Alternative Fuels and Air Pollution

Kim Brady

EAS 6792

Types of Alternative Fuels

Ethanol* Biodiesel – produced from vegetable oils or

animal fats Natural Gas – mixture of hydrocarbons (CH4) Propane – by-product of natural gas processing

and crude oil refining Hydrogen – produced from fossil fuels, biomass,

electrolyzing water Electricity – power electric and plug-in hybrids Methanol – CH3OH

US Dept of Energy

Ethanol

Renewable fuel produced from starch-and sugar based feedstock (corn and sugar cane) or cellulosic feedstock (grass, wood, crop residues, etc.)

Produced in blends: E10, E15-20, E85 High octane, 34% less energy than

gasoline

US Dept of Energy

Hamelinck, Carlo and Andre Faaij (2005)

Ethanol Controversy

Space intensive Increased need for farmland Are rainforests at risk?

Impact on global food prices “Food vs Fuel” debate

Depletes groundwater reserves

Increased use of fertilizers Viable long term solution?

US Dept of Energy

Case Study (Hill, et al.)

Looks at GHG contributing to climate change and PM2.5

Consider 3 methods of corn ethanol: using natural gas, coal, and corn stover

4 methods of cellulosic ethanol: corn stover, switchgrass, prairie biomass, Miscanthus

Hill, Jason, et al. (2008)

Hill, Jason, et al. (2008)

Hill, Jason, et al. (2008)

US Dept of Energy

Conclusion

Emissions from corn ethanol up for debate However, corn ethanol emissions would improve

if advances in technology were applied Reduced fertilizers Increase crop yields Improved conversion processes

Cellulosic ethanol appears to lower GHG and PM2.5 emissions when compared to gasoline

Emerging Alternative Fuels…

Biobutanol Biogas Biomass to Liquids Coal to Liquids Fischer-Tropsch Diesel Gas to Liquids Hydrogenated-Derived Renewable Diesel P-Series Ultra-Low Sulfur Diesel

For more info go to: http://www.afdc.energy.gov/afdc/fuels/