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Burning coal to produce electricity is one of the main contributors of carbon dioxide emissions to the atmosphere. This study aims to find out if it is practical and cost-effective to reduce those emissions in NSW by burning waste materials along with the coal, separating the carbon dioxide from the rest of the combustion gases and storing the carbon dioxide deep underground Municipal Solid Waste (MSW), or rubbish, is a combination of many different materials, many of which cannot be burned (such as glass and metal), but also many that can burn. The materials this study is interested in are dry materials that were derived from plants, such as wood and paper waste, as they are easier to burn in a power plant and can be separated more easily than other wastes. When wood and paper are burned, the carbon in them just returns to the atmosphere because it was absorbed from the air when the plants were growing, but if that carbon is separated and stored deep underground, then the amount of carbon dioxide in the atmosphere is reduced. This technology is known as “Bioenergy with Carbon Capture and Storage”, or BECCS. For this study, BECCS involves burning coal along with wood and paper waste to generate electricity, while separating the carbon dioxide, transporting it via pipeline, compressing and storing it deep underground in western NSW, at a well site in the Darling Basin: Mena Murtee-1 in the Pondie Range Trough. We consider implementing this type of BECCS at the three younger coal power plants in NSW where wood and paper could be easily burned: Mt Piper, Eraring and Bayswater. We also consider burning different amounts of waste at each power plant, but even if all available wood and paper waste in NSW was used, it would only amount to about 5% of the fuel burned in those three plants. According to this study, burning paper and wood waste alongside coal reduces the amount of carbon dioxide added to the atmosphere, but produces more ash than burning coal alone. This means it will be necessary to add extra equipment to catch the extra dust before it is released to the atmosphere. If one-tenth of the fuel is wood and paper, carbon emissions are only slightly reduced (less than 3%), but if carbon capture and storage is also implemented (thereby implementing BECCS) then the power plant will only emit about one-fifth of the emissions of a normal coal plant over its whole life, which is similar to the overall emissions of electricity produced by solar panels. BECCS can also completely offset the carbon emissions from coal if more than a third of the fuel burned is wood and paper waste, thereby achieving negative emissions. Although the cost of getting rid of the carbon dioxide becomes lower as more waste is burned, the cost of the electricity is increased, because less electricity is produced. This study concludes that BECCS can help significantly reduce carbon emissions in NSW. Still, it is important to consider other waste sources (for example textiles, garden waste, agricultural waste), as availability of waste is a strong limitation for further use of this technology. |
