Natural gas is extracted and purified from gas streams associated with oil and g

Question

Natural gas is extracted and purified from gas streams associated with oil and gas wells. It consists primarily of methane, CH4. Because menthane liquifies only at very low temperatures and high pressures, it is normall distributed through gas lines across the country that terminate at homes and businesses. The New York State Energy Research and Development Authority (www.nyserda.org), reports that the average price in New York State for natural gas is $14.69/1000 cubic feet. Even though the amount of gas used is measured volumetrically and therefore depends on the pressure and temperature of the gas, variations in the temperature and pressure appear not to be of concern to either the sellers or buyers of natural gas.

Therefore, in your calculations assume that standard thermodynamic conditions apply (1 atm pressure, 298K). Use what you have learned in this activity to estimate the fuel value, energy density, economic value, and environmentl value of natural gas. In your calculations, use standard enthalpies of formation to estimate the enthalpy of combustion, and use the ideal gas law to estimate the density of methane. For each of the four merit criteria, identify whether methane ranks higher or lower than any of the other fuels analyzed in this activity.

Please be very specific when you are explaining your answer.  If it isn't specific you will not be chose as best answer. Thank you!

Explanation / Answer

HEating value of methane = HHV(C) +2*HHV(H2) -[methane bond dissociation energy]= 393.5 + 4(141.8)

= 960.7 KJ/mol

In the given conditions, 1 mol of gas occupies 22.4 lit

Energy density = 960.7 KJ/22.4 lit = 42.9 KJ/lit = 42.9MJ/m3 = 42.9/35.31=1.215 MJ/cubic ft

Economic value = 14.69/1.215 $/MJ = 12.1$/MJ energy

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