Sustainability Assessment for the Integration of Solid Oxide Fuel Cell (SOFC) Technologies in Natural Gas Processing Plant

The oil and gas industry generate a significant amount of harmful greenhouse gasses that cause irreversible environmental impacts. The level of influence is worsened by the world’s utter dependence on fossil fuels as its primary source of energy, as well as the low efficiency of energy plants processing such fuels. Utilizing renewable energy sources is the ultimate long-term solution to this problem. However, it cannot be over the night due to technological, economic, and social limitations. Hence, there will be a transitional phase from fossil fuels-based economy to a projected economy based on cleaner energy resources, and natural gas is predicted to play a significant role in such a transition. The primary purpose of this dissertation is to develop a fundamental understanding to enhance operational efficiency and to reduce emissions associated with gas operations by integrating a clean energy conversion system - Solid Oxide Fuel Cell (SOFC). SOFCs have been proven to be highly efficient electrochemical devices that directly convert chemical energy to electricity with the potential to improve system efficiencies. The dissertation focuses on the areas of improvements in a natural gas plant where the integration of SOFC with (i) a boiler, (ii) flare unit, and (iii) PV systems are intensively studied. For the SOFC-Boiler case with 20 MW power generation capacity, almost 40% less fuel is used, through which annual saving of about 160,000 tons of CO₂ eq. is achievable, and the levelized cost of electricity is calculated as 0.049 USD/kWh. For the SOFC-Flare system, 20 MW electricity is generated using 70% of the purge gas with a corresponding annual CO₂ eq. saving of about 60,000 tons. The levelized cost of electricity, in this case, is calculated as 0.03 USD/kWh with a net present value of 30M USD. For the SOFC-PV case, the levelized cost of electricity is found to be 0.11 USD/kWh, where it can even reach as low as 0.04 USD/kWh in the (projected scenario). Overall, SOFC integration into a typical natural gas operation plant is found to reduce emissions significantly. Enabling an effective integration and smarter utilization of SOFC systems at different scales can lead to overall system efficiency improvements. The dissertation outcome encourages the integration of SOFC systems in energy-intensive and highly pollutant oil and gas operations, to convert them into sustainable and greener processes.