3 rd Curtin Engineering Faculty Research Colloquium

rd 3 Curtin Engineering Faculty Research Colloquium 6th November 2007 Book of Abstracts Curtin Engineering Faculty Research Colloquium 6 November...
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3 Curtin Engineering Faculty Research Colloquium 6th November 2007

Book of Abstracts

Curtin Engineering Faculty Research Colloquium

6 November, 2007

STREAM A – LIST OF PAPERS A1

Dedet Riawan

Energy Conversion Efficiency of Solar Charge Controller Fed by a-SI & c-SI PV Modules

A2

Kaveh Soltaninaveh

The Properties of Geopolymer Concrete Incorporating Red Sand as Fine Aggregate

A3

Fonny Lastari

CO2 Sequestration in a Glance

A4

Ganesh Kumar Veluswamy

CFD Modelling of FCC Strippers

A5

Muhammad Imran Khalid

Fault Detection and Diagnostics in Wastewater Treatment Systems

A6

Tahir M. Rafique

Monitoring, Diagnostics and Improvement of Process Performance

A7

Yu Zhao

Design of a SCADA Controlled Mini-grid Hybrid Power and Water Supply System for Remote Areas

A8

Samuel Panggalo

Adaptive ofdm in power line communication

A9

Xie Jinfei

Pattern-Based Characterization of Financial Time Series

A10

Andrew Foong Jun Li

Microchannel with longitudinal internal fins

A11

Agus Ulinuha

Impact of Harmonics on Optimal Control of Voltage/Reactive Power in a Distorted Distributed System

A12

Yenny Rojas

Investigation of Kinetic Inhibition of Methane Hydrates Formation

A13

Zhenhe Song

The Influence of Disturbed Zone on Capacity of Suction Embedded Plate Anchors

A14

Muhammad Sheikh Sadi

Transient Fault Protection in System on Chip Architectures

Curtin Engineering Faculty Research Colloquium

6 November, 2007

STREAM B – LIST OF PAPERS

B1

Noor Hakim Bin Rafai

An Investigation Into Dimensional Accuracy and Surface Finish Achievable in Dry Turning: Preliminary Study

B2

Hu Xiao Lin

Stability Analysis of Networked Control Systems

B3

Monita Olivia

Cover Quality Testing as an Indicator of Geopolymer Concrete Durability

B4

Lai Sin Pin

Analysis of the Conductivity of the Transformer Oil Due to Aging From Spectral Response

B5

Susanne Christina Sugiarto

Power System Stability and Quality Improvement and Renewable Energy Utilisation Through WECS with Cascaded CC-VSI and VC-VSI

B6

Agus Saptoro

Learning Criteria for Neural Network Training

B7

Fu Qiang

Energy and Economic Analysis of Cryogenic O2 Production for Oxyfuel Combustion Technology

B8

Chirayu Siddharth Shukla

Modeling and Simulation of Permeable Reactive Barrier for Groundwater Remediation

B9

Bejoy Bharatiya

Recovery of Sulphur by Modified Claus Process

B10

Yun Yu

Economic Viability of Ethanol Production From Mallee Biomass in Western Australia

B11

Shariff Ibrahim

Removal of Emulsified Oil in Wastewater Using Barley Straw

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-1

ENERGY CONVERSION EFFICIENCY OF SOLAR CHARGE CONTROLLER FED BY A-SI & C-SI PV MODULES D.C. Riawan [email protected] Department of Electrical and Computer Engineering

Small-scaled stand-alone photovoltaic (SAPV) systems are widely used in remote areas. The SAPV comprises a single or couple of PV modules, charge controller, battery and load. Efficiency is a major concern in SAPV due to the limited number of installed PV modules. In such system, the generated power by the PV module is delivered through the wiring into the battery and load using a charge controller to protect the battery from overcharging or over discharging. All the power cannot be delivered to the load or battery due to losses in the wiring, converter and battery. Many techniques have been presented to increase the SAPV efficiency in terms of optimizing the PV module output power or by reducing losses in converter. Since the output power of PV module is directly affected by module surface temperature, integration of PV module and water cooler into one structure is proposed by [1]. Another approach is proposed by [2], where a modified converter topology using parallel power transfer method could increase the efficiency in a dc-dc converter. To obtain better both economical and technical performance, integration of inverter and PV module was proposed [3].

140

1200

120

1000

100

800

80 600 60 400

40 a-Si output power c-Si ouput power Irradiance

20

Fig. 1. Schematic of the experimental test setup.

0 04:48

07:12

09:36

12:00

Solar Irradiance (W/m2)

PV Output Power (Watt)

Among thin-film technologies, amorphous silicon (a-Si) technology is already manufactured commercially. Compared to the established crystalline silicon (c-Si) module, a-Si module has different characteristics, which produces higher output voltage. Therefore, using a-Si module, a wide input voltage range of charge controller is selected. This study examines the energy efficiency of two similar charge controllers that are fed by different types of PV module, i.e. c-Si and a-Si. Detailed mathematical model based on small-ripple approximation [4] is developed to study energy efficiency of system. Long term test results using different PV module is performed to show the actual energy efficiency of a solar charge controller.

200

14:24

16:48

0 19:12

Fig. 2. Solar charge controller efficiency during field test. Time (hour)

References [1]

S. Krauter and F. Ochs, "The integrated solar home system," presented at IEEE Third World Conference on Photovoltaic Energy Conversion, 2003.

[2]

D. Snyman and J. Enslin, "Novel technique for improved power conversion efficiency in PV systems with battery back-up," presented at IEEE 13th Telecommunications Energy Conference, 1991.

[3]

S. Islam, A. Woyte, R. Belmans, P. Heskes, P. M. Rooij, and R. Hogedoorn, "Cost Effective Secon Generation AC-modules: Development and Testing Aspects," Energy, pp. Article In Press, 2005.

[4]

R. W. Ericson, Fundamentals of Power Electronics, 2nd ed ed. Massachusetts: Kluwer Academic Publisher, 2001.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-2

THE PROPERTIES OF GEOPOLYMER CONCRETE INCORPORATING RED SAND AS FINE AGGREGATE Kaveh Soltaninaveh [email protected] Department of Civil Engineering

Concrete is the most common building material in the world. Geopolymer concrete is an inorganic alumino-silicate polymer synthesized from predominantly Silicon, Aluminium and by-product materials like fly ash. Fly ash is a by-product from coal-fired power plants and is abundantly produced and available. Red sand is a by-product generated from the manufacture of alumina from bauxite by the Bayer process. This research looks into the replacement of natural sand with red sand as the fine aggregate in geopolymer concrete. So far, many trial mixtures have been made and various properties of geopolymer concrete using Red Sand have been studied. Some of the major investigations are as follow: •

Using various grading of aggregates to find the optimum percentage of required RS



Workability of GPC+RS



Effect of super plasticizer on workability and compressive strength of GPC+RS



Effect of added water on workability and strength of GPC+RS



Effect of curing method



Effect of curing temperature on strength



Effect of rest day on strength



Compressive strength of GPC+RS on different ages



Indirect tensile strength



Determining the modulus of rupture



Determining the modulus of elasticity and poison’s ratio



Determining the Water absorption and apparent volume of permeable voids



Determining the Drying shrinkage of GPC+RS during time after casting

Results Using Red sand in place of Normal sand decreases the workability of fresh concrete and consequently affects the strength because a non-workable mixture can not be compacted well. During the project, by using different grading of aggregate and altering the proportions, a workable mixture was achieved and the above tests were carried out. Results show that Geopolymer concrete incorporating Red sand exhibits good compressive, indirect tensile and flexural strength. It suffers low drying shrinkage and the water absorption and AVPV results fall within the accepted limits. So, it could be an appropriate replacement for Natural sand. References Wahyuni, AS, Nikraz, H, Jamieson, E, Cooling, D 2006, Sustainable Use of Residual Bauxite Tailings in Concrete, Green processing Conference, Newcastle, 5-6 June.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-3

CO2 SEQUESTRATION IN A GLANCE Fonny Lastari [email protected] Department of Chemical Engineering

Global warming as a result of green house gas emission has received a great deal of attention in the world of research. Carbon dioxide is one of the green house gases that increase significantly in the atmosphere as a result of human activities. Carbon dioxide is generated from various sources such as power generation plant, industrial processes, and vehicles’ emission. Various approaches are needed to reduce carbon dioxide emission include efficient use of energy, substitution to lower carbon-intensive fuel, greater use of renewable energy, and geo-sequestration. Geo-sequestration for a deep cut reduction in carbon dioxide emission to the atmosphere is currently under intensive research. Geo-sequestration includes capturing, transporting, injecting at high pressures, and storage of CO2 in the geological formation. Different techniques are used in capturing CO2 from various sources such as absorption, adsorption, membrane, and low temperature processes. The captured CO2 is then transported from the source to the geological storage site via pipeline or by truck, rail, or tanker. Next the CO2 is injected deep underground into the geological reservoir such as depleted oil and natural gas fields and deep saline formations. The Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) is one of the world’s collaborative research organizations focused on CO2 geo-sequestration. CO2CRC is undertaking various studies on the geological formation in Australia and New Zealand that is suitable for safe and long-term CO2 storage. CO2CRC also observes the CO2 migration upwards to the ground surface by analysing the CO2 behaviour in the geological formation. Furthermore, risk assessments on the environment are also performed by observing any change in soil, groundwater, air, and deep groundwater. CO2CRC has established Otway project and LaTrobe valley project to simulate CO2 sequestration project and monitor the effect of geological sequestration to the environment as well as provide proof to the community and government at all levels and industry. References D Hilditch, A Palmer, J Torkington, 2007, CO2 Sequestration Seminar, Society of Underwater Technology. www.co2crc.com.au www.ictpl.com.au http://en.wikipedia.org/wiki/Greenhouse_gas J.W Johnson, 2000, A Solution for Carbon Dioxide Overload, Lawrence Livermore National Laboratory. T.A Torp, The Sleipner and Snohvit CO2 juelich.de/ptj/projekte/datapool/page/1330/SACS.pdf)

Projects,

Statoil,

Norway

(http://www.fz-

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-4

CFD MODELLING OF FCC STRIPPERS. Ganesh K Veluswamy [email protected] Department of Chemical Engineering

Fluid catalytic cracking (FCC) is the main heavy oil conversion process in most refineries (Avidan et al., 1990), allowing a higher yield of premium petroleum products such as gasoline. In FCC units the cracking reactions take place as the vaporized gas oil feed and catalyst flow up the riser. After disengagement of the product gas and catalyst, the catalyst must be regenerated because of deactivation due to coke deposition. The hydrocarbons present in the interstitial gas are entrained and adsorbed on the catalyst surface. It is important to strip these hydrocarbons quickly and efficiently prior to regeneration. Stripping is generally accomplished in a dense, moving fluidized bed by adding steam which bubbles upwards, counter-current to the down flowing catalyst emulsion. Ideally, the catalyst and steam are evenly distributed for efficient contacting with minimal back mixing. Entrained hydrocarbons are then transferred from the catalyst emulsion phase into the steam bubble phase. The resulting steam-hydrocarbon mixture flows up into the reactor vessel, allowing the recovery of the stripped hydrocarbons as product. Usually the stripper is either an annular vessel located around the riser circumference, or a full cylindrical vessel. Baffles are normally installed in strippers to promote better distribution and contacting of gas and solids (King, 1992). Incomplete stripping results in loss of valuable products due to combustion in the regenerator. Increase in hydrocarbon burned increases the regenerator temperature. This higher temperature adversely affects the FCC unit heat balance. The FCC Stripper section infact acts as a bottle neck in the whole process. A little has been studied and reported in literature on FCC stripers. Mckeen et al., 2003 have reported 2-D CFD studies on stripper hydrodynamics. This work was carried out for an experimental scale stripper and in this form it can’t be accepted as representative of industrial scale stripper. This emphasis the need for 3-D simulations, which will give us a better understanding and optimization of this multiphase process.Intial stage simulations are carried out and the results were validated qualitatively. Steam Outlet

Catalyst Inlet

Steam Inlet Catalyst Outlet

No Ring

Full Ring

References Avidan, A.A., Edwards, M., Owen, H., 1990. Innovative improvements highlight FCC’s past and future. Oil and Gas J., Vol. 88, No. 2, 33-54. King, D., 1992. “Fluidized catalytic crackers: an engineering review”, in: “Fluidization VII”, O.P. Potter, D.J. Nicklin Eds., Engineering Foundation, New York, 15-26. McKeen, Tim., Pugsley, S., 2003. Simulation of Cold Flow FCC Stripper Hydrodynamics at Small Scale Using Computational Fluid Dynamics. International Journal of Chemical engineering.1, A18.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-5

FAULT DETECTION AND DIAGNOSTICS IN WASTEWATER TREATMENT SYSTEMS Imran M. Khalid [email protected] Department of Chemical Engineering

Fault detection and diagnosis (FDD) is a vital issue in modern process industries. As the central part of Abnormal Event Management (AEM), it has recently attracted lots of attention due to the economical and safety incentives associated with it. The petrochemical industry alone incurs 20 Billion dollars in annual losses due to poor AEM. FDD have been addressed through a variety of techniques ranging from Analytical, Knowledge Based and Data Driven, each methodology having its own limitations. Unlike Analytical and Knowledge Based techniques, Data Driven has the edge with its application on large and complex processes. Neural networks, Principal Component Analysis (PCA), Independent Component Analysis (ICA) and Partial Least Square (PLS) are the most popular Data Driven techniques but also with limitations such as explanation ability that lacks in PCA. One realises that no single method has all the key characteristics of a better diagnostic system. Inductive data mining using Genetic Programming on process data is used in this research to identify the cause of malfunctions and the possible improvement of the process. Data from a wastewater treatment plant is used as a case study. The methodology is then evaluated against the desirable characteristics of a diagnostic system. The mathematical model of the process for the diagnostic purposes is then developed and effort will be made to fulfil those characteristics left by data driven methods.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-6

MONITORING, DIAGNOSTICS AND IMPROVEMENT OF PROCESS PERFORMANCE Tahir M Rafique [email protected] Department Of Chemical Engineering

The monitoring of the Process has always been an important issue with regard to consistent product quality and safety. To monitor the process performance, Multivariate Statistical Process Control (MSPC) has been used quite successfully but in many cases MSPC do not function properly. As in MSPC it is assumed that monitored variables have Gaussian distribution so in those cases where process variables do not strictly form a Gaussian distribution MSPC do not work very well like PCA. Independent Component Analysis (ICA) is a strong tool which distinguishes itself from PCA by the fact that it searches for the components that are both independent and non-Gaussian(Ge and Song, 2007).so considering both of these we know that ICA is interested in the non-Gaussian information, whereas PCA is looking for the Gaussian information. so considering all the properties of PCA and ICA, with regard to fault detection and diagnosis, we can easily say for the complete diagnosis of the process, after the non-Gaussian information is extracted from the process, the remaining Gaussian part should also be analysed so a model based analysis of combination of PCA and ICA, should be developed. Ge and Song (Ge and Song, 2007) have contributed in this regard by developing combination of PCA-ICA but their proposed methods are limited to capturing the linear nature of the process. In this research a model based analysis will be carried out along with statistical methods which will help diagnosis of fault in non-linear and on-line processes and consequently will lead to gross error detection in the system. This will also be tested on continuous and batch processes by applying the proposed methodology to some mineral industry like Alumina refinery and waste water treatment facility. Also based on all the work done a frame work of guide lines for future improvements in the field of fault detection and diagnosis will be suggested.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-7

DESIGN OF A SCADA CONTROLLED MINI-GRID HYBRID POWER AND WATER SUPPLY SYSTEM FOR REMOTE AREAS Yu Zhao [email protected] Department of Electrical and Computer Engineering

There are many remote or rural residential areas have no access to reliable power and potable water supply. This situation is largely caused by the geographical location of the areas, which makes it uneconomic to build any connection to the existing power grid. Many rural communities use diesel generators as their primary power supply source. The electricity produced from such system is expensive and not environmental friendly. Meanwhile due to lack of skilled technicians, operation and control of these diesel generators may not be effective. Mini-grid hybrid power system can provide electricity in a flexible as well as unpolluted way. Furthermore, efficiency and effectiveness of the system can be improved by utilizing a SCADA (Supervisory Control and Data Acquisition) network with a built-in PID (Proportional Integral Derivative) control algorithm in each water treatment pump controller. The advantages of using renewable energy sources for generating power in remote region are obvious such as the cost of transported fuel are often prohibitive fossil fuel as there is increasing concern on the issues of climate change and global warming. The disadvantage of standalone power systems using renewable energy is that the availability of renewable energy sources has daily and seasonal patterns which results in difficulties in regulating the output power to cope with the load demand. Furthermore, as the distance between each generator could be considerately large, e.g. range from a few metres to a couple of kilometres. Together with PID control algorithm, SCADA appears to be useful in managing such hybrid power generation/supply and water treatment/supply systems. The detailed design of a SCADA controlled mini-grid hybrid power and water supply system for remote/rural areas will be carried out as this research project proceeds. The integration of such power system with a small-scale RO desalination plant will also be simulated and tested empirically. Eficiency enhancement will be recorded and compared as opposed to the common control system operated systems.

References A. A. Setiawan, Y. Zhao, and C. V. Nayar, "Design of a SCADA Controlled Mini-grid Hybrid Power and Water Supply System for Remote Areas," in International Symposium of Power Electronics for Distributed Generation Systems; Hefei, China: IEEE-PELS, 2007. C. V. Nayar, S. J. Phillips, W. L. James, T. L. Pryor, and D. Remmer, "Novel wind/diesel/battery hybrid energy system," Solar Energy, vol. 51, pp. 65-78, 1993. D. Renne, R. George, B. Marion, D. Heimiller, and C. Gueymard, "Solar Resource Assessment for Sri Lanka and Maldives," National Renewable Energy Laboratory, Colorado 2003. Y. Zhao, Master Degree Thesis - Reverse osmosis desalination in a mini renewable energy power supply system, Curtin University of Technology; Perth, Australia, 2006.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-8

ADAPTIVE OFDM IN POWER LINE COMMUNICATION Samuel Panggalo [email protected] Department of Electrical and Computer Engineering

Power Line communication is the use of the electrical power distribution grid for communication purpose [1]. It has been shown in literature that the power line as a communication channel has bad propagation characteristics particularly it has very high attenuation at frequencies greater than 30 MHz and it is likely to encounter severe multiple echoes due to impedance mismatch. Because of excessive attenuation of power line cable at high frequency, the operating frequencies are restricted to below 30 MHz.[2] In this research, the use of adaptive Orthogonal Frequency Division Multiplexing (OFDM) in power line communication will be investigated. Power line communication (PLC) technology has been developed in such a way that the power line can be used for data transmission for up to 14 Mbps and recent research is targeting a transmission rate up to 200 Mbps[3]. In order to increase the data rate through the power line, it is important to have a good knowledge of the channel characteristic. This severe band limitation of the channel will limit the maximum transmission rate possible. This study proposes the use of adaptive OFDM to over come some of the undesirable properties of a power line channel. An important investigation is channel estimation. The estimated channel response will be used to adaptively adjust the modulation order for the different frequency bands by the channel. This research aims at maximizing the throughput of a power line channel.

Data out

Data In

OFDM- Tx

OFDM- Rx

PL- Channel

Feed back

Channel Est.

References 1

O.Hooijen andA.J Han Vinck,1997, “International Symposium on PLC and its applications” 2nd Edition.

pp 1 2

C.Hensen, 1998, “Data transmission application via low voltage power line using OFDM technique”

Proceding, IEEE 5th Int.Symp. on Spread Spectrum and application.vol.1 pp210-214 3

IEEE 802 PLC standardization tutorial, Orlando March 2007, DS2 PLC Technology

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-9

PATTERN-BASED CHARACTERIZATION OF FINANCIAL TIME SERIES Jinfei XIE (Jeffrey) [email protected] Department of Electrical and Computer Engineering

In recent years, there has been a lot of research interest in time series data mining. A time series is a sequence of real values which may represent digital signals, stock prices, temperature records, or medical measurements. One major problem in data mining is the high dimensionality of time series. Many researchers have made efforts to reduce the dimensionality by extracting features of time series. Feature extraction is a way to reveal main characteristics of a (or a set of) time series and it is an effective pre-processing step for time series clustering, indexing and similarity search. A well-known future extraction method is to transform a sequence from time domain to a new sequence in another domain (e.g. digital Fourier transform, digital wavelet transform, etc) and only keep a few elements of the transformed sequence to characterize the original sequence. Other methods divide a sequence into segments (can be equal length or variable length) and use the mean value or a straight line to approximate the segment. The above mentioned methods focus on the actual values of a sequence and try to minimize the approximation error. They are not able to reflect certain important characteristics of a sequence in financial applications. For instance, the local changes in a financial time series (like a stock price sequence) may be important to some stock analysts (especially speculators) whose main concern is to identify patterns that reflect short term market behavior. As a part of our research project, we propose a pattern-based characterization method which mainly focuses on the shape instead of values or approximation error of a time series. We first define extreme points which indicate the locations of minima and maxima of a certain range in a time series. Based on certain extreme points, we define the convex pattern and concave patterns which are segments in a time series satisfying some simple conditions. Patterns reflect the shapes of different segments of a time series. By knowing the patterns, we can divide the sequence into shaped-oriented segments and have a clear picture of the shape of each segment without the need of knowing the actual values. Two sequences can be compared in terms of pattern-related features. Furthermore, we can cluster sequences in a database based on patterns and obviously the resulting clusters have a more clear visual meaning than those using numerical clustering methods.

References [1] E. Keogh and S. Kasetty, 2002, On the need for time series data mining benchmarks: a survey and empirical demonstration, In the 8th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, pp 102-111. [2] J. Xie and W. Yan, 2007, Pattern-based characterization of time series, International Journal of Information and Systems Sciences, Vol 3, pp 479-491.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-10

NUMERICAL STUDY OF LAMINAR CONVECTIVE HEAT TRANSFER IN A SQUARE AND RECTANGULAR MICROCHANNEL WITH LONGITUDINAL INTERNAL FINS Andrew Foong Jun Li [email protected] Department of Mechanical Engineering

A numerical study was conducted to investigate the fluid flow and heat transfer characteristic of a square and rectangular microchannel with four longitudinal internal fins. Three dimensional numerical simulations were performed on the microchannel with variable fin height ratio undergoing a thermally developing laminar flow. The boundary condition of the heated side walls are circumferential uniform wall temperature with constant wall heat flux (H1 boundary condition). The four longitudinal internal fins are passive enhancement technique that is used to increase the surface heat transfer area and to disrupt the velocity flow pattern in the channel. Based on the temperature and heat transfer across the longitudinal internal fins, the local Nusselt numbers with respect to the fin height ratio are presented as a function of the channel length. An optimum value of the local Nusselt number is obtained as the fin height extends into the fluid. Generalised correlations corresponding to the optimisation of rectangular microchannel with internal fins were obtained. The proposed correlations are then compared with other conventional correlation and good agreements are achieved.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-11

IMPACT OF HARMONICS ON OPTIMAL CONTROL OF VOLTAGE/REACTIVE POWER IN A DISTORTED DISTRIBUTION SYSTEM A. Ulinuha [email protected] Department of Electrical and Computer Engineering

The objective of operation planning in distribution system is to consistently satisfy the electricity demand in the most optimum way. The constantly changing load leads the operation planning to be quite complicated. As a result, the planning objective may not be successfully achieved. If not carefully managed, the load changing may result in either uneconomic distribution operation due to power loss escalation or the customer will receive the electricity technically unacceptable due to the voltage limits violation. An adaptable enhancement is therefore required to control the system resulting in voltage improvement as well as loss reduction. This may be carried out by optimally controlling the voltage/reactive power in distribution system. The extensive and ever increasing applications of nonlinear loads have introduced harmonic distortion problems in distribution system and including them in the optimal planning is necessary. Disregarding harmonics may lead the planning to generate unacceptable results due to increased distortion levels, further voltage violation, and additional power losses. The implementations of the planning for the IEEE 123-bus distorted system [1] using Genetic Algorithm [2] and its combination with Fuzzy Concept [3] indicate the excessive harmonic distortion and voltage violation indicated by the following figures. Voltage Violations

THDv of sinusoidal schedule

1.07

8 Voltage at bus 150

Voltage at bus 1

hour 1

hour 2

hour 3

hour 24

7.5 1.05

7 1.03 THDv (%)

THDv (%)

6.5

1.01

6

5.5 0.99

5 0.97

4.5

4

0.95 1

3

5

7

9

11

13

(a)

15

17

19

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23

1

11

21

31

41

51

61

71

81

91

101

111

350 Bus

Hour

(b)

Figure 1. (a) voltage violation and (b) excessive harmonic distortion due to exclusion of harmonics in optimal control of voltage/reactive power References [1] A. Ulinuha, M. A. S. Masoum, and S. M. Islam, "Optimal Scheduling of LTC and Shunt Capacitors in Large Distorted Distribution Systems using Evolutionary-Based Algorithms," accepted for publication on IEEE Transactions on Power Delivery. [2] A.Ulinuha, M. A. S. Masoum, and S. M. Islam, "Optimal Dispatch of LTC and Shunt Capacitors in the Presence of Harmonics using Genetic Algorithms," in Power Systems Conference and Exposition (PSCE) IEEE, Atlanta, Georgia, USA, 2006. [3] A.Ulinuha, M. A. S. Masoum, and S. M. Islam, "A Hybrid GA-Fuzzy Algorithm for Optimal Dispatch of LTC and Shunt Capacitors in Distribution System," in Australasian Universities Power Engineering Conference (AUPEC), Melbourne, Australia, 2006.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-12

INVESTIGATION OF KINETIC INHIBITION ON METHANE HYDRATES FORMATION Yenny Rojas* Ailin Ding Xia Lou [email protected] Department of Chemical Engineering

Natural gas hydrate is a form of energy mineral found in sediments in the ocean bottoms and Polar Regions under certain conditions of temperature and pressure. Over a long period following their discovery in 1811, interests in clathrate hydrates were purely academic [1]. It was not until 1934, however, that they were extensively studied, when Hammerschmidt found that natural gas transport lines could be blocked by the formation of gas hydrates [2]. This raised a lot of attention in the oil and gas industry, prompting more research to be performed on clathrate hydrates of natural gas. Four main processes have been investigated in order to combat hydrate plugs and ensure regular flow: chemical, hydraulic, thermal and mechanical [1]. The chemical method involves the injection of additives called thermodynamic inhibitors in the pipe in order to shift the equilibrium temperature, thus preventing gas hydrate crystallization [3]. It is an efficient method, but is limited by the large quantity of additives required and the high cost associated with the operation and recovery [4]. This has prompted the search of novel, cheap and environmentally acceptable types of additives capable of inhibiting hydrate formation at far lower concentrations. Low-dosage hydrate inhibitors become an alternative. These new inhibitors are designed either to delay hydrate formation or to modify the hydrate crystal morphology. According to this, they can be classified as kinetic or anti-agglomerators inhibitors [5]. In this presentation, I will report a general overview on the current progress of the research and development activities involving low-dose kinetic hydrates inhibitors. This will include 1), materials design and development, 2), methods and experiments for inhibition efficiency evaluation, 3), possible inhibition mechanisms, and 4) the integration of modern technology and techniques to characterise the physical and chemical behaviour of methane hydrates with and without the presence of chemical inhibitors.

References [1] Chatti I., Delahaye A., et al. (2005). Benefits and drawbacks of clathrate hydrates: a review of their areas of interest. Energy Conversion and Management, 46, 1333–1343. [2] Hammerschmidt, E.G. (1934). Formation of Gas Hydrates in Natural Gas Transmission Lines. Industrial Engineering Chemistry, 8(26), 851-855. [3] Englezos, P. (1993). Clathrate Hydrates. Industrial Engineering Chemistry Research, 32, 1251-1274. [4] Mokhatab, S., Wilkens, R. J. and Leontaritis, K. J. (2007). A Review of Strategies for Solving Gas-Hydrate Problems in Subsea Pipelines. Energy Sources, Part A, 29:39-45. [5] Kelland, M.A. (2006). Reviews. History of the Development of Low Dosage Hydrate Inhibitors. Energy & Fuels, 3(20), 825-847.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-13

THE INFLUENCE OF DISTURBED ZONE ON CAPACITY OF SUCTION EMBEDDED PLATE ANCHORS Zhenhe Song [email protected] Department of Civil Engineering

In recent years oil and gas mining has moved into increasingly deeper water in search of undeveloped fields. As water depths exceed 500 m conventional offshore foundation systems become inefficient and ineffective in stabilising platforms and floating production storage units. The trend of supporting structure design in deep water has been to install catenary and taut leg mooring systems. Consequently, many types of anchoring systems are being developed and used in order to withstand large mooring forces. The SEPLA (Suction Embedded Plate Anchor) is ideal for use in this situation. In this paper, finite element analysis and centrifuge test of plate anchors in disturbed soil were conducted. In finite element analysis, the disturbed zone was simulated depending on caissons with a stiffener or without a stiffener. For caisson without a stiffener, the disturbed zone is assumed to be 3 times of the thickness of the caisson wall. For caisson with a stiffener, the disturbed zone is assumed up to the fully disturbed zone in a caisson. Centrifuge tests of suction embedded plate anchors in normally consolidated clay were conducted at the Centre for Offshore Foundation Systems (COFS), at the University of Western Australia in transparent soil and Kaolin clay. Results show a loss of bearing capacity up to 40 % of that for an anchor in undisturbed soil. The loss of bearing capacity of anchor depends on both the size of the disturbed zone and the reduced soil strength in the disturbed zone. The numerical results agree well with the centrifuge test data.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper A-14

TRANSIENT FAULT PROTECTION IN SYSTEM ON CHIP ARCHITECTURES Muhammad Sheikh Sadi [email protected] Department of Electrical and Computer Engineering

A transient fault is a temporary unintended change of state within a logic circuit that lasts for few state transitions only. Transient fault is a great concern for designing high availability systems or systems used in electronic-hostile environments such as outer space [1, 2]. These errors are also severe in those systems where reliability is a great concern [3]. Previous approaches to prevent transient faults focused on recovery after detection. Almost no research has been directed towards preventive measures. But in real-time systems, hard deadlines are performance requirements that absolutely must be met and a missed deadline constitutes an erroneous action and a possible system failure. This research proposes the use of metrics to refine system design for transient fault protection in system on chip architectures. Specifically this research examines the use of metrics in design space exploration that highlight where in the structure of the model and at what point in the behaviour, protection is needed against transient faults. As these metric improve the ability of the system to provide functionality, they are referred to here as reliability metrics. For any reasonable embedded system, to assess every point of the structure at every stage of the behaviour for the possible impact of transient faults is a near-impossible task. Thus the developing metrics are the heuristic processes employed to scan the system model and look for key indicators that highlight where protection is needed. That is to say, they examine the structure for points where transient faults could be damaging, assess what behavioural conditions could make that so and then estimate if this system can have such behaviour. The intention of this research is to prevent serious loss of system functionality or system failure though it may not be able to eliminate the impact of transient faults completely. References [1] Zhang, M., et al., 2006, Sequential Element Design with Built-In Soft Error Resilience. IEEE Transactions on Very Large Scale Integration (VLSI) Systems, Volume 14, No 12, pp 1368:1378. [2] Saggese, G.P., et al., 2005, An experimental study of soft errors in microprocessors, IEEE Micro, Volume 25, Issue 6, pp 30:39. [3] Gold, B.T., et al., 2005, TRUSS: a reliable, scalable server architecture, IEEE Micro, Volume 25, Issue 6, pp 51:59.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-1

AN INVESTIGATION INTO DIMENSIONAL ACCURACY AND SURFACE FINISH ACHIEVABLE IN DRY TURNING: PRELIMINARY STUDY Noor Hakim Rafai [email protected] Department of Mechanical Engineering

Dry turning is a machining technique used for the manufacture of cylindrical component parts without the application of cutting fluids. In recent years, it has gained renewed interest for its potential environmental and economic benefits. However, the dimensional accuracy and surface finish, which are the two fundamental quality requirements for component parts, may suffer due to application of this technique. This presentation presents experimental and analytical results of a preliminary investigation into dimensional accuracy and surface finish achievable in dry turning. The Taguchi method and Pareto ANOVA analysis is used to determine the effects of the three major controllable machining parameters, viz. cutting speed, feed rate and depth of cut on dimensional error, surface roughness and circularity, and subsequently to find their optimum combination. The results indicate that while the cutting parameters have varying influence on the quality characteristics at different levels, the utilization of low feed rate can optimize the dimensional error, surface roughness and circularity of cylindrical component parts concurrently. References [1] P. S. Sreejith and B. K. A. Ngoi, "Dry machining: Machining of the future," Journal of Materials Processing Technology, vol. 101, pp. 287-291, 2000. [2] N. R. Dhar, M. W. Islam, S. Islam, and M. A. H. Mithu, "The influence of minimum quantity of lubrication (MQL) on cutting temperature, chip and dimensional accuracy in turning AISI-1040 steel," Journal of Materials Processing Technology, vol. 171, pp. 93-99, 2006. [3] T. Yandayan and M. Burdekin, "In-process dimensional measurement and control of workpiece accuracy," International Journal of Machine Tools and Manufacture, vol. 37, pp. 1423-1439, 1997. [4] J. Kopac and M. Bahor, "Interaction of the workpiece material's technological past and machining parameters on the desired quality of the product surface roughness," Journal of Materials Processing Technology, vol. 109, pp. 105-111, 2001. [5] S. C. Black, Principles of engineering manufacture, 3rd ed. London New York: Arnold ; Halsted Press, 1996. [6] I. Korkut and M. A. Donertas, "The influence of feed rate and cutting speed on the cutting forces, surface roughness and tool-chip contact length during face milling," Materials & Design, vol. 28, pp. 308-312, 2007. [7] M. Nalbant, H. Gokkaya, and G. Sur, "Application of Taguchi method in the optimization of cutting parameters for surface roughness in turning," Materials & Design, vol. 28, pp. 1379-1385, 2007. [8] J. G. Lima, R. F. Avila, A. M. Abrao, M. Faustino, and J. P. Davim, "Hard turning: AISI 4340 high strength low alloy steel and AISI D2 cold work tool steel," Journal of Materials Processing Technology, vol. 169, pp. 388-395, 2005. [9] N. Cho and J. Tu, "Roundness modeling of machined parts for tolerance analysis," Precision Engineering, vol. 25, pp. 35-47, 2001. [10 K. Palanikumar, "Cutting Parameters Optimization for Surface Roughness in Machining of GFRP Composites using Taguchi's Method," Journal of Reinforced Plastics and Composites, vol. 25, pp. 17391751, 2006. [11] P. J. Ross, "Taguchi Techniques for Quality Engineering," Mc-Graw-Hill, New York, 1988. [12] S. H. Park, "Robust Design and Analysis for Quality Engineering," Chapman & Hall, London, 1996. [13] H. Saglam, S. Yaldiz, and F. Unsacar, "The effect of tool geometry and cutting speed on main cutting force and tool tip temperature," Materials & Design, vol. 28, pp. 101-111, 2007. [14] J. R. R. Mayer, A.-V. Phan, and G. Cloutier, "Prediction of diameter errors in bar turning: a computationally effective model," Applied Mathematical Modelling, vol. 24, pp. 943-956, 2000. [15] R. Azouzi and M. Guillot, "On-line prediction of surface finish and dimensional deviation in turning using neural network based sensor fusion," International Journal of Machine Tools and Manufacture, vol. 37, pp. 1201-1217, 1997. [16] I. S. Jawahir and X. Wang, "Development of hybrid predictive models and optimization techniques for machining operations," Journal of Materials Processing Technology, vol. 185, pp. 46-59, 2007.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-2

STABILITY ANALYSIS OF NETWORKED CONTROL SYSTEMS Shawn Hu [email protected] Department of Electrical and Computer Engineering

Over the past few decades, cheap and ubiquitous sensing, communications and computation have enabled new application of control to large-scale, complex systems such as remote sensors and distributed control systems. In the literature, this type of the system whose feedback control loops close through a real-time shared-medium network are called networked control systems (NCS). NCSs intend to integrate networks and control systems in a large area. In such systems, the estimation and control functions can be distributed across multiple processors. Sensor, actuator, diagnostic and coordination signals travels over networks which are shared by other devices such as routers, computers. The main advantages of NCSs include low costs, flexibility in system design, installation and maintenance. However, several practical factors of the network, such as bandwidth, packet dropping and packet delay, often affect the system performance, even cause instability. This project involves packet dropping analysis, stability analysis, controller design of NCSs. We also discuss the stability robustness in the cases where information is exchanged between the controller and planet by single packet transmission policy and multiple-packet transmission policy. A designing approach is provided to improve the stability robustness subject to packet dropping. These results are also extend to the case where the networks suffer packet dropping and a fixed packet delay.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-3

COVER QUALITY TESTING AS AN INDICATOR OF GEOPOLYMER CONCRETE DURABILITY Monita Olivia [email protected] Department of Civil Engineering

Geopolymer concrete is an alternative construction material obtained from reaction of fly ash with alkaline solution. Previous research has shown good engineering properties of geopolymer concrete. An extensive research on its durability is important for its application as a construction material. The ability to perform well during its service life without any sign of degradation caused by physical and chemical attack is defined as durability. Durability related properties can be measured through several criteria, such as corrosion (carbonation and chloride ion penetration), cover quality (water absorption, AVPV, water permeability) and chemical attack (sulfate, alkali-aggregate reaction, acid). The effects of concrete cover, constituents, curing and compaction are significant on durability of concrete. Concrete cover becomes essential because it can protect the reinforcement from corrosion. Some tests such as water absorption, AVPV and water permeability can be used as measurements of the cover quality. Hence, the aim of this research is to study the cover quality of the low calcium fly ash geopolymer concrete. In this research, water absorption and Apparent Volume of Permeable Voids (AVPV) tests are carried out based on Australian Standard 1012.21 1999 (Determination of water absorption and apparent volume of permeable voids in hardened concrete). The water permeability test is performed in accordance with the DIN 1048 Standard. The variables of the tests are concrete strength, age of concrete, water binder ratio, curing and compaction method. For each variable, three concrete cylinders will be cast form the same concrete mixtures. OPC concrete mixtures will be used for all variables as control mixes. In addition, SEM observation will be used to observe the microstructure of geopolymer concrete. From the study, it is expected that the geopolymer concrete has low water absorption, permeability and VPV. This condition will provide appropriate cover quality to prevent ingress of harmful substances in the long term.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-4

ANALYSIS OF THE CONDUCTIVITY OF THE TRANSFORMER OIL DUE TO AGING FROM SPECTRAL RESPONSE Lai S. Pin [email protected] Department of Electrical and Computing Engineering

Large oil-filled electrical power equipment, such as transformer and reactors, is a critical element of an electrical power system. The reliability itself and regular maintenance carried out on the machine has been the fundamental technique in continuous transmission and profitable generation. The cost of acquisition, replacement, transportation, installation and repairs is among the highest in the power system. Its failures create losses in revenues and, when catastrophic, will create substantial costs in terms of connected equipment destruction and environmental damages. Therefore, utilities around the world has focused on maintenance and life extension of existing transformers to maximize the return of investment even though most of the transformers are operating closed to their design limits. Furans concentration presence in aged-transformer oil has been one of the key indicators of the solid dielectric deterioration. They are the by-products from the cellulose degradation of insulation paper caused by heat, oxidation and electrical stress. In the presence day, furans concentration is measured by High-Performance Liquid Chromatography (HPLC) or Gas Chromatography-Mass Spectrometry (GC/MS). Both methods of analysis are accurate and reliable in detecting the concentration of furans derivatives (2-Acetyl furan, 2-furfural, 5hydroxy methyl 2-furfural, 2-furfurylalcohol and 5-methyl-2-furfural). However, the analysis required trained personnel, time consuming and expensive equipments. The objectives of this research to be achieved is to develop a method that could determine the furans concentration without requiring specific trained personnel, much lower cost and time-saving. Experiment is conducted by studying the correlation between the furans content and its UV-spectral response. The experiment has showed significant differences in absorbance peaks and bandwidth at different level of furan concentration. The next stage of the research is to develop a model that could calculate the furan concentration from the corresponding spectral response.

Figure 1: UV-spectral response of new transformer oil and aged in-service transformer oil with furan concentration at 3ppm, 5ppm and 10ppm

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-5

POWER SYSTEM STABILITY AND QUALITY IMPROVEMENT AND RENEWABLE ENERGY UTILISATION THROUGH WECS WITH CASCADED CCVSI AND VC-VSI Susanne Sugiarto [email protected] Department of Electrical and Computer Engineering

This research program is intended to achieve the objective of developing, simulating and verifying a power electronics configuration and control mechanism to mitigate both current harmonics and voltage harmonics, stabilise both current and voltage, correct power factor and provide active renewable power and reactive power support in a power system that is supported by a Wind Energy Conversion System (WECS). The proposed system is intended to be part of a wind farm and acts as a renewable energy generator while providing global compensation. To significantly improve the power quality, it is necessary to compensate both voltage disturbances from the grid so it does not propagate to disturbances sensitive load as well as to compensate current harmonics from non-linear load so it does not pollute the grid. One way to achieve both of these compensations is through the utilisation of multiple VSIs system. In most publications, multiple VSIs system that is used to improve power quality consists of a series-connected VSI and a shunt-connected VSI. The series-connected VSI is usually a VCVSI that is sized at a limited power value and is utilised to mitigate voltage disturbances.[1, 2] However, VC-VSI required a regulated DC supply.[1, 2] This is provided by the shuntconnected VSI, which usually is a CC-VSI. This CC-VSI is used to regulate the DC supply as well as mitigate current harmonics from non-linear load.[3] The innovative aspect of this research is the integration of the cascaded Current Controlled Voltage Source Inverter (CC-VSI) and Voltage Controlled Voltage Source Inverter (VC-VSI) with the WECS. It is envisaged that, with the inclusion of the proposed system, less harmonics from non-linear loads will pollute the grid and more power perturbation sensitive loads can be protected. The outcome of this research program, which includes the design and verification of the three-phase cascaded CC-VSI and VC-VSI integrated with the WECS, will be useful to increase the feasibility and efficiency of the energy conversion system, in the process of solving the growing energy consumption through the utilization of non-depleting renewable energy source as well as eliminating the power quality and stability problem caused by the increasing number of non-linear loads connected to the grid. References [1] F. Liccardo, P. Marino, C. Schiano, and N. Visciano, "Three-phase Robust Series Compensator for Voltage Disturbances," in IEEE Power Technology Conference, Bologna, 2003. [2] R. Cao, J. Zhao, W. Shi, P. Jiang, and G. Tang, "Series Power Quality Compensator for Voltage Sags, Swells, Harmonics and Unbalance," in Transmission and Distribution Conference and Exposition, 2001, pp. 543547. [3] H. H. Tumbelaka, "A Grid-controlling Shunt Active Power Filter using Polarized Ramptime Current Control," in Department of Electrical and Computer Engineering Perth: Curtin University of Technology, 2006.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-6

LEARNING CRITERIA FOR NEURAL NETWORK TRAINING Agus Saptoro [email protected] Department of Chemical Engineering

The network weights and biases of neural networks are adapted by performing a training based on a certain learning criterion. To obtain these optimum network parameters, any one of existing learning criteria can be used in this regards. Among many available learning criteria, the mean squared error (MSE) is the most popular criterion to be used in training supervised neural networks The selection of a learning criterion for training neural networks has also an important on the neural networks model performance. However, to date there is no research study which highlights any considerations in how to choose the suitable error criteria for training neural networks. This paper provides an overview of the use of existing learning criteria for neural network training and presents a comprehensive analysis of their characteristics.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-7

ENERGY AND ECONOMIC ANALYSIS OF CRYOGENIC O2 PRODUCTION FOR OXYFUEL COMBUSTION TECHNOLOGY [email protected] Department of Chemical Engineering

The scope of this study is to examine and evaluate the oxyfuel oxidant-high purity O2 (up to 99%) production via cryogenic air separation process in both energy and economic point of view. This multi-objective optimisation analysis explores a broader range of key factors than found in recent publications and the trade-off between manufacturing cost and energy cost was obtained. In particular, we examine the effects of the product oxygen purity, as well as plant capacity for 4 configurations. The results show: 1. 96% oxygen purity scenario gives the best performance combining energy and economic analysis results; 2. At the oxygen production rate of about 5000 ton/day, the manufacturing cost is minimised; 3. by using two gas quench towers (Nitrogen tower and oxygen tower), the manufacturing cost can be reduced on the cost of a higher humidity of the product gases. 4. Using one nitrogen tower, the energy cost can be minimised and the oxygen production cost is low and therefore this configuration is considered as the optimal. The energy cost and the manufacturing cost under the optimised condition is 27.14kJ/mole O2 and AU$60.61/ton O2 respectively.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-8

MODELING AND SIMULATION OF PERMEABLE REACTIVE BARRIER FOR GROUNDWATER REMEDIATION Chirayu S. Shukla [email protected] Department of Chemical Engineering

Over the past decade there has been an increasing recognition of the problems associated with contaminated land. The problem is of special importance in Australia and Western Australia because of our reliance on groundwater and the threat posed by land contamination to groundwater quality and public health (Australia State of Environment Report 2001). So, our overall objective of this project is to investigate the physiochemical and hydrological properties of Australian contaminated sites and devise an effective permeable reactive barrier for complete degradation of toxic organic pollutants and some heavy metals from the contaminated subsurface water by combining chemical (advanced) oxidation and adsorption techniques. So, for that we will use Visual MODFLOW Premium to build, calibrate and evaluate groundwater flow, contaminant transport models and display and interpret the modeling results in full 3D. We will also establish simple mathematical model predictions based on experimental results. I focused on collecting data of contaminated sites available in Australia and especially in Western Australia. From this data, it was seen that common contaminants available in Perth Region were BTEX and other hydrocarbons, heavy metals like arsenic, lead, nickel, Perchlorethylene (PCE) etc. From my study I found that the common contaminant sources were service station operations and fuel storage, chemical manufacturing industries, metal processing and manufacturing industries, mining and extractive industries, land filling and waste disposal activities. Simultaneously, I also studied Hydrogeology and Geological properties of Groundwater resources of Perth region. From this study, I found that there are three main aquifers (superficial, Leederville and Yarragadee) and thousands of drill holes and wells in the Perth region alone. To get better acquainted with Visual Modflow, I simulated a simple contaminant transport model of Plane Refuelling area located in Waterloo, Canada. This model demonstrated the potential impact of the fuel contamination on the municipal water supply wells and created a 3D volumetric representation of the contaminant plume located beneath the Refueling Area by creating an isosurface for a selected concentration value.

References: [1]

Visual MODFLOW v.4.2 user’s manual

[2] Prommer H., Barry D.A. and Zheng C. (2003) MODFLOW/ MT3DMS-based reactive multicomponent transport modelling. Groundwater, 41(2), 247–257.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-9

RECOVERY OF SULPHUR BY MODIFIED CLAUS PROCESS Bejoy K. Bharatiya [email protected] Department of Petroleum Engineering

A single stage conventional Claus reactor was modified by adding a cold bed adsorption (CBA) reactor in series with the former. Activated alumina catalysts in the form of cylindrical pellets impregnated with a promoter were used for the Claus reaction 2 nH

2

S + nSO

2

=

3n S X

x

+ 2 H 2O ;

∆ H = − 109 . 2

kJ mol

at low temperatures (~1750C) to enhance the H2S conversion from 70% in the Claus reactor to more than 99 percent in the modified equipment. This has been possible by operating the CBA reactor at temperatures below the dew point of sulphur in the reaction mixture. Effects of temperature and catalyst bed depth in the CBA reactor on H2S conversion have been investigated. At the lowest temperature studied (1750C) the exit gases contained only 0.05 per cent of the acid gases. The catalytic deactivation through the deposited sulphur was not analysed but it was predicted that the deactivation of catalysts did not happen as fast as was expected because sulphur partly plays the role of an auto-catalyst in the Claus reaction. Catalyst regeneration by simple elimination of the deposited sulphur did not result in full recovery of the activity of the fresh material.

Schematic Diagram of Experimental Set-up

The experimental results of Claus conversion carried out in this study using a Claus reactor and a CBA reactor, have provided the basis for selecting the optimum conditions for the CBA reactor in the two stage unit. Under suitable process conditions it has been possible to achieve a conversion efficiency higher than 99%. Inclusion of CBA reactor proved to

be unique since it is simple, logical extension of Claus sulphur recovery plant. However, further work is obviously needed to improve upon the existing low temperature Claus processes: 1. Typical reactor feed gas compositions of operating sulphur recovery plants. 2. Develop suitable kinetic model based on experiments and plant operating data. 3. Evaluate commercial catalysts from catalyst manufacturers e.g. Kaiser, RhônePoulenc, Engelhard, Alcoa, BASF and others. Acknowledgements The authors wish to thank Prof. Robert Amin, Curtin University and Prof. Waheed Al-Masry, King Saud University, Riyadh for their support in the research work in progress. References: 4

Bharatiya B. K. , M. Tech Thesis, 1980, Indian Institute of Technology, Kanpur, India

5

Alvarez, E.; Mendioroz, S.; Palacios, J. M.; Muñoz,V., Applied Catalysis B: Environmental, Volume 9, Issues 1-4, 2 September 1996, Pages 179-199

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-10

ECONOMIC VIABILITY OF ETHANOL PRODUCTION FROM MALLEE BIOMASS IN WESTERN AUSTRALIA Yun Yu [email protected] Department of Chemical Engineering

This paper investigates the economic feasibility to produce ethanol from mallee biomass using the lignocellulosic ethanol technology. An economic model has been established, taking into account ethanol plant capital and operation operating costs, feedstock cost and transport cost. A base case scenario was established based on the NERL lignocellulosic ethanol production process [1] at 2000 dry tonnes mallee/day processing capacity in WA. The analysis shows the ethanol production cost is $0.70/litre, which suggests that the malleederived ethanol be potentially competitive in Australia, considering its substantial environmental benefits including sequestration of CO2 by tree crops, reductions in dryland salinity and air pollution. Over 47% of the ethanol production cost is due to the use of raw materials (31.4% for feedstock material and 15.7% for non-feedstock materials). Transport cost, capital depreciation, fixed operation costs and tax contribute to 9.5%, 15.3%, 8.2% and 11.2% of the ethanol production cost, respectively. The surplus electricity for sale contributes 10.7% reduction in the ethanol cost. Therefore, the ethanol production cost is largely controlled by the price of raw materials, especially the cost of mallee biomass. The optimal ethanol plant capacity is estimated to be 9520 dry tonnes per day, considering the trade-off between increasing feedstock transport cost vs decreasing plant costs as the plant size increases. The optimal ethanol plant is too large to be practical, in despite of a low ethanol production cost of 61.45 cents/litre. Practically, a plant capacity between 2000~3000 dry tonnes per day seems to be reasonable. Analyses have been further performed to determine the sensitivity of the ethanol production cost to variations in key system parameters. The results indicate that feedstock price and advances in lignocellulosic ethanol production technology have significant impacts on the ethanol production cost. Transport rate has significant impacts on large plants while the total capital investment index shows significant impact on small plants. Transportation distance factor, mallee belt land coverage and mallee belt annual yield per hectare, have some impacts while the influence of capital investment exponent is limited. The ethanol production cost can be further reduced in the future through (1) technological advances in lignocellulosic ethanol production technology; (2) reduction of mallee biomass feedstock price, or the use of residue mallee biomass such as leaf residue after oil extraction, twig and bark; (3) co-location of the plant with existing facilities such as biomass combustors and waster treatment facilities; and (4) optimisation of the plant location to be near the farm that has a high feedstock production density.

References [1] A Aden, M Ruth, K Ibsen, J Jechura, K Neeves, J Sheehan and B Wallace, 2002, Lignocellulosic biomass to ethanol process design and economics utilizing co-current dilute acid prehydrolysis and enzymatic hydrolysis for corn stover, NREL/TP-510-32438, National Renewable Energy Laboratory, U.S. Department of Energy.

Curtin Engineering Faculty Research Colloquium, 6 November, 2007

Paper B-11

REMOVAL OF EMULSIFIED OIL IN WASTEWATER USING BARLEY STRAW Shariff Ibrahim [email protected] Department of Chemical Engineering

Oily wastewater is a by-product of many industrial and commercial small quantity generator (SQG) operations. Businesses often need to treat their oily wastewater before it can be discharged to the sanitary sewer [1]. Oil appears in wastewater in a number of different forms including free oil and grease (FOG), mechanically emulsified oil, oily wet solids, chemically emulsified oil and dissolved oil [2]. Oil/water emulsions are simply mixtures of oil droplets, generally less than 30 microns in diameter, suspended in water [1]. Unlike free oil which is floating on the surface of the water, emulsified oil are difficult to remove. Barley straw are cheap and abundantly available biomass which ability to undergo ion- exchange and adsorption. The overall purpose of this study is to assess the feasibility of using barley straw as a potential adsorbent for the removal of the emulsified oil in wastewater including an effort to improve its performance by altering/modified its surface. The preliminary result in Figure1, indicate that the modified barley straw capable of removing more than 98% of emulsified oil depending on the contact time, straw loading, initial emulsified oil concentration, pH and temperature. However, only about 60% removal of emulsified oil was achieved for unmodified barley straw.

120.0 unmodified straw modified straw

residue oil(%)

100.0

80.0

60.0

40.0

20.0

0.0 0

50

100

150

200

250

300

Contact time(min)

Fig 1. Emulsified oil sorption on unmodified and modified barley straw References [1].

King, S., Small quantity generator oily wastewater management study, final report., in 1999, Local Hazardous Waste Management Program in King County: Seattle, WA.

[2].

Alther, G.R., How to remove emulsified oil from wastewater with Water/Engineering & Management [H.W. Wilson - AST], 2001. 148(7): p. 27.

organoclays.