Fast pyrolysis of two biomass materials (mallee wood and pine wood) at 1300 °C was conducted in a novel drop tube furnace (DTF) with a double-tube configuration, which enables the direct determination of char yields. Three particle sizes (90–106, 150–250, and 250–355 μm) were considered for investigating the effect of particle size on char yield, retention of alkali and alkaline earth metallic (AAEM) species, and shape of derived char particles from pyrolysis at such a high temperature. The experimental results show that the char yield increases with the biomass particle size and that the use of the ash tracer method with total ash, Mg, and Ca as a tracer can substantially overestimate the char yield by as high as 4.0% (absolute error) at actual char yields of mere ∼1.0–3.4%. Additionally, a decrease in particle size significantly enhances the release of AAEM species during biomass pyrolysis. Such observations can at least be attributed to the considerably higher heating rate experienced by small particles during rapid pyrolysis, which is estimated to be 5.4 times of that experienced by large particles. For mallee wood, rapid pyrolysis of small biomass particles (90–106 μm) forms nearly spherical char particles, while that of large biomass particles (250–355 μm) tends to retain their elongated shape. This is due to extensive melting of small particles during rapid pyrolysis at 1300 °C, while large biomass particles only experience partial melting. For pine wood, particle size has no obvious effect on particle shape of pine chars that are mainly cenospheres with smooth surfaces, demonstrating severe melting of the cell structure.

This study reports the adsorption characteristics of bio-oil on biochar in biochar/bio-oil slurry (i.e., bioslurry) systems at three biochar loading levels (2.4, 4.8, and 16.7%, respectively). At low biochar loading levels (2.4 or 4.8%), heavy organic compounds (particularly those containing fused aromatic systems) in bio-oil was selectively adsorbed onto the biochar. Such selective adsorption also resulted in reduced concentrations of alkali and alkaline earth metallic (AAEM) species in the adsorbed bio-oil phase compared to that in the bio-oil blank. A comparison between the experimental and calculated distributions of AAEM species in bio-oil indicates that at least part of the AAEM species adsorbed on biochar is associated with heavy organic compounds. Consequently, such selective adsorption results in changes in the unadsorbed bio-oil phase that has decreased viscosity and aromaticity and increased polarity. It is interesting to note that the selective adsorption was weakened with an increasing biochar loading level in the bioslurry, and such a phenomenon was not observed in the bio-oil−water-soluble fraction (WSF)/biochar system because of the absence of fused aromatic compounds in the WSF.

Growth performance and meat quality of commercial groups from two different three-line crossbreds, SWS and WSS, was compared. All birds were raised under the same condition and body weight was measured at two weeks interval. On d 70, 24 male chickens were randomly selected, and on d 180 and 240, 24 female chickens were randomly selected for euthanised. Carcass performance, meat quality and sensory was determined. At 6-12 weeks of age, body weight of chickens from WSS was higher than that of SWS (p < .05). Percentage of breast and leg muscle was higher in WSS as compared with birds from SWS in 70 d males (p < .05). At 240 d of age, chickens from WSS exhibited higher semi-eviscerate, breast muscle and liver percentage, lower abdominal fat content (p < .05). Male birds at 70 d, shear force, intramuscular fat content (IMF) and L Ã was higher in SWS (p < .05). A higher IMF of breast meat was detected in 180 d SWS female birds (p < .05). The appearance acceptability and flavour of WSS male chickens was more preferred by panellists (p < .05). The texture of breast meat from 180 d SWS chicken was more preferred (p < .05). Soup cooked from 240-d-old chickens was more preferred in SWS crossbred (p < .05). The WSS had better growth performance and meat quality in male chickens, while the SWS had more abdominal fat in female chickens which led it more flavour of its soup.

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Rapid pyrolysis of mallee and pine wood particles (250–355 μm) was conducted in a drop-tube furnace (DTF) at 1300 °C in argon atmosphere for collecting partially pyrolyzed char samples at various particle residence times (0.31–0.68 s). A novel feature of the DTF is its double-tube configuration that realizes direct determination of the char yield via experiments. This further enables investigations into the evolutions in the char yield, transformation of alkali and alkaline earth metallic (AAEM) species in chars, and char particle shape/morphology during rapid pyrolysis. The char yield decreases with the particle residence time but remains unchanged at 3.8 and 2.8% after 0.51 and 0.41 s for mallee and pine chars, respectively, indicating that the pyrolysis reactions are mostly completed. Similarly, the retention of AAEM species decreases with particle residence time, although the retention of AAEM species in pine char continues to decrease after 0.41 s. The continuous reduction in O/C and H/C molar ratios after 0.41 s suggests that the nascent char continues to experience thermochemical condensation reactions that lead to the scission of oxygen-containing groups. Chemical fractionation of mallee char with particle residence times of ∼0.32 and ∼0.51 s shows an increase in the amount of ion-exchangeable Na and K retained in partially pyrolyzed mallee wood and then a decrease as pyrolysis continues. These can be attributed to the transformation of water-soluble Na and K into ion-exchangeable Na and K, with partial release as a result of char deoxygenation. However, Mg and Ca, presented mainly in water-soluble or ion-exchangeable forms in the parent biomass, were increasingly transformed into acid-soluble or acid-insoluble forms. As pyrolysis progresses, the char particle length and diameter continue to shrink and char particles become increasingly spherical. Mallee wood shows stronger resistance to deformation because its original elongated shape is maintained, while pine char particles rapidly melt at the early stage of pyrolysis.