Flexibility in the Production of Hydrogen and Electricity from Fossil Fuel Power Plants

Concerns about global climate change have led to the formulation of a number of fossil fuel power plant concepts, which are intended to capture the carbon dioxide produced, so that it can be stored in geological structures. In the medium and long-term future, these plants will have to operate in a market where a large fraction of the electricity that is produced will come from wind and solar power. Because these renewables are intermittent sources of energy, it is likely that the main use of fossil fuel plants will be to compensate for shortages in the supply of electricity, with plants operating on a very irregular basis. However, electricity-only plants, which capture carbon dioxide, are unlikely to be economic, as they will be either operating at part load or will be shut down for much of the time. Alternatives to electricity-only generation concepts are those based on systems that produce both hydrogen and electricity from a fossil fuel. In these processes, the production of hydrogen, before it is then used to generate electricity, converts the carbon in the fuel into CO2, which can then be removed using chemical or physical absorbents. However a plant producing a fixed ratio of hydrogen-to-electricity will have the same disadvantages as an electricity-only generating plant. As electricity demand falls away, the amount of hydrogen will also decline. A hydrogen/electricity plant should have high flexibility, being able to vary its ratio of hydrogen-to-electricity. Ideally the plant should be able to vary the ratio from 100% hydrogen to 100% electricity over a short period. In this way the plant would always operate as a base load unit, selling its energy, either as electricity or hydrogen, into the most profitable market. Such a plant would need to be designed so that the gasifier section and combined cycle section of the plant would need to work independently. Some of the main features of such a plant are highlighted. Keywords: Hydrogen, Electricity, Fossil Fuel, Flexibility, Cycling

STARR Frederick;  STEEN Marc;  PETEVES Estathios; 

TZIMAS Evangelos; 

2005-11-30

UNIDO-ICHET

JRC31287

https://publications.jrc.ec.europa.eu/repository/handle/JRC31287,