In the present study, an Eulerian-Eulerian computational fluid dynamics (CFD) model, combined with a comprehensive biomass reaction scheme, was used to simulate fast pyrolysis of four different biomass types in the fluidized bed reactors. The study focuses on the influence of biomass components of different biomass types on the yields, formations, and contents of compositions of pyrolysis products. The result showed that the bio-oil yield of cellulose-rich biomass was higher than other biomass types, and char was mainly produced by the fast pyrolysis of LIG-C of biomass. Moreover, the contents of bio-oil components were affected by the fast pyrolysis of biomass components. Further, the energy recovery coefficient (ERC) of bio-oil obtained from pyrolysis of different biomass types was also calculated and analyzed in this paper.

In gas turbines, inverse diffusion flames form when film-cooling air reacts with fuel-rich packets from the combustor. Investigations have focused on the quantitative radiation heat transfer in oxygen-enriched inverse diffusion flames (IDFs) since it plays an important role not only in fundamental combustion research, but also in much research on industry combustion, such as gas-turbine engines. To investigate the quantitative radiation properties of oxygen-enriched IDFs, a midinfrared thermal camera coupled with two different band-pass filters was selected to acquire the thermal radiation intensity of carbon dioxide and soot. The oxygen mole fraction in the oxidizer was varied from 21% to 100% using a co-flowing inverse flame burner to produce steady flames. The radiation intensities from carbon dioxide are approximately 15 to 20 times stronger than those from soot with different oxygen enrichment in IDFs. Both radiation from carbon dioxide and soot increased as the oxygen index of the oxidizer was increased, and the increase in radiation from carbon dioxide was more drastic than that from soot when the oxidizer was more enriched. However, the growth rate of the maximum radiation emission from carbon dioxide along the flame centerline decreased when the oxygen index of the oxidizer exceeded 80%. Furthermore, a second peak appeared along the flame centerline in the radiation curves from soot when the oxygen index of the oxidizer exceeded 40%. The axial position of the second peak was closer to the burner exit than that of the first peak. Moreover, the values of the second peak presented a steeper growth rate than the first one with greater oxygen enrichment.

Intense investigations have been focused on radiative heat transfer in oxygen-enhanced inverse diffusion flames since it plays a significant role not only in fundamental combustion research, but also in terrestrial and spacecraft fire safety study. To investigate the characteristics of the radiative heat transfer, a calibrated mid-infrared camera was used to acquire images of radiation intensity including soot and carbon dioxide in the 2–5μm wavelength range. The mole fraction of oxygen in the oxidizer varied from 21% to 100% with co-flowing inverse flame burner used to stabilize the flames. The characteristics of axial and radial radiation intensity distribution in different oxygen enhanced conditions are compared and analyzed. The results indicated that oxygen enhancement broadens the radial range of inner blue reaction zone and stretches the axial height of the plume zone. Similar to radial peak radiation intensity value and the growth rate of radial radiation intensity in different axial heights from X = 1D to X = 3D (X: axial height above the burner along the flame centerline; D: diameter of oxidizer exit), the peak value of radiation intensity and the growth rate of radiation intensity along the flame centerline both have a positive linear relationship with the oxygen mole fraction in the oxidizer.