Liquefied natural gas (LNG) often has a higher heating value and is richer in heavier hydrocarbons than is permitted by typical natural gas pipeline specifications. The FLUT 1 regasification configuration, for which patents are pending, processes a wide range of LNG compositions to produce natural gas meeting pipeline standards. Thus, allowing
importers to purchase LNG from the most economical source. Electric power, LPG, and LNG and CNG vehicle fuels can be produced.
LNG from storage is pressurized by LNG pump P1 to about 500 psig. Approximately 50% of this LNG is sent to the demethanizer (V1) as reflux. LNG power cycle pump P2, pressurizes the remaining LNG. This high-pressure LNG is used as a working fluid to recover low level heat from the power plant flue gas.
High-pressure LNG from P2 is heated in two heat exchangers, E1 and E2. The reflux condenser E1 in the deethanizer (V2) overhead increases the LNG temperature to –190°F. Using LNG to satisfy the fractionation process refrigeration requirement eliminates a costly propane refrigeration system.
LNG leaving the reflux condenser is heated to 300°F and vaporized in glycol-water exchanger E2, using waste heat from the power plant flue gas. A glycolwater heat medium is used to transfer heat between the power block and the LNG regasification facility.
This indirect heat exchange system isolates the LNG from direct heat exchange with the power block. A backup heat source can use this heat transfer fluid to vaporize the LNG if the power plant is not in operation.
Possible backup heat sources include a fired heater or duct firing of the waste heat recovery units. Hot LNG vapor is then expanded in EP1 to produce power. The low temperature of the LNG working fluid results in a highly efficient power cycle.
The process can recover up to 99% of the propane and over 90% of the ethane in LNG. For a 1.2 billion scfd integrated LNG regasification power plant facility, the total power produced is 541 MW vs. 474 MW for a non-integrated power plant. 37,700 bpd of ethane, 51,200 bpd of LPG, and 1,070 million scfd of 999 Btu/scf HHV pipeline gas are also produced.
Fluor also has a process option, FLUT 2, that produces low cost vehicle grade LNG and CNG along with additional power.
Licensor: Fluor Enterprises, Inc.
