Heat integration for heating liquid and two-phase hydrocarbon streams

An apparatus comprising:

• a flash drum or a first column having an inlet and an outlet;
• a first heat exchanger having a first inlet, a first outlet, a second inlet, and a second outlet, the first inlet being in downstream fluid communication with the outlet of the flash drum or the first column;
• a fired heater, or an electric heater or furnace, or combinations thereof having an inlet and an outlet, the inlet of the fired heater, or the electric heater or furnace, or combinations thereof being in downstream fluid communication with the first outlet of the first heat exchanger;
• a two phase separator having an inlet, a vapor outlet, and a liquid outlet, the inlet of the two phase separator being in downstream fluid communication with the outlet of the fired heater, or the electric heater or electric furnace, or combinations thereof;
• a second heat exchanger having a first inlet, a first outlet, a second inlet, and a second outlet, the first inlet of the second heat exchanger being in downstream fluid communication with the vapor outlet of two phase separator, the second inlet of the second heat exchanger being in downstream fluid communication with a source of a process stream;
• the second inlet of the first heat exchanger being in downstream fluid communication with the first outlet of the second heat exchanger;
• a manifold having a first inlet, a second inlet, and an outlet, the first inlet of the manifold being in downstream fluid communication with the second outlet of the first heat exchanger, the second inlet of the manifold being in downstream fluid communication with the liquid outlet of the two phase separator;
• and
• a second column having an inlet and an outlet, the inlet of the second column being in downstream fluid communication with the outlet of the manifold;
• a first heater or heat source in thermal communication with a line between the vapor outlet of the two phase separator and the first inlet of the second heat exchanger;
• a second heater or heat source in thermal communication with a line between the first outlet of second heat exchanger and the second inlet of the first heat exchanger.

A process for preheating a feed stream to a second column, the feed stream comprising a stream from a flash drum or a stream from a first column, comprising:

• heating the feed stream in a fired heater, or an electric heater or furnace, or combinations thereof forming a heated feed stream comprising a mixture of liquid and vapor;
• separating the heated feed stream in a two phase separator into a vapor stream and a liquid stream;
• heating the vapor stream forming a heated vapor stream;
• heat exchanging the heated vapor stream with a first process stream in a first heat exchanger forming a cooled vapor stream and a heated process stream;
• combining the cooled vapor stream from the heat exchanger and the liquid stream from the two phase separator forming a combined vapor and liquid stream;
• and
• introducing the combined vapor and liquid stream to the second column.