A method is provided for determining a state of a distillation column having multiple column stages for separating a feed fluid stream into individual fluid components. The state is determined by means of a model in a manner dependent on pressure differences prevailing between adjacent column stages. In the model, both gaseous and liquid flows between adjacent column stages are brought about by the pressure differences prevailing between adjacent column stages. A substance quantity flow characterizing gaseous flow between two column stages is given by {dot over (N)}.sub.V.Math.R.sub.V=C.sub.V.Math.Δp.sub.V. A substance quantity flow characterizing liquid flow between two column stages is given by {dot over (N)}.sub.L.Math.R.sub.L=C.sub.L.Math.Δp.sub.L. Δp.sub.V,L is a total pressure difference between two adjacent column stages. R.sub.V,L is a coefficient of resistance between two adjacent column stages and C.sub.V,L is a conductance value of flow between two adjacent column stages.

Systems and methods for controlling a natural gas production system in an upset scenario, and/or during startup of turbo-expander system are disclosed. In one embodiment, a method of operating a Joule-Thomson valve of a natural gas production system includes determining an upset event within the natural gas production system, obtaining a flow rate through at least one expander prior to the upset event, and calculating, based on the flow rate, a percent opening of the Joule-Thomson valve. The method further includes opening the Joule-Thomson valve to the percent opening, controlling the Joule-Thomson valve by a PID controller in a set point tracking mode for a period of time, and controlling the Joule-Thomson valve by the PID controller in an automatic mode.

A set of process equipment for use in an enhanced oil recovery (EOR) process comprises first piping, a dehydrator, second piping, and a natural gas liquids recovery column. The first piping is configured to receive a wet carbon dioxide recycle stream from a recovery well. The dehydrator is configured to receive the wet carbon dioxide stream from the first piping and configured to dehydrate the wet carbon dioxide recycle stream using ethylene glycol to produce a dry carbon dioxide recycle stream. The second piping is configured to receive the dry carbon dioxide recycle stream from the dehydrator. The natural gas liquids recovery column is configured to receive the dry carbon dioxide recycle stream from the second piping and configured to separate the dry carbon dioxide recycle stream into a carbon dioxide reinjection stream and a natural gas liquids stream.

A method for configuring a control system for a process plant using a dynamic model of the process plant, the dynamic model being based on at least one of thermo fluidic correlations, thermo dynamic correlations, phenomenological correlations, and equations, and being based on geometry and/or topology of components of the process plant, the dynamic model receiving process parameters as input values, the dynamic model being adapted to represent a transition from one to another state of the process plant and the dynamic model covering the entire operating range of the process plant wherein the dynamic model is used in an offline mode, in which the dynamic model is used in stand-alone fashion, wherein, based on input and output values of the dynamic model, a behaviour of the process plant is predicted, and wherein, based on the predicted behaviour of the process plant, the control system is configured.

A method for operating a process plant using a dynamic model of the process plant, the dynamic model being based on at least one of thermo fluidic correlations, thermo dynamic correlations, phenomenological correlations, and equations, and being based on geometry and/or topology of components of the process plant, the dynamic model receiving process parameters as input values, the dynamic model being adapted to represent a transition from one to another state of the process plant, wherein the dynamic model is used in an online mode, in which the dynamic model is used in parallel with the operation of the process plant, wherein signals from a control system of the process plant, the signals representing values of at least one first process parameter, are received and fed into the dynamic model.

Provided is a method of designing a heat exchanger group being installed in a processing plant and having multiple ACHEs. In a first step, at least one design variable relating to ACHE design and the number of installed ACHEs are set as variable parameters, and a variable range and a change unit of each of the variable parameters are set. In a second step, a design value of the ACHE, which includes a value of a design variable non-selected as the variable parameter, is set. In a third step, Pareto solutions for at least two objective functions selected from an objective function group consisting of an installation length of the heat exchanger group, a total heat transfer area of heat transfer tubes, and total power consumption of fans are calculated by using a computer while the variable parameter are changed.

A supply quantity adjustment device 500 comprises: a total demand quantity calculation unit 502 that calculates a total demand quantity used at a supply destination, based on plant information; an excess/deficit information setting unit 503 that compares the total demand quantity and a flow rate set value and sets a first calculated pressure value; a backup coefficient setting unit that sets a backup coefficient set value based on a reference gasholder pressure, the first calculated pressure value, a reference backup pressure set value, and a measured gasholder pressure value; and a production coefficient setting unit that compares a production pressure set value obtained by adding the reference gasholder pressure and a first pressure output value with the measured gasholder pressure value, and sets a production coefficient so as to modify a variation in the quantity of product gas produced by the air separation apparatus.

A method for identifying a trajectory for each vehicle involved in an accident. The method begins by plotting on a Cartesian Coordinate Plane GNSS locations corresponding to a vehicle involved in the accident. Next, the method identifies GNSS locations on the Cartesian Coordinate Plane where the vehicle was speeding. Next, the method marks those GNSS locations on the Cartesian Coordinate Plane where the vehicle involved in the accident was skidding. The process of plotting and identifying speeding as well as skidding is repeated for all vehicles involved in the accident. The Cartesian Coordinate plane then having all vehicle trajectories residing therein is sent to an output device.

A method for recovering natural gas liquids from a recycle stream having natural gas liquids includes receiving a carbon dioxide recycle stream that comprises carbon dioxide, natural gas, and the natural gas liquids. The carbon dioxide recycle stream is separated into a purified carbon dioxide recycle stream and a natural gas liquids stream. The purified carbon dioxide recycle stream comprises the carbon dioxide and the natural gas, and the natural gas liquids stream comprises the natural gas liquids. In another embodiment, a system comprises piping and a separator. The piping is configured to receive a recycle stream, and the separator is coupled to the piping and is configured to separate the recycle stream into a purified recycle stream and a natural gas liquids stream.

A method includes receiving input corresponding to a proposed configuration of a liquefaction facility and identifying a plurality of components utilized to produce LNG and/or LIN at the facility. The method includes determining an alternative configuration that is different from the proposed configuration. Determining the alternative configuration may include identifying resources accessible to a proposed location for the liquefaction facility and whether at least one of the resources accessible to the proposed location corresponds to a resource generated by a component identified by the proposed configuration, and determining whether to omit at least one component of the plurality of components identified by the proposed configuration. The method includes omitting the at least one component from the alternative configuration, and generating a report based on the proposed configuration and the alternative configuration. The report includes information indicating a difference between the proposed configuration and the alternative configuration.