September 15, 2009
Christopher Buehler, PhD, PE from Exponent's Houston office, and Rengie Chan, PhD from Exponent's Bellevue office have published a paper entitled “Greenhouse Gas Emissions: Characterization and Management” that appears in the current (September) issue of Hydrocarbon Processing (HP) in the Special Report on Refining Developments.
Recent developments in US climate change legislation and regulation of greenhouse gases (GHGs) are encouraging refiners to take a serious look at the GHG emissions from their facilities, and to explore strategies to reduce their GHG footprints.
The refining process involves separation and reaction processes that have significant energy requirements that are largely met through the combustion of fossil fuels, resulting in both direct GHG emissions at refineries, and indirect emissions when the energy is imported. Additional GHG emissions are generated from the combustion of accumulated carbon during catalyst regeneration, during hydrogen (H2) production via steam reforming of hydrocarbons, and from numerous other sources and activities throughout the refinery.
Increasingly stringent specifications on the allowable sulfur content in gasoline and diesel fuel have boosted H2 consumption in US refineries, while the processing of heavier crude oil has necessitated additional conversion processes, resulting in greater energy and H2 consumption. With the ongoing trend of heavier and more sour crude oil feeds to US refineries,1 the GHG footprint of refining is expected to increase unless active mitigation steps are taken. Strategies for reducing the refining GHG footprint may include energy efficiency improvements, fuel switching, carbon capture and increasing the share of transportation fuels that have lower life cycle GHG emissions.
The paper is available for download (subscription only) on the Hydrocarbon Processing website.