This paper introduces the application of PI/PID controller tuned with Particle Swarm Optimization (PSO), Adaptive Weighted Particle Swarm Optimization (AWPSO) algorithms into the field of chemical engineering. The application deals with the temperature and concentration control for Continuous Stirred Tank Reactor (CSTR). The optimization step has been achieved based on three error criterion. They are: Integral of Square Error (ISE), the Integral of Absolute Error (IAE) and the Itegral of Time Absolute Error (ITAE). The temperature and concentration performance of the CSTR has been tested for robustness by changing some of the CSTR parameters. Better performance of the PID tuned by the AWPSO proposed algorithm is noticeable. Also the temperature and concentration performance of the CSTR due to changing some system parameters has been noted in very little values (almost zero) which enrich the idea of the selected PID tuned by the AWPSO for robustness.