Brian D. Jønson and Mads U. Sieborg
Bachelor Thesis – Energy Technology - 2017
The present energy sources are mainly based on fossil fuels, which is not a long-lasting solution. Research in alternative energy source, as the biogas production with anaerobic digestion, are therefore in focus. The biogas production aims to utilize second generation biomasses as lignocellulosic straw, so the energy source becomes sustainable.
The objective of this thesis is to investigate innovative pretreatment methods to increase the biogas yield of lignocellulosic biomass. The thesis is composed of two distinct researches fulfilling the overall objectives. First, we investigated the co-ensiling effect of straw (S) and sugar beet (SB) at different ratios and ensiling periods. For the second activity, a combination of mechanical, chemical and hydrothermal pre-treatment was attempted, while tannery waste water was alternatively applied to replace costly commercial chemicals.
We examined the influence of the physiochemical characteristics of the pretreated biomasses on the mono- and co-ensilage biomasses on the biodegradability (BD). The anaerobic digestion (AD) of the pretreated biomasses was investigated with biochemical methane potential (BMP) from batch experiments to determine the effect that the different pretreatments had on lignocellulosic biomass. The pre-treatment effects were evaluated with synergistic effect and first order kinetics. Further was the effect of the pretreatment investigated with scanning electron microscope (SEM) and Fourier transform infrared spectres to evaluate the physical and chemical changes that the pretreatment made.