Hazop Evaluation and Safety Integrity Level (SIL) analysis on steam system in ammonia plant PetroKimia Gresik Ltd.

Abstract

Steam is utilized to actuate 101 JT and 103 JT compressor turbines in the ammonia making process. Steam production is done through several processing steps in several units. HAZOP method and Safety Integrity Level (SIL) analysis is to observe the risk level using Fault Tree Analysis (FTA) method to calculate the security level of each node. The nodes used are deaerator, steam drum, and superheater burner. The hazard risk level is obtained from the multiplication of likelihood and consequence based on Petrokimia Gresik Ltd. standard. SIL value of the system is derived from the calculation of Probability Failure on Demand (PFD) total value in the Safety Instrumented System (SIS) arranged in each unit. Based on the analysis results, it was obtained that "high" of the hazard level occurred on steam drum with low level deviation and superheater burner with high pressure deviation. The PFD total value on the steam system was 0.06845 and classified as SIL 1. A given recommendation to decrease the risk level on superheater burner node with high pressure deviation was done by adding transmitter. SIL value obtained both before and after adding transmitter was SIL1. However, the RRF value before the component addition was 20.1 but 37.7 after component addition. It indicated that the component addition can reduce the risk on the system.