#TITLE_ALTERNATIVE#

• Main Author: MINERVA (NIM 10107076); Pembimbing : Prof. Dr. Roberd Saragih, M.T, DHISA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/14116
• Institution: Institut Teknologi Bandung

Reduction process, which is the main process in steel making in Krakatau Steel, needs an input of natural gas in a very high temperature. Therefore, natural gas has to be heated first through a system known as gas heater. In gas heating process, if methane is contained in natural gas mixture then it will be broken down into smaller molecules due to heating process, those are carbon and hydrogen. Carbon which is formed as solid may cause a crust in piping system of gas heater. Then, it will cover the surface of inside pipes and may effect the speed of gas flow and also the concentration of methane output. To minimize carbon deposit, steam will be injected into piping system of gas heater so the steam may react with the carbon and afterward reducing carbon deposit on pipe surface. However, injecting steam has a limited tolerance due to company's policy. Therefore, carbon deposit issue becomes optimal control problem of injecting steam. Pontryagin's minimum discrete principle is used to find out value of optimal steam as the controller for minimizing carbon deposit. Numerical method and simulation is used to find out the optimal input control.