CASE STUDY- SURGE ANALYSIS OF METHANOL TRANSFER PIPELINE FROM PRODUCTION COMPLEX TO TANK FARM

Methanol produced at methanol complex (L1) is transferred to TANK FARM (L2) through 14'' carbon steel pipeline. The transferred methanol is stored in three tanks at TANK FARM area. Each tank is provided with motor operated loading valves. These loading valves can be operated locally as well as remotely. Two set of methanol transfer pumps are employed at methanol complex, in which one set of pumps are operated ata-time for methanol transfer. Methanol transfer is carried out batch-wise and loading of each tank is performed separately. During operation the valves are operated before the start-up of methanol transfer pump and closed sequentially after the shutdown of pumps when the methanol reaches the loading tank high level. However, the loading valves will be closed automatically during an emergency condition. This paper presents the evaluations carried out to investigate the magnitude of surge pressure using AFT Impulse software at different transient cases. Based on this analysis additional controls and line items are recommended to incorporate in the system to limit the surge pressures within the design limits.