In 2013, CO 2 levels surpassed 400 ppm for the first time in recorded history. So, we are facing global warming due to the increase levels of atmospheric carbon dioxide (CO 2 ). As a method of reducing CO 2 emissions from the thermal power plants, there are carbon dioxide capture and storage (CCS) technologies. Oxyfuel combustion is one of the CO 2 Capture technologies and IHI have developed it since 1989. Then, Callide Oxyfuel Project commenced to apply oxyfiring technology in an existing coal fired power plant and to demonstrate an oxyfuel power plant in March, 2008. Demonstration began in 2012 after existing boiler was retrofitted. During the demonstration for approximately three years, many tests were conducted and many data were collected for commercial use. As a result, we confirmed characteristics of oxyfiring such as total heat absorption, combustion characteristics, emissions of NOx, SOx, carbon-in-ash, operational flexibility from 15MWe (50%L) to 30MWe (100%L) and behavior of injected CO 2 at the injection site. Total heat absorption of the boiler under oxyfiring was 2 to 3MW higher because of decreasing heat loss in flue gas and rising temperature of boiler feed water by a flue gas cooler. NO was decomposed in the furnace under oxyfiring because flue gas was recirculated. On the other hand, reaction between SO 2 and absorbent such as Ca, Mg in ash was not so active regardless of high concentrated SO 2 under oxyfiring. Carbon-in-ash was almost 40%~70% in oxyfirng compared with in airfiring because of longer residence time in the furnace. Operational flexibility is important to control oxyfiring operation and it was confirmed that oxyfiring can be operated as well as airfiring. In this paper, operational results are presented in Callide Oxyfuel Project.
While the efforts to control global warming are being strengthened all over the world, expectations for CO 2 Capture, Utilization and Storage (CCUS) technology for coal fired power plants are increasing. IHI has been working on development of oxyfuel-combustion technology since 1989 with the aim of easily capturing and storage CO 2 emitted from coal fired power plants. For the demonstration of oxyfuel-combustion technology, IHI participated in the Callide Oxyfuel Project with collaboration between Australian and Japanese under the financial support of Australian, Queensland state and Japanese governments. In the project, the oxyfuel-combustion process was applied to the existing coal power plant in Queensland, Australia, and demonstration was carried out and successfully completed without any significant technical barrier to commercialization in March, 2015. In Oxyfuel-combustion, the coal-fired boiler is operated with an inlet O 2 content of 27 vol% in order to achieve the same furnace heat transfer as in conventional air-firing. The first outcome of oxyfuel-combustion is a significant reduction in NOx production, typically 60% reduction, measured in mgNOx/MJcoal. The second outcome of oxyfuel-combustion is a reduction in the actual volumetric flow of flue gas, typically a 60% to 70% reduction in gas flow measured as m
CCS (Carbon Dioxide Capture and Storage) is one of the technologies able to adequately displace CO 2 from fossil fuel fired power plants and the only technology capable of reducing large-scale emissions. In particular, coal emits a lot of CO 2 , although it is an important energy resource in terms of energy security. To address this situation, IHI had developed oxyfuel combustion technology to capture CO 2 from coal-fired power plants, and the demonstration using a 30MWe unit in Australia was successfully carried out. In order to commercialize the technology widely, how to configure the primary gas system is one of the important examination items. When adding oxygen into the primary gas system, depending on the type of mill, pulverized coal deposited in the mill may ignite spontaneously. To investigate the spontaneous combustion characteristics of the deposited pulverized coal under oxyfuel conditions, therefore, laboratory-scale experiments were carried out. A pulverized coal was deposited in a 100mm cubic mesh box, and it was installed in a thermostatic chamber. Then the mixed gas of N 2 /O 2 or CO 2 /O 2 was introduced into the chamber, and the temperature in the coal sample was measured. From the results, there was little temperature difference at which spontaneous combustion occurred between N 2 /O 2 and CO 2 /O 2 atmosphere, but there was a tendency that it might be relatively hard to occur under CO 2 /O 2 atmosphere. The results also showed a tendency that the influence of temperature was stronger than the oxygen concentration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.