I just came across some data regarding what is effectively the cleanest of commercial hydrocarbons - natural gas.
As its transportable form - LNG - this is an increasingly important global commodity. LNG tankers are transporting product from port hubs as far as halfway around the world.
LNG is not, however, so durable a product as one might hope. The gas is chilled to approximately -200ºF/-130ºC (at atmospheric pressure it boils at -260, but it is transported in pressure vessels so a slightly higher temperature is available).
There is, though, always some boil-off. The world's current tanker fleet boil-off average is .15% per day; new ships are achieving .1% and the best ship in the world has achieved .08%.
Now: the average length of trip from the biggest US LNG port - Sabine Pass in Louisiana - is 7,500 miles which, at the industry mean of 14.3 knots, takes 22 days.
This gives us transit boil-off totals of 3.3%, 2.2% and 1.8% given the data above.
All of that raw methane goes straight into the atmosphere. And that's a lot of cow farts.
Some of the above information came from here: The Gas Tankers Lurking at Sea Looking for a Better Deal
As its transportable form - LNG - this is an increasingly important global commodity. LNG tankers are transporting product from port hubs as far as halfway around the world.
LNG is not, however, so durable a product as one might hope. The gas is chilled to approximately -200ºF/-130ºC (at atmospheric pressure it boils at -260, but it is transported in pressure vessels so a slightly higher temperature is available).
There is, though, always some boil-off. The world's current tanker fleet boil-off average is .15% per day; new ships are achieving .1% and the best ship in the world has achieved .08%.
Now: the average length of trip from the biggest US LNG port - Sabine Pass in Louisiana - is 7,500 miles which, at the industry mean of 14.3 knots, takes 22 days.
This gives us transit boil-off totals of 3.3%, 2.2% and 1.8% given the data above.
All of that raw methane goes straight into the atmosphere. And that's a lot of cow farts.
Some of the above information came from here: The Gas Tankers Lurking at Sea Looking for a Better Deal
