Union Carbide Corporation

Praxair Technology, Inc.

Thomas C Hanson

Joseph Alfred Weber

Theodore F Fisher

Dante Patrick Bonaquist

Ravindra F Pahade

Leslie Charles Kun

Solomon A Dadebo

Frank J Klein, Iii

Michael D Jordan

A method of controlling a distillation column having control valves to control both reflux and the vapor rate within the column. In accordance with the present invention, a temperature sensed in a top section of the column is magnified and utilized within the model predictive controller so that control is more aggressive as temperatures increase beyond a threshold temperature. Additionally, in the distillation column, or in fact in any other system in which two or more manipulated variables control two or more common controlled variables, special modeling techniques are utilized to make controller tuning easier to accomplish. In such modeling techniques, each manipulated variable is assumed to be able to have an effect on a controlled variable by a single step response model and other step response models are utilized so that the other manipulated variable(s) that also would have an effect on the same controlled variable are taken into account by the controller as feed forward variables.

Model predictive control having application to distillation

A method for producing two or more products from a production site such as an air separation plant to satisfy a given demand for each of the products in which energy consumption and the rate of product production are correlated so that product production may be determined from a conventional mixed integer linear programming model the solution of which will provide an optimum production schedule for producing product to meet total product demand at minimum energy cost over a given time horizon.

Chemical process optimization method

Statistical process control system for an air-separation plant using off-line and on-line computer means to define control chart limits, trend thresholds and dynamic models for use with on-line process variable data for determination of statistical process control.

Statistical process control for air separation process

A process to produce methane gas product with reduced product compression requirements comprising pumping liquid methane from a cryogenic nitrogen rejection plant to a high pressure thereby utilizing available excess refrigeration, and rewarming the pumped liquid methane product against incoming process streams.

Process to produce high pressure methane gas

A process to produce liquid cryogen wherein subcooled supercritical liquid is expanded without vaporization and a portion thereof is used to carry out the subcooling by vaporization under reduced pressure.

Process to produce liquid cryogen

A process to produce cold helium gas suitable for use as a feed to a helium liquifier comprising employing refrigeration from a nitrogen rejection unit to reduce the temperature of the helium gas just prior to its passage to the liquifier thus enabling a reduction in the liquifier energy requirement.

Process to produce cold helium gas for liquefaction

A process to produce helium gas from a feed to a nitrogen rejection unit comprising employing refrigeration from the nitrogen rejection unit to increase the recovery of helium by cooling crude helium prior to further processing.

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Buffalo, NY, United States of America

Thomas C Hanson