Personal mobility is a key hallmark of our quality of life in the United States.

Question

Personal mobility is a key hallmark of our quality of life in the United States. Consider the data in the table below: Annual Average Personal Transportation Data for the U.S. Automobiles (Cars) 27.5 mpg (average) 1.6 persons per automobile 6 mpg diesel (estimated) 30 persons per bus Buses Other data and conversion Factors: 150,000 BTU/gallon gasoline*, 163,000 BTU/gallon diesel* 4.3+19.4 lb CO2 equivalents/gallon gasoline (production + combust.) 3.6+22.2 lb CO2 equivalents /gallon diesel (production + combust.) * includes production energy and feedstock energy over the fuel life cycle. a) Define an appropriate functional unit for a comparison of the bus and car transportation from the table above for personal mobility. (10 Points) b) Calculate the gallons of fuel needed to satisfy the transportation functional unit, and then convert gallons to energy (BTUs per functional unit). Also, calculate the CO2 emissions per functional unit (Ub CO2 emitted / functional unit). (10 Points)

Explanation / Answer

a) The objective of any passenger transportation mode is transporting the maximum number of passengers and the distance. Hence, an appropriate functional unit for a comparison of the transportation is the number of people transported per distance(mile).

b) Automobiles -

Transports- 1.6 persons/automobile

Mileage - 27.5 miles/gallon gasoline/automobile

15000 BTU/gallon gasoline.

To find -

BTU/functional unit =>BTU/(person-mile)

1/1.6/27.5 = 0.023 gallons/person-mi.

BTU/person-mi = 150000*0.23 = 3409 BTU/person-mi

To find CO2 emmited/person-mi -

we multiply BTU/person-mi and CO2 equivalents/gasoline

CO2 emmitted/person-mi = 3409*(4.3+19.4) = 0.55 lb CO2equivalents/person-mi

Bus -

Transports- 30 persons/bus

Mileage - 6 miles/gallon diesel/bus

163000 BTU/gallon diesel.

To find -

BTU/functional unit =>BTU/(person-mile)

1/30//6 = 0.0056 gallons/person-mi.

BTU/person-mi = 163000*0.056 = 906 BTU/person-mi

To find CO2 emmited/person-mi -

we multiply BTU/person-mi and CO2 equivalents/diesel

CO2 emmitted/person-mi = 906*(3.6+22.2) = 0.14 lb CO2equivalents/person-mi

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.