Removing heavy hydrocarbons to prevent defrost shutdowns in LNG plants

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 an upstream heavy hydrocarbon stream using an upstream piping low point drain line, wherein the upstream 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,
• wherein the contaminant is selected from a group consisting of:
• a lubrication oil, an additive in a lubrication oil additive package, a plurality of C20+ compounds, a plurality of C40+ compounds, an additive which causes conglomeration of hydrocarbons, and combinations of the same.