Design, implementation and control of microwave plasma gasification system for syngas production

This thesis provides a solution for sustainable energy production. It applies the newest technologies of microwave plasma on a traditional method known as gasification. The simulation of this system has been achieved through a high frequency structure simulator to decide the best design of the structure. Microwave radiation at the frequency of 2.45 GHz has been applied to ionise argon gas and convert it into plasma. It has been proven that plasma can be self-initiated with an appropriate electric field applied. This microwave-induced plasma is the heart and soul of the Liverpool John Moores University's gasification system. It is coupled to a gasification chamber to gasify the feedstock placed inside and extract its energy as synthesis gas (i.e. hydrogen and carbon monoxide). Feedstock used in this study is carbon based material including pieces of wood and palm date seeds. This work is novel as no other work upto the date of this thesis completion has studied the different variables affecting plasma creation, plus the automation and the fully control of the microwave plama gasification system. Results reveal that after improvement of the microwave-induced plasma by automated control, it was possible to increase the synthesis gas production to 25.7% hydrogen and more than 57.6% carbon monoxide. This study has included the effects of some parameters on the plasma created, thus on its efficiency. These parameters are; the power of the microwave radiation, the reflected power from the system, the flow rate of argon and the pressure inside the gasification chamber. Other effects were taken into consideration throughout the project such as the study of the sample's moisture levels on the gas production and the use of helium gas instead of argon for plasma creation. The system has proved the benefits of applying microwave-induced plasma technology on the gasification technology. These benefits can be summarised as the reduction of the input power needed for the procedure from the range of megawatts to 1 kilowatt, and the flexibility achieved through controlling the plasma jet for an improved process

Real-time Optimisation of a Microwave Plasma Gasification System

A microwave plasma gasifier has been designed to produce syngas from waste. Gasification using microwave plasma has various controllable parameters to achieve optimal syngas production. These parameters include the microwave power applied, the reflected power from the microwave plasma jet, the EH tuner arm position, the gas flow and pressure, in addition to the temperature inside the gasifier. A variety of sensors are required to provide feedback and control for each of these parameters. This paper discusses the benefits of gasification, particularly via microwave plasma techniques, the first steps toward the optimisation of such a system and some preliminary results of this optimisation

Rule-based energy management of hybrid electric vehicles focus on load following strategy

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Synthesis of purely silica MFI-type nanosheets for molecular decontamination

Conventional syntheses of zeolites generally lead to the formation of crystals whose sizes are of the order of several microns which is not detrimental in a large number of industrial applications. However, the capacity and kinetics of pollutant adsorption which are sensitive to diffusion phenomena, surface and porous volume could potentially be improved by the use of nanocrystal or hierarchical zeolites (micro/mesoporous or micro/macroporous). Indeed, zeosil nanosheets hold great potential because of their small size and their high porous volume that promote access of pollutants and increase the adsorption capacity. Herein, silicalite-1 zeosil with a lamellar morphology was successfully synthesized under hydrothermal conditions (110 degrees C, 10 days) using diquaternary ammonium as structuring agent. Compared to the conventional silicalite-1 material, the porous volume of the synthesized nanosheets determined from the N-2 adsorption-desorption isotherms was found to be multiplied by 3.5 (0.62 cm(3) g(-1)) without altering the microporous volume (0.18 cm(3) g(-1)). This result was also confirmed by the increase of the n- hexane adsorption capacity and kinetics in the silicalite-1 nanosheets compared to the conventional silicalite-1. This approach indicates a new way for obtaining zeosil materials of controlled sizes and shapes for molecular decontamination

Influence of the Particle Sizes on the Energetic Performances of MFI-Type Zeolites

Nanoporous materials have an important role in addressing some of the major energy and environmental-related problems facing society. Herein, four MFI-type zeosils with crystallite size ranging from nanometer to micrometer were synthesized (nanosheets, nanocrystals, honeycombs, and big crystals) in order to establish a relation between the crystal size of these zeosils and their energetic performances under high-pressure intrusion extrusion experiments (mechanical energy storage). The intrusion-extrusion behavior of water and concentrated LiCl aqueous solution (20 M) in these four zeosils was evaluated at room temperature. Whatever the crystal size, the "Silicalite-1-water" systems displayed a spring behavior, whereas "Silicalite-1-LiCl aqueous solution" systems moved slightly toward a shock-absorber behavior with an increase in the intrusion and extrusion pressures (273-285 MPa) compared to "Silicalite-1-water" systems (88-96 MPa). Therefore, in the case of the LiCl aqueous solution (20 M), the energetic performance was tripled. Compared to the big crystal sample, both the honeycomb and the nanocrystal samples showed a slight decrease of the intrusion and extrusion pressures. A decrease of the intrusion and extrusion volumes was observed in the case of nanocrystal sample compared to both big crystal and honeycomb samples, which is attributed to the noncrystallized silica regions infused within the nanocrystals. Contrary to these three samples, liquid intrusion occurred at atmospheric pressure for the nanosheet sample, which is likely due to both the presence of a high number of surface defects and the low thickness of the zeolite nanosheets (2 nm). Solid-state NMR spectroscopy and thermogravimetric analyses provided evidence on the presence of local defects on the nonintruded samples and the breaking of some siloxane bridges after the intrusion extrusion step