Pyrolysis is one of the thermochemical technologies for converting biomass into energy and chemical products consisting of liquid bio-oil, solid biochar, and pyrolytic gas. Depending on the heating rate and residence time, biomass pyrolysis can be divided into three main categories slow (conventional), fast and flash pyrolysis mainly aiming at maximising either the bio-oil or biochar yields. Synthesis gas or hydrogen-rich gas can also be the target of biomass pyrolysis. Maximised gas rates can be achieved through the catalytic pyrolysis process, which is now increasingly being developed. Biomass pyrolysis generally follows a three-step mechanism comprising of dehydration, primary and secondary reactions. Dehydrogenation, depolymerisation, and fragmentation are the main competitive reactions during the primary decomposition of biomass. A number of parameters affect the biomass pyrolysis process, yields and properties of products. These include the biomass type, biomass pretreatment (physical, chemical, and biological), reaction atmosphere, temperature, heating rate and vapour residence time. This manuscript gives a general summary of the properties of the pyrolytic products and their analysis methods. Also provided are a review of the parameters that affect biomass pyrolysis and a summary of the state of industrial pyrolysis technologies.

Lignocellulosic biomass pyrolysis: A review of product properties and effects of pyrolysis parameters

Influence of pyrolysis temperature on production and nutrient properties of wastewater sludge biochar.

An overview of the organic and inorganic phase composition of biomass

Influence of pyrolysis temperature on properties and environmental safety of heavy metals in biochars derived from municipal sewage sludge

An overview of the behaviour of biomass during combustion: Part I. Phase-mineral transformations of organic and inorganic matter

Melt/substrate contacting experiments have been carried out under controlled laboratory conditions designed to approximate the conditions encountered during the initial solidification period in strip casting. Immersion experiments were performed with various substrates embedded in a moving paddle; the substrates had both smooth and textured surfaces. The melt was 304 austenitic stainless steel, and the substrates were made from copper blocks. The apparatus and instrumentation were designed for 'millisecond' resolution of heat transfer behaviour. The experimental variables chosen for study were substrate texture, gas atmosphere, immersion velocity and melt superheat. The conclusions drawn were based on an analysis of transient interface heat fluxes during the first 50 milliseconds of contact, the observed nucleation behaviour and the resultant surface and internal solidification structures. The aim of the work was to add to the fundamental understanding of melt/substrate contacting in the meniscus region, since this will inevitably be critical to strip surface quality.

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Experimental Studies of Interfacial Heat Transfer and Initial Solidification Pertinent to Strip Casting

The pyrolysis behavior of wheat straw and mallee residue and resulting gases, liquids, and chars were examined. The specific heat and thermal conductivity of both species were measured using computer-aided thermal analysis at heating rates of 10 and 100 °C/min to a temperature of 1000 °C. The sample decomposition was also measured by thermogravimetry. Gas chromatography detected evolved gases, and the bio-oils were characterized using GC-MS. Chars were examined using FTIR, proximate, and ultimate analysis. Both species initially displayed endothermic behavior, followed by rapid decomposition and fluctuating specific heat and thermal conductivity between 250 and 500 °C. Oxides of carbon were the primary gases evolved, with small amounts of hydrocarbons and hydrogen. The bio-oils predominantly contained oxygenated aromatics and organic acids, and the chars had high fixed carbon and low sulfur. In all instances approximately half of the product output was liquid. Straw produced 14% gas and 32% solid at 500 °...

Thermal Decomposition of Wheat Straw and Mallee Residue Under Pyrolysis Conditions

A process for electrochemically reducing a metal oxide, such as titania, in a solid state in an electrochemical cell that includes a bath of molten electrolyte, a cathode, and an anode, which process includes the steps of: a) applying a cell potential across the anode and the cathode that is capable of electrochemically reducing the metal oxide supplied to the molten electrolyte bath, b) continuously or semi-continuously feeding the metal oxide in powder and/or pellet form into the molten electrolyte bath, c) transporting the powders and/or pellets along a path within the molten electrolyte bath and reducing the metal oxide as the metal oxide powders and/or pellets move along the path, and d) continuously or semi-continuously removing metal from the molten electrolyte bath. Also disclosed and claims is an electrochemical cell for carrying out this process.

Electrochemical reduction of metal oxides

An experimental study of initial solidification of 304 stainless steel melts in direct contact with copper substrates under conditions approximating the meniscus region of a strip caster has highlighted the importance of interfacial heat transfer during the first 30 ms of contact. The mechanisms governing initial heat transfer are strongly influenced by dynamic wetting phenomena. This has been illustrated experimentally by the effects of the buildup and melting of oxide films such as manganese silicates at the interface during successive immersions, by the role of surface active agents such as tellurium in the melt, and by the use of specially designed substrate textures to control contact areas.

Mechanisms of initial melt/substrate heat transfer pertinent to strip casting

Inverse numerical techniques have been applied in a range of different thermal studies in the past. These techniques require measurements of boundary conditions and temperatures at known position within the sample in order to determine thermal properties of the material of interest. Typically, they have been applied to highly specific applications and designs. In the current work the authors have designed a novel instrument in order to measure apparent specific heats of a range of different materials during continuous heating. Measurements of surface heat flux, surface and centre temperatures of the sample were obtained under controlled heating for temperatures of up to 1000°C. Measured data was used to quantify specific and latent heats by employing inverse numerical modelling technique. The instrument was calibrated with calorimetric calibration materials and results were compared with the literature values. The average experimental error was estimated to be approximately 0.9% for the reaction peak temperatures and 1.7% for the latent heats. Detailed experimental and calculation procedures as well as measured results of specific heat and enthalpy for a number of materials are presented here.

Les Strezov

Papers

Experimental Studies of Interfacial Heat Transfer and Initial Solidification Pertinent to Strip Casting

Thermal Decomposition of Wheat Straw and Mallee Residue Under Pyrolysis Conditions

Electrochemical reduction of metal oxides

Mechanisms of initial melt/substrate heat transfer pertinent to strip casting

Computer aided thermal analysis