Steam-moderated oxy-fuel combustion

Comprehensive investigation of process characteristics for oxy-steam combustion power plants

“…(5) Coal mass flow rates and theoretic volumes of oxygen for coal burning are calculated from Eqs. (1) and (2) [8], which are described as below:…”

“…(2) As the plant configuration of oxy-steam combustion power plant becomes simple and compact, air in-leakage in oxy-steam combustion is supposed to be 1% of total gas entering into burner [8] while it is assumed as 2% [11] in oxy-CO 2 combustion. (3) Excess oxygen coefficient in oxy-steam combustion is calculated inversely through CO level in wet flue gas whilst in oxy-CO 2 combustion the excess oxygen coefficient is assumed constant at 1.05 [11,18].…”

“…[21] for oxy-CO 2 combustion, wet FGD with 95% efficiency is considered in this study. (2) As unit size can be reduced by 40% because less amount of overall flow rate is required in oxy-steam combustion [2,8], six-tenths rule [19,26], which allows to estimate cost of an equipment or plant at a given capacity or size to be calculate when cost of the same equipment or plant at a different capacity or size is known, is employed here to calculate the total investment cost of the whole base power plant for oxysteam combustion. And investment cost of heat exchanger for heating recycled water is not considered here, but it affects little on economic assessment results since it accounts quite small proportion in that of whole power plant.…”

“…Based on the previous study [6], Cai et al [7] further analyzed the effects of the physical-chemical properties of H 2 O on the ignition of coal under oxy-steam combustion by numerical simulation, showed that the steam shift reaction is the primary reason for the advanced ignition of coal in the H 2 O/O 2 atmospheres while the steam gasification reaction is a minor reason for the phenomenon. On the process simulation front, Seepana and Jayanti [8] presented flame structure analysis for determining oxygen concentration to get a stable combustion and thermodynamic analysis to compare it with corresponding air-combustion. It was concluded that oxygen concentration in oxidant should be 36% by mass and net efficiency penalty would be 8 percentage points.…”

Numerical study of H 2 O addition effects on pulverized coal oxy-MILD combustion

“…While in fact, H 2 O also can be used as "inert" gas like CO 2 to moderate flame temperature, namely oxy-steam combustion. It was first proposed by CanmetENERGY [38] as an alternative for the next generation of oxy-fuel combustion and has raised concerns all around the world in recent years [39][40][41]. The most significant advantage of this technology is the avoided flue gas recirculation for easy CO 2 recovery and reduced system complexity.…”