Environmental regulations are becoming more stringent in the United States and globally to reduce the climate change and human health impacts of fossil fuel use. This thesis investigates two case studies of current and future environmental regulations by developing a life cycle assessment (LCA) framework to estimate the effect on greenhouse gas (GHG) emissions of 1) an international 0.5% sulfur marine fuel limit, and 2) regional and seasonal variability in U.S. gasoline and diesel specifications.
Additional modelling capability is added to the previously developed Petroleum Refining Life Cycle Inventory Model (PRELIM), which is used together with other public LCA tools including OPGEE: the Oil Production Greenhouse Gas Emissions Estimator and The Greenhouse Gases, Regulated Emissions and Energy Use in Transportation Model (GREET). For PRELIM, empirical correlations from the literature are used to expand the product slate options and user inputs that are available, and model outputs such as product specifications are added.
Using hydrotreated residual marine fuel, distillate marine fuel or unhydrotreated residual marine fuel with on-board scrubbers to comply with 0.5% S marine fuel affect life cycle GHG emissions by only 2-4% from current typical operations, while using LNG engines or biodiesel blending reduce life cycle GHG emissions by 8% and 51% respectively. A life cycle cost analysis is used to compare economic viability of each option.
Gasoline and diesel specifications generally contribute less to refining GHG emissions than crude quality and refinery configuration. However, variability in cetane number is the one exception which contributes largely to refining GHG emissions when comparing across the extremes of cetane standards that currently exist in the U.S.
The outcome of this research provides insights into the magnitude and variability of life cycle GHG emissions as a result of downstream environmental regulations. It provides value to industry, policy makers, consumers and academics who wish to understand the economic, environmental and social trade-offs associated with these environmental regulations and their potential compliance options.