Abstract: Process optimization plays an important role in design,operation,control and computer(integrated) control of process industries.This paper presents the description of steady-state optimization,(dynamic) optimization,and the optimization of process structures based on changing market conditions in(process) industries.Characteristics of these optimization problems are addressed and state of the art solution approaches are proposed.Sequential quadratic programming and orthogonal collocation is used to solve the dynamic optimization problem.Finally,the dynamic optimization to minimize the energy cost of a heatintegrated distillation column system is illustrated as an example.