Biodiesel as a Substitute for Petroleum-based Diesel Fuel
Biodiesel is derived from plant or animal fat-based oils or their transesterified counterparts. Several studies have found HC and PM benefits from the use of biodiesel, and its lubricity characteristics and renewability are also motivators for its use. Several municipalities and States are considering mandating the use of low levels of biodiesel in diesel fuel.
Description of Analyses
Using existing data, the EPA's biodiesel emissions analysis program sought to quantify the air pollution emission effects of biodiesel for diesel engines that have not been specifically modified to operate on biodiesel. The program examined the emission impacts of biodiesel and biodiesel/diesel blends for both regulated and unregulated pollutants, as well as fuel economy.
- Engine durability
- Renewability/full fuel lifecycle emissions
- Materials compatibility
- Biodiesel production feedstocks or costs
- Fuel storage stability
- Cold flow properties
- Engine/vehicle technology
- Base fuel to which biodiesel is added
- Light versus heavy-duty
- Highway versus nonroad
- Test cycle
- Type of biodiesel
The degree to which these variables were taken into account depended on the amount and type of available data.
- Draft Technical Report: A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions (PDF)(126 pp, 727 K, EPA420-P-02-001, October 2002)