Patent ID: 8671699

Claim:
A method for vaporizing a liquefied natural gas stream, the method comprising: a) heating a liquefied natural gas stream in a first heat exchanger via indirect heat exchange with an ambient air stream to thereby produce a warmed, at least partially vaporized natural gas stream and a condensed water stream; b) cooling an exhaust gas stream from a gas turbine in a second heat exchanger via indirect heat exchange with a liquid stream to thereby produce a cooled exhaust gas stream and a first heated liquid stream; c) passing the cooled exhaust gas stream through a NO x removal unit to thereby produce a NO x -depleted cooled exhaust gas stream; d) introducing the NO x -depleted cooled exhaust gas stream into a lower inlet of a quench column; e) immediately subsequent to its withdrawal from the first heat exchanger, introducing the vaporized natural gas stream into a third heat exchanger; f) further heating the vaporized natural gas stream introduced into said third heat exchanger via indirect heat exchange with at least a portion of said first heated liquid stream withdrawn from the second heat exchanger to thereby produce a warmed natural gas product stream having a product temperature of at least 40° F. and a cooled liquid stream; and g) heating said cooled liquid stream withdrawn from said third heat exchanger in said quench column via direct heat exchange contact with said NO x -depleted cooled exhaust gas stream to produce a further cooled exhaust gas stream and a second heated liquid stream, wherein said liquid stream used to cool said exhaust gas stream withdrawn from the gas turbine in said second heat exchanger comprises said second heated liquid stream; and h) adjusting the amount of heat transferred from the first heated liquid stream introduced into said third heat exchanger, wherein said adjusting is carried out to reduce the flow rate of the ambient air stream through said first heat exchanger while still heating said vaporized natural gas stream in the third heat exchanger to the product temperature.