Patent ID: 7946127

Claim:
An apparatus comprising: at least one memory configured to store at least one model, the at least one model associated with one or more manipulated variables and one or more controlled variables, the one or more manipulated variables and the one or more controlled variables associated with a cascade liquefied natural gas facility, one of the one or more controlled variables associated with an overall load placed on multiple refrigeration systems in the cascade liquefied natural gas facility; and at least one processor configured to determine how to adjust the one or more manipulated variables using the at least one model so as to (i) maintain the one or more controlled variables within defined limits and (ii) increase the overall load placed on the refrigeration systems; wherein the at least one processor is configured to determine how to adjust the one or more manipulated variables by identifying a maximum of: (i) a first projected feed gas rate to operate a propane refrigeration system at a propane maximum load, (ii) a second projected feed gas rate to operate an ethylene or ethane refrigeration system at an ethylene/ethane maximum load, and (iii) a third projected feed gas rate to operate a methane refrigeration system at a methane maximum load.