Energy balance calculation of selected refinery concepts for Energy from Waste facilities

Abstract: Three different EfW (Energy from Waste) scenarios are constructed consisting ofcombinations of incineration, gasification, anaerobic digestion, and fuel celltechnology. Each scenario represents different EfW concepts but uses the same basicstructure and operational condition. All scenarios consist of two waste treatmentprocesses; thermal and biological treatment. The first scenario is an adaption of theBorås waste treatment facility reference case where fluidized bed CHP cycle is usedto incinerate combustible waste and anaerobic digestion is used for biological waste.The second scenario is foreseeable future concept where gasification and incinerationtake place. The third is scenario is the futuristic scenario where waste is gasified andused in fuel cell for electricity conversion. The three scenarios have the samebiological process where waste turns into biogas and upgrade for high methaneconcentration.In order to investigate the energy production, an energy and mass balance calculationfor each scenario was made using information collected from actual waste treatmentfacility and literature data. The balance model was created and evaluated usingperformance data collected from actual plant, literature data, and estimations. Thebiological process is based on the Sobacken biogas plant and Läckeby water biogasupgrade plant.The energy from waste reference case with 100 000 ton combustible wastes and30 000 ton biological waste produce 18.4 GWh of 97.5% methane biogas, 62.7 GWheand 220 GWhheat annually. Using the same structure and operation condition, Scenario1 produced 26 GWh of 97.5% methane biogas, 62.7 GWhe and 214.12GWhheat.The second scenario with gasification using gas turbine and steam cycle produce 26GWh of 97.5% methane biogas, 70.1 GWhe and 181.61 GWhheat. The third scenariowith gasification and fuel cell technology produced 26 GWh of 97.5% methanebiogas, 81.7 GWhe and 93.4 GWhheat.The integration of gasification in second and third scenario has affected the heat andelectricity production of the power plant.Considering the heat and power generation on the sustainable perspective, the thirdscenario is the best option for Energy from waste.