Fractional distillation of C.sub.2 /C.sub.3 hydrocarbons at optimum pressures

• US 4,430,102 A
• Filed: 11/03/1982
• Issued: 02/07/1984
• Est. Priority Date: 09/04/1981
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Institute (University System of Georgia)
• Original Assignee: Georgia Tech Research Institute (University System of Georgia)
• Inventors: Tedder, Daniel W.
• Primary Examiner(s): Sever, Frank
• Application Number:
  US06/438,935
• Time in Patent Office: 461 Days
• Field of Search: 62/21, 62/24-28, 208/351, 208/DIG. 1, 208/364
• US Class Current: 62/628
• CPC Class Codes: C07C 7/04 by distillation

Abstract

A method of recovering by distillation the separate components of a hydrocarbon gas mixture comprising ethylene, ethane, propylene and propane which comprises separating the ethylene as an overhead from an ethane, propylene and propane bottom in a first distillation tower at from about 500 to about 650 psia, separating ethane as an overhead from a propylene and propane bottom in a second distillation tower at from about 390 to about 520 psia, and separating propylene as an overhead from a propane bottom in a third distillation tower at from about 100 to about 170 psia is disclosed.

A method of separating ethylene and ethane from propylene and propane in a first distillation tower at from about 400 to about 600 psia, separating the overhead product from the first tower in a second tower at from about 600 to about 700 psia to produce ethylene and ethane products, and separating a propylene/propane mixture in a third tower at from about 100 to about 170 psia is disclosed.

The heat for operating the propylene/propane splitter is derived from the cooling water of a heat exchange system or from hot quench tower oil.

Claims

1. Method of optimizing the expense of the recovery of C₂ /C₃ hydrocarbons from a fluid mixture through fractional distillation comprising operating a system of towers in which each tower receives a single feed and produces two effluents and maintaining the pressure of each tower within ±

15 psia of the pressure calculated from formulae;

##EQU2## wherein;

P*=the pressure of each tower in psia

T_FB =tower feed mixture bubble point temperature (°

R) evaluated at 485 psia

T.sub..0.B =tower overhead product mixture bubble point temperature (°

R) evaluated at 485 psia

T_BD =tower bottom product mixture dew point temperature (°

R) evaluated at 485 psia.