Apparatus for ethane liquefaction with demethanization

An apparatus for the liquefaction of ethane using a mixed refrigerant refrigeration cycle with demethanization, the apparatus comprising:

• a conduit configured to provide an ethane feed under pressure, wherein the ethane feed is comprised primarily of ethane, wherein the ethane further comprises methane;
• a first cooler configured to cool the ethane feed to a first temperature in a first heat exchanger, wherein the first temperature is sufficiently warm to prevent ice formation;
• a dryer system configured to remove water from the ethane feed upstream or downstream the first heat exchanger to form a dry ethane feed;
• means for splitting the dry ethane feed into a first portion and a second portion;
• a main heat exchanger in fluid communication with the means for splitting the dry ethane, wherein the main heat exchanger is configured to cool the first portion of the dry ethane feed to form a partially cooled ethane stream;
• a distillation column having a top section, an intermediate section, and a bottom section, wherein the intermediate section of the distillation column is in fluid communication with the main heat exchanger such that the distillation column is operable to receive the partially cooled ethane stream into the first intermediate location of the 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;
• an expansion device configured to expand the second portion of the dry ethane feed;
• a phase separator in fluid communication with the expansion device, such that the phase separator is configured to receive the expanded second portion of the dry ethane feed;
• a top gas conduit configured to transfer a top gas from the top of the phase separator to the heat exchanger, such that the top gas is cooled in the main heat exchanger;
• a cooled top gas conduit in fluid communication with the heat exchanger and the distillation column, such that the cooled top gas conduit is configured to transfer the cooled 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;
• a bottom liquid conduit in fluid communication with the phase separator and the distillation column, the bottom liquid conduit being configured to transfer a bottom liquid from the bottom of the phase separator to a third intermediate location of the distillation column, wherein the third intermediate location is located at least one tray below the first intermediate location;
• a bottom conduit in fluid communication with the bottom section of the distillation column and the heat exchanger, such that the heat exchanger is configured to receive the ethane rich liquid from the distillation column;
• and
• a mixed refrigerant refrigeration cycle configured to provide refrigeration used to cool the ethane rich liquid to produce a liquid ethane product.