Qatar Foundation Annual Research Forum Volume 2011 Issue 1

Fischer-Tropsch synthetic paraffinic kerosines (FT-SPKs), such as Gas-to- Liquids (GTL) Kerosine, are now accepted as suitable blend components for Jet fuel production, via ASTM D7566. This sets limitations on distillation profiles for the final fuel and neat SPK, and the cycloparaffin content of the neat SPK. SPKs, from FT and other production routes, can be envisaged that would fall outside these limits yet produce perfectly acceptable, even desirable fuels. They are not generally available yet but one can define their compositions in terms of key components (normal paraffins, iso-paraffins and cycloparaffins) and carbon number distributions, derived from 2-dimensional gas chromatography. Surrogate blends approximating to these compositions have been produced with existing FT kerosines and commercial solvents.

The methodology used to blend these surrogate fuels will be presented as well as the results of the first experimental campaign at Rolls-Royce Derby on 5 real and surrogate SPKs in Technology Readiness Level 3 (TRL 3) altitude relight tests, with a baseline crude-derived Jet A-1. SPK choices permitted the impact of several main compositional variables on laboratory and performance measures to be determined from the small fuel set. Standard specification tests and altitude relight tests were performed. Not only were engine/combustor performances assessed but also combustion processes were captured with high speed flame imaging subject to a poster by DLR (Mosbach et al). Laboratory tests showed some sensitivity to SPK composition (e.g. viscosity increasing and lower heating value decreasing with increased cycloparaffin content) but these were less evident with ignition relight test results. All SPKs ignited, suggesting that the distillation criteria could be relaxed from current values. There may be a positive impact of lower iso/normal content on ignition performance, but this needs testing in more advanced (higher TRL) equipment.

Increasing oil prices, strict environmental regulations and lack of sufficient growth in renewable energy sector have led to renewed interest in Fischer- Tropsch technology. Improved understanding of reaction mechanisms and development of detailed kinetic models for Fischer-Tropsch synthesis (FTS) would facilitate better design and optimization of all FTS reactor configurations.

In this work, detailed kinetic models have been developed utilizing mechanistic approach. Experiments were conducted over 25% Co/0.27%Ru/Al2O3 (in parts by weight) catalyst in a 1L stirred tank slurry reactor over a wide range of conditions. Langmuir-Hinshelwood-Hougen-Watson type rate expressions were derived for the entire product spectrum. Models are based on the assumption that 1-olefins re-adsorb on active sites. Effective pressure of olefin (PCnH2n*) at the catalyst surface was assumed to vary exponentially with carbon number (according to Henry's law).

The genetic algorithm followed by Levenberg-Marquardt method was used to estimate kinetic parameters for 13 models using a single set of process conditions (i.e. T = 220°C, P = 2.4 MPa, H2/CO feed ratio of 2.1, and gas space velocity of 6 NL/g-cat/h). Two models FT-6 and FT-8 showed carbon number dependent chain growth probability and olefin to paraffin ratios. The model predictions were in good agreement with experimental data. Model FT-6 is based on dissociative adsorption of CO, followed by Eley-Rideal reaction with molecular H2, while FT-8 follows dissociative adsorption of CO and H2, to form building block monomer CH2. For both of the models, chain growth takes place by alkyl mechanism and oE-olefins are formed by aB-hydride elimination reaction. Formation of paraffin occurs via single-site reaction with molecular hydrogen (FT-6) or via dual site reaction with adsorbed hydrogen (FT-8).

Parameter estimation resulted in at least one negative parameter in both models. However, to assess the physical meaningfulness of results and the true values of kinetic parameters, one has to use data at multiple sets of process conditions. This work is in progress. Nevertheless, from a qualitative point of view initial results provide valuable insight into selection of reaction mechanisms and rate determining steps for future developments and refinements.

Plastics, which are basically polymer materials, are now an integral part of our daily lives: packaging, transport, textile, Hi-technology… Total Petrochemicals produces and develops useful lightweight and durable plastics that play a key role in the sustainable development of our world, making our lives easier, cleaner, safer and more enjoyable. These products include polyethylene, polypropylene, polystyrene but also since recently polylactic acid, a biopolymer based on a renewable raw material.

Plastics are produced by polymerizing monomer units (ethylene in the case of polyethylene) under certain temperature and pressure conditions and most of the time in the presence of a catalyst. Catalysts, and more particularly organometallic species, are the cornerstones of the production of these polymers. Since 1980, the polyolefin field has undergone a revolution with the development of single-site catalysts referred to as metallocenes. The metallocene catalyst technology helps produce polyolefins, which boast improved chemical and physical properties and are less heavy and less bulky than those traditionally produced.

Total Research Center-Qatar (TRC-Q) researchers, jointly with Total Petrochemicals Research and Development teams, prospect and develop new catalysts to design and manufacture innovative high-level performance plastics. The objective is to optimize the catalysts synthesis for industrial scale application and to produce such catalysts in high yields in the most efficient way.

There is a direct relation between the catalyst structure and the polymer chemical and physical properties. The relation is investigated by changing the size and type of the catalyst substituents; metallic centers … (steric, electronic and symmetrical modifications of the catalysts); and studying the impact of such changes on the polymer microstructure.

A set of products has been selected to explain this relation and bring to light new advances in polyolefins and biopolymers catalysis.

Membrane distillation differs from other membrane technologies in that the driving force for desalination is the difference in vapor pressure of water across the membrane, rather than total pressure. The membranes for MD are hydrophobic, which allows water vapor (but not liquid water) to pass. The vapor pressure gradient is created by heating the source water thereby elevating its vapor pressure. The major energy requirement is for low-grade thermal energy. Moreover, the Qatari economy is based on its massive hydrocarbon industry. In such industries water is routinely used in a number of applications in the form of process or cooling water. In a number of cases the water used can be seawater but with certain restrictions due to corrosion, fouling and water composition, large volumes of fresh water are required around the chemical plants. It is well known that many processes produce large amounts of excess heat i.e., heat beyond what can be efficiently used in the process. Industrial waste heat recovery methods attempt to extract some of the energy as work that otherwise would be wasted. Typical methods of recovering heat in industrial applications include direct heat recovery to the process itself, economizers, regenerators, and waste heat boilers.

An investigation into the potential of using industrial low-grade waste heat in desalination using membrane distillation has been carried out. Three well-known chemical processes were considered: LNG, ethylene and VCM. Using an approach based on pinch technology for heat integration, process streams in the three processes were screened to eliminate unsuitable sources of low-grade heat. Consequently, the LNG and ethylene processes were eliminated because of their unsuitable cooling curves that tended to highlight extreme temperatures. The VCM process on the other hand showed a promising outlook, in particular in the direct chlorination section where a major vapor stream is condensed through the temperature range 118 to 460C. This is precisely the ideal range for low -grade heat recovery. Exploiting literature data and modeling concepts, a flowsheet for a potential MD plant was designed with relevant terminal temperatures.

In the recent years, development of alternative jet fuels is gaining importance owing to the demand for diversifying fuel and cleaner combustion. Liquid fuels have high volumetric energy content and ease of handling therefore preferred by the aviation industry. However, liquid fuels add additional complications in combustion process in thrust generation due to the needed preparatory steps of atomization and vaporization. Alternate jet fuels then must meet the vital needed requirements such as rapid atomization, vaporization, quick re-ignition at high altitude, stable combustion before being used.

At TAMUQ - Micro-Scale Thermo Fluids Laboratory (MSTF), an experimental facility is designed and developed to carry out a detailed investigation on the spray characteristics of jet fuels at different injection conditions. The spray characteristics such as droplet size, velocity and spray cone angle are investigated at different injection pressures. These details are obtained using the state-of-the-art non-intrusive laser diagnostics techniques. Experimental techniques involving both point-wise as well as plane-wise measurements are planned using the Phase Doppler Particle Analyzer (PDPA) and Global Sizing Velocimetry (GSV) respectively to obtain the spray characteristics.

Initially, water is used to tune and establish experimental parameters in TAMUQ spray characterization facility followed by the conventional jet fuel, JetA1. The spray characteristics of water will then be compared with that of JetA1 fuel. This facility will later be used to study the spray characteristics of different gas-to-liquid (GTL) fuels as part of the on-going Qatar Science and Technology Park (QSTP) funded project involving Texas A&M at Qatar (TAMUQ), German Aerospace Laboratory (DLR), and Rolls-Royce (UK). The main objective of this work is to support the initial phase of the QSTP funded project. The spray characterization facility developed at TAMUQ will help to explore the potential of GTL fuels as an environmental friendly, alternate jet fuel.

Cobalt (Co) turnover frequency (TOF) has been reported to be independent of Co dispersion and support type. However, wide discrepancies in Co TOF values exist in the literature. Differences in catalyst preparation, process conditions, and characterization technique could be major factors that may account for the discrepancies. Therefore, a more accurate assessment of Co turnover frequency (TOF) is needed. In this study, Co TOFs over different Co/Al2O3 catalysts promoted with Pd, Ru, Pt and Re at the beginning of reaction and at steady state were determined. The catalysts were prepared in different batches, which resulted in two Co cluster sizes: small Co particle size (∼6 nm) and large Co particle size (11.5 nm). Fischer-Tropsch synthesis (FTS) reaction was carried out at different conditions in a continuous stirred tank reactor (CSTR). All promoted Co catalysts were characterized using BET, TPR, H2-chemisorption and pulse re-oxidation. The FTS was conducted at 220–230 °C, 1.5 MPa, 6–13 Nl/gcat/h and H2/CO = 2.1. Results indicate that catalyst preparation including promoter effect and process conditions significantly impact initial and steady state TOF values. The Co catalysts with larger particles had a larger Co TOF and low space velocity (SV) reduced the number of Co active sites due to severe catalyst deactivation at high CO conversion. For SV of 8.0–13.0 Nl/g-cat/h and 1.5 MPa, high Co TOF values (0.074–0.082 s⁻1, at 210 °C) over the Re and Pt promoted 25%Co/Al2O3 were achieved and were in good agreement with recently published value (0.073s⁻1) in a few literature. Moreover, these values are about two times the values (0.023–0.045 s⁻1) reported in some Co related literature under similar conditions. Therefore, true TOF on single Co cluster with the size of 11.5 nm at 210 °C and 1.5–2.0 MPa should be about 0.073–0.082 s⁻1 (this value is conversion dependent). The effect of promoters (Pd, Ru, Pt and Re) and process conditions on FTS activity and selectivities (hydrocarbons, watersoluble oxygenates and CO2) was also studied.

The current technology for CO2 reduction is CO2 capture and storage (CCS). An alternative technology is to capture CO2 and convert it to chemicals by thermal catalysis. The technology is not appropriate to low concentration of CO2 (<1%), such as CO2 in air except it has to be driven by thermal energy mainly produced by fossil fuel combustion. The solar energy driven CO2 conversion is an only technology without extra CO2 emission (neutral carbon process) and very compatible with atmospheric CO2 condition. Solar energy is most abundant in the world. However, it is difficult to store the produced electric energy in large quantities using the present technologies. Hereby there is still a real need to exploit other methods to easily convert and store solar energy alongside discovering new technologies to largely store electric energy. Photocatalysis, utilizing solar energy to drive chemical reactions over a photocatalyst, is a novel and advanced technology. Solar hydrogen production is an approach to convert solar energy to chemical energy hydrogen by means of photocatalysis. Alternatively, the photoreduction of CO2 directly to a renewable fuel, such as methanol is another approach to convert and store solar energy in chemical bonds. Compared with hydrogen, methanol is a superior fuel due to 1) its higher energy density (1000 times higher than hydrogen per volume) and 2) easier storage and transporation.

Photocatalytic CO2 conversion towards methanol mimics natural plant photosynthesis. Nature represents the blueprint for storing sunlight in the form of chemical fuels (such as sugars) by CO2 conversion. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into separated electron/hole pairs. The holes of this wireless current are then captured by the oxygen-evolving complex (OEC) to oxidize water to oxygen, which allows the electrons are captured by PSI to reduce NADP+ to NADPH (the reduced form of NADP+).

In this paper we will offer an overview of this emerging technology and its potential applications by using cheap inorganic photocatalyst instead of complex proteins/enzymes while the reduction product is methanol rather than NADPH.

Qatar has high increasing electrical energy demand, from less than 50MW 1954 to 5,250MW in 2010. Electrical energy generating was only 1,500MW in 1995, 4,535MW in 2009, and soon will be 9,000MW. The expected additional capacity needed by 2016 is 5,500MW with high average emission CO2 of 32 tons/capita/year.

Qatar has strong solar energy potential, (2070–2250)kWH/m2yr, which could takes place to fulfill the future need energy balance towards Qatar Vision 2030. The mean hourly, daily, monthly and yearly solar irradiation data measured on ground and by satellite collected for several cities such as: Doha, Dukhan, Al-Khor, Ruwais, Abu-Samra, Al-Utoriyah, and Rodhat Al-Faras have been investigated. The measured data on ground is compared with the satellite's data. This preliminary investigation and data analysis could be good preliminary design for “Qatar Solar Atlas”.

The electrical energy consumption breakdown by sectors: residential, commercial, government, industrial, and the total consumption through (2007–2009) are studied. The residential sector is the highest consumption 35 % while the industrial sector uses less. Residential villa consumes three times residential flat. This sector needs energy auditing to save energy in A/C and lighting energy.

The objective of this research is to assist and lead the authority and government to the energy roadmap, energy footprint, Qatar solar atlas, and energy policy to secure energy future with minimizing energy demand and presenting the solar energy potential.

In this research the energy demand and energy forecasting for the nearest future to achieve Qatar Vision 2030 are presented. The energy required to be installed is addressed with emphasize on the solar energy potential with gradually application using mature and proven solar technology. Several scenarios to present Qatar forecasting electrical power demand to 2024 as base case, low and high expected values is presented. The peak expected load through 2022 world football club is considered.

The world is running out of energy, thus energy preservation is of paramount importance. Using current technology, ethylene is purified from petroleum feed stocks using the very energy intensive cryogenic distillation method. However, a purification procedure based on the redox properties of nickel bis-dithiolene complexes has been theoretically studied, in order to design a more convenient route to ethylene purification. Several possible addition routes of ethylene to neutral and anionic Ni(S2C2(CN)2)2 complexes have been modeled using density functional theory. An intraligand addition and subsequent decomposition is preferred for the neutral complex, while the interligand adduct is formed in the presence of the anion, in line with previous experimental results. The effect of the anion, whose role is as a mediator in the initial step of the reaction, is discussed, and the ability of this compound to avoid poisoning by acetylene is investigated. The results from the CN substituted complex are then compared with that of ethylene addition to CF3, H, and OH substituted nickel dithiolene complexes.

Miniaturization and increase in performance of electronic devices, resulted in an increase of energy density loads generated. In recent times, micro-scale cooling devices such as microchannel heat sinks have evolved as a plausible solution to the above heat transfer challenge. Nanofluids emerged as a good candidate in improving the cooling performance of micro cooling systems. Nanofluids are colloidal suspensions consisting of nano-sized particles (less than 100nm) dispersed in a base fluid. Nanofluids are considered ideal for micro-channel devices because they not only improve the heat transfer capabilities, due to increased thermal conductivity, but also minimize the clogging problem. Present work experimentally investigates the heat transfer performance of nanofluids through a microchannel with constant temperature wall boundary condition. Laminar flow of SiO2-water nanofluids inside a rectangular microchannel flow assembly is examined. The effect of flow rate on thermal performance of nanofluid is analyzed along with variation in thermo-physical properties. Interestingly, experimental results shows heat transfer enhancement at lower flow rates and heat transfer degradation at higher flow rates. Theoretical reasoning for this kind of opposing trend is given based on flow conditions and thermo-physical properties of nanofluids. Moreover, Novel near surface velocity measurement of Nanofluids compared with that of regular fluid at the same condition.

I. Introduction

Photovoltaic (PV) energy generation has been one of the most active research areas in the past decades, because it is essentially inexhaustible and environmental friendly with respect to the conventional energy sources.

However, nowadays the higher initial installation cost, lower efficiency and reliability of the PV system still block its widespread application. To overcome these problems, our project focuses on a novel PV system, including the novel PV interface inverter by combination of the battery into the quasi-Z-source inverter (qZSI). All of these aim at controlling output power of the PV system to the grid flexibly, thus, to extremely improve the scientific and economic developments of Qatar.

II. Methods And Results

This paper proposes the charging and discharging control of qZSI with battery for PV power generation system.

1) To monitor the battery state of charge (SOC), the output power-based SOC control is designed.

2) The closed-loop control of shoot-through duty ratio and direct power control of space-vector modulation are separately designed to acquire the stability of DC and AC voltages.

3) Related simulations and experiments are performed.

4) A 3 KW hardware experimental platform is being set up based on the TMS320F28335 32-bit floating-point DSP controller and PM100CLA120 Intelligent Power Module (IPM) for main power switching devices. We have done optimization design on the hardware circuits. Up to now, the hardware prototype has been partly set up.

III. Conclusions And Future Work

The acquired results indicate that the proposed control algorithm could stabilize the DC bus voltage and realize the battery charging and discharging without extra circuits, providing a significant method to enhance the performances of PV power generation systems.

Next step is to go on building the setup and perform related experiments, and then apply the designed control methods on the multilevel PV system, which is in accordance with our project timeline.

This paper highlights the recent work carried out at Texas A&M University at Qatar (TAMUQ) in the development of novel synthetic fuels geared towards the aviation industry's utilization. The research activities implemented involve a unique multi-disciplinary collaboration between academia and industry, which was facilitated by QF through funding provided by the Qatar Science and Technology Park (QSTP) and Rolls-Royce. This project utilizes the expertise of academia in fundamental research and the R&D expertise of world leading industrial firms (Shell and Rolls-Royce).

The broad objective of the project is to upgrade Gas-to-Liquid (GTL) derived Synthetic Paraffinic Kerosene (SPK) based fuels to meet the standards and properties as required by the aviation industry. The work done by our group at TAMUQ is concerned with formulating and testing GTL derived jet fuels for their suitability as replacements for kerosene. The SPK fuels being developed play an important role in the diversification of Qatar's natural gas resources, while also being guided by Qatar Airways inspiration on becoming the world leader in alternative clean fuel utilization.

This paper specifically looks at the relationship between the chemical compositions of SPKs and their physical properties. The chemical groups that compose SPK are normal-, iso- and cyclo- paraffins. The role these paraffins had on jet fuel properties (e.g. density, freezing point, flash point, etc…) were tested and correlated with their hydrocarbon composition. TAMUQ built a world-class Fuel Characterization Laboratory to conduct experimental investigations aimed at developing a wide array of blends using a diverse portfolio of solvents and base chemicals. The experimental data provide a basis for developing statistical models for composition vs. property relationships. Of the properties tested, the freezing point relationship was the most interesting as it showed high nonlinearity over wide range of compositions. Furthermore, a unique aspect of the freezing point testing protocol was the capturing of images of the fuel crystals as it showed a variety of crystal shapes based on blend profiles. A key aspect of the further planned studies is the inclusion of important new chemical groups such as aromatics in the preparation of blends.

Natural gas and oil processing, among many other applications in the chemical industry, depends on accurate predictions of the thermodynamic and transport properties for their accurate and reliable design. Especially in the energy sector, in which the flow rates of process streams are large and equipment is big, improper design can be costly, both in terms of investment and operating costs. Equations of state (EOS) enable the evaluation of thermodynamic properties over a wide range of temperature and pressures and are routinely used for chemical process design. Many EOS exist but relatively few have become widely used, most notably the Peng-Robinson EOS in the oil and gas industry. However, the Peng-Robinson EOS and most other cubic EOS are unsuitable for predicting the phase behavior of mixtures that contain polar compounds. Such mixtures occur even in industries normally associated with the processing of non-polar substances (e.g., hydrocarbons). For example, natural gas may be contaminated by small amounts of water, carbon dioxide, and hydrogen sulfide, often removed using amines and glycols. Modern models such as the SAFT (statistical associating fluid theory), and its variants, and the CPA (cubic plus association) EOS are suitable alternatives but require solving the association equations before computing any thermodynamic property. The Mattedi-Tavares-Castier (MTC) EOS is an entirely explicit model that avoids this drawback but is capable of predictions of accuracy similar to that of the SAFT and CPA EOS. In this paper, we show results of calculations of phase equilibrium and calorimetric properties with the MTC EOS for systems of interest to gas processing industries.

Many developed and developing economies are seeking to mitigate future climate change risks by developing strategies to reduce carbon emissions and the use of fossil fuels. Industrial energy use efficiency can be significantly enhanced by better energy recovery and integration promises significant potential to reduce emissions at low cost. These approaches are seen as crucial enablers of sustainable solutions in industries and are expected to reduce energy consumption significantly within existing technology. Many concepts and methods have been proposed for optimizing energy systems for individual processes and multiple processes linked through central utility systems. Pinch analysis along with other principles for process integration is the most widely applied approach to maximize process heat recovery. Systematic methods are also available for energy integration in an overall plant, or Total Site, consisting of multiple processes served by a common utility system. Scientific community also takes attention on development of sustainable industrial zone.

Even though not adequately covered by design approaches, reductions can be further advanced by energy recovery between multiple plants to exploit synergies between heating, cooling and power requirements in industrial zones or cities. In these zones significant quantities of fuel are combusted in order to provide the necessary energy for industrial activities. In many countries, substantial reductions in fuel consumption and GHG emissions at a national level would require efficiency gains in the industrial zones. Multiple processing plants are typically concentrated in a zone, with each plant consisting of one or more processes. Plants have their own independent operating and maintenance schedules, utility systems, and are owned and operated by different entities. The distances between plants can be considerable. To date, waste heat recovery and reuse across processing plants in industrial zones is a largely unexplored research area. We present an approach to enable the targeting of waste heat recovery and cogeneration potentials across plants in industrial zones and the development of concrete integration options based on economic criteria.

To face new hydrocarbon production metering systems and back allocation challenges, Total E&P Qatar and its Research Center (TRC-Q), located in the Qatar Science and Technology Park (QSTP), test novel approaches to improve current production metering system in the Al-Khalij field. This field is operated under a Production Sharing Agreement (PSA) with Qatar Petroleum (QP).

A field pilot, which involves three platforms offshore, is currently conducted to test a Data Validation and Reconciliation (DVR) software. This tool is used for production accounting, monitoring and as an alarm system related to equipments’ failure. The main outcome to be expected from this pilot will be an automatic validation of on-line production data before their final recording in the database.

The key advantage of the DVR approach is to take into account all the information redundancy and data uncertainties. In the DVR approach, a realistic uncertainty is associated with the information (measurement / model parameter) and a statistical method is applied to re-estimate and improve simultaneously the information and its subsequent uncertainty.

The current status of this study is presented along with improvements and challenges.

A few examples of on line monitoring of Al-Khalij Wells’ production are presented through a comparison between the DVR on-line virtual meter outputs and the on-site production tests. The results, obtained from sensitivity analysis are also discussed to assess the improvements achieved by applying the DVR approach.

There have been a number of studies regarding the efficiency of state-of-the-art thermal (Multi-Effect Distillation, MED), power driven (sea water reverse osmosis, SWRO) and hybrid (MED/SWRO) desalination systems. The comparisons between desalination technologies can be made on a number of critical parameters such as (i) cost of produced water, (ii) energy efficiency, (iii) environmental impact, (iv) reliability and (v) footprint. Whilst the reported relative advantages with respect to parameters (iii) through (v) are conclusive, there remain conflicting recommendations with respect to parameters (i) and (ii), partly due to energy pricing assumptions. Furthermore, existing studies work on the implicit assumption that there is demand for surplus power from integrated power generation and desalination systems.

The presented assessments compare the different thermal, power driven and hybrid desalination systems for output (water/power) achieved from identical energy inputs into thermal power and co-generation cycles for different ratios of desired water and power outputs. This eliminates energy and water pricing issues from the analysis and makes the findings applicable to a range of conventional (e.g. natural gas) and renewable (e.g solar) thermal energy sources. A number of simulations studies have been performed to identify the most energy efficient and cost effective desalination technologies for different water and power generation needs. The key parameters such as power and heat requirements and capital expenditures used in the thermodynamic and economic assessments are in line with ranges reported in the literature and existing plant data. Trade-offs between capital intensity and energy efficiency, which are particularly pronounced in thermal technologies, have also been studied. The paper makes clear recommendations as to the preferred desalination technology for a given seawater quality and water and power demand situation. The paper further explores the impact of technological advances in the form of lower capital costs and higher energy efficiency in the two broad classes of (i) power driven, and (ii) thermal desalination technology. All studies have been performed for seawater qualities observed in the Arabian Gulf.

The estimated sulphur output from Qatar is around 4 Mtpa by 2012, primarily from gas processing operations(Sulphur magazine, March/April 2009). Shell is using novel technologies to utilize sulphur in various applications such as concrete (Shell Thiocrete*), asphalt (Shell Thiopave*) and fertilizers (Shell Thiogro*). The sulphur utilization programme in Qatar Shell Research and Technology Centre is part of a global research and development effort to develop Shell's sulphur concrete and sulphur modified asphalt technologies, with particular emphasis on the needs of the Gulf region. Shell's innovative sulphur concrete technology has the potential to take sulphur concrete from use in niche applications such as chemical flooring to more mainstream applications such as garden products, road construction products (e.g. pavers and traffic barriers) and marine products. This is because the relatively low cost of the modification technology allows sulphur concrete to be considered in applications previously covered only by Portland cement. The first field trial of sulphur concrete in Qatar is a 16 square metre area of sulphur concrete tiles in the Pearl GTL Worker's Village, Ras Laffan Industrial City, Qatar, laid in May 2008. Laboratory results showed that the bending strength of all the sulphur concrete mixtures was greater than the strength of the cement concrete. Moreover, the water absorption of the sulphur concrete tiles was lower than that of the cement concrete tiles. Shell's sulphur-modified asphalt is a technology developed by Shell Sulphur Solutions in 2003, enabling a portion of the bitumen in an asphalt mix to be replaced by modified sulphur, resulting in a pavement that has enhanced mechanical properties such as increased stiffness and significantly reduced permanent deformation. A trial two-lane section of roadway of asphalt mix containing sections of Shell Thiopave and conventional asphalt mixture was constructed in October 2007 at Pearl GTL Worker's Village. The results of the field monitoring study showed that the total road section (sulphur-modified asphalt and conventional mixture) was free of any moderate or major distresses. Industrial hygiene monitoring during laying operations showed that SO2 and H2S emissions remain below the maximum limits when the temperature is controlled than 1450C.The laboratory characterization showed that the sulphur-modified asphalt mixture exhibited better resistance to permanent deformation and higher stiffness than the conventional mixture.

Background: Laser - Ultrasound is a new non-contact technique used to detect the defects in the hot surfaces like hot billets etc. Determination of corrosion in the plates, using this non-contact technique seemed a promising research effort.

Objectives: In this work, an inspection system has been presented that uses Laser-Ultrasound (LU) technique for Nondestructive testing (NDT) of metallic structures with specific interest in Oil & Gas sector.

Methods: The developed system is the first one of its kind in the Middle- Eastern region. The nature of signals is quite unique as well and traditional signal processing runs into a lot of algorithmic complications with them. A new approach has been developed for this setup in order to efficiently enhance signal to noise ratio for the underlying signals so that any subsequent classification/intelligent-detection system can be based on the outcomes of this algorithm. Multiform Tiltable Exponential Distribution (MTED) kernel, which is a generalization of 2nd order Cohen's class functions in Time-Frequency Representation (TFR) space, has been used in this work to isolate the essential frequency components with temporal and frequency based masking filters.

Results: While detecting defect points is quite similar to the conventional ultrasonic testing, the detection of corrosion is quite different. The reason being is the surface properties, and hence the surface vibrations, are quite different for a corroded surface as compared to a polished surface. In this respect, we have observed the propagation of the surface Rayleigh waves manifests a pattern that can be mapped to the corrosion concentration on the surface.

Conclusion: Interesting observation has been made with coated corroded surfaces where the behavior has been found to be quite similar. Thus, the underlying technique can be applied without any need to remove the coatings from the sample under study.

To adequately predict reliability and optimize the time-to-maintenance for complex system design and reliability problems, this research develops a new model for complex systems, which are subject to performance degradation and multiple dependent failure modes. In particular, the hazard rate corresponding to each failure mode depends both on time and system state. The system state stochastically degrades over time, and the degradation is described by a stochastic process. The degradation rate, in particular, depends on time and is also a function of the degradation level.

This research develops a reliability model for complex systems, which are subject to performance degradation and multiple dependent failure modes. A joint model of system degradation and failure time is constructed. The system state stochastically degrades over time, and the degradation is described by a stochastic process. Unlike existing reliability models, we consider a realistic scenario where the degradation rate is, not only a function of time, but also the degradation level at that time.

The goal of this research project is to develop the optimum Condition-Based Maintenance (CBM) schedules. The developed model will be used as the basis in our future research on CBM scheduling.

Depleting oil reserves, environmental pressure, as well as abundant reserves of coal, natural gas and biomass, have all contributed to a revived interest in Fischer-Tropsch (F-T) technology for producing ultra-clean, virtually sulfurfree, transportation fuels and chemicals. F-T technology involves conversion of synthesis gas (i.e., a mixture of H2 and CO) to a wide spectrum of hydrocarbons. In this study, the kinetics of the Fischer Tropsch (FT) synthesis reaction over 0.27 % Ru 25 % Co/Al2O3 catalyst was studied in a 1L stirred tank slurry reactor (STSR). Supported cobalt catalysts and slurry reactors are used in commercial processes for natural gas conversion to liquid fuels (e.g. ORYX GTL in Qatar). With known kinetics one can size reactors and predict their performance as a function of process conditions. Experiments were conducted at reactor pressures of 1.4 MPa and 2.4 MPa, temperatures of 205°C and 220°C, H2/CO feed ratios of 1.4 and 2.1 and gas space velocities ranging from 2 to 15 NL/g-cat*h.

Langmuir-Hinshelwood-Hougen-Watson (LHHW) type rate equations were derived on the basis of a set of reactions originating from carbide, Eley-Rideal and enolic pathways, and two empirical power laws from the literature were used to describe CO disappearance rates.

Model rate laws were fitted to isothermal experimental rates using least-squares nonlinear regression to obtain model parameter values. Physical and statistical tests were used to discriminate between rival models. Optimisations were performed by first applying bounds to obtain realistic values of the parameters and then assumptions were made regarding the degree of adsorption for some species. Finally, nonlinear regression of model rate laws using non-isothermal experimental rates was also performed by applying Arrhenius law-based constraints to obtain physically meaningful results.

Goodness of fit for the most physically significant models were compared using qualitative (parity curves) and quantitative (mean absolute relative residuals (MARR), R-square and F-test) analysis. It was found that the model based on carbide mechanism involving dissociative CO and hydrogen adsorption (M1) and the model based on hydrogen-assisted dissociative adsorption of CO followed by hydrogenation of dissociatively adsorbed CO (M3) provided the best fit to the experimental data.

Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal efficiencies, in addition to low nitric oxides (NOx) and particulate matter (PM). HCCI combustion is achieved through the auto-ignition of a compressed homogeneous fuel-air mixture, thus making it a “fusion” between spark-ignition and compression-ignition engines. The main challenge experienced when developing HCCI engines is the absence of a combustion trigger hence making it difficult to control its combustion timing.

The aim of this research project is to develop a natural gas HCCI engine to improve the performance of stationary power plants in Qatar. Since HCCI primarily depends on temperature and chemical composition of the mixture, exhaust gas recirculation (EGR) and adjusting intake temperature are the techniques that will be used to control ignition timing. Previously, a simulation model was developed using a highly sophisticated program, GT-Power. It was noticed that simulation time for such a model was high. Therefore a simple, non-linear model was developed to capture the main thermodynamical features of the HCCI engine. In this oral presentation, we will explain how the model was developed as well as the optimization technique used to adjust an experimental correlation to predict ignition timing. We will show that performance data produced by our model is in accordance with the data acquired from GT-Power. In addition, several methods were exhausted to further simplify the model and produce a linear version that could be used in linear control schemes. Data from the finalized linear model were compared to the initial non-linear model and proved to be a sufficient approximation. A Linear Quadratic Regulator Controller scheme will be used on our final linear model to control the EGR ratio and intake temperature, which will ultimately control the combustion timing. Finally, a block diagram of the proposed control scheme was developed. Further work for validation and implementation of the proposed scheme will be discussed.

Qatar is one of the largest producers of polymers in the Middle East, with a total annual turnover of $3.5 billion. The annual consumption of industrial and domestic polymers in the region generates significant amount of plastic waste in Qatar and in Gulf Corporation Countries (GCC). Recently, recycling of plastics has become an optimum waste management solution due to the efficiency of incorporating the plastic waste management stream into commodity and structural applications. One of the main obstacles in the region is collection and sorting of plastics, due to the variety and high volume of waste streams. To solve this problem, and to upgrade the recycled polymer applications, optimisation of additives and processing techniques were used in this work, such as the addition of glass fibre reinforcement, wood, mica and date palm fibre in selected volume fractions, in order to minimise the effect of the residual “secondary” polymers in the main composite.

A tremendous improvement has been achieved in the mechanical properties and the thermal stability of the selected systems, due to the synergistic effect of the complementing additives. In addition to their much-improved thermomechanical performance, the life cycle assessment (LCA) of the new recycled composites showed to have improved effect on the environment compared to the unadulterated systems. A complex analysis showing the interdependencies between the improved materials properties and the positive environmental impact is presented for the first time.

Qatar has experienced great change in its infrastructure, continuous upgrading of its major industrial cities, of its network of roads and highways and major construction and development along its coastline in particular the eastern coastline. These activities can all have an impact on the marine life and terrestrial wildlife, vegetation and floristic composition.

One strip of coastline on the north-eastern section of Qatar remains in parts virgin land and the coastal zone is considered a least impacted zone. A baseline survey was commissioned to record all physical/chemical and biological data of the Qatar marine zone.

This survey, representing field data collected between February and April 2010, encompassed a 35km long stretch of coastline and extended 20km offshore and as far inland as 1km, it also included Umm Tais Island and Al Jasasiya. The seabed and the water body were documented by video photography. Fish population was studied by deployment of fish nets. Mangrove forests were studied in detail. The coastline was surveyed covering landform, vegetation and observations on wildlife. The benthic community of corals, seagrass meadows and microalga beds were fully mapped. Seawater and sediment physicochemical parameters and biota were analyzed. Current meters were deployed to study the sea current speed and direction in the study area.

A full record of terrestrial geology, morphology and vegetation, along with coastal and intertidal biota have been documented. An extensive range of physiochemical parameters have been documented and analyzed according to international standards. State of the art mapping techniques have been employed to provide visual records of both physiochemical and biological constituents. This study documents a large number of organisms not previously reported for the Arabian Gulf. These include almost 106 species belonging to 8 phyla, 17 classes, 36 orders and 63 families.

This project, carried out by the Qatar University, Environmental Studies Center, exemplifies a comprehensive, well run and well documented ecological baseline study. This information will enable future monitoring and substantial data on which stakeholders can take prudent action to conserve, preserve or sustain.

Nanotechnology is regarded as the next great scientific/industrial revolution due to the possibility of designing nanostructured materials that possess novel electronic, optical, magnetic, and catalytic properties. Nanomaterials could potentially be applied in pollution control, catalysis, water remediation, clean energy.

Nanocatalysis is a phenomenon of significant research and important practical applications in a variety of fields such as materials, environmental and atmospheric sciences. Low-temperature catalytic oxidation of carbon monoxide (CO) is one of the most important problems in pollution since even small exposures to CO (ppm) can be lethal. Nanophase metal and metal oxide catalysts, with controlled particle size, high surface area, and more densely populated unsaturated surface coordination sites, could potentially provide significantly improved catalytic performance over conventional catalysts. It is therefore, expected that nanoparticle catalysts would show high catalytic activity for the low temperature oxidation of CO than bulk materials.

Noble metals are well known oxidation catalysts with high activity and stability, even in the presence of moisture and sulfur compounds, and they are usually used in gas exhaust emissions control. The high cost of precious metals and their sensitivity to sulfur poisoning motivated re-searchers to search for new catalysts. Alloying is a phenomenon that can either improve the catalytic properties of the original single-metal catalysts for CO oxidation. Recently, we reported the effect of support on the catatalytic activity of Au catalyst.

We have prepared metallic and bimetallic nanocatalysts on different supports using differ-ent synthesis methods. The catalytic activity of each catalyst was carried out by using a flow tube reactor coupled to an infrared detector. Our results indicate that unsupported AuCu alloy shows higher activity than Au or Cu alone. These results attributed to the formation of CuO within the bimetallic nanoparticles, which improves the catalytic activity of Au-Cu alloy nanoparticle. On the other hand, Au nanoparticles supported on CeO2 exhibit higher catalytic activity than Cu, CuO, and AuCu alloy supported on CeO2. These results attributed to the strong interaction of Au with CeO2.

Barchan dunes in Qatar are restricted to the southeastern region of the country. They are currently a disappearing natural habitat due to the northwesterly Al Shamal winds, which are scouring the landscape and spreading desertification, as they pass. This research aims to understand whether the synergy between the physical transport of dust, moisture retention and microbial growth beneath the dune surface, could be exploited to stop erosion of an active dune. Microbial communities at the surface down to 30cm below have been quantified using direct counts of live/dead cells through fluorescent stains, culturing sand microbes in media selective for general heterotrophs, fungi and/or cyanobacteria, and by conducting culture-independent phylogenetic characterization based on 16S/18S rRNA analysis. Current results show that there is more genetic material found in barchans at depths between 15 to 30 cm deep than at the surface, due to the cooler, moister, and UV-protected sand below the surface. Isolated colonies sequenced from barchans include Arthrobacter and Marmonicola sp., which are typical of bacteria associated with soils. Capacitance and thermal probes recording the humidity and temperature were deployed just beneath the sand surface. For the first time, diurnal variations of temperature and humidity profiles below a dune surface have been recorded. A correlation for migration velocity of Qatar dunes west of Umm Said was established. We anticipate that greater understanding of dune biology will lead to the development of new engineering technology to stabilize Barchans.