Date of Award
December 2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Chemical Engineering
First Advisor
Bethany Klemetsrud
Abstract
As the energy industry shifts towards a heavier priority on decreasing the environmental impact caused by power plants, an innovation that repurposes existing coal processing facilities has been in high demand. A Techno-Economic Analysis (TEA) that focuses on transporting and co-firing biogas, a renewable fuel obtainable from landfills or through anaerobic digestion, with waste coal, which is a source of pollution in need of remediation, has been conducted to evaluate the benefits of net-negative carbon emissions. ASPEN Plus V14 simulations were constructed and utilized to aid the process estimation for the proposed power plant designs. The Levelized Cost of Electricity (LCOE) and Total As-Spent Costs (TASC) were derived for eight retrofit configurations, which varied biogas flow rates as fuel, and nine greenfield configurations, which varied co-firing gaseous fuel sources and power output. The combination of results from the various cases were then used as the basis for justifying feasibility by providing insight into the economic effects of the process and the state of current market infrastructure that can be utilized. This technology as a retrofit was determined to have a LCOE between $60.1 /MWh and $117.3 /MWh based on varying quantities of biogas co-firing and capture percentages. The effects of this proposed construction on the cost of electricity was further determined to be no larger than as $0.3 /MWh when the revenue accrued through tax credit incentives was considered for qualifying designs, suggesting this technology can be viable through the justification of legislative incentives. As a greenfield construction, the viability of implementing a new powerplant was determined to be strongly influenced by the accessibility to biogas and the cost associated with pipeline construction. Due to the scarcity of biogas currently accessible, the utilization of natural gas was investigated as a co-firing fuel that is readily available with mature infrastructure to support operation. The varying fuel compositions resulted in this technology ranging from $195 /MWh to $242 /MWh in a 100 MW-net configuration and $100.6 /MWh to $126.9 /MWh in a 650 MW-net configuration. The Net Present Value for the designs was determined to be negative for all 100 MW-net configurations and positive for the 650 MW-net designs, ranging from $727 million to $1,617 million. Despite the predicted profitability of the designs, these designs cannot support the operational demands of biogas and thus necessitate natural gas to be viable in today’s market which, while viable, fails to meet the sustainability goals of this study. While this study showed the viability of this technology in several configurations and regions, the accessibility to biogas, and its accompanying infrastructure, is not currently mature enough to be justify this technology as an optimal option for the remediation of waste coal.
Recommended Citation
Hernandez, Marco, "Techno-Economic Analysis Of Biogas Utilization In Refuse Power Plants" (2024). Theses and Dissertations. 6533.
https://commons.und.edu/theses/6533