Techno-Economic Analysis and GHG Emissions’ Footprints of Solvent-steam-based Bitumen Extraction

  • Author / Creator
    Hoque, Mustakimul
  • The oil sands are a critical source of unconventional fossil fuel. The Canadian oil sands are among the world’s largest crude oil deposits. Several oil sands extraction techniques have been developed in recent decades, including solvent-steam based bitumen extraction technology, an emerging process that has the potential to replace new greenfield projects. The solvent-steam process is based on the gravity drainage method, in which a mixture of steam and solvent is used to extract bitumen from a reservoir. The oil sands extraction process is an energy intensive process and results in large amount of greenhouse gas (GHG) emissions. There is a need to develop technologies which can help in the reduction of GHG emissions from oil sands extraction.
    In this study, a process simulation model was developed to assess the economics and GHG footprint of the solvent-steam extraction method for a plant established in Alberta, Canada using natural gas and Alberta’s grid mix electricity as the sources of energy. A capacity of 25,000 barrels per day of bitumen was considered, with hexane as the solvent. Sensitivity and uncertainty analyses were conducted to observe how the supply cost, energy consumption, and GHG emissions of the solvent-steam process change with changes in input parameters. The supply cost in the base case scenario is CAD 55.5/bbl at a 10% internal rate of return. Capital cost, solvent price, and transportation and blending cost affect the supply cost. The supply cost ranges from CAD 53 to 65.4 per bbl.
    The results also showed that energy consumption and associated GHG emissions are 0.92 GJ/bbl and 61.75 kgCO2eq/bbl, respectively. When uncertainty is considered, the energy consumption and GHG emissions range from 0.7 to 1.2 GJ/bbl and 49.7 to 82.6 kgCO2eq/bbl at a 90% confidence level, respectively. The overall GHG emissions are more sensitive to the steam-to-oil ratio (SOR) and heater efficiency compared to the solvent-to-oil ratio (SvOR) and emission factors. The use of natural gas combined cycle (NGCC) and biomass for producing heat and electrical energy was also assessed in order to explore their potential to reduce the GHG emissions of the process. Natural gas used to produce steam and solvent vapor is the prime contributor (97%) to overall GHG emissions. A less emission-intensive source of energy such as biomass to generate heat could reduce emissions by up to 91%. The findings of this study will assist oil sands industries and government in evaluating the economic and environmental feasibility of the solvent-steam bitumen extraction process.

  • Subjects / Keywords
  • Graduation date
    Fall 2023
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.