Reid Vapor Pressure determination and control in fractional distillation
AssigneePhillips Petroleum Company
InventorsEdwin D. Soderstrom, III, Terrence A. Davis
Life of this patent
Estimating the term…
Abstract
The Reid Vapor Pressure of a hydrocarbon mixture consisting essentially of hydrocarbons selected from the same series is determined based on the actual temperature and vapor pressure of the hydrocarbon mixture. The thus determined Reid Vapor Pressure may be compared to a set point for the Reid Vapor Pressure with the results of the comparison being utilized to maintain the actual Reid Vapor Pressure substantially equal to the desired Reid Vapor Pressure.
Claims6
Apparatus comprising:
- a fractional distillation column;
- means for providing a feed stream to said fractional distillation column, wherein said feed stream consists essentially of a mixture of hydrocarbons selected from the same series;
- means for providing heat to said fractional distillation column;
- means for withdrawing a bottoms product stream from said fractional distillation column;
- means for establishing a first signal representative of the temperature of said bottoms product stream;
- means for establishing a second signal representative of the vapor pressure of said bottoms product stream;
- means for establishing a third signal representative of the actual Reid Vapor Pressure of said bottoms product stream in response to said first and second signals, wherein an analysis of said bottoms product stream is not utilized to determine said Reid Vapor Pressure;
- means for establishing a fourth signal representative of the desired Reid Vapor Pressure of said bottoms product stream;
- means for comparing said third signal and said fourth signal and for establishing a fifth signal which is responsive to the difference between said fourth signal and said fifth signal;
- and
- means for manipulating the rate at which heat is supplied to said fractional distillation column in response to said fifth signal to thereby maintain the actual Reid Vapor Pressure for said bottoms product stream substantially equal to the desired Reid Vapor Pressure represented by said fourth signal.
A method for controlling the Reid Vapor Pressure of the bottoms product stream withdrawn from a fractional distillation column to which a feed stream consisting essentially of a mixture of hydrocarbons selected from the same series is provided, said method comprising the steps of:
- establishing a first signal representative of the temperature of said bottoms product stream;
- establishing a second signal representative of the vapor pressure of said bottoms product stream;
- establishing a third signal representative of the actual Reid Vapor Pressure of said bottoms product stream in response to said first and second signals, wherein an analysis of said bottoms product stream is not utilized to determine said Reid Vapor Pressure;
- establishing a fourth signal representative of the desired Reid Vapor Pressure of said bottoms product stream;
- comparing said third signal and said fourth signal and establishing a fifth signal which is responsive to the difference between said fourth signal and said fifth signal;
- and
- manipulating the rate at which heat is supplied to said fractional distillation column in response to said fifth signal to thereby maintain the actual Reid Vapor Pressure for said bottoms product stream substantially equal to the desired Reid Vapor Pressure represented by said fourth signal.
Dependencies are inferred from the claim text.