Universiti Teknologi Malaysia

About: Universiti Teknologi Malaysia is a education organization based out in Johor Bahru, Malaysia. It is known for research contribution in the topics: Membrane & Adsorption. The organization has 21644 authors who have published 39500 publications receiving 520635 citations.

Improved SPC chart pattern recognition using statistical features

Abstract: Increasingly rapid changes and highly precise manufacturing environments require timely monitoring and intervention when deemed necessary. Traditional Statistical Process Control (SPC) charting, a popular monitoring and diagnosis tool, is being improved to be more sensitive to small changes and to include more intelligence to handle dynamic process information. Artificial neural network-based SPC chart pattern recognition schemes have been introduced by several researchers. These schemes need further improvement in terms of generalization and recognition performance. One possible approach is through improvement in data representation using features extracted from raw data. Most of the previous work in intelligent SPC used raw data as input vector representation. The literature reports limited work dealing with features, but it lacks extensive comparative studies to assess the relative performance between the two approaches. The objective of this study was to evaluate the relative performance of a feature-...

Development of biogas combustion in combined heat and power generation

Abstract: Based on the biogas feedstock and its generation cycle, a considerable part of biogas ingradients are noncombustible gases. Low calorific value (LCV) of biogas is one of the most important barriers of biogas development in the combined heat and power (CHP) generation. Biogas purification is usually performed in sensitive utilizations, however modification methods such as cryogenic and membrain are not economic. Therefore, new methods of biogas utilization should be experimented. In this study, characteristics of biogas are investigated under various combustion regimes such as biogas conventional combustion, hydrogen-enriched biogas traditional combustion, biogas flameless mode and hydrogen-enriched biogas flameless combustion. Since biogas conventional combustion is not well-sustained due to LCV of biogas, hydrogen addition to the biogas components could improve combustion stability however NOx formation increases. Although flameless combustion of fosil fuel have been developed, few documents could be found about biogas flameless mode. Flameless combustion of biogas could be one of the best methods of pure biogas utilization in CHP generation. Combustion stability and low pollutant formation are the main advantages of biogas flameless combustion. The initial cost of flameless combustion instalation is high due to the cost of instrumentation and special equipments. In order to maintain the temperature inside the flameless chamber, some especial materials such as ceramic should be utilized. Biogas flameless combustion could be modified by hydrogen-enrichment strategy. The temperature distribution inside the flameless chamber is more uniform when small amounts of hydrogen added to the biogas components and the flameless regime is more sustained. In this circumstance the rate of pollutant formation is a little higher than pure biogas flameless combustion.

Recent advancements in engineering approach towards design of photo-reactors for selective photocatalytic CO2 reduction to renewable fuels

Abstract: Photocatalytic conversion of CO2 to solar fuels, an artificial photosynthesis, is a promising solution to resolve the energy crisis and global warming issues. The overall efficiency of photo-reduction of CO2 to fuels can be improved through the development of highly efficient catalyst and suitable photoreactor configuration. Significant efforts have been devoted to the design and developments of photo-catalysts, but very little focus has been given towards photo-reactors development. In this perspective, this review presents state of the art accomplishments in photocatalytic CO2 reduction through engineering approach towards reactor configuration and design aspects. In the main stream, the perspectives of different types of photo-reactors employed for the photocatalytic conversion of CO2 has been discussed. Slurry, fixed bed and membrane photo-reactors have been identified as the main categories that are critically discussed based on their operational mode, type of bed, number of phases involved, membrane used and type of light source. Comparative analysis of photo-reactors is also being employed to improve selectivity and photo-conversion rates of these photo-reactors. The influence of the factors such as light position and distribution, material of construction, temperature and pressure on the production of fuels has also been explicated. Moreover, perspective gives an overview of basic principles, thermodynamics and mass transfer involved in photocatalytic conversion of CO2 to fuels. Finally, conclusions and future perspectives paves further improvements in the design of photo-reactors to be made to increase the efficiency of CO2 conversion to renewable fuels.