16. A method comprising: receiving balance equations describing a chemical process to be controlled by a process controller using a model; generating, using at least one processing device, model information representing the balance equations; generating an equation stack using the model information, the equation stack representing the balance equations; receiving evaluation information from the process controller; evaluating at least one of the balance equations using the evaluation information and the equation stack; receiving states and inputs of the model from the process controller, estimated parameters of the model, and equations evaluated for the states and inputs of the model; generating a linearized model by linearizing non-linear equations in the evaluated equations based on the states and inputs, the estimated parameters, and an output from the evaluation of the at least one balance equation; and providing the linearized model to the process controller in order to control the process.
16. A method comprising: receiving balance equations describing a chemical process to be controlled by a process controller using a model; generating, using at least one processing device, model information representing the balance equations; generating an equation stack using the model information, the equation stack representing the balance equations; receiving evaluation information from the process controller; evaluating at least one of the balance equations using the evaluation information and the equation stack; receiving states and inputs of the model from the process controller, estimated parameters of the model, and equations evaluated for the states and inputs of the model; generating a linearized model by linearizing non-linear equations in the evaluated equations based on the states and inputs, the estimated parameters, and an output from the evaluation of the at least one balance equation; and providing the linearized model to the process controller in order to control the process. 18. The method of claim 16 , further comprising: storing the model information in a data store; and reading the model information from the data store before generating the equation stack.