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Thermochemical conversion of world top crops (rice and wheat) has been extensively investigated (TGA, DTF, SEM, XRD, BET, EA), and main insights are discussed in light of materials and process kinetics. Overall, the results show that the rice husk presents lower reactivity than the wheat straw for all thermal processes regardless of the final temperatures (300°C− 1300°C), residence times (0.6 s−300 min), and atmospheres (100−340 mL·min −1 N 2 /air). The higher reactivity of wheat straw is attributed not only to higher alkali and ash contents but also to differences in both silica morphology and graphitic structure after pyrolysis. Chars produced from slow pyrolysis present more homogeneous characteristics than those produced from fast pyrolysis. Combustion of the chars from slow pyrolysis (up to 900°C) show similar kinetic parameters with activation energies, E a , of 101.8 and 101.0 kJ·mol −1 with pre-exponential factor, A, of 4.3 × 10 7 and 9.6 × 10 7 min −1 for rice husk and wheat straw, respectively; while chars from fast pyrolysis (up to 1300°C) show a range of values. Reaction times at 90 wt % loss (min) and rate constants k o (min −1 ) gives a more clear difference in values even for chars from slow pyrolysis with 12.4 and 0.221 for rice husk and 4.3 and 0.499 for wheat straw, correspondingly. These results are discussed herein according to changes in the physical and chemical characteristics of the nascent chars and, consequently, on their reactivity.

We have modelled the surface diffusion and growth of BaO and SrO both in the homoepitaxial and heteroepitaxial (BaO on SrO and SrO on BaO) cases. The diffusion proceeds most favourably by an exchange mechanism involving the surface layer. When impurities are adsorbed on the surface this can lead to intermixing between the layers. This strongly suggests that ionic materials may not be grown on a substrate with a similar structure without significant intermixing. Island growth begins with the formation of individual clusters which grow and merge together.

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The OxyCAP-UK (Oxyfuel Combustion -Academic Programme for the UK) programme was a £2M collaboration involving researchers from seven UK universities, supported by E.On and the Engineering and Physical Sciences Research Council. The programme, which ran from November 2009 to July 2014, has successfully completed a broad range of activities related to development of oxyfuel power plants. This paper provides an overview of key findings arising from the programme. It covers development of UK research pilot test facilities for oxyfuel applications; 2-D and 3-D flame imaging systems for monitoring, analysis and diagnostics; fuel characterisation of biomass and coal for oxyfuel combustion applications; ash transformation/deposition in oxyfuel combustion systems; materials and corrosion in oxyfuel combustion systems; and development of advanced simulation based on CFD modelling.