Table 3 Results from risk assessment of production concept 3: Hydrogen production by natural gas
reforming. Process unit Production unit
Identified hazards/risks Tube rupture inside reformer
Suggested risk reducing measures Cu-catalyst as sulphur guard in the bottom
caused by hotspot development on reformer tubes initiated by deactivation of reformer catalyst say by sulphur poisoning, risk for material damages. Tube rupture inside reformer caused by hotspot formation on reformer tubes initiated by deactivation of reformer catalyst by coke formation from higher hydrocarbons (C2+) in natural gas
of ZnO bed. Pre-reforming upstream reformer Gas quality requirements to NG supplier
Pre reforming Design with low inlet temperature to reformer, short connecting lines to reformer High S/C (Steam/Carbon) ratio
due to varying quality of natural gas, risk for material damages. NG leak in heat exchanger due to metal dusting, risk for material damages.
Natural gas (NG) leak inside reformer due to metal dusting, material risk. Pipe rupture caused by pressure explosion due to valve failure or human failure, risk for persons or equipment.
High S/C ratio Appropriate material selection Improved design (use of boiling water and steam for cooling) High S/C ratio Appropriate material selection
Remote operated process will reduce the probability of human failure. Regularity requirements to suppliers of control system (PLC and valve operation)
Large leak of flammable gas NG/H2/CO-mixture inside container due to wear and tear or human failure, risk for material damages and for persons.
Gas detection which activates: a) emergency ventilation, b) opening of ceiling an/or walls and c) closure of segmentation valves Segmentation valves should be located outside container in an area with good natural ventilation. Explosion relief of container