An insight into Flexible CCS Network Development (FleCCSnet)

Written by Dr Eva Sanchez Fernandez working on UKCCSRC Call 1 Project: Flexible CCS Network Development (FleCCSnet)

A typical CCS network (Fig 1) comprises all elements necessary to capture, purify and compress CO2 from different sources and transport and inject this CO2 in different suitable sinks. At an early stage, the elements of the network (capture plant, transportation pipeline and storage site) are selected to comply with specific site and design constraints matching the source and the sink requirements. As CCS advances, CO2 capture will be deployed in a range of power plants that operate more flexibly and in other industrial sites. At this stage, the intermittent contribution of renewable energy to the electricity grid will have an impact on the operation of power plants leading to daily and seasonal variations in CO2 flows that are sent to the CCS chain. In addition, the geological storage sites will impose additional variability and constraints to the pipeline, due to maintenance at the injection point or changes in the injection rates. Therefore, the pipeline network would need to respond and accommodate short, medium and long term variations in CO2 flows.

The aim of this project is to provide design and operating guidelines for CCS pipeline networks to ensure that they can react effectively to variations in the availability and flow of CO2 from capture plants. The proposed work will study the flexibility of CO2 transport networks and their ability to react to changes in the flow rate of CO2 across the whole CCS chain. This research will use proprietary software to model the transient flow in different pipeline networks that will be designed to accommodate predicted variations in CO2 flows.

The current work is looking at realistic scenarios of operations of power plants and other sources of anthropogenic CO2. For this scenario development, the effect of a selected number of variables from both capture and storage sites on the CO2 flow that needs to be transported is being investigated. Based on this study, a number of operational scenarios will be devised and used to analyse the impact of the variations identified on a range of pipeline network scenarios.

For instance the CO2 flows will depend on the type of power plant where they originated, fuel and size. The operation of the power plant through the year is influenced by the electricity demand, start-up and shut-down times, planned and /or unplanned outages, the power plant place in the merit order, etc.  All these variables are being analysed to create several CO2 flow profiles that will be used to model transient CO2 flow through pipelines. In addition, options for CO2 storage at the capture site and / or geological site are being investigated.

The outcome of this research will facilitate the engineering of CCS networks, identifying possible bottlenecks within the CCS chain and providing design guidelines for a flexible network that can respond to all the CO2 fluctuations imposed by multiple varying CO2 sources and storage sites.

Watch this space for more updates in the future