Development of Fuzzy Logic Controller for Packed Bed Reactor
Ahmad Zuhairi Abdul Ghafar, Norliza Abd Rahman, Faezah Esa
Corresponding author (email) : faey_z@yahoo.com.my
Abstract
Fuzzy logic control system on simulation model was created using MATLAB Simulink R2011a in order to control the isomerization process of glucose to fructose in recycled and non-recycled packed bed reactor. Immobilized glucose isomerase catalysts the process along with regulation of pH and temperature. Mathematical equations on rate of fructose production,temperature changes and pH changes were created and modulated into a simulation model. Fuzzy logic controller was applied onto this simulation model to control the pH and temperature. The calculated error from fuzzy logic control system was compared with PID control and ON/ OFF control at constant pH (pH 8) and temperature (60°C) respectively. Fuzzy logic control system was found to exhibit lower error compared to ON/OFF control system in both non-recycled and recycled packed bed reactor. The same finding was obtained on camparison to PID control system. Conserving pH and temperature at optimum conditions are important for an efficient process. Thus, lower calculated error of fuzzy logic control indicated its potential in regulating isomerization process of glucose to fructose in packed bed reactor.
Keywords : Isomerization; packed bed reactor; fuzzy logic control; PID control; ON/ OFF control
Abstrak
Sistem kawalan logik kabur terhadap model simulasi direka menggunakan perisian Simulink MATLAB R2011a untuk mengawal proses pengisomeran glukosa kepada fruktosa di dalam reaktor lapisan terpadat kitar semula dan reaktor lapisan terpadat tidak kitar semula. Enzim glukosa isomerase pegun digunakan sebagai pemangkin proses disertai pengawalan terhadap pH dan suhu. Persamaan matematik terhadap kadar penghasilan fruktosa, kadar perubahan suhu dan kadar perubahan pH dibentuk dan diterbitkan kepada sebuah model simulasi. Sistem kawalan logik kabur seterusnya dibangunkan untuk mengawal suhu dan pH di dalam reaktor lapisan terpadat. Perbandingan ralat di antara sistem kawalan logik kabur dan kawalan PID dilakukan pada pH malar (pH 8) manakala perbandingan terhadap sistem kawalan ON/OFF dilakukan pada suhu malar (60°C). Sistem kawalan logik kabur didapati menghasilkan ralat yang lebih rendah berbanding sistem kawalan ON/OFF bagi reaktor lapisan terpadat tidak kitar semula dan kitar semula. Keputusan yang sama turut diperoleh apabila perbandingan dilakukan terhadap sistem kawalan PID. Penetapan pH dan suhu pada keadaan optimum adalah penting untuk memastikan proses pengisomeran berlaku dengan berkesan. Oleh itu, penurunan ralat yang diperoleh menunjukkan sistem kawalan logik kabur berpotensi mengawal proses pengisomeran glukosa kepada fruktosa di dalam reaktor lapisan terpadat.
Kata kunci: Pengisomeran; reaktor lapisan terpadat, kawalan logik kabur; kawalan PID; kawalan ON/ OFF