(189e) Risk Analysis of Hydrogen Gas Transmission Using Natural Gas Infrastructure

Hydrogen has been identified as an important future energy carrier reducing greenhouse gas emissions significantly. To be a successful energy carrier, the safety issues associated with hydrogen applications must be fully investigated and understood. Transmission of hydrogen gas using the existing natural gas pipeline infrastructure has been considered the most economical candidate in the future. However, for a successful conversion from natural gas to hydrogen gas service, the hazards and risks of a hydrogen gas pipeline delivery system should not exceed those of natural gas. The dominant effects associated with leakage of any flammable gas from pipelines gas are thermal radiation from a sustained fire and over pressure from a gas cloud explosion. In general, the fire hazard followed the explosion has a slightly greater effect.

In this study we present a simplified method to calculate the individual risk in the immediate vicinity of the pipeline using reasonable accident scenario and failure data of European Gas Pipeline Incident Data Group(EGIG). The risks between hydrogen gas and natural gas pipelines are then compared. The individual risk is approximately proportional to the diameter of pipeline and the square root of the operating pressure. For the hydrogen use through the gas pipeline, the risk is about 15 percent lower than that of natural gas while there is some limitation in energy transmission capacity comparing to natural gas.