A new WSGG radiation model of CO/CO2 mixed gas for solar-driven coal/biomass fuel gasification

Abstract

Gasification driven by solar energy with CO2 is an ideal way of low-carbon resource utilization. However, there is a lack of research on the radiation heat transfer process which is important in gasification simulation. In this study, we developed a new the weighted-sum-of-gray-gases (WSGG) model to calculate the radiation heat transfer properties of CO and CO2 mixtures in solar-driven coal/biomass fuel gasification. Benchmarked against the statistical narrow-band model (SNB) of the EM2C laboratory, the WSGG model is suitable for the temperature range of 400–2500 K and the path length range of 0.001–60 m. This study also explored the effect of the CO/CO2 molar ratio on the overall emissivity of the mixture. Furthermore, the model introduces a pressure term into the emissivity calculation process and broadens the pressure range (1 bar, 5 bar, 45 bar). For the first time, the WSGG model is applied to the case where the H/C element ratio is 0, and the fluctuating temperature distribution case (1000 – 2000 K) is analyzed, which is suitable for coal/biomass fuel gasification. In addition, this study calculated the one-dimensional radiation transfer equation. The results show that the average radiation source term difference between the new WSGG and the benchmark SNB model is within 5 % in common solar gasification engineering conditions (5 bar, 5 m). Meanwhile, this study also clarified the effect of pressure on the radiation heat transfer with different temperatures.