Process integration for natural gas liquid recovery

A method for recovering natural gas liquid from a feed gas, the method comprising:

• transferring heat from a plurality of hot process streams to a plurality of cold process streams through a cold box, the cold box comprising a plurality of compartments that segment a plate-fin heat exchanger into a plurality of sections, wherein transferring heat from the plurality of hot process streams to the plurality of cold process streams through the cold box comprises transferring heat from one or more of the plurality of hot process streams to one or more of the plurality of cold process streams through each compartment of the cold box, the plurality of hot process streams comprising:
• a feed gas comprising a first mixture of hydrocarbons;
• a dehydrated first chill down vapor from one or more feed gas dehydrators of a natural gas liquid recovery system;
• and
• a second chill down vapor from a second chill down separator of the natural gas liquid recovery system, and the plurality of cold process streams comprising:
• a high pressure residue gas from a third chill down separator of the natural gas liquid recovery system;
• an overhead low pressure residue gas from a de-methanizer column of the natural gas liquid recovery system;
• a de-methanizer reboiler feed from the de-methanizer column;
• and
• a de-methanizer bottoms from the de-methanizer column;
• transferring heat to a refrigeration system through the cold box, the refrigeration system comprising a primary refrigerant loop in fluid communication with the cold box, the primary refrigerant loop comprising a primary refrigerant comprising a second mixture of hydrocarbons;
• separating the feed gas into a liquid phase and a refined gas phase using the first chill down separator;
• and
• removing water from the refined gas phase using the one or more feed gas dehydrators to produce the dehydrated first chill down vapor, wherein transferring heat from the plurality of hot process streams to the plurality of cold process streams through the cold box comprises:
• transferring heat from the dehydrated first chill down vapor to the high pressure residue gas through four of the compartments of the cold box;
• transferring heat from the dehydrated first chill down vapor to the overhead low pressure residue gas through four of the compartments of the cold box;
• transferring heat from the dehydrated first chill down vapor to the de-methanizer reboiler feed through one of the compartments of the cold box;
• and
• transferring heat from the dehydrated first chill down vapor to the de-methanizer bottoms through one of the compartments of the cold box.

A system comprising:

• a first chill down separator;
• a second chill down separator;
• a third chill down separator;
• one or more feed gas dehydrators positioned downstream of the first chill down separator;
• a de-methanizer column;
• a cold box comprising a plurality of compartments that segment a plate-fin heat exchanger into a plurality of sections, each compartment of the cold box configured to transfer heat from one or more of a plurality of hot process streams to one or more of a plurality of cold process streams;
• the plurality of hot process streams, each of the plurality of hot process streams flowing through one or more of the plurality of compartments, the plurality of hot process streams comprising:
• a feed gas comprising a mixture of hydrocarbons;
• a dehydrated first chill down vapor from the one or more feed gas dehydrators;
• and
• a second chill down vapor from the second chill down separator;
• the plurality of cold process streams, each of the plurality of cold process streams flowing through one or more of the plurality of compartments, the plurality of cold process streams comprising:
• a high pressure residue gas from the third chill down separator;
• an overhead low pressure residue gas from the de-methanizer;
• a de-methanizer reboiler feed from the de-methanizer column;
• and
• a de-methanizer bottoms from the de-methanizer column;
• and
• one or more refrigerant streams, each of the one or more refrigerant streams flowing through one or more of the plurality of compartments, wherein the cold box is configured to transfer heat from the dehydrated first chill down vapor to the high pressure residue gas through four of the compartments of the cold box, from the dehydrated first chill down vapor to the overhead low pressure residue gas through four of the compartments of the cold box, from the dehydrated first chill down vapor to the de-methanizer reboiler feed through one of the compartments of the cold box, and from the dehydrated first chill down vapor to the de-methanizer bottoms through one of the compartments of the cold box.