Wood will share key lessons from recent detailed FEEDs they have performed for several carbon dioxide networks in the UK, covering:

1. What are the regulatory and code requirements for CO2 pipelines, including safety / location classes, design factors and future land use?
2. What are the safety differences for CO2 pipelines, including separation distances and risk criteria, crossings and block valves?
3. How do the mechanical design requirements for CO2 pipelines differ from natural gas lines?
4. How does the line pipe requirements differ from natural gas?
5. What are the optimum design solutions for control of running ductile fracture?
6. What is the preferred pre commissioning strategy including the need drying vs replacement of the system pressure test?

A summary of recent code developments and industry testing will be presented.

Carbon dioxide pipelines are designed to ensure the public are safe along the route and the UK uses the ALARP approach with respect to risk management. The impact of the CO2 in gas and dense phase on the failure probabilities is discussed. The differences in risk acceptance criteria are presented. The large impact on separation distances of QRA methods and criteria will be presented. The impact on consenting, routing and land use planning will be demonstrated by examples. The need for clearer industry guidance and early QRA is identified.

The impact of the recent guidance, numerical modelling and testing on design against running ductile fracture and low temperature brittle fracture will be presented and how this impacts the design solutions in terms of wall thickness and the need for fracture arrestors.

The measures taken to manage the significant differences in the safety, materials and engineering for CO2 pipelines from natural gas pipelines are discussed along with the impact on project CAPEX and schedule.