In applying computation technique to improve the operation of existing chemical processes
a computer-aided process optimization method is proposed-the improved two-tier method based on Successive Quadratic Pro-gramming(SQP). By inserting extra variables in SQP
a new quadratic programming problem is constructed
and a decomposition strategy for the quadratic programming is also presented
which has been found to be always feasible when the matrix is singular. This new two-tier method based on SQP has better performance both in numerical stability and in convergence behavior. Satisfactory result is obtained in applying this algorithm to optimize a methanol synthesis process
thus leading to implementation in actual practice.