Qatar Foundation Annual Research Forum Volume 2010 Issue 1

The impending shortage of fossil fuels and environmental consequences of fossil fuel consumption are two of the most imperative problems in the world. This presentation is about a novel design of a solar reactor cavity system composed of a camera-like aperture and moving-wall system to house a unique thermo-fluid-chemical process known as ‘solar cracking’.

Differing from typical solar powered Rankine cycles, solar cracking uses concentrated solar energy as a heat source for direct decomposition of natural gas into gaseous H2 and particulate carbon. This process offers a CO2 emission free hydrogen production method, as the carbon is collected in a high-grade and/or nanotube form. However, solar cracking reactors have two implicit major problems:

The intrinsic losses in energy conversion efficiency as a result of the high internal temperatures and corresponding re-radiation losses as well as the inherently transient nature of the solar energy. Literature on solar reactors reveals a distinct focus on optimal reactor design for steady state efficiency, but little regarding transient inefficiencies. This presentation provides an advanced perception to solar cracking reactors by presenting you the latest results of our research at Sustainable Energy Research Lab on the design of a ‘smart solar reactor’ that is sensitive to variations in solar flux, and can adjust itself accordingly to maintain quasi-equilibrium internal conditions. A unique system design is presented featuring a solar-flux intensity sensitive aperture that can enlarge the aperture diameter when the flux is low and reduce the diameter when the flux is high.

Carbon particle deposition on the reactor window, walls, and at the exit. Carbon deposition. particularly at the exit, causes reactor clogging. There have been many innovative reactor designs aimed to achieve increased conversion efficiencies through novel flows developed at ETH-Zurich, CNRS-France, WIS-Israel, Colorado-USA, Florida-USA, and DLR-Germany. From vortex-flow to tornado, and from fluidized bed to rotating cavity, the designs of these reactors have moved toward the goal of seeking enhanced flow conditions that result in improved overall efficiencies, but have not solved the carbon deposition problem. Our latest research results at Sustainable Energy Research Lab shows that our ‘aero-shielded cyclone solar reactor’ concept provides a laminar flow shield covering the walls as a thin layer flow with a velocity that is strong enough to sweep carbon particles away. This presentation will show you the results of our research on this concept with a 3D animation of the reactor.

In view of the burgeoning market in international carbon trading and the long-term global regulatory constraints on fuel emissions, the need for an alternative to petroleum oil is both large and immediate. The primary goal of our project is to establish a global infrastructure for the production of biofuel from cyanobacteria and microalgae that can sustain economic and environmentally sound operations of the aviation industry. The business plan includes biofuel production as a driver for the development of a diverse biotechnology industry in Qatar, based on research, development, acquisition of intellectual properties, training and education. These activities are in full accordance with the 2030 National Vision for Sustainability in Qatar. The partners in this enterprise are the state airline of Qatar (Qatar Airways), the state university of Qatar (Qatar University) and the conduit for support of innovative research in Qatar; Qatar Science and Technology Park. Our research program is conceived to trigger the paradigm shift in technology that is required to make the near-term establishment of a viable biofuel technology in Qatar a reality. The program is focused on the growth, physiology and molecular biology of cyanobacteria and microalgae isolated from extreme terrestrial, freshwater and marine environments in Qatar. A diverse culture collection of photosynthetic microorganisms is now established at Qatar University and strains are currently under investigation for their utility in large-scale growth, expression of superior survival in engineered Qatar environments, amenability to novel harvesting techniques, and capacity for copious oil production.

The concept of cognitive networks has recently emerged as an efficient means for utilizing the scarce spectrum by allowing spectrum sharing between a licensed primary network and a secondary network. Cognitive networks can be divided into three different types; namely, interweave, underlay, and overlay. For the interweave type, the secondary users are only allowed to use the spectrum of the primary network whenever it is idle, which requires continuous sensing of the primary spectrum by the secondary network. For the underlay network, simultaneous transmissions are allowed by letting the secondary network share the spectrum with the primary network, under the condition of maximum interference power level allowed at the primary receiver. Finally, for the overlay type, the secondary network is aware of the signal characteristics of the primary network that are exploited to achieve an enhanced performance for the secondary network by minimizing the interference incurred by the primary transmissions.

In this poster, we present an overview of the three types of cognitive networks. We focus on the underlay cognitive network model, whereby we present the fundamental capacity results of these networks under various power constraints on both the transmit power and the interference power attained at the primary receiver. We then explore practical methods for achieving these capacity results by employing adaptive transmission techniques at the secondary users.

Environmental monitoring is an important tool in the overall environmental management strategy. In particular, a planned monitoring strategy can help in quantifying the level of impact that has occurred during country/region development and enables the predictions of potential air pollution changes to be verified. A quantitative assessment of environmental change following industrial activities is important when future environmental liabilities need to be considered. Additionally, environmental monitoring data can enable a better understanding of the processes by which impacts may arise.

Traditional environmental monitoring systems are characterized by bulky nodes, expense (in the range of USD 1 million ), and disperse (tens of kilometers) nodal allocation. Traditional systems rely on extrapolating localized measurements to project air quality information over a large geographical area. Therefore, along with the high cost, traditional networks suffer from inaccurate predications/assessment to regional mapping of air quality information, as well as non-flexible gas monitoring and selection.

As a result, many research institutes and governmental agencies worldwide are actively involved in research activities for finding more robust and cost-effective alternatives. The underlying technology for those activities is the utilization of wireless sensor networks (WSN). WSN promise to bring low cost, large scale advanced remote monitoring and automated applications to a wide range of technical areas and industries. In addition to lowering capital and operating expenses, WSN provides improved reliability, increased installation flexibility and scalability.

The project aims to architect, design, and develop an innovative solution utilizing the WSN. The solution under consideration is ubiquitous and cost effective and provides real-time data transmission and remote/online data processing and accessibility. Innovative, smaller, inexpensive and with different sensing capability, sensor nodes are integral to the solution. Such sensors are emerging, but not yet mature, and therefore substantial effort will be invested in working with sensor vendors to ensure the design and development of the right sensor nodes.

The project also includes research activities related to innovative network architecture for robustness and cost effectiveness as well as software development activities for data processing, information presentation and dissemination. This will ensure that localized and personalized information can be delivered to diverse customers.

The capture of CO2 from flue gases derived from fossil fuelled power plants and the absorption of CO2 from natural gas sweetening processes are two relevant industrial problems closely related with very important environmental, economical and technological problems that need to be solved. Porous inorganic compounds have received attention in recent years due to their possible applications in the carbon dioxide capture and storage field. In this work, we prepared new metal carbonates by reacting CO3 ^2- solution with solutions of Zn²⁺-Mg²⁺ metal ions in different stoichiometric ratios. The samples were characterized with powder x-ray diffraction analysis (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Furthermore, these samples were measured with a Rubotherm magnetic suspension balance to investigate their CO2 adsorption behavior and performance.

Laser ultrasonic inspection (LUI) is the name given to the techniques in which a laser beam interacts with the surface of a test sample and replaces piezoelectric transducers for launching and probing elastic sound waves. When this wave returns to the surface, a separate laser interferometer detects the small resulting displacement. This technique is strictly non-contact and is therefore suitable for in-process inspection of parts while at high temperature or moving at high speed. In the field of non-destructive techniques (NDT), the association of laser generation with optical detection provides a completely remote inspection system.

As this process involves hitting of high power laser beam on to the surface to be inspected and ablation of the superficial layer of the surface, one of the objections from the conventional oil and gas industry to LUI system is apprehension of potential damage or adverse effect on the surface property and integrity. This possible problem is seen as severe on pressurized pipes to the extent of being dangerous to the system.

This work attempts to present a qualification methodology which was experimentally applied to known metallic samples and with standard LUI testing conditions. Binary image processing techniques have been used with hybrid filtering and statistical measurements to quantify the findings. A relational approach is used within the digital image processing domain to qualify the extent of metal loss that occurs during a prolonged exposure of the clean metallic surface to the laser beam. A comparative study has been done on Duplex steel (UNS S31803) and Carbon steel. Samples were studied for relative metal loss, possible changes in hardness and micro-structural anomalies (if any). A new qualification method has been developed using digital image processing to approximate the damage sustained by the exposure. The results are quite promising and alleviate many doubts that conventional NDT experts may have in connection with the LUI system, especially in the oil and gas scenarios.

Life cycle assessment (LCA) is gaining wider acceptance as a method that evaluates the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment, and assesses the impact of the energy and material used and released to the environment. It is also considered as one of the best environmental management tools that can be used to compare alternative eco-performances of recycling or disposal systems.

In this study, life cycle assessments of polymer recycling are reviewed with a view to protecting the global environment and to control waste in the polymer industry in Qatar. Incremental increases in population in this region have resulted in a dramatic increase in plastic consumption and unfortunately, the waste management system has not been properly managed to date. During the study, real data from the industry was used in the analysis of the environmental impact of plastics recycling by applying the LCA methodology to the products and processes involved in recycling. The results obtained will help to understand the importance of the use of recycled polymer materials and highlight the clear advantages from an eco-efficiency viewpoint, of plastic recycling against direct manufacturing from petroleum.

During the last four decades, synthetic chemical pesticides have provided many benefits to agriculture and food production, but they pose some hazardous problems to humans, animals and environment. Chemical pesticides leave undesirable residues in food, water and the environment where they are not used properly. It is estimated that one million people are affected by chemical pesticide poisoning every year and more than 20,000 die as a result of being unaware of the risks involved in the handling or use of chemical pesticides.

This study showed that integrated pest management (IPM) was an effective alternative to synthetic chemical pesticides. The study also revealed that the components of IPM, such as cultural practices, biological control, pheromone traps, soil solarization and plant extracts provided cost effective and environmentally sound methods to control agricultural pests and diseases. As a result many growers and researchers are applying an IPM approach to maintain pest populations at levels below those causing economically unacceptable damage or loss.

In addition, this study has identified the use of IPM methods in the Arabian Gulf countries to manage some insects and diseases affecting date palm trees. The main goal of IPM is to reduce any harmful impact chemical pesticides may have on humans, wildlife, soil and water quality. The usage of chemical pesticides in the IPM programme should be rational, judicious and applied at the most vulnerable time in an insect/disease life cycle.

As part of the project studying the fundamentals of carbonate reservoir pore/fracture scale physics and chemistry within the Qatar Carbonates and Carbon Storage Research Centre at Imperial College London, sponsored by Qatar Petroleum, Shell and Qatar Science and Technology Park, we present experimental data on the dynamics of fluid-rock interaction during acid injection in carbonate rock. This has implications for CO2 sequestration in geological sinks as well as in well acidization that has been used in carbonate reservoirs to enhance oil recovery.

The effect of grain size distribution and flow rate on dissolution kinetics was studied in laboratory columns packed with calcite grains at ambient conditions. For each set of different experiments the columns were packed with 150-250µm (fine), 300-500µm (medium) and 600-850µm (coarse) calcite grains. The evolution of fluid-rock interaction was investigated by using inductively coupled plasma-atomic emission spectroscopy (ICP-AES) to study the time dependent profiles in Ca²⁺ cation concentrations inside the column and in the effluent stream. A scanning electron microscope (SEM) imaging technique was performed prior to, and after, acid injection to illuminate the nature of calcite dissolution at the rock surface.

ICP-AES and SEM analysis highlighted the complex nature of the dissolution, characterized by the creation of additional surface roughness and wormholes in single grains that resulted in the formation of a more heterogeneous porous medium. The in situ Ca²⁺ concentration, measured by slicing the column at the outlet, is greater than the effluent concentration, confirming that Ca²⁺ residesin stagnant regions of the pore space.

After starting acid injection, the chemical reaction occurs in the column, resulting in a gradual increase in Ca²⁺ concentration in the effluent that eventually reaches a steady-state value. Thus, the time needed to reach this steady state defines an important time-dependent reaction dynamics regime. The duration of this regime is longer as the grain size distribution becomes finer. As the finer media has a more complex structural heterogeneity, the corresponding surface area takes a longer time to be reached by the injected acid and the transport of the created products takes a longer time to breakthrough. This implies a transport-limited reaction.

The analysis of stable carbon and oxygen isotope composition is one of the most commonly used techniques in stratigraphic and diagenetic research of carbonate rocks. The wide-spread use and easy access of this long-established method has the side effect that little attention is paid to fundamental calibrations. Dolomite is often measured against a calcite standard (NBS19), and the acid fractionation factor used to calibrate is based on the one for calcite. To date, no reference material exists for dolomite.

In this study, which is part of dolomite research in the Qatar Carbonates and Carbon Storage Research Centre project, we focus on two main goals. First, we characterize a current standard of dolomite used for major and minor elemental geochemistry, and assess its suitability as a new dolomite standard for δ¹⁸O and δ ¹³C. Second, we attempt to better constrain the acid fractionation factor for dolomite and assess the influence of different dolomite types on this fractionation factor. As only two thirds of the total oxygen in the carbonate is released in the form of CO2 during acid reaction, a fractionation between the reacting carbonate and the resulting gas will occur. A recent study improved on the acid fractionation factors for calcite and aragonite. Often, the acid fractionation factor for dolomite is used to calculate δ¹⁸O and δ ¹³C from the values obtained by calibration with the calcite standard. Only two studies (from the 1980's) have attempted to constrain the acid fractionation factor for dolomite, of which only one did experiments not only at 25ºC, but also at 50 and 100ºC. The dataset of the latter experiment is, however, very limited and contains only two dolomite samples. We aim at improving the constraints on the acid fractionation factor of dolomite by reacting a wide range of different types of dolomite at a wide range of acid temperature, and compare this to the absolute isotopic composition of the samples measured on a fluorination line.