Q$5)$ US residents consume roughly $10$ million barrels per day of gasoline for transportation fuel.

a$)$ Using the ethanol yields projected to be attainable from advanced fermentation

technology in the table below, how many acres would need to be devoted to cellulosic

biomass production to supply $10\%$ of the miles traveled on gasoline using fermentation

ethanol as the automotive fuel? Hint: Is ethanol provide the same fuel economy as

gasoline? Compare your answer with the total area of Missouri, and if Missouri is smaller

than this area, then add the area of states that border Missouri $($and if needed, then add the

areas of states that are next$-$nearest$-$neighbors to Missouri$)$ in order to more descriptively

illustrate the area needed.

Data on Land Availability and Product Yields for Production of Ethanol by Fermentation of Corn or

Cellulosic Biomass

Federally idled US cropland

Possibly available for energy crops

Ethanol yield from fermentation of cellulosics, advanced technology

Ethanol yield from cellulosics by land area, at $8\mathrm{.}4$ tons$/$acre

Ethanol yield from corn fermentation by land area $($large plant$)$

$60$ million acres ${?}^a$

$35$ million acres ${?}^a$

$107\mathrm{.}7$ gallons$/$ton ${?}^a$

$905$ gallons$/$acre ${?}^a$

$275$ gallons$/$acre ${?}^b$

${?}^a$ Source: Lynd $(1996).$

${?}^b$ Source: Pimentel $(1991).$

b$)$ If ethanol displaces gasoline as stated in a$),$ are $CO2$ emissions reduced, increased, or

remain unchanged? Please show calculations and use a kilogram mass basis for $CO2.$