After Burning Phenomenon as the cause of HP and MP Steam Superheater Tube Burst during Plant Start Up 2002

摘要

Medco Methanol Bunyu is a methanol producer whose plant is located in Bunyu island, East Kalimantan, Indonesia. The plant has been in operation since 1986 using Lurgi Low Pressure Methanol Synthesis technology with design capacity of 330,000 mt /year. Low sulphur natural gas from Medco E&P Indonesia and Pertamina E&P is used as the raw material and source of fuel. PT Medco Methanol Bunyu faced a failure in the plant start-up in October 2002. The failure was initially indicated by rupture in HP and MP steam super heater tubes. The first indication that showed abnormality was the unusual temperature profile at the reformer flue gas channel. Moreover, the inability of the steam system to reach its operating pressure (steam lost) confirmed the failure in the steam superheater. According to material analysis conducted by B4T (an independent organization for testing and material research) and Department of Metalurgy (Bandung Institute of Technology), the tubes failure was caused by local overheating that decreased the material hardness and tensile strength. Based on the operation data of the second start-up (22 October 2002), and field inspection, the overheating was caused by after burning phenomenon.