Research Seminar Series 2012 archive

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Hydrothermal Liquefaction of Algal Biomass

Speaker: Yaya He
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 9 November 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Extensive research and development is now focused on utilising algal biomass as a source of biofuels and bio-chemicals due to a number of advantages. Hydrothermal liquefaction (HTL) in sub- and supercritical water is one of the most promising technologies available for the conversion of biomass.

Although HTL batch processes of commercially available algae are well studied and show promising results, continuous flow processing of such biomass has not been reported despite the substantial operational advantages acknowledged. A continuous flow pilot plant at the University of Sydney was designed and constructed for the development and optimisation of algal biomass processing under hydrothermal conditions.

This seminar will present preliminary results of commercial microalgae, from both a continuous flow as well as a batch HTL reactor system, under sub-critical water conditions (200-350C, 100-200 bar and 2-10 minutes residence time). Additionally, this work provides an insight into processing a unique green algae poly-culture currently being developed at a coal fired power station for HTL processing.

About the Speaker:

Yaya He is a PhD candidate under the supervision of Professor Brian Haynes and Dr. Alejandro Montoya in the school of Chemical and Biomolecular Engineering.


The Engineered Ligament-to-Bone Interface

Speaker: Ali Negahi
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Wednesday, 7 November 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details

Ligaments perform essential roles in stabilization of the body by maintaining bone alignment and guiding motions. Anterior cruciate ligament (ACL) connects the tibia to the femur and is recognised as the most vulnerable ligament in the knee joint. The self healing of ACL is very poor and current therapeutic methods including biological or synthetic reconstructions suffer from some limitations. Donor site morbidity, potency and disease transmission are the main drawbacks of biological reconstructions. The non-degradable ligament prostheses resemble mechanical properties of ligament. However, the high risk of rupture and synovitis are the major obstacle for their application. These limitations have promoted ongoing research to engineer a replacement that resembles native ligament in term of biological properties and mechanical durability.

The aim of this study is to design a new generation of gradient ligaments made of proteins and bioactive phosphate glass in structure that stimulates integration and remodelling of ligaments in vivo. Specifically this project will manufacture ligaments with gradient of different types of glasses that are incorporated into protein-based scaffolds in specific regions. Osteoprogenitor cells will be cultured into 3D structures to evaluate their osteogenic profiles. Preliminary results have indicated that natural-based nanocrystallines elevate the mechanical properties. Therefore, these nanostructures will be incorporated into scaffold to increase compression strength in bone attachment site.

About the Speaker:

Ali is a PhD candidate working with Associate Professor Fariba Dehghani in the School of Chemical and Biomolecular Engineering.


Synthesis of Protein Reactive, Injectable, Smart Polymer for Cartilage Repair

Speaker: Ali Fathi
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 2 November 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Osteoarthritis (OA), mainly from sport injuries, is one of the major health issues worldwide. Australian Institute of Health and Welfare reported that, OA affects more than 1.3 million Australian in 2007. The existing trend suggests that in 2050, more than 7 million Australian will be affected by OA. In modern approaches for OA and cartilage repair cells are cultured in vitro on bioengineered scaffolds, followed by in vivo implantation through open surgery process. The massive invasion in joint during the open surgery has adverse impacts on the healing process of surgical joint. Less invasive approaches for delivery of cartilaginous construct to the defected site, is required to address the current problems in cartilage tissue engineering.

The aim of this project is to synthesise an injectable polymer with favourable properties, suitable for cartilage repair. The designed polymer comprised of four segments which imparted thermo-responsive, good mechanical strength, protein reactive site, and hydrophilic properties to the smart polymer. At ambient temperature, cells can be mixed with polymer solution, followed by injection through an 18 G needle. Subsequently, the suspension forms hydrogel in situ at 37C. Mechanical, gelation, and degradation properties of this system were optimised by changing the composition of polymer to match the requirements for cartilage repair.

The presentation will provide an insight on features of this smart polymer for cartilage repair. The summary of results achieved so far and future plan will be discussed.

About the Speaker:

Ali is a PhD student working with Associated Professor Fariba Dehghani in the School of Chemical and Biomolecular Engineering.


Improved Zinc Bromine Flow Battery

Speaker: Martin Schneider
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 12 October 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details

In light of global warming and dwindling fossil fuel resources, an energy transition away from fossil fuels towards renewable energy sources is underway. Renewable energy sources however, are generally not constant in supply, making them difficult to match with demand. It is therefore necessary to provide appropriate energy storage solutions.

The zinc bromine flow battery has been in development for decades. It is promising for stationary energy storage as well as electric vehicle applications; it can easily be scaled up and the active material zinc bromide is comparatively cheap and abundant. However key performance parameters, such as energy efficiency, durability and energy and power density need further improvement. The aim of this PhD project is to design and test a novel zinc-bromine flow cell with improved performance. The project includes:

  • Development of a zinc bromine flow cell in classical design which acts as benchmark.
  • Development of an optimised electrode manufacturing process.
  • Designing and testing of novel zinc bromine flow cell.
  • Testing of pulse plating technology for zinc deposition.
  • Testing of simultaneous use of different bromine electrodes in one cell.
  • Testing of a novel bromine sequestration agent provided by the School of Chemistry

This presentation gives an introduction to the project, summarises the progress so far and outlines the future work.

About the Speaker:

Martin Schneider is a PhD candidate working with Prof. Anthony Vassallo from the School of Chemical and Biomolecular Engineering and Prof. Thomas Maschmeyer from the School of Chemistry.


Guest Speaker Peter Coppin

Securing Our Renewable Energy Future with Storage

Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Tuesday, 9 October 2012
Time: 3.30pm

Details:

In a future reliant on increasing amounts of renewable energy, coping with the inherent variability in generation from weather driven sources such as wind, solar and wave will become a major issue. Shifting energy from windy or sunny days or filling in shorter wind lulls and cloudy periods is seen as an ideal role for storage. Established storage technologies such as pumped-hydro and compressed air are able to achieve this where they are feasible. The current power generation, transmission and market systems are, in fact able to cope with these longer term-trends while variable renewables remain at modest penetration levels. There is another class of applications for storage, perhaps more pressing than energy shifting by hours or days. When highly convective or stormy weather conditions are widespread, the fluctuating wind speeds can produce substantial variations in wind energy generation with periods of 1 hour or less. Similarly, intermittent cloud can produce very sharp changes in PV solar power generation. These conditions can lead to very significant problems on the grid, reducing carrying capacity of lines and increasing the amount of spinning reserve and regulation services required to unachievable levels. The only alternative is to curtail the renewable generation, which is already being done in several markets.

A number of electrical storage technologies are being developed to both remove these rapid fluctuations and provide support to grid systems with large amounts of solar and wind power. Most of these are now being demonstrated at the MW-scale. These include lithium-ion, flywheel, flow-batteries and new-generation hybrid lead-acid batteries such as the CSIRO-developed UltraBattery technology which utilises an internal ultra-capacitor to give faster charge/discharge capability and longer life. These storage systems are designed only to remove the short-term variations and do not attempt to store total generation. This results in an effective system without the normally high capital cost. The smoothing system is controlled by predictive algorithms which utilise solar and wind forecasting techniques which can significantly reduce the amount of storage needed. Examples of a number of commercial, MW-scale trials of these systems will be outlined.

About the Speaker:

Peter Coppin received the B.Sc.(Hons) degree in 1974 and the Ph.D. degree in micro-meteorology from Flinders University of South Australia in 1978. After completing a post-doctoral fellowship at the University of Hannover, Germany, 1978-1980 in wind energy, he was appointed as a research scientist at CSIRO in 1980.

He was Director of the CSIRO Wind Energy Research Unit until 2009 and is currently Leader of the Storage for Renewables Stream at the CSIRO Energy Transformed Flagship. His research interests include boundary-layer meteorology, renewable energy storage and forecasting.


Development of Active Compounds from a Molluscan Hemolymph for treatment of viral infections

Speaker: Negar Talaei
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 5 October 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Herpes simplex virus type-1 (HSV-1) is the major cause of cold sores affecting 76% of Australian population. The ability of virus to mutate and cause latent genital herpes and the emergence of resistance against the licensed anti-HSV drug (acyclovir), as well as the low bioavailability of acyclovir motivated researchers to find or synthesize new compounds blocking HSV-1 infections. The hemolymph of crustaceans such as molluscs and arthropods, which is composed of glycoproteins and peptides, has shown to possess antiviral activity against a few members of herpes virses including HSV-1. However, little is known about the major component responsible for such activity, its physical and chemical characteristics and mode of action.

This project focuses on identifying the active compound of hemolymph and its characterisation with the aim of understanding its mechanism of action. Analytical methods have been established and validated for the physico-chemical characterisation of a complex glycoprotein which is the key component of hemolymph. These methods include SDS- and Blue-Native PAGE, transmission electron microscopy and LC-MS/MS analysis. In addition, antiviral activity assay has been developed to determine the activity of hemolymph components.

The presentation will provide an insight on features of this glycoprotein. The summary of results achieved so far and future plan will be discussed.

About the Speaker:

Negar Talaei is a PhD student working with Associated Professor Fariba Dehghani in the school of Chemical and Bimolecular Engineering.


Emulsion Polymerisation of Amphiphilic polymers: Mechanism and Modelling

Speaker: Samira Ghasemi
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 21 September 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Despite a long history of research, the synthesis of amphiphilic polymers remains usually a matter of know-how than know-why. Hydrophilic monomers bearing carboxylic acid groups are often used as functional monomers in emulsion polymerisation recipes to provide the final products with sites for post-polymerisation reactions and to enhance the chemical and mechanical stability of the latex particles.

The objective of this study is to explore the emulsion polymerisation mechanism in the presence of hydrophilic comonomers. A dynamic model also has been developed to simulate the polymerisation in order to obtain more knowledge about the mechanism of particle formation and growth stages in these systems. It was observed that methacrylic acid (MAA) and acrylic acid (AA) comonomers changes the mechanism of emulsion polymerisation significantly and this behaviour depends on the reaction condition and hydrophilicity of hydrophilic comonomers.

About the Speaker:

Samira is a PhD candidate working with Associate Professor Vincent Gomes in the School of Chemical and Biomolecular Engineering and Associate Professor Brian S Hawkett in the school of Chemistry.


Thermal stability of hemocyanins: Steps towards formulation of new protein pharmaceuticals

Speaker: Gavin Marshall
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 14 September 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Hemocyanins are a class of proteins with potential medicinal applications (e.g. as anti-viral drugs). Our work aims to characterise the properties of a particular molluscan hemocyanin and this project is specifically investigating the structure and stability of the protein.

The denaturation and aggregation behaviour of this hemocyanin has been studied as a function of the thermodynamic or kinetic stability of the protein thereby investigating the reversible or irreversible nature of these transitions. The effect of changes in solvent concentration is investigated and relevant kinetic models are assessed. This allows some insight into the intramolecular forces which hold the hemocyanin into its native state.

The aim of this research is twofold: we simultaneously intend to create a stable formulation of this therapeutic compound and to create a better understanding of the forces which stabilise large proteins so that a methodology by which stabilising formulations may be created for a range of other similar proteins.

About the Speaker:

Gavin is a PhD candidate working with Associate Professor Vincent Gomes and Associate Professor Fariba Dehghani in the School of Chemical and Biomolecular Engineering.


Multi-Walled NanoTubes (MWNT) – Chlorophyll Hybrids: Self Assembly and Photoresponse

Speaker: Alice King
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 31 August 2012
Time: 11am

Morning Tea served from 10.45am in the common room

Details:

Non-covalent attachment of light harvesting molecules to carbon nanotubes (CNTs) has the potential to open up new hybrid nanostructures. Since this does not introduce covalent defects into the graphitic carbon backbone, the conductive properties of the CNT are preserved, enabling charge transfer between the molecule and the CNT support. Here we demonstrate that a simple solution mixing process can produce non-covalent hybrids of chlorophyll and CNTs that demonstrate self assembly and charge transfer. These hybrids display a photocurrent even as thin films, and have improved characteristics in the presence of a hydrogel electrolyte.

About the Speaker:

Alice is a PhD candidate working with Professor Andrew Harris and Associate Professor Andrew Minett in the School of Chemical and Biomolecular Engineering.


Optimisation of Lovastatin Biosynthesis by Aspergillus Terreus

Speaker: Zi Chun Wang
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 17 August 2012
Time: 11am

Morning Tea served from 10.45am in the common room

Details:

Cardiovascular disease (CVD) refers to diseases of the blood vessels and heart and is the leading cause of deaths globally. According to the World Health Organisation (WHO), it is estimated that over 23.6 million people will die from CVD by 2030. One of the major risk factors of CVD is high cholesterol levels in the body as it promotes atheroma development in arteries also known as atherosclerosis.

Statins are a group of drugs which are most commonly prescribed for the treatment of CVD. Statins act by specifically inhibiting 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, a rate-limiting enzyme of cholesterol biosynthesis in the liver. This mechanism has been shown to effectively reduce the cholesterol level in the body by as much as 40%. Recent preliminary studies have also reported that statins may also be beneficial for the treatment of other diseases such as osteoporosis, Alzheimer's and cancer.

One of the major microbial producers of statins is the fungus Aspergillus terreus which has been shown to produce a statin called lovastatin as a secondary metabolite through controlled conditions in a bioreactor. However, there are still gaps in the knowledge in terms of achieving enhanced yields of lovastatin.

In this talk, Hafiz will present his project which aims to optimise lovastatin production by A. terreus. Achieving this aim requires understanding how the media composition and bioreactor conditions influence the behaviour of the fungus. This understanding will inform future genetic modifications of the fungus on one hand and modelling and optimisation of production on the other. Another aspect to be discussed is the use of abundantly available waste industrial products namely crude glycerol as the substrate for lovastatin production by A. terreus.

About the Speaker:

Hafiz is a PhD candidate working with Dr Ali Abbas in the School of Chemical and Biomolecular Engineering.


Synthesis of supported metal nanocatalysts for biomass catalytic transfer

Speaker: Zi Chun Wang
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 10 August 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Biomass is the only renewable resource with great potential for sustainable production of chemicals and fuels. Catalytic transformation represents the state-of-art accomplishments to generate fuels and value-added chemicals from biomass with high yield and selectivity. The progress in this area could exert profound effect on human future. The key of catalytic biomass transformation into valuable chemicals and fuels is the revolution of catalyst development. Due to the concept of green catalysis, the use of nanotechnology to develop heterogeneous catalysts is becoming one of the most important scientific challenges. Supported metal catalyst is one of the most favourable heterogeneous catalysts for biomass transfer reactions. Extensive efforts have been devoted to this area. However, the synthesis of supported metal nanocatalysts in an efficient way with controllable morphology and high catalytic performance for biomass transformation is still a challenge.

The aim of this project is to develop a systematic method based on flame spray pyrolysis (FSP) method for the synthesis of supported metal nanocatalysts in a single step with unique physicochemical properties and high catalytic performance.

Speaker Details:

Zi Chun Wang is a PhD student working with Dr Jun Huang in the School of Chemical and Biomolecular Engineering.


SCALABLE PRODUCTION OF MOLLUSC HEMOCYANIN USING ANIMAL CELL CULTURE

Speaker: Fareed Sairi
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 27 July 2012
Time: 11am

Refreshments served from 10.45am outside the venue (Prior to earlier seminar, see below)

Details:

Hemocyanin is an oxygen carrier protein that has been used intensively in biomedical field research. Current applications include hemocyanin as a carrier protein to vehicle drugs or smaller peptides, immunotherapy against bladder cancer and antiviral compound against Herpes Simplex Virus 1 (HSV1). Due to this, hemocyanin, especially from mollusc, is considered as an attractive compound for pharmaceutical industry commercialization.

Currently, hemocyanin supply is still dependant on live animals. It has to be extracted and purified from the animal's hemolymph. This practice however, raised a number of concerns regarding the availability of the hemocyanin in the future, whether it can catch up with increasing demand in the future or not. Thus, an alternative approaches to supply more hemocyanin in the future is needed.

This study proposed one of the alternative approaches to supply hemocyanin in near future. This approach is the synthesis of hemocyanin using in-vitro method, in specific, cell culture.

About the Speaker

Fareed Sairi is a PhD student working with A/Prof. Fariba Dehghani and A/Prof. Vincent Gomes in the school of Chemical and Bimolecular Engineering.


Guest Speaker Associate Professor Avner Rothschild

Resonant light trapping in ultrathin films: Boosting the efficiency of a-Fe2O3 photoanodes for water splitting

Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 27 July 2012
Time: 10am

Refreshments served from 9.45am outside the venue

Details:

Semiconductor photoelectrodes for efficient solar hydrogen production by water photoelectrolysis must employ stable, non-toxic, abundant and inexpensive semiconductor visible light absorbers. Iron oxide (a-Fe2O3) is one of few materials meeting these requirements, but its poor transport properties present challenges for efficient charge carrier generation, separation, collection and injection. Here we show that these challenges can be addressed by means of resonant light trapping in ultrathin films designed as optical cavities. Interference effects between forward and backward propagating waves enhance light absorption in quarter-wave or, in some cases, deeper sub-wavelength films, amplifying the intensity close to the surface wherein photogenerated minority charge carriers (holes) can reach the surface and oxidize water before recombination takes place. Our approach enables efficient light harvesting in a-Fe2O3 films thinner than 50 nm, thereby suppressing the recombination loss and overcoming the tradeoff between light absorption and charge collection efficiencies. We show that water photooxidation current densities as high as 4.8 mA cm-2 may be achieved in simple stratified structures comprising ultrathin a-Fe2O3 films on a reflective substrates.

About the Speaker

Avner Rothschild is an associate professor at the Department of Materials Engineering of the Technion - Israel Institute of Technology. After graduating from the Technion (BSc in Physics and in Materials Engineering in 1997, PhD in 2003) he spent three years at MIT as a postdoctoral researcher in Harry Tuller's group. In 2006 he returned back to the Technion as a faculty member. Avner is heading the Electroceramic Materials & Devices research group, working on semiconducting, ionic and mixed ionic electronic conducting oxides for applications in electronic and optoelectronic devices, gas sensors and solar cells. He is a member of the editorial board of the Journal of Electroceramics, the Technion Energy Team, and Israel's Solar Fuels Consortium.


Yield Improvement in Large-scale Bubble Column Fermenters

Speaker: Dale McClure
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 13 July 2012
Time: 11am

Refreshments served from 10.45am outside the venue

Details:

Bubble columns are widely used in the biotechnology industry to produce a range of products including amino acids, antibiotics, vitamins and baker's yeast. Current processes used to produce these compounds at a commercial scale results in a yield drop of 7-20% compared to pilot scale production. The cause of this difference in yield is thought to be poor mixing in the large scale (50-150 m3) bubble columns used in commercial production.

The aim of this work is to develop a Computational Fluid Dynamics (CFD) model of industrial bubble columns and use this as a tool to identify ways in which mixing can be improved, with the aim of increasing yield in commercial columns. Many authors have developed CFD models of bubble columns, but very few have examined the issue of mixing. Additionally there are several outstanding issues in the modelling of two-phase flow at high gas volume fractions, some of which this project will attempt to address.

Thus far a CFD model in good agreement with experimental results from two bench-top experimental rigs has been developed. Future work will involve extending this model to larger geometries, as well as extending the model to systems which contain surfactants which are more representative of fermentation media.

About the Speaker

Dale is a PhD candidate working with Dr John Kavanagh, Professor Geoff Barton and Professor David Fletcher in the School of Chemical and Biomolecular Engineering.


CO2 Reforming of Methane: Design and Synthesis of Hierarchically Ordered Nickel and Calcium Aluminate Catalysts and Supports

Speaker: Nikki Amos
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 29 June 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

Carbon dioxide reforming of methane used in conjunction with biomass gasification of renewable carbonaceous feedstocks, offers a sustainable way to convert two greenhouse gases, CO2 and CH4, into syngas. Compared to steam methane reforming, this syngas has a low H2/CO ratio and is best suited for use in, for example, gas to liquids (GTL) technologies such as the Fischer Tropsch process.

Nickel catalysts are known to have a high catalytic activity towards CO2 methane reforming, are inexpensive and abundant, however, they are prone to deactivation via coke deposition. Materials containing either NiAl2O4 or CaAl2O4 and bimetallic catalysts such as Ni-Rh or Ni-Co have stabilised nickel catalyst particles and are reported to have a lower degree of coke formation. Also, it is thought that mass transport/pore diffusion limitations will be overcome by a hierarchically ordered pore system.

This seminar will describe the design and synthesis of mesoporous and hierarchically ordered alumina and calcium and nickel aluminate materials via a soft-templating nanocasting technique using structure-directing agents to afford hierarchically ordered catalysts. The results of preliminary (sorption-enhanced) steam methane reforming experiments using these materials will be presented. Strategies for applying these materials to the CO2 reforming of methane process will be discussed in light of previous catalytic experiments and available literature data.

About the Speaker

Nikki Amos is a PhD student working with Professor Andrew Harris and Dr. Tamara Church in the school of Chemical and Bimolecular Engineering.


Energy Saving in Spray Drying: a Basis for Energy Auditing in Drying Processes

Speaker: Perry William Johnson
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 8 June 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

This work studies the compatibility and suitability of a combined, or integrated, optimisation approach using Inversion temperature, Pinch analysis and Exergy analysis to optimise spray-drying systems. The importance of energy saving is significant since the energy use associated with dryers accounts for between 4 and 10% of total energy use, or between $1.6 and $4 billion per annum.

This work utilises and compares various methodologies, as applied to spray drying, to develop an objective methodology to optimise the quality of energy used, as well as the quantity, while integrating different forms of energy into the analysis to allow for a simple comparison on the basis of cost and environmental impacts.

Key results from this comparison are that the steam dryer sets the Pinch temperature, while the air dryer does not set the Pinch temperature, rather the fresh inlet gas temperature does. This means that steam drying, when run at 1 atm, works across the Pinch while the air dryer works above the Pinch on its own, meaning that the steam dryer is easier to integrate into other systems. Also the steam system has less sensitivity to temperature and flow changes in terms of energy requirements than the air system. This is a due to the steam circuit being a recycle stream, rather than a once-through system commonly used for air drying.

The preliminary results of the exergy analysis showed that some electrically fed heat recovery options are viable for this drying system, and have the potential to reduce energy use in ways that the pinch analysis is unable to determine.

About the Speaker

Perry is a PhD candidate working with Professor Timothy Langrish in the School of Chemical and Biomolecular Engineering.


Vertically-aligned Carbon Nanotubes Supported Iron-cobalt-nitrogen Complex as Electrocatalyst in Proton Exchange Membrane Fuel Cell

Speaker: Adrianus Leonardy
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 1 June 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

Depleting supply of platinum is major threat to the fuel cell commercialisation. Non-noble metal based electrocatalysts in the proton exchange membrane fuel cell (PEMFC) application have become more attractive due to their low cost and promising electrochemical activity that can potentially replace the expensive and unstable commercially available platinum based electrocatalyst. However, improvement in activity and stability will always remain a challenge.

In this project, after investigating several methods and optimisation works vertically-aligned carbon nanotubes supported iron cobalt-nitrogen complex (FeCo-Nx/VACNT) electrocatalyst was successfully prepared via injection chemical vapour deposition (CVD) system. Active sites, which contain iron/cobalt coordinated by pyridinic nitrogen functionalities on the body of nanotubes array support, are believed to play critical role in the oxygen reduction reaction (ORR). Excellent controllability of carbon nanotubes array support height offers the advantage of efficient mass and electron transport. Combining those two key factors will lead to major contribution in the improvement of non-noble metal based electrocatalyst performance.

About the Speaker

Adrianus Leonardy is a PhD student working with Professor Andrew Harris and Associate Professor Andrew Minett in the school of Chemical and Biomolecular Engineering.


Synthesis, Dispersion and Applications of Nitrogen-Doped Carbon Nanotubes

Speaker: Agus Husin
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
[[b||Date: Friday, 25 May 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

Doping of Carbon Nanotubes (CNTs) with nitrogen atoms provide a route for modification of CNTs' structural, physical and chemical properties. In this body of work, three main areas associated with nitrogen doping will be explored, namely the synthesis of nitrogen-doped carbon nanotubes (N-CNTs), their dispersion characteristics and potential applications.

N-CNTs were successfully synthesised using a chemical vapour deposition technique. The synthesised N-CNTs were then studied for their dispersion characteristics. This is important because CNTs have a tendency to agglomerate due to attraction between individual CNTs, which is detrimental to their electrical and mechanical properties. Dispersion of CNTs in organic solvents offers a simple method of CNTs separation. Thermodynamical consideration of CNTs-solvents interactions was considered by applying the Hansen solubility theory. Stable solution with N-CNTs concentration of 110mg/L was obtained in the study, comparable to that for undoped CNTs. A number of new solvents not previously reported in the literature for CNTs dispersion were found form stable N-CNTs solutions, namely Gamma-valerolactone (GVL), triethylphosphate and 1,3-dimethylimidazolidin-2-one (DMI).

The inherent difference in electronegativity between carbon and nitrogen atoms offers N-CNTs increased reactivity compared to undoped CNTs. Of an area of interest is their catalytic activity, with a large number of catalysis works reported in the literature for oxygen reduction reaction in fuel cells. Future work therefore takes the direction of investigating catalytic activity of N-CNTs, in particular the role that different N species within the carbon lattice plays as catalytically active sites.

About the Speaker

Agus Husin is a PhD student working with Professor Andrew Harris and Associate Professor Andrew Minett in the school of Chemical and Biomolecular Engineering.


Renewable H2 by Aqueous Phase Reforming of Oxygenated Hydrocarbon over Supported Catalyst

Speaker: Rahman Mohammad Mizanur
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 18 May 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

Hydrogen, which is a clean fuel emitting only water when combusted or oxidised, is growing high demand due to the technological advancements made in the fuel cell industry. Among the technologies, Aqueous Phase Reforming (APR) plays a great role for producing fuel cell grade H2 in a single step process, at mild reaction conditions (200-250 oC, 10-50 bar) from biomass derived oxygenated hydrocarbons.

Catalysts, particularly noble metals (Pt, Pd), containing ceria as support or promoter are very important due to the unique acid-base and redox properties of ceria However, the utilization of ceria alone as support is not suitable due to its low surface area. Therefore, alumina together with ceria permits the development of new materials combining the high surface area of alumina with the unique properties of ceria. Considering that hydrothermal stability, higher dispersion, WGS reaction, coke resistance and prohibited to methanation would be very useful in the APR of glycerol, we developed a series of Pt catalysts supported on ceria-doped alumina. The goal of this work is to investigate the effect of ceria doping on alumina support for the APR of glycerol with higher activity and selectivity towards hydrogen.

About the Speaker

Rahman is a PhD candidate working with Professor Andrew Harris in the School of Chemical and Biomolecular Engineering.


Experimental Study of Fluid Flow and Heat Transfer in Tortuous Microchannels

Speaker: Zhenhui Dai
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 11 May 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

With the miniaturisation of heat transfer devices, approaches by which heat transfer performance can be improved without large pressure drop penalties have become a subject of great interest. The tortuous micro-channel, where secondary flows (Dean vortices) occur due to the channel curvature, is of critical importance as it provides a means of heat transfer enhancement.

While there are a considerable number of numerical investigations of the flow and heat transfer performance in wavy micro-channels, very few verified experimental data can be found due to technical difficulties in making detailed velocity and temperature measurements in micro-scale devices. Recent developments in non-intrusive technologies, such as Micro-resolution particle image velocimetry (Micro-PIV) and Micro-Laser Induced Fluorescence (Micro-LIF), have provided the potential to make new and exciting measurements.

This study aims to develop novel experimental techniques to investigate the fluid dynamics and heat transfer characteristics in tortuous micro-channels and to validate numerical models. Simultaneous flow visualisation and heat transfer experiments in tortuous micro-channels will be carried out to understand the fundamental mechanisms responsible for the heat transfer enhancement, assisting with channel design and optimisation of compact plate heat exchangers.

About the Speaker

Zhenhui Dai is a PhD student working with Professors Brian Haynes and David Fletcher in the School of Chemical and Biomolecular Engineering.


Biohydropyrolysis of Polymeric Components of E-waste

Speaker: Amy Chan
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 4 May 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

The revolution in information and communication technology (ICT) has brought huge technical benefits and wealth, but has created a major global problem: the generation of vast amounts of electronic waste, or e-waste through product obsolescence. Most countries do not have suitable end-of-life programs to deal with e-waste. The biggest challenge is developing a process that can adapt to the complexity, changing compositions, toxicity and volume of e-waste.

The majority of technologies that are being developed to re-process e-waste are concentrating only on the recovery of the metallic fractions. This has resulted in a growing concern in the generation of a new tertiary waste in form of non-metallic waste from e-wastes. Toxic tertiary products from recycling operations are unacceptable as feedstock to existing processes and their disposal in landfills results in adverse environmental problems. These issues are magnified by huge volumes of e-waste. In the light of these concerns, the search for a cost effective and environmentally friendly method of reclaiming value added materials and energy from the polymeric component of e-waste is an urgent goal.

This study aims to address this shortfall by developing a low-energy technology for recycling these polymeric wastes from WEEE through a process called bio-hydropyrolysis. This process harnesses the ability of the organisms to degrade the polymeric waste and forms the foundation for a lower temperature recovery of the material and energy content of the waste by pyrolysis. The basis of this technology is the utilisation of microbial degradation to pre-treat polymers to lower the degradation temperature.

About the Speaker

Amy is a PhD student working with Associate Professor Marjorie Valix in the School of Chemical and Biomolecular Engineering.


Investigation on the Mechanism of Inverse Heterophase Polymerization of Water Soluble Monomers

Speaker: Zohreh Abdollahi
Venue: Lecture Theatre 2, J01 Chemical Engineering Building
Date: Friday, 27 April 2012
Time: 11am

Refreshments served from 10.45 a.m. outside the venue

Details:

Polyacrylamides (PAAMs) including both homo- and copolymers of acrylamide constitute the largest group of water soluble polymers which are used in various industrial applications. High molecular weight PAAMs are challenging to produce and are in high demand in industries such as waste water treatment and enhanced oil recovery (EOR) as flocculant and viscosifier, respectively.

The common industrial method for synthesis of high molecular weight PAAMs is inverse heterophase polymerization (including inverse suspension, micro suspension and emulsion polymerizations); however, still considerable disagreement exists regarding the mechanism of this type of polymerization. Therefore, the goal of my study was set to investigate the mechanism of inverse heterophase polymerization and develop computer model based on mechanistic understanding of polymerization in order to enable design and scale-up of processes.

In this presentation, I will provide detailed information of my current work as a PhD student in the School of Chemical and Biomolecular Engineering. The results of my work will be discussed in light of the available literature data.

About the Speaker

Zohreh Abdollahi is a PhD student working with A/Prof. Vincent Gomes and Prof. Brian Hawkett in the school of Chemical and Bimolecular Engineering and Key Centre for Polymer Science.