Method for ethane liquefaction with demethanization

A method for the liquefaction of ethane using a mixed refrigerant refrigeration cycle with demethanization, the method comprising the steps of:

• providing an ethane feed under pressure, wherein the ethane feed is comprised primarily of ethane, wherein the ethane further comprises methane;
• cooling the ethane feed to a first temperature in a first heat exchanger, wherein the first temperature is sufficiently warm to prevent ice formation;
• removing water from the ethane feed upstream or downstream the first heat exchanger to form a dry ethane feed;
• splitting the dry ethane feed into a first portion and a second portion;
• cooling the first portion of the dry ethane feed in a main heat exchanger to form a partially cooled ethane stream;
• introducing the partially cooled ethane stream into a first intermediate location of a distillation column under conditions effective to cause an ethane rich liquid to accumulate near the bottom portion of the distillation column and a methane rich gas to accumulate near the top portion of the distillation column;
• expanding the second portion of the dry ethane feed and introducing the expanded second portion of the dry ethane feed to a phase separator;
• withdrawing a top gas from the top of the phase separator, cooling the top gas in the main heat exchanger, and then introducing the top gas into a second intermediate location of the distillation column, wherein the second intermediate location is located at least one tray above the first intermediate location;
• withdrawing a bottom liquid from the bottom of the phase separator and then introducing the bottom liquid into a third intermediate location of the distillation column, wherein the third intermediate location is located at least one tray below the first intermediate location;
• withdrawing an ethane stream from the bottom portion of the distillation column;
• and
• cooling the ethane stream from the bottom portion of the distillation column to produce liquid ethane product by exchanging heat with a mixed refrigerant refrigeration cycle within the main heat exchanger.