Removing heavy hydrocarbons to prevent defrost shutdowns in lng plants
AssigneeCheniere Energy, Inc.
InventorsHamish David William Horne, Scott Oliver, Timothy King Jordan, Matthew Peter Henderson
Life of this patent
Estimating the term…
Abstract
Embodiments provide a method for preventing shutdowns in LNG facilities by removing heavy hydrocarbons from the inlet gas supply. According to an embodiment, there is provided an LNG facility treating pipeline quality natural gas that is contaminated with lubrication oil and low concentrations of heavy hydrocarbons. Due to contamination, the behavior of the pipeline quality natural gas is not properly predicted by thermodynamic modeling. In an embodiment, heavy hydrocarbons are removed by a drain system in a heat exchanger. In an embodiment, heavy hydrocarbons are removed by a treatment bed.
Claims19
A method for preventing heat exchanger operation loss by removing contaminants, the method comprising the steps of:
- introducing a natural gas stream to an LNG facility, wherein the natural gas stream has been transported long distances in pipelines requiring compression, such that the natural gas has come into contact with a lubrication oil, wherein the lubrication oil comprises a contaminant, and wherein the natural gas stream comprises methane, ethane, and a plurality of heavy hydrocarbon species;
- reducing the temperature of the natural gas stream in a heat exchanger process unit such that the contaminant in the lubrication oil allows for a conglomeration of the heavy hydrocarbon species;
- and
- removing the conglomeration of the heavy hydrocarbon species from the heat exchanger process unit through one or more drains, such that the conglomeration of the heavy hydrocarbons is removed preventing a blockage in the heat exchanger process unit, wherein the blockage would require a defrost to remove.
A method to remove heavy hydrocarbons to prevent maintenance shutdowns at an LNG facility treating pipeline quality natural gas, the method comprising the steps of:
- providing a natural gas stream wherein the natural gas stream comprises methane, ethane, and heavy hydrocarbons;
- splitting the natural gas stream to generate a heat exchanger feed stream and a bypass portion;
- controlling an amount of the bypass portion by a bypass valve;
- passing the bypass portion through the bypass valve generating a bypass stream;
- reducing the temperature of the heat exchanger feed stream in a heat exchanger;
- removing a heat exchanger outlet stream from the heat exchanger, wherein the heat exchanger outlet stream is at a lower temperature than the heat exchanger feed stream;
- removing a downstream heavy hydrocarbon stream from a downstream drain line, wherein the downstream heavy hydrocarbon stream comprises heavy hydrocarbons that have been congealed due to a contaminant in the natural gas stream;
- passing the heat exchanger outlet stream through a heat exchanger outlet flow control valve generating a cooled natural gas stream;
- and
- introducing the cooled natural gas stream to the bypass stream to generate a combined outlet stream.
A method for removing heavy hydrocarbons from pipeline quality natural gas at an LNG facility, the method comprising the steps of:
- introducing a bed feed stream to a treatment bed, wherein the bed feed stream comprises methane, ethane, heavy hydrocarbons, and a contaminant, and further wherein the treatment bed comprises an absorbent material operable to remove heavy hydrocarbons from the bed feed stream;
- absorbing heavy hydrocarbons from the bed feed stream in the treatment bed, such that heavy hydrocarbons accumulate in the absorbent material;
- removing a treated natural gas stream from the treatment bed;
- generating an LNG feed from the treated natural gas stream;
- and
- introducing the LNG feed to an LNG plant, the LNG plant operable to process and liquefy natural gas generating a liquefied natural gas stream.
Dependencies are inferred from the claim text.