Failure analysis and damage assessment of reformer tubes

Reformer tubes are used in the production of hydrogen gas from natural gas. In the process, natural gas is mixed with steam which then react in reformer at temperature of 1100 oC. The reaction between natural gas and steam produces syngas containing carbon monoxide and hydrogen gas to be used in petrochemical products. The failure event was indicated by the drop of syngas, reformer inlet flow and pressure drop. These values indicated the loss of process gases flow to the reformer. Root cause failure analysis was performed and concluded that the most probable cause was overheating. The overheating was caused by the loss of process fluid flow to the reformer due to the diverting of flow to the flare lines by the failure of control valve to close. The damaged parts analyzed were control valve, reformer tubes and catalyst. Reformer tubes damages after the incident were analyzed based on visual observation and replica test. The results showed microcracking in reformer tubes. The study recommended the replacement of the tubes due to the considerable repair efforts which include overall tube assessment, damage portion removal and substitution, reliability issues of the future operation with repaired tubes as well as economical consideration.