摘要：The feasibility of meeting California's low carbon fuel standard (LCFS) using ethanol from
various feedstocks is assessed. Lifecycle greenhouse gas (GHG) emissions, direct
agricultural land use, petroleum displacement directly due to ethanol blending, and
production costs for a number of conventional and lignocellulosic ethanol pathways are
estimated under various supply scenarios. The results indicate that after considering
indirect land use effects, all sources of ethanol examined, except Midwest corn
ethanol, are viable options to meet the LCFS. However, the required ethanol
quantity depends on the GHG emissions performance and ethanol availability. The
quantity of ethanol that can be produced from lignocellulosic biomass resources
within California is insufficient to meet the year 2020 LCFS target. Utilizing
lignocellulosic ethanol to meet the LCFS is more attractive than utilizing Brazilian
sugarcane ethanol due to projected lower direct agricultural land use, dependence on
imported energy, ethanol cost, required refueling infrastructure modifications and
penetration of flexible fuel E85 vehicles. However, advances in cellulosic ethanol
technology and commercial production capacity are required to support moderate- to
large-scale introduction of low carbon intensity cellulosic ethanol. Current cellulosic
ethanol production cost estimates suffer from relatively high uncertainty and
need to be refined based on commercial scale production data when available.
