Process Integration and Optimization of an NGCC Power Plant with CO2 Capture, Hydrogen Production and Storage
Power plants equipped with carbon capture and storage (CCS) technologies can reduce the cost of net-zero carbon systems, but the addition of variable renewable energy (VRE) sources like wind and solar can make them difficult to design and operate while limiting their commercial potential. Increased cyclic operation of electricity generators could also reduce capacity factor and efficiency, increase operations and maintenance costs, and potentially increase CO2 emissions. Improving CCS processes and designs could enable a low-cost, net-zero carbon electricity system.
Project Innovation + Advantages:
Linde Gas aims to develop a system for natural gas-fired power plants using post-combustion carbon capture and hydrogen technologies. This unique process produces and stores hydrogen when it is not profitable for the power plant with carbon capture to export electricity to the grid. The process then uses that stored hydrogen to offset natural gas fuel consumption when electricity prices are high. Integrating an electrolyzer for hydrogen production and tanks for hydrogen storage with a natural gas power plant that has carbon capture will enable the plant to operate under more steady-state conditions, improve its efficiency, and increase its capital utilization. Eliminating frequent starts and stops of these large power systems will also reduce fugitive carbon emissions during ramp-ups and ramp-downs. This project is the first of its kind to consider the effect of CO2 emissions certificate prices on the value proposition of hydrogen systems in the electric grid when hydrogen is mainly used for co-firing in the gas turbine. The value of this process design becomes greater as the differential in high and low prices of electricity increases and value for CO2 emissions improves.
Improvements in the design and processes of CCS-equipped plants in high VRE environments could dramatically reduce the cost of a net-zero carbon system. Benefits include:
Flexible CCS systems can enable the continued use of low-cost domestic fuel for electricity generation and increase the reliability of a deeply decarbonized electricity system.
Flexible CCS systems can achieve high CO2 capture rates from flue gas. For example, a power generator could be enabled to shift the times it exports electricity to the grid, allowing the power generator and CCS plant to operate under steady-state conditions and with reduced emissions.
Flexible CCS systems can reduce the cost of a net-zero carbon electricity system by providing dispatchable power to a high-VRE grid.