808 155 Potential Effects of Pulsed Electric Pre-treatments on Methane Production of Waste S. M. Safavi and R. Unnþórsson School of Engineering and Natural Sciences, University of Iceland, Iceland INTRODUCTION The produced amount of organic waste is increasing dramatically each year, which can lead to a significant environmental pollution. Considerable amounts of greenhouse gasses are emitted during disposal and storage of organic waste contributing to global climate change. Anaerobic digestion (AD) converts organic waste into the useful and valuable product (methane) that can be used to generate electricity, heat and as a substitute for fossil fuels. The question arises here is whether it is possible to improve the performance of AD with pulsed electric field (PEF) pre-treatment and reach a higher yield of methane production. The purpose of this study is to evaluate the effect of PEF as a pre-treatment method for increasing methane potential of pig slurry (PS), landfill leachate (LL), and fruit/vegetable waste (FVW). METHODS The PEF system produces a pulsed high-voltage in the substrate, which induces arc discharge. Electric power of the arc discharge in substrate generates a strong electric field that eventually destroys the cell wall of sludge. This impact elevates anaerobic digestibility of the substrates being pre-treated with three different intensities of 54, 108 and 180 kJ/kg and results in more methane production. Samples were analyzed for total solids, volatile solids, chemical oxygen demand, soluble chemical oxygen demand, total suspended solids and volatile suspended solids before and after pre-treatment. Then mesophilic batch AD assays were performed on the treated and untreated samples. The anaerobic digestibility of the pre-treated samples compared against the untreated ones to determine the effect of the PEF pre-treatment on the substrates. RESULTS AND CONCLUSION The influence of pre-treatment on methane production was investigated via the batch AD tests. The results of the PEF pre-treatment on all the substrates (PS, LL and FVW) showed positive effects on the methane production. The highest methane improvement was obtained from the PEF pretreated PS (with 50% increase) and the PEF pretreated LL (with 48% increase) , while only 13% improvement was acheived from the PEF pretreated FVW. Methane production of the PS and LL increased with the highest intensity (180 kJ/kg). On the contrary, FVW showed that lowest intensity (54 kJ/kg) was the intensity by which the highest amount of methane was achieved. WASTE AND RECYCLING FREE STYLE IDEA MASTER THESIS
Grøn Dyst 2016
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