TECHNO-ECONOMIC ANALYSIS AND SIMULATION OF EXCESS BIOGAS UTILIZATION

Sammanfattning

This degree project studied the impact of external factors on biogas utilization produced at VafabMiljö facility located in Västerås due to decreased demand from the public transportation company VL due to electrification of the biogas driven bus fleet. The purpose and aim of this project were to identify possible pathways for converting excess biogas into sustainable and techno-economically feasible solution to maintain financial profitability. A methodology based on thermodynamic simulations in Ebsilon Professional along with mass, energy and economic calculations in Microsoft Excel was applied. Seven different scenarios were developed based on three pathways: combined heat and power plant, hydrogen production through steam methane reforming and liquefied biogas conversion. The results highlighted that CHP systems achieved highest overall energy efficiency with values exceeding 90%, though due to low electricity and heat market prices, economic viability could not be achieved. The electricity and heat produced increased the operational resilience of VafabMiljö. The revenue produced by the combined heat and power scenarios ranged between 3,62 to 16,91 million SEK annually. Hydrogen yielded higher economic results despite the lower energy efficiency of 66%, generating 29,33 to 90,5 million SEK annually. However, hydrogen feasibility was constraineddue to infrastructural limitations. Liquefied biogas conversion provided the strongest technoeconomic performance with high efficiencies of 89% along with highest revenue ranging from 33,47 to 103,28 million SEK annually. The technology was supported by high market demand along with broad market reach to the heavy transport and maritime vessels sectors. To conclude, the CHP scenarios improved operational resilience, hydrogen production providedhigh potential revenue but faced infrastructure challenges and liquefied biogas represented the most favourable pathway.