OxyNG: Advanced modeling of oxy-fuel combustion of natural gas (ForskEL 10256)

Global warming is one of the main environmental threats to the world. The dominating cause is believed to be the increased CO2 level in the atmosphere. Electrical power generation currently produces around one-half of the total annual CO2 emissions. Oxy-fuel combustion is one of the promising CO2 capture technologies. The main idea of oxy-fuel combustion is to use oxygen, instead of air, as comburant in order to obtain flue gas mainly consisting of CO2 (high con centration), H2O, O2 and other pollutants, as sketched in Fig. 1. The recycled flue gas, consisting mainly of CO2 and H2O, is used to control the flame temperature and make up the missing N2 to ensure there is enough gas to carry the heat through the boiler. Oxy-fuel combustion provides some good opportunities, e.g., reduced boiler heat losses and compact boiler design, and zero-emission power plant. However, combustion under oxy-fuel conditions is fundamentally different from air combustion, which presents some new challenges. Among these are, for instance, fundamentals (including flame properties, combustion process, heat transfer in particular radiation, gas phase kinetics, behavior of sulfur and nitrogen in an O2/CO2 atmosphere and so on), and boiler and burner design.



The goal of the project is to investigate oxy-combustion of natural gas (methane) through advanced modeling, in which mixing, chemistry and heat transfer will be sufficiently resolved.

The main objectives to be achieved from the project are defined as follows:



To verify the applicability of existing models, which are developed for gas radiation properties under air-firing conditions, in oxy-fuel conditions and/or to develop a new model for oxy-fuel combustion.



To correctly describe, identify and model the chemistry-mixing interaction in oxy-fuel combus-tion, which will lead to a “simplified”, robust and reliable CFD modeling methodology for oxy-fuel combustion.



To help identify the most important intermediate species in oxy-fuel flames, which will in turn initialize the development of non-intrusive measuring techniques for quantitative characteri-zation of flame radical emissions.