The delignification of hemp trough the enzyme laccase with mediator HBT: with the addition of a bleaching process of pre-treated hemp with hydrogen peroxide

The purpose of this project was to get a better understanding of the delignification kinetics of the enzyme laccase with the mediator HBT (Hydroxybenzotriazole) on hemp and lignin as a substrate. The end goal was to find the ideal ratio of enzyme/ HBT/ substrate. In addition, a bleaching process was done on the same pre-treatment hemp as that of the enzyme treatment. The first step was the pre-treatment of the hemp. With the last step of the pre-treatment, the chemical delignification through an alkaline treatment. The hemp before and after the alkaline treatment are tested trough the lignin determination test, FTIR and TGA. These tests gave good results where it was clear that this process indeed partly delignifies the hemp but also removes other constituents in the process. The following step was to determine the effect of the enzyme laccase, HBT and laccase together with HBT on two different alkaline treated hemps. After the reaction, an UV-vis spectroscopy was done on the liquor of the reactions and the percentage of lignin left from the pure lignin samples were determined. After that, the lignin content in the treated hemp samples was also determined. The found results gave an unchanged lignin percentage in the hemp samples. After the lignin determination test, the lignin received from this test was put under an FTIR spectrometer. In the pure lignin there was a drop in the amount of lignin left but not in an expected way. It was decided not to work any further on this section in this project. In the end, a bleaching process with H2O2 was done on the two same alkaline treated samples. On these bleached samples, a DP test was done. On a few selected samples an FTIR and TGA were also performed. The bleaching process gave interesting results but more research needs to be done to get a better understanding of what exactly is happening towards the hemp in the bleaching process.
Incoming