Repurposing Networks for Hydrogen

Abstract

This paper presents an overview for repurposing and the potential blockers with respect to current code compliance based on Wood case studies of international code requirements and recent repurposing study work. Based on rudimental calculations, comparing both energy Natural Gas (NG) and H2 carriers, repurposed pipelines can be capable of achieving circa 80-90% of the energy flow rate if design pressure can be maintained, or 50-60% if the design pressure is de-rated. If other operational restrictions are considered, such as flow velocity it can potentially have additional knock-on effect on the achievable flowrate and consequently to energy ratio. The feasibility of pipeline repurposing for hydrogen service is critical to the energy transition. Careful consideration of code requirements, and further research and development currently ongoing is required in order to remove over-conservatisms in design to maximise the achievable energy flow rate when repurposing to hydrogen service.