Plasma-catalytic conversion of CO2 to CO over binary metal oxide catalysts at low temperatures

Non-thermal plasma (NTP) technology is gaining increasing interest for CO2 conversion due to its potential to convert inert and stable CO2 to value-added fuels and chemicals at ambient conditions. Combining catalysts with plasma can enhance conversion and energy efficiency simultaneously, overcoming the trade-off barrier commonly present in plasma processes. This work reports the influence of various ceria-promoted iron oxide catalysts on the decomposition of CO2 to carbon monoxide and oxygen in a packed bed, dielectric barrier discharge (DBD) reactor at low temperatures and ambient pressure. As ceria is an expensive rare earth metal, its combination with a cheap, abundant metal such as iron can make the process far more economical. The optimum CO2 conversion (24.5%) and energy efficiency (13.6%) were achieved using γ-Al2O3 supported 5Fe5Ce, almost twice the conversion attained using 10Fe (13.3%). Catalysts were characterized using N2 adsorption, X-ray diffraction (XRD), Raman spectroscopy, H2-temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) analysis. A solid solution formed from the mixture of iron oxide and ceria. A critical concentration of iron oxide is required to increase the number of oxygen vacancy sites in the solid solution. The synergy between Fe and Ce, and thus the oxygen vacancy sites, can also be optimized via the synthesis method. A reaction mechanism has been proposed for CO2 conversion at the catalyst surfaces

Research on orchard navigation method based on fusion of 3D SLAM and point cloud positioning

Accurate navigation is crucial in the construction of intelligent orchards, and the need for vehicle navigation accuracy becomes even more important as production is refined. However, traditional navigation methods based on global navigation satellite system (GNSS) and 2D light detection and ranging (LiDAR) can be unreliable in complex scenarios with little sensory information due to tree canopy occlusion. To solve these issues, this paper proposes a 3D LiDAR-based navigation method for trellis orchards. With the use of 3D LiDAR with a 3D simultaneous localization and mapping (SLAM) algorithm, orchard point cloud information is collected and filtered using the Point Cloud Library (PCL) to extract trellis point clouds as matching targets. In terms of positioning, the real-time position is determined through a reliable method of fusing multiple sensors for positioning, which involves transforming the real-time kinematics (RTK) information into the initial position and doing a normal distribution transformation between the current frame point cloud and the scaffold reference point cloud to match the point cloud position. For path planning, the required vector map is manually planned in the orchard point cloud to specify the path of the roadway, and finally, navigation is achieved through pure path tracking. Field tests have shown that the accuracy of the normal distributions transform (NDT) SLAM method can reach 5 cm in each rank with a coefficient of variation that is less than 2%. Additionally, the navigation system has a high positioning heading accuracy with a deviation within 1° and a standard deviation of less than 0.6° when moving along the path point cloud at a speed of 1.0 m/s in a Y-trellis pear orchard. The lateral positioning deviation was also controlled within 5 cm with a standard deviation of less than 2 cm. This navigation system has a high level of accuracy and can be customized to specific tasks, making it widely applicable in trellis orchards with autonomous navigation pesticide sprayers

Plasma-catalytic CO2 hydrogenation to ethane in a dielectric barrier discharge reactor

Anthropogenic greenhouse gas emissions have caused changes to the Earth's climate, resulting in catastrophic weather events that are becoming more frequent and intense. Developing carbon-neutral processes for CO2 conversion powered by renewable energy is one way of attaining a circular economy, as waste CO2 is converted to a new carbon-containing product, without also being created as a by-product during the process. Plasma-catalysis is gaining increasing interest for CO2 conversion and utilisation under mild conditions, particularly CO2 conversion to green chemicals and fuels using renewable hydrogen, as this electrified process can easily be combined with clean and renewable energy to ensure a carbon-neutral process. Previous studies have mainly focussed on the production of methane from CO2 and H2; however, ethane (C2H6) is a much more valuable product. In this work, we report a non-thermal plasma-catalytic process for the conversion of CO2 into C2H6 in a dielectric barrier discharge (DBD) reactor. The influence of a variety of alumina-supported metal catalysts (Ru, Cu, Ni and Fe) on the plasma-catalytic CO2 hydrogenation to C2H6 was evaluated. The Ru catalyst attained the highest selectivity towards C2H6, at almost 40%. The Ru catalyst also increased the energy efficiency of the process to around 18%, in comparison to the plasma reaction using pure alumina (12%). The Ru catalyst also achieved the highest H2 conversion at 29%. Plasma-assisted production of C2H6 is a new promising process for the utilisation of CO2 via carbon-neutral electrified gas conversion.</p

Molecular dynamics simulation of water transport through carbon nanotubes

Carbon nanotubes present an exciting area of research, with a large portion of current nanoscience research involved in carbon nanotubes. Due to their impressive mechanical, electrical, and transport properties, it is proposed for a variety of applications. An introduction of carbon nanotubes and their physical and thermal properties are reviewed in this report. This report also summarises a few properties of carbon nanotubes concluded from existing literature, namely, diffusivity of water, density, and hydrogen bond dynamics of confined water. An overview of desalination and various aspects of the Reverse Osmosis desalination process is provided. The limitations of current RO desalination processed are discussed and the possible application of Carbon nanotube in the desalination process is assessed.Bachelor of Engineerin

Social-optimized Win-win Resource Allocation for Self-organizing Cloud

Abstract—With the increasing scale of applications and the number of users, we design a Self-organizing Cloud (SoC) which aims to make use of the distributed volunteer computers or dedicated machines to provide powerful computing ability. These resources are provisioned elastically according to user’s specific demand, by leveraging virtual machine (VM) resource isolation technology. Based on such a framework, we propose a social-optimized auction-based resource allocation scheme, which mainly tackles two issues: (1) how to make full use of the widely dispersed multi-attribute idle resources to construct a win-win situation, such that each task schedule could let both sides (resource providers and consumers) be satisfied with their final payoffs. (2) The total resource utility welfare should also be optimized to guarantee the overall performance around the global system. The key challenge of getting the win-win effect with social optimization is its provable NP-completeness. Finally, we validate that our approach can effectively improve the resource contributor’s payoffs up to about five times as the level without our method via simulation work. Meanwhile, our approach can also keep a high level of the processing rate for the task scheduling. I

Supported nickel catalyst for synthesis gas preparation

US20040054016A1Published Applicatio

Supported nickel catalyst for synthesis gas preparation

US7108804Granted Paten