Exercise 8

Question 1

Why is natural gas a good alternative fuel?

Answer 1

• Have high octane number which result in engine operating in high compression rate, which result in high efficency.
• Low CO2 emissions
• Very available fuel

Question 2

Why is natural gas not a good alternative fuel

Answer 2

• Low energy density
• Low engine volumetric eff if pre-mixed
• Need for large pressurized fuel tanks
• Longer time needed for refueling