Core Research Projects: Capture, AC4 – Integration options for hydrogen and clean power synergies

Why is this research needed?

Electricity and hydrogen are two key low-carbon energy vectors to decarbonise energy used in the transport sector, space heating and industrial sectors. In future energy supply systems, both vectors may be generated at the same locations, i.e. low-carbon CCUS industrial clusters and may benefit from a shared infrastructure for natural gas supply, electricity grid connection, and transport and geological storage of CO₂. This work investigate the integration of the process of hydrogen production with electricity generation using the same fuel source, i.e. natural gas with the ultimate objective of achieving cost reduction via the sharing of subcomponents of the CO₂ capture process and via flexibility to cope with variations of both vectors in demand over time.

What is this research investigating?

Steam methane reformers (SMRs) and combined cycle gas turbine power plants (CCGTs), when combined with CCUS, have the potential to produce large quantities of low cost, on demand and near-zero carbon hydrogen and power.

This work investigates the scope for cost reduction by integration to use a single post-combustion carbon capture (PCC) system for both the SMR and the CCGT power plant. Sharing the CO₂ capture process is possible via sequential combustion^[1][2] of the SMR fuel gases in the gas turbine exhaust flue gas, containing a relatively large amount of excess oxygen, resulting in the co-generation of both low-carbon energy vectors in combined flue and power (CFP) plants with a single CO₂ capture plant. Potential benefits therefore include shared sub-systems and an improved thermal integration that maximises either power or hydrogen production. Moreover a CO₂ capture rate of 99.8% corresponding to net carbon neutrality may be achieved at no additional energy penalty when compared to a direct integration configuration in which the flue gases from each plant are mixed and feed to the capture plant. This research also focuses on establishing operational maps for a part load operation to decouple low carbon electricity and hydrogen generation in the CFP plant.

^[1] Sanchez Del Rio, M., Gibbins, J., Lucquiaud, M. Int. J. Greenh. Gas Control, 2016

^[2] Gonzalez Diaz, A., Sanchez Fernandez, E., Gibbins, J., Lucquiaud, M. 2016, Int. J. Greenh. Gas Control, 51, 330-345

What does the research hope to achieve

Linking hydrogen and power production with CCUS may help to overcome adverse effects of short- and long-term variability in demand for both products (for example, see the Leeds H₂1 Citygate project) . Relevant modelling work is undertaken using gPROMS Process Builder (PSE), a process modeling platform that allows to create customised models and conduct analysis for an optimal thermal integration.

It is envisaged that, if this exploratory study indicates that the novel approaches being developed show promise, it may lead to more detailed work and collaboration with potential stakeholders, including hydrogen producers, utilities and OEMs. These results will feed forward into the research in work package AC5: Reduced Order Models.