An apparatus for the production of air gases with variable liquid production by the cryogenic separation of air can include a cold box having a heat exchanger, and a system of columns; a pressure monitoring device; and a controller. The cold box can be configured to receive a purified and compressed air stream under conditions effective for cryogenically separating the air stream to form an air gas product. The apparatus may also include means for transferring the air gas product from the cold box to an air gas pipeline. The pressure monitoring device is configured to monitor the pipeline pressure, and the controller is configured to adjust the product pressure of the air gas product coming out of the cold box based upon the pipeline pressure and to further adjust liquid production from the cold box based on the adjusted product pressure.

A method of controlling an industrial gas production facility comprising: receiving time-dependent power data receiving time-dependent operational characteristic data; defining one or more power constraints for the operational parameters of the power network; defining one or more process constraints for the operational parameters of each industrial gas plant; generating, based on the power data, the operational characteristic data, the one or more power constraints and the one or more process constraints, control set point values for the one or more industrial gas plants to achieve a pre-determined production parameter for the industrial gas production facility; and sending the control set point values to a control system to control the one or more industrial gas plants by adjusting one or more control set points of the industrial gas plants to achieve the pre-determined production parameter for the industrial gas production facility.

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.

The present disclosure provides a carbon-based oxygen-enriched combustion method for recirculation of flue gas from a cement kiln. The combustion method includes recirculating the flue gas generated by the cement kiln to a certain degree to concentrate and enrich carbon dioxide in the flue gas of the cement kiln, mixing the carbon dioxide-rich recirculating flue gas of the cement kiln with the pressurized oxygen to obtain the carbon-based oxygen-enriched products, and mixing the carbon-based oxygen-enriched products with the atmospheric-pressure oxygen to obtain carbon-based air which serves as combustion-supporting gas of the cement kiln.

A method of controlling an industrial gas production facility comprising: receiving time-dependent power data receiving time-dependent operational characteristic data; defining one or more power constraints for the operational parameters of the power network; defining one or more process constraints for the operational parameters of each industrial gas plant; generating, based on the power data, the operational characteristic data, the one or more power constraints and the one or more process constraints, control set point values for the one or more industrial gas plants to achieve a pre-determined production parameter for the industrial gas production facility; and sending the control set point values to a control system to control the one or more industrial gas plants by adjusting one or more control set points of the industrial gas plants to achieve the pre-determined production parameter for the industrial gas production facility.

The present disclosure discloses a method for evaluating estimation accuracy of energy consumption per ton in distillation processes, and belongs to the technical field of evaluation of estimation performance of energy consumption per ton in distillation processes. The method includes building a state space model of a distillation process, determining a state estimation model, and obtaining an estimated value of energy consumption per ton in the distillation process according to the state estimation model and the state space model; obtaining an estimated value of a state variable with the optimal overall evaluation using a determined evaluation function, describing interference information making the estimated value deviate from a true value and being reflected in an observed value, and transferring the interference information from the observed value to the estimated value of the state variable to obtain an estimation accuracy of the state variable; and unitizing the interference information affecting the estimated value, and evaluating the estimation accuracy of energy consumption per ton based on the unitized interference information. The present disclosure may well reflect the deviation between the estimated value and the true value without the true value, and evaluate the same object using different estimation methods under the same architecture, so that the evaluation results may cross different estimation methods and still have practicality.

A method for starting up an air separation plant having a higher-pressure column, a lower-pressure column, and a falling film vaporizer disposed within a lower section of the lower-pressure column is provided. The method can include the steps of: introducing a cooled and compressed air stream into the higher pressure column; withdrawing an oxygen-enriched liquid stream from a bottom section of the higher-pressure column and introducing said oxygen-enriched liquid stream to an upper section of the lower-pressure column; and exchanging heat between nitrogen gas coming from a top section of the higher-pressure column and liquid oxygen from the lower-pressure column within the falling film vaporizer. During a start-up period, flow of liquid oxygen is at least reduced to the closed core. This reduces the available heat exchange area during start up, which increases ΔT and ΔP in the condenser/reboiler.

A method for starting up an air separation plant having a higher-pressure column, a lower-pressure column, and a falling film vaporizer disposed within a lower section of the lower-pressure column is provided. The method can include the steps of: introducing a cooled and compressed air stream into the higher pressure column; withdrawing an oxygen-enriched liquid stream from a bottom section of the higher-pressure column and introducing said oxygen-enriched liquid stream to an upper section of the lower-pressure column; and exchanging heat between nitrogen gas coming from a top section of the higher-pressure column and liquid oxygen from the lower-pressure column within the falling film vaporizer. During a start-up period, flow of liquid oxygen is at least reduced to the closed core. This reduces the available heat exchange area during start up, which increases ΔT and ΔP in the condenser/reboiler.

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.