Comparison of nickel- and iron-based oxygen carriers in chemical looping combustion for CO2 capture in power generation

• In chemical looping combustion (CLC), a solid oxygen carrier circulates between two fluidised bed reactors and transports oxygen from the combustion air to the fuel: thus, the fuel is not mixed with air and an inherent CO2 separation occurs. In this paper, CLC is integrated in a natural gas fired combined cycle (NGCC). In this system, nickel- and iron-based oxygen carriers are compared regarding the system's electrical and exergy efficiencies. Furthermore, the feasibility of CLC in two interconnected pressurised fluidised bed reactors (IPFBR) is studied for both oxygen carriers. The hypothetical layout plus dimensions of the IPFBR is presented for a capacity of 800 MW input of natural gas. Finally, top-firing is proposed as an option to overcome the apparent limitation in operating temperature of the reactor equipment and/or the oxygen carriers. The results indicate that there is no significant difference in the system's efficiency if both oxygen carriers could operate at the same temperature. However, CLC seems easier to be technically realised in an IPFBR with a nickel-based oxygen carrier.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Keyword

chemical looping combustion

carbon dioxide capture

nickel oxide

iron oxide

oxygen carrier

natural gas fired combined cyclce

exergy analysis carrier

separation

particle

system

Energiteknik

Publication and Content Type

ref (subject category)

art (subject category)