Question

Suppose 3 large tankers containing liquefied natural gas (LNG) leave a gas export terminal every day. The methane is stored in liquid form in the tankers, at -260°F, in a volume 600 times smaller than would be needed in gas form, at STP (Standard Temperature and Pressure: 0°C temperature, 1 atm pressure). Suppose the average tanker at this port carries an amount of LNG equivalent to 125 million cubic meters of methane at STP. The energy content of methane is 38.5 MJ per cubic meter at STP. How many gigawatts (GW) of power does this daily flow of natural gas through the port represent?

Answer 1

Number of Tankers = 3         

            T of gas is   -260 deg F

Volume of gas 6.00E+02 times smaller than STP

Amount of gas 125 million cubic meter per tanker

Energy contain 38.5 MJ per cubic meter

Solution:

Amount of LPG in three tankers

= 3 tanker x 125 million cubic meter

=375 million cubic meter

Amount in cubic meter

=375 Million cubic meter x 1 E6 Cubic meter / 1 Million cubic meter

= 375000000 m³

We know

Power = Energy/time

Calculate for 1 day:

Energy/day:

= 375000000 m³ x 38.5 MJ/ m³

= 14437500000           MJ/day

Watt = J / s

Therefore we need to convert this into J /s

Power = 14437500000 MJ/day x (1E6 J / 1 MJ) x ( 1 day / 86400 second)

=1.67101E+11 J/second

Power in G watt

1 Gwatt = 1E9 watt

=1.67101E+11 watt x 1 Gwatt/ 1 E9 watt

=167 Gwatt.

So the Power is 167 Gwatt.