Modeling of an oxy-coal flame under a steam-rich atmosphere

Effects of H2O Gasification Reaction on the Characteristics of Chars under Oxy-Fuel Combustion Conditions with Wet Recycle

“…Oxy-fuel combustion is considered to be one of the most promising strategies of CO 2 capture for both new and retrofitted coal-fired power plants. − In oxy-fuel combustion, flue gas mainly containing CO 2 and H 2 O is recycled to the furnace to combust with the coal. − Due to the position of the recycle for the flue gas, the recycle mode can be mainly classified as wet recycle and dry recycle. Some researchers suggested that wet recycle with a higher energy efficiency is more appropriate for oxy-fuel combustion. ,− Under wet recycle, recycled flue gas is at a relatively high temperature and without or just with partly water condensation; thus, the H 2 O concentration can be 15–30% and even up to 40% in oxy-fuel combustion. ,− As physicochemical properties of H 2 O are clearly different from those of CO 2 , the high concentration of H 2 O could potentially influence the oxy-fuel combustion with wet recycle, and it deserves for further in-depth study.…”

Investigation on the transformation behaviours of Fe-bearing minerals of coal in O2/CO2 combustion atmosphere containing H2O

“…Taken into consideration that the experiment was conducted at a relatively high temperature (1450 C), we should keep in mind that the diffusion-limited reaction rate will be sensitive to experimental conditions. 16,18 The O 2 concentration of 30% and a low H 2 O level are favorable for the establishment of pulverized coal combustion in oxy-fuel combustion atmosphere. 33 On the one hand, water vapor replaces part of the dilute CO 2 gas, and O 2 diffusion is faster in H 2 O.…”

“…The coal char will be gasified much easier in a higher water vapour content atmosphere. 18 When water vapour and carbon dioxide are both present in the furnace atmosphere, water molecules will primarily occupy active sites in char. 19 In this respect Yadav and Mondal 20 found that the char gasification reaction was enhanced in water vapor enrichment cases, affecting the flame temperature distribution and the incident radiation profile of the combustion furnace.…”

Experimental Investigation and Process Simulation of Oxy-fuel Flue Gas Denitrification in CO2 Compression Process

“…One of the main causes of global climate and eco-environment changes is the increasing emission of CO 2 , to which the anthropogenic activities contributes most because of the combustion of fossil fuel. Carbon capture and storage (CCS) technologies which could achieve a meaningful reduction in CO 2 emissions have gained much attention. , Among several CCS technologies, oxy-fuel combustion or O 2 /CO 2 combustion is considered as a potential technology with the advantages of large-scale CO 2 emission control and suitability for retrofit. − In an oxy-fuel boiler, coal is combusted in the mixture of almost pure O 2 and recycled CO 2 , instead of O 2 /N 2 , which produces highly enriched CO 2 in exhausted flue gas. Because O 2 is used in place of O 2 /N 2 , the formed NO x is significantly reduced in oxy-fuel combustion plants. − Although the amount of NO x emission per unit of energy is reduced, the concentration of the impurity remains high because of the recycle of flue gas. , The presence of NO x may cause a potential acidic corrosion risk to the pipelines and equipment. , Consequently, it is essential to remove the impurity to produce NO x -lean oxy-fuel-derived CO 2 before transportation, storage, and utilization, such as geological disposal and enhanced oil recovery.…”