Catalytic reforming of tar during gasification. Part III. Effects of feedstock on tar reforming using ilmenite as a catalyst

Australia mallee wood, bark and leaf samples (Eucalyptus loxophleba, subspecies lissophloia) werepyrolyzed to produce volatiles for in situ catalytic steam reforming with ilmenite as a catalyst. The results demonstrated that the properties of biomass feedstock (wood, bark and leaves) significantly influenced their product yields and properties. Bark produced the highest amounts of solid products, whereas leaf generated the highest amounts of tar during pyrolysis. The differences in the chemical composition and the tar yields among wood, bark and leaf decreased with increasing temperature. It is also found that ilmenite showed good activity for the reforming of all tars from different parts of mallee trees. However, its activity for reforming tar from bark and leaf decreased with prolonging feeding time due to their high gradual coke deposits. Compared with sintering, the accumulated coke deposited on ilmenite is a dominant factor to its deactivation during the steam reforming process. Burning coke is an effective method to regenerate the catalyst activity of ilmenite

Catalytic reforming of tar during gasification. Part II. Char as a catalyst or as a catalyst support for tar reforming

Char, char-supported catalysts and ilmenite were investigated for the steam reforming of biomass tar derived from the pyrolysis of mallee wood in situ. Special attention was given to the reforming of aromatic ring systems in tar. The results indicated that the char-supported iron/nickel catalysts exhibited much higher activity for the reforming of tar than the char itself. Ilmenite and the char-supported iron catalyst contained similar active phase but showed different tar reforming activities. Kinetic compensation effects demonstrated that the reaction pathways on the char-supported catalysts were similar but were different from those on ilmenite. The proprieties of support could play important roles for the activities of the catalysts and the reaction pathways on the catalysts. Char would not only disperse the catalysts but also interact with the catalysts to enhance their activity for the steam reforming of tar

Catalytic reforming of tar during gasification. Part IV. Changes in the structure of char in the char-supported iron catalyst during reforming

Our previous parts of this series have shown the char-supported iron catalysts to possess high activity for the reforming of tar during biomass gasification. This study aims to investigate the changes to the structure of char in the char-supported iron catalyst during the reforming of tar derived from the pyrolysis of mallee wood biomass. The char structure was characterised with Raman spectroscopy and its intrinsic reactivity at 400 °C in a thermogravimetric analyser. The results showed that the Raman peak area in the range of 800–1800 cm-1 of the catalysts changed slightly after being used for the steam reforming of biomass tar. The changes in the Raman band area ratio of ID/I(Gr+Vl+Vr) indicated that the relative ratio of larger and smaller aromatic ring systems increased after reforming at temperatures at 800 °C or higher. The changes in the char-air reactivity before and after reforming provided further insights to the changes in char structure as well as the importance of alkali and alkaline earth metallic species deposited on the char-supported catalysts during reforming

Pore size distribution and soil water suction curve from micro-tomography measurements and real 3-D digital microstructure of a compacted granular media by using direct numerical simulation technique

Predictive measurement of capillary pressure - saturation relationship of a porous media is obtained based on the actual microstructure obtained from high resolution tomography data. X-ray micro-tomography provided a high contrast for silica phase, and actual geometry of sand particles and void distribution. The morphological opening (erosion + dilation) is used to get a pore size distribution using the concept of granulometry. Full-morphology approach is used to model the quasi-static wetting and non-wetting phase distribution of a primary drainage process. Predicted soil water suction curves for a compacted silica sand sample is presented along with the effects of assumed contact angle between water and silica surface

Hybrid Nanoimprint-Soft Lithography for Highly Curved Surface with Sub-15 nm Resolution

Nanoimprint lithography is a high-resolution, high-throughput and low-cost technology to pattern nanostructure, but it only works well on planar surface. To solve this issue, a hybrid nanoimprint-soft Lithography (HNSL) was developed to pattern nanostructures on highly curved surfaces (e.g. the sidewall of an optical fiber). Moreover, double transfer UV-curing nanoimprint lithography, an improved version of HNSL, was introduced to enable high fidelity pattern transfer. Optical fibers can be patterned using this technology, and that opened the door to numerous applications