no odor and must be free of components which could inhibit the polymerization process or the performance of the produced polymers. To accomplish this oxidation processes have shown to be very promising, as seen for example in the bleaching of paper made from kraft pulping. To get a detailed view of the impacts of the used oxidation on the technical lignins the oxidations of monomeric and dimeric aromatic model substrates have been screened using analogue reaction parameters. Characteristic products of dearomatization and oxidation fragments of the propyl group have been found. While succinic acid and its derivatives are products of dearomatization, lactic acid derives from the propyl group. It was also found that glyceric and threonic acid are oxidation products of sugars. Taking these results into account, a method to deodorize technical lignins has been found. Using this method it is possible to generate 3,6 kg of short chained carboxylic acids from kraft lignin and 9,4 kg of the same from organosolv lignin per ton of used lignin solution. With the remaining deodorized lignins it is possible to manufacture 41 kg of phenolic resins from kraft lignin and 42,5 kg of the same from organosolv lignin which contain a mass percentage of up to 82 % of the deodorized technical lignins. The phenolic resins exhibit excellent chemical and mechanical attributes and could be used for a wide variety of different applications.

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